Receiving method

Abstract

To provide a receiving method capable of appropriately acquiring a communication content in response to reception of a broadcast content.SOLUTION: A receiving method in a broadcast communication cooperation service includes receiving a broadcast content transmitted by broadcasting, receiving acquisition information through broadcasting, which is information for reproducing communication content transmitted through communication in synchronization with received broadcast content, and is information related to acquisition of communication content (S203), and obtaining communication content on the basis of the received acquisition information (S205).SELECTED DRAWING: Figure 19

Description

Technical Field

[0001] The present invention relates to a receiving method and the like for synchronously reproducing contents such as video, audio, and subtitles obtained through broadcasting and communication respectively.

Background Art

[0002] In recent years, various services that combine broadcasting and communication have been proposed.

[0003] As a device for enjoying such services, for example, the following receiving devices have been proposed (see, for example, Patent Documents 1, 2, and 3).

[0004] The receiving device receives broadcast content from a digital broadcast signal, receives communication content linked to the broadcast content from a communication network, and presents the broadcast content and the communication content in synchronization.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] Broadcast content is usually transmitted from a broadcasting station at a predetermined time. Therefore, when presenting (reproducing) the broadcast content and the communication content in synchronization, the receiving device acquires and reproduces the communication content in response to the reception of the broadcast content.

[0007] However, in the receiving apparatus, there are restrictions on the acquisition of communication content, such as the capacity of the buffer for communication content. Therefore, there is room for consideration regarding the method of acquiring communication content in the receiving apparatus.

[0008] The present invention provides a receiving method and the like that can appropriately acquire communication content in response to the reception of broadcast content.

Means for Solving the Problems

[0009] A receiving method according to an aspect of the present invention is a receiving method in a broadcast communication cooperation service, which receives broadcast content transmitted by broadcast, and communication content transmitted by communication is information for reproducing in synchronization with the received broadcast content, and acquisition information related to the acquisition of the communication content is received through broadcast, and the communication content is acquired based on the received acquisition information.

[0010] These general or specific aspects may be implemented by a system, a device, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM. Further, these general or specific aspects may be implemented by any combination of a system, a device, an integrated circuit, a computer program, and a recording medium.

Effects of the Invention

[0011] According to the receiving method according to an aspect of the present invention, communication content can be appropriately acquired in response to the reception of broadcast content.

Brief Description of the Drawings

[0012]

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[0013] (Knowledge 1 on which the invention is based) The receiving device described in Patent Document 1 receives broadcast content from a digital broadcast signal, and receives communication content linked to the broadcast content from a communication network. The receiving device then temporarily stores the received broadcast content in a first synchronization buffer, and temporarily stores the received communication content in a second synchronization buffer. The receiving device controls the output time of content output from either the first synchronization buffer or the second synchronization buffer according to a time specified by an instruction execution unit, and delays the presentation of either the broadcast content or the communication content. This makes it possible to present the broadcast content and the communication content, which are received at different times, in a synchronized manner.

[0014] Moreover, the receiving device described in Patent Document 2 synchronizes the presentation of the broadcast content with the communication content by delaying the presentation of the broadcast content. In this receiving device, communication content is acquired in response to an external operation or control signal, and after the acquisition of the communication content is completed, delayed presentation is started, which presents the broadcast content at a delayed presentation time from the presentation time when the broadcast content is normally presented. This makes it possible to present the broadcast content normally even while the communication content is being acquired.

[0015] In the conventional receiving devices described in the above Patent Documents 1 and 2, when switching from a state in which broadcast content is being played back but not communication content to a state in which both broadcast content and communication content are being played back, it is necessary to delay the presentation of the broadcast content according to the delay time of the communication content relative to the reception time of the broadcast content. As a result, the broadcast content presented to the viewer is temporarily interrupted. The greater the delay time of the communication content relative to the reception time of the broadcast content, the greater the impact on the viewer.

[0016] Similar problems also occur when the reception time of the broadcast content is delayed with respect to the reception time of the communication content. That is, when switching from a state where the communication content is being played and the broadcast content is not being played to a state where both the communication content and the broadcast content are being played, it is necessary to delay the presentation of the communication content according to the delay time of the reception time of the broadcast content with respect to the reception time of the communication content. As a result, the communication content presented to the viewer will be temporarily interrupted. This will have a greater impact on the viewer as the delay time of the reception time of the broadcast content with respect to the reception time of the communication content is greater.

[0017] However, so far, no technical solutions to this problem have been considered.

[0018] Therefore, the inventors considered a technical solution to this problem.

[0019] As a result of this consideration, the inventors obtained the knowledge that, for example, by notifying the viewer of the synchronization between broadcasting and communication before and after delaying the presentation of the broadcast content or before and after delaying the presentation of the communication content, the impact on the viewer can be reduced.

[0020] Hereinafter, embodiments and the like based on the solution obtained based on this knowledge will be described.

[0021] (Embodiment 1) FIG. 1 is a block diagram showing the configuration of a receiving device 1 which is a broadcast communication cooperation receiving device according to Embodiment 1 of the present invention.

[0022] The receiving device 1 includes a digital broadcast receiving unit 11, a separation unit 12, a buffer 13, a decoding unit 14, a communication transmission / reception unit 21, a buffer 22, a decoding unit 23, a content generation unit 31, a communication transmission / reception unit 41, an operation input unit 42, and a control unit 51.

[0023] However, the receiving device 1 is a device such as a television receiver, a portable television, a recorder, a set-top box, a smartphone, a tablet, etc.

[0024] The digital broadcast receiving unit 11 takes as input the digital broadcast signal received by the external broadcast antenna 3. Then, the digital broadcast receiving unit 11 selects a desired channel from the digital broadcast signal, performs demodulation processing, error correction processing, etc. on the digital broadcast signal of the selected desired channel, generates a transport stream, and outputs it to the separation unit 12. Note that the receiving device 1 may be provided with the broadcast antenna 3 inside.

[0025] However, digital broadcasts include, for example, terrestrial digital broadcasts, BS (Broadcasting Satellite) digital broadcasts, CS (Communications Satellite) digital broadcasts, cable television, broadcasts using an IP (Internet Protocol) network such as optical fiber, etc.

[0026] The separation unit 12 separates the transport stream generated by the digital broadcast receiving unit 11 into video data, audio data, data broadcasts, etc. Also, the separation unit 12 acquires various control information included in the transport stream.

[0027] The control information included in the transport stream includes, for example, PSI (Program Specific Information) which is system information, SI (Service Information), PCR (Program Clock Reference) which is synchronization information, and an application data table (Application Information Table: AIT) which is information related to the application. The AIT describes, for example, an application ID for identifying the application, a control code capable of controlling the life cycle such as the start and end of the application, and the location information of the application.

[0028] In addition, video data, audio data, etc. output from the separation unit 12 are configured as PES (Packetized Elementary Stream) packets. In the PES header included in each PES packet, PTS (Presentation Time Stamp) and DTS (Decoding Time Stamp) are stored as presentation time information for synchronization. Note that in some cases, either one or both of PTS and DTS may not be included in the PES header.

[0029] The separated video data, audio data, etc. are output from the separation unit 12 to the buffer 13, and PCR, AIT, etc. are output from the separation unit 12 to the control unit 51.

[0030] The buffer 13 stores video data, audio data, etc. output from the separation unit 12. Then, the buffer 13 outputs content data for each component such as video and audio to one or both of the decoding unit 14 and the communication transceiver unit 41 in units of PES packets at the timing instructed by the control unit 51. Note that the buffer 13 will be described later with reference to FIG. 2.

[0031] The decoding unit 14 converts PES packets for each component such as video and audio output from the buffer 13 into an elementary stream (ES), and extracts PTS and DTS from the PES header of the PES packet. In addition, the decoding unit 14 outputs the extracted PTS and DTS to the control unit 51. Then, the decoding unit 14 decodes the elementary stream for each component and outputs it to the content generation unit 31. However, when the order of the picture frames before decoding of the video content is different from the order of the picture frames after decoding, the decoding unit 14 uses a buffer provided inside to swap the order and then outputs it to the content generation unit 31.

[0032] The communication transceiver unit 21 acquires applications and AV content from content servers provided by operators related to broadcasters or other operators via a communication network. Also, the communication transceiver unit 21 may acquire control information such as AIT via the communication network. AV content provided by a communication operator includes file data, video data, audio data, etc. The communication transceiver unit 21 outputs the acquired applications and control information to the control unit 51. The communication transceiver unit 21 outputs the acquired AV content to the buffer 22.

[0033] The communication transceiver unit 21 and the communication transceiver unit 41 described later use, for example, a communication method compliant with communication standards such as wireless LAN (Local Area Network), Bluetooth (registered trademark), Ethernet (registered trademark), USB (Universal Serial Bus), PLC (Power Line Communication), and HDMI (registered trademark) (High-Definition Multimedia Interface) to perform communication. However, the communication transceiver unit 21 and the communication transceiver unit 41 may have the same configuration or different configurations.

[0034] The buffer 22 stores the content data of the AV content output from the communication transceiver unit 21. Then, the buffer 22 outputs the content data for each component such as video and audio in PES packet units to one or both of the decoder unit 23 and the communication transceiver unit 41 at the timing instructed by the control unit 51. Note that the buffer 22 will be described later with reference to FIG. 2.

[0035] The decoding unit 23 converts the PES packets for each component such as video and audio output from the buffer 22 into elementary streams (ES), and extracts the PTS and DTS from the PES header of the PES packet. Further, the decoding unit 23 outputs the extracted PTS and DTS to the control unit 51. Then, the decoding unit 23 decodes the elementary stream for each component and outputs it to the content generation unit 31. However, when the order of the picture frames before decoding of the video content is different from the order of the picture frames after decoding, the decoding unit 23 uses the buffer provided inside to perform the order swapping and then outputs it to the content generation unit 31.

[0036] The content generation unit 31 uses the content data of each component (video, audio, subtitle, etc.) output from the decoding unit 14 and the content data of each component (video, audio, and subtitle, etc.) output from the decoding unit 23, and generates the presentation content of the service according to the instructions of the control unit 51. The presentation content generated by the content generation unit 31 is output to the external presentation unit 5 and presented by the presentation unit 5. Note that the receiving device 1 may be provided with the presentation unit 5 inside.

[0037] The communication transceiver 41 executes communication between a content presentation device different from the presentation unit 5 and an input interface operated by the viewer. Examples of the content presentation device include a television receiver, a portable television, a smartphone, and a tablet, etc. The communication transceiver 41 transmits the PES packets output from the buffers 13 and 22 to the content presentation device. Also, the communication transceiver 41 transmits the data received from the control unit 51 to the content presentation device. Examples of the input interface include a remote control, a tablet terminal, a smartphone, a keyboard of a personal computer, a mouse, a camera, and a microphone, etc. Further, the communication transceiver 41 outputs the input content received from the input interface to the operation input unit 42 or the control unit 51. Note that the content presentation device and the input interface may be the same device or different devices.

[0038] The operation input unit 42 acquires a control signal corresponding to an operation using an input interface by a viewer from an external input interface or a built-in input interface, and transmits control information corresponding to the acquired control signal to the control unit 51. Examples of the input interface include a remote control, a tablet terminal, a smartphone, a keyboard of a personal computer, a mouse, a camera, and a microphone. The operation using the input interface by the viewer is, for example, pressing a button physically or virtually arranged on the screen, a gesture, an operation by voice, and a combination thereof. Further, the control signal from the input interface may be input to the operation input unit 42 via the communication transceiver unit 41, or may be directly input to the control unit 51 via the communication transceiver unit 41. When the control signal from the input interface is directly input to the control unit 51 via the communication transceiver unit 41, the receiving device 1 may not include the operation input unit 42.

[0039] The control unit 51 generates a reference clock signal using the PCR output from the separation unit 12. This generated reference clock signal is used for controlling the output timing of the buffers 13 and 22.

[0040] The control unit 51 generates control information for aligning the output timing between each content (video content, audio content, etc.) sent in the broadcast using the PTS output from the decoding unit 14, and outputs it to the PES buffer 71 described later in the buffer 13. Further, the control unit 51 generates control information for aligning the output timing between each content (video content, audio content, etc.) sent in the communication using the PTS output from the decoding unit 23, and outputs it to the PES buffer 71 described later in the buffer 22.

[0041] Furthermore, the control unit 51 calculates the delay time between the broadcast content and the communication content using the PTS output from the decoding unit 14 and the PTS output from the decoding unit 23. Then, based on the calculated delay time, the control unit 51 generates control information for aligning the output timings of the broadcast content and the communication content, and outputs the control information to a synchronization buffer 72 (to be described later) in the buffer 13 and the synchronization buffer 72 (to be described later) in the buffer 22. In addition, the control unit 51 gives an instruction to the content generation unit 31 regarding notification (synchronization presentation notification) related to the synchronization of the broadcast content and the communication content for the viewer.

[0042] Note that the synchronization presentation notification is, for example, notification to the viewer of the occurrence of discontinuous video presentation when switching from the normal presentation (to be described later) of the broadcast content to the delayed presentation (to be described later), notification to the viewer of the occurrence of overlapping video presentation, etc. Specific examples of this synchronization presentation notification will be described later.

[0043] Hereinafter, a configuration example of the buffer 13 and the buffer 22 will be described with reference to FIG. 2. Note that since the buffer 13 and the buffer 22 can have the same configuration, they will be described together.

[0044] FIG. 2 is a block diagram showing a configuration example of the buffer 13 and the buffer 22 in FIG. 1.

[0045] The buffers 13 and 22 include a PES buffer 71 and a synchronization buffer 72.

[0046] The PES buffer 71 is a buffer for aligning the output timings between contents such as video content and audio content. The PES buffer 71 converts each content such as video content and audio content into PES packets, and outputs the content data in units of PES at the output timing instructed by the control information by the control unit 51.

[0047] The synchronization buffer 72 is a buffer for aligning the output timings between the broadcast content and the communication content. The synchronization buffer 72 outputs content data in units of PES at the timing indicated by the control information by the control unit 51.

[0048] However, the PES buffer 71 and the synchronization buffer 72 can output content data in units of PES with an arbitrary delay time and an arbitrary output timing, and all of the delay time and the output timing follow the instruction of the control unit 51.

[0049] Hereinafter, a synchronization presentation method for presenting the broadcast content and the communication content while matching the output timings of the broadcast content and the communication content will be described.

[0050] For the broadcast communication cooperation service, there are a method of controlling the cooperation between the broadcast and the communication by an application such as HTML5, and a method of controlling the cooperation between the broadcast and the communication without intervening the application. In the following, the case of providing the broadcast communication cooperation service by an application will be described as an example, but the application may be an HTML5 application or a resident application of the receiver. Further, a part of the resident application or the function of the receiver may be provided as an API and controlled by another application such as HTML5.

[0051] The broadcast communication cooperation service includes a dependent service in which the application is linked to the AV content and an independent service in which the application is not linked to the AV content. Also, there are various types of communication content.

[0052] In the following description, in the dependent service linked to the broadcast content, a use case for presenting the communication content linked to the broadcast content is considered. Also, it is assumed that the communication content is a multicast distribution of real-time live video that cannot acquire packets in advance in terms of time.

[0053] An example of the state transition of content presentation in the receiving device 1 used to explain a specific example of the synchronization presentation method for broadcast content and communication content is shown in FIG. 3.

[0054] In the state transition diagram of FIG. 3, the receiving device 1 starts from the power-off state (broadcast-off / communication-off state). Then, by turning on the broadcast content presentation, the receiving device 1 transitions from the broadcast-off / communication-off state to the state where only the broadcast content is presented (broadcast-on / communication-off state). Further, the receiving device 1 transitions from the broadcast-on / communication-off state to the state where both the broadcast content and the communication content are presented (broadcast-on / communication-on state) by turning on the communication content presentation.

[0055] Hereinafter, the "broadcast-on / communication-off state" is defined as "state A", and the "broadcast-on / communication-on state" is defined as "state B". Also, the period from when the transition from "state A" to "state B" is determined until the transition is completed is defined as the "transition period".

[0056] In order to provide the broadcast communication cooperation service, it is a prerequisite that the application is running. Therefore, when the application is not running when providing the broadcast communication cooperation service, it is necessary to start the application. Also, in order to provide only the broadcast service, it is not necessarily required that the application is running.

[0057] For example, when transitioning from state A to state B, if the application is not running in state A, it is necessary to start the application. At this time, the application starts based on the AIT included in the broadcast signal.

[0058] As for the activation timing of the application, there are cases where the viewer explicitly designates based on the AIT stored in the broadcast content or communication content, and cases where it is dynamically automatically activated in conjunction with the content based on the activation information of the AIT application. Also, as for the termination timing of the application, there are cases where the viewer explicitly designates based on the AIT stored in the broadcast content or communication content, and cases where it is dynamically automatically terminated in conjunction with the content based on the termination information of the AIT application.

[0059] As a method of turning on the communication content while presenting the broadcast content, there are methods such as the viewer explicitly designating based on the AIT stored in the broadcast content, and a method of automatically starting based on the AIT stored in the broadcast content.

[0060] Generally, since the reception of communication content has a larger delay compared to the reception of broadcast content, when transmitting live video by both broadcast and communication, on the receiving side, the communication content is received with a delay relative to the broadcast content.

[0061] In order to start presenting the communication content while presenting the broadcast content and synchronously present the broadcast content and the communication content, it is necessary to present the broadcast content with a delay.

[0062] An example of a synchronous presentation method of broadcast content and communication content in the content presentation state transition shown in FIG. 3 will be described with reference to FIGS. 4 and 5.

[0063] FIG. 4 is a diagram showing a signal image for explaining an example of a synchronous presentation method of broadcast content and communication content in the content presentation state transition shown in FIG. 3.

[0064] FIG. 4(a) represents the time signal of the broadcast content without delay. The case of performing broadcast presentation using this signal is defined as "normal presentation".

[0065] Figure 4(b) represents the time signal of the delayed broadcast content. The case of performing broadcast presentation using this signal is defined as "delayed presentation". Note that "D" in the figure is the delay time of the reception time of the communication content with respect to the reception time of the broadcast content.

[0066] Figure 4(c) represents the time signal of the communication content.

[0067] Figure 4(d) represents the time signal of the broadcast content actually presented.

[0068] Figure 4(e) represents the time signal of the communication content actually presented.

[0069] The receiving device 1 normally presents the broadcast content during the period up to time T1 and during the period from the time T1 when the acquisition of the communication content starts to the time T2 when the preparation for presenting the communication content is completed, that is, until the transition from state A to state B is completed.

[0070] Then, the receiving device 1 delays the presentation of the broadcast content and presents the communication content during the period after the time T2 when the preparation for presenting the communication content is completed, that is, after the transition from state A to state B is completed.

[0071] In this way, at the timing when the transition from state A to state B is completed, the presentation of the broadcast content switches from normal presentation to delayed presentation. For this reason, at the timing when the transition from state A to state B is completed, the presentation of the broadcast content becomes a presentation of discontinuous video or the like. Also, for a certain period after starting the delayed presentation, the presentation of the broadcast content becomes a duplicate presentation of the same video or the like as the video or the like presented once in normal presentation. The presentation of discontinuous video or the like or the duplicate presentation of video or the like gives a sense of discomfort to the viewer and may sometimes give an unpleasant feeling.

[0072] Therefore, during the overlapping presentation period of the broadcast content, the receiving device 1 provides notification (synchronization presentation notification) regarding the synchronization between the broadcast content and the communication content to the viewer (for example, presents to the presentation unit 5 a message to the effect that "the broadcast content is being presented in an overlapping manner to synchronize the broadcast content with the communication content").

[0073] By providing such synchronization presentation notification, the viewer can understand the reasons for the presentation of discontinuous videos or the like and the overlapping presentation of videos or the like, and it becomes possible to alleviate the sense of strangeness and discomfort given to the viewer's viewing.

[0074] FIG. 5 is a flowchart showing an example of the processing operation of the synchronization presentation method between the broadcast content and the communication content by the receiving device 1 in the content presentation state transition shown in FIG. 3. However, at the start point of the flowchart in FIG. 5, the receiving device 1 is in the power-off state (broadcast OFF / communication OFF state).

[0075] The receiving device 1 transitions from the power-off state (broadcast OFF / communication OFF state) to the broadcast ON / communication OFF state (state A) by turning on the broadcast content presentation (step S11). The receiving device 1 starts acquiring the broadcast content and starts the normal presentation of the broadcast content (step S12).

[0076] Next, the receiving device 1 starts acquiring the communication content on the occasion of acquiring the application (step S13).

[0077] The receiving device 1 determines whether the preparation for presenting the communication content is completed (step S14). The process of step S14 is performed until it is determined that the preparation for presenting the communication content is completed (S14: No). Then, when it is determined that the preparation for presenting the communication content is completed (S14: Yes), the process of step S15 is performed. Note that the determination as to whether the preparation for acquiring the communication content is completed is made, for example, when a predetermined amount of content data of the communication content is accumulated in the buffer 22, it is determined that the preparation for acquiring the communication content is completed.

[0078] In the receiving device 1, the control unit 51 compares the PTS of the broadcast content after decoding with the PTS of the communication content, and calculates the delay time of the communication content with respect to the broadcast content (step S15).

[0079] The control unit 51 generates control information for aligning the output timings of the broadcast content and the communication content based on the delay time calculated in step S15, and outputs it to the synchronization buffer 72 in the buffer 13 and the synchronization buffer 72 in the buffer 22. The synchronization buffer 72 in the buffer 13 delays the buffer output based on the delay time calculated in step S15 according to the control information, and the synchronization buffer 72 in the buffer 22 performs the buffer output according to the control information. As a result, the receiving device 1 switches the presentation of the broadcast content from normal presentation to delayed presentation and starts the delayed presentation, and at the same time, starts the presentation of the communication content. Further, the control unit 51 instructs the content generation unit 31 to present a message for synchronous presentation notification (for example, a message to the effect that "the broadcast content is being presented repeatedly to synchronize the broadcast content and the communication content"), and the content generation unit 31 starts presenting the message for synchronous presentation notification to the presentation unit 5 based on this instruction (step S16).

[0080] The control unit 51 determines whether or not the repeated presentation of the broadcast content has ended based on the delay time calculated in step S15 (step S17). The process of step S17 is performed until it is determined that the repeated presentation of the broadcast content has ended (S17: No). When it is determined that the repeated presentation of the broadcast content has ended (S17: Yes), the control unit 51 instructs the content generation unit 31 to end the presentation of the message for synchronous presentation notification, and the content generation unit 31 ends the presentation of the message for synchronous notification to the presentation unit 5 based on this instruction (step S18).

[0081] (Supplement to Embodiment 1) The supplement to Embodiment 1 will be described below.

[0082] (1) The synchronization presentation method of the broadcast content and the communication content described in the first embodiment is an example and is not limited thereto.

[0083] For example, the synchronization presentation method shown in FIG. 6 may be used. However, the time signals in FIGS. 6(a) to 6(e) are of the same type as the time signals in FIGS. 4(a) to 4(e), respectively.

[0084] In the synchronization presentation method of FIG. 4, during the state transition period, that is, during the period from the start of acquisition of the communication content to the completion of preparation for presentation of the communication content, the broadcast content is presented normally.

[0085] In contrast, in the synchronization presentation method of FIG. 6, during the state transition period, that is, during the period from the start of acquisition of the communication content to the completion of preparation for presentation of the communication content, the presentation of the broadcast content is interrupted and the screen of the presentation unit 5 is blacked out. At the same time, the receiving device 1 presents a message indicating that it is waiting, for example, to synchronize the broadcast content and the communication content, to the presentation unit 5 for notifying the viewer of the synchronization presentation.

[0086] Also, various synchronization presentation methods are possible by changing the control method of the buffer clock timing or the presentation timing. For example, there is a synchronization presentation method shown in FIG. 7. However, the time signals in FIGS. 7(a) to 7(e) are of the same type as the time signals in FIGS. 4(a) to 4(e), respectively.

[0087] In the synchronization presentation method of FIG. 7, upon acquiring communication content, the receiving device 1 starts slow-playing the broadcast content, and while comparing the completion of the preparation for presenting the communication content with the playback time of the broadcast content, it transitions to a state where it presents the broadcast content with a delay and presents the communication content. At the same time, the receiving device 1 presents to the presentation unit 5 a message indicating, for example, that the broadcast content is being slow-played for synchronizing the broadcast content and the communication content for the synchronization presentation notification to the viewer. Note that slow-playing can be realized by widening the time interval of the buffer output. The broadcast content is gradually adjusted for delay by slow-playing, and when the delay adjustment is completed and the presentation time of the broadcast content coincides with the presentation time of the communication content, the broadcast content and the communication content are presented in synchronization. In this case, the completion time of the communication presentation preparation and the synchronization presentation timing do not coincide.

[0088] The control unit 51 controls the playback timing and clock control. Also, the control unit 51 outputs appropriate presentation and presentation timing to the content generation unit 31 according to the synchronization presentation method.

[0089] In the synchronization presentation method of FIG. 7, when presenting the broadcast content and the communication content in synchronization, these presentations can be made smoother.

[0090] (2) In the synchronization presentation method of Embodiment 1, upon completion of the preparation of the communication content, the presentation of the broadcast content is switched from normal presentation to delayed presentation. However, it is not limited to this. For example, the broadcast content may be pre-delayed for presentation, and an example of this will be described using the flowchart of FIG. 8. However, at the start point of the flowchart of FIG. 8, the receiving device 1 is in the power-off state (broadcast OFF / communication OFF state).

[0091] By turning on the broadcast content presentation, the receiving device 1 transitions from the power-off state (broadcast-off / communication-off state) to the broadcast-on / communication-off state (step S51). The receiving device 1 starts acquiring the broadcast content and starts the normal presentation of the broadcast content (step S52).

[0092] During the normal presentation of the broadcast content, the receiving device 1 launches, as the first application, an application that delays the presentation of the broadcast content (hereinafter referred to as the "delay presentation application") (step S53). Examples of the delay presentation timing of the broadcast include the timing specified by the viewer, the timing specified by the broadcaster or other operators through communication or the AIT of the broadcast, or the timing specified by an application acquired based on the AIT.

[0093] After launching the delay presentation application, the receiving device 1 acquires the communication content in the control unit 51, compares the PTS of the decoded broadcast content with the PTS of the communication content, and calculates the delay time of the communication content with respect to the broadcast content (step S54).

[0094] Based on the delay time calculated in step S54, the control unit 51 controls the output delay of the synchronization buffer 72 in the buffer 13. As a result, the receiving device 1 switches the presentation of the broadcast content from the normal presentation to the delay presentation and starts the delay presentation. Further, the control unit 51 instructs the content generation unit 31 to present a message for synchronous presentation notification (for example, a message to the effect that "the broadcast content is presented repeatedly to synchronize the broadcast content and the communication content"), and the content generation unit 31 starts presenting the message for synchronous presentation notification to the presentation unit 5 based on this instruction (step S55).

[0095] The control unit 51 determines whether or not the overlapping presentation of the broadcast content has ended based on the delay time calculated in step S54 (step S56). Until it is determined that the overlapping presentation of the broadcast content has ended (S56: No), the process of step S56 is performed. When it is determined that the overlapping presentation of the broadcast content has ended (S56: Yes), the control unit 51 instructs the content generation unit 31 to end the presentation of the message for synchronous presentation notification, and the content generation unit 31 ends the presentation of the message for synchronous presentation notification to the presentation unit 5 based on this instruction (step S57).

[0096] In the state of broadcast ON / communication OFF and during the delayed presentation of the broadcast content, the receiving device 1 starts the second application and thereby starts acquiring the communication content (step S58).

[0097] The receiving device 1 determines whether or not the preparation for presenting the communication content is complete (step S59). Until it is determined that the preparation for presenting the communication content is complete (S59: No), the process of step S59 is performed. When it is determined that the preparation for presenting the communication content is complete (S59: Yes), the receiving device 1 starts presenting the communication content (step S60).

[0098] In the case of a program that may be presented with a delay, by presenting the broadcast content in advance with a delay at a timing with little discomfort to the viewer, such as at the start of broadcast reception, channel selection, or the timing of a CM (commercial), smooth synchronous presentation of the broadcast content and the communication content becomes possible.

[0099] Note that, for example, depending on the timing for disclosing the delayed presentation of the broadcast content (for example, at the start of broadcast reception or channel selection), the message for synchronous presentation notification may not be presented.

[0100] (3) The content and period of the notification (synchronous presentation notification) regarding the synchronous presentation of the broadcast content and the communication content to the viewer in the synchronous presentation method described in the first embodiment are examples and are not limited thereto.

[0101] Below, the synchronous presentation notification will be described including the content described in Embodiment 1.

[0102] Examples of the content of the synchronous presentation notification include the presentation of a message related to the synchronous presentation of broadcast content and communication content, and the presentation of an animation of discontinuous video.

[0103] Specifically, for example, it is presented as follows. · Display a message or icon or the like indicating the set synchronous presentation method to the viewer. · Display a message or icon or the like indicating to the viewer that discontinuous video display occurs or has occurred. · Display a message or icon or the like indicating to the viewer that the video is being presented repeatedly. · Insert an animation function between videos to eliminate discontinuous display.

[0104] In addition to the display of messages or icons or the like, there are also caption displays and voice outputs. Also, it may be presented using an external device.

[0105] Examples of the timing or period of the synchronous presentation notification include the period during which duplicate presentation of broadcast content is performed, the period from the start of acquisition of communication content until the end of duplicate presentation of broadcast content, the startup timing of the application, the timing when the preparation of communication content is completed, etc., the timing or period according to the events of the receiving device 1. There is also timing according to the viewer's interface operation. Note that the synchronous presentation notification may be performed only while the viewer permits the synchronous presentation notification.

[0106] ​The control unit 51 determines the content, timing, or period of the synchronous presentation notification according to, for example, the synchronous presentation method specified in the application, a predetermined rule, or the settings of the receiving device, and instructs the content generation unit 31. The content generation unit 31 executes the synchronous presentation notification of the content determined at the timing or period determined according to the instruction of the control unit 51. Note that the settings of the receiving device may or may not be set by the viewer.

[0107] In addition, it may be such that a broadcaster, a business operator related to the broadcaster, or another business operator can instruct the content, timing, or period of the synchronous presentation notification according to the content, for example, by embedding a control signal instructing the content, timing, or period of the synchronous presentation notification in the broadcast or communication.

[0108] (4) In the first embodiment, the acquisition timing of the communication content has been described as being the same as the acquisition timing of the application, but the present invention is not limited to this, and may be another timing. The acquisition timing of the communication content follows, for example, an instruction of the application.

[0109] (5) In the first embodiment, the state transition of the receiving device 1 has been described as the state transition shown as an example in FIG. 3, but the present invention is not limited to this, and may be, for example, as follows.

[0110] Even in the state transition of the receiving device 1 from the state of normal presentation of the broadcast content and activation of an independent communication application not linked to the content (the state of broadcast ON / communication independent application ON / linked application OFF) to the state in which an application linked to the broadcast is activated (the state of broadcast ON / communication independent application ON / linked application ON), it is necessary to delay the broadcast content. Also in this case, it is possible to apply substantially the same content as the synchronous presentation method and the synchronous presentation notification in the synchronous presentation method described in the first embodiment and the supplement to the first embodiment.

[0111] (6) In Embodiment 1 and the supplement (2) of Embodiment 1, in order to calculate the delay time between the broadcast content and the communication content, the calculation is performed using the PTS output after decoding. However, the present invention is not limited to this, and the calculation may be performed using the DTS, or the calculation may be performed using the two pieces of information of the PTS and the DTS. Further, the calculation may be performed using the PTS or DTS before decoding. Further, the calculation may be performed using the PCR, the clock (STC) generated based on the PCR, the PTS, and the DTS. When the reference clock is NTP, the calculation may be performed using the NTP. When the broadcast content and the communication content use different reference clocks, the calculation may be performed using the timeline auxiliary information indicating the correspondence relationship between the respective reference clocks.

[0112] Further, the control timing of the buffer is calculated in consideration of the location where the PTS and DTS are calculated and the position of the buffer. As an example in which the location where the PTS and DTS are calculated and the position of the buffer are different, the following configuration can be used.

[0113] In Embodiment 1, PTS and DTS are extracted in the decoding unit 14. However, the conversion from PES packets to ES and the extraction of PTS and DTS may be performed not in the decoding unit 14 but in the PES buffer 71 in the buffer 13. In this case, it is desirable that the positions of the PES buffer 71 and the synchronization buffer 72 in the buffer 13 are reversed. The PES buffer 71 outputs the extracted PTS and DTS to the control unit 51. The PES buffer 71 outputs content data for each component such as video and audio to one or both of the decoding unit 14 and the communication transceiver unit 41 at the timing instructed by the control unit 51. Similarly, the conversion from PES packets to ES and the extraction of PTS and DTS may be performed not in the decoding unit 23 but in the PES buffer 71 in the buffer 22. In this case, it is desirable that the positions of the PES buffer 71 and the synchronization buffer 72 in the buffer 22 are reversed. The PES buffer 71 outputs the extracted PTS and DTS to the control unit 51. The PES buffer 71 outputs content data for each component such as video and audio to one or both of the decoding unit 23 and the communication transceiver unit 41 at the timing instructed by the control unit 51. Note that the above configuration is equivalent to the configuration described in Embodiment 2 to be described later, and the PES buffer 71 in FIG. 2 corresponds to the separation buffer 114 in FIGS. 14 and 18.

[0114] (7) In Embodiment 1, it was explained that content data for each component such as video and audio is output to the communication transceiver unit 41 in units of PES packets at the timing instructed by the control unit 51, and the communication transceiver unit 41 transmits the content data and the data received from the control unit 51 to the content presentation device. More specifically, in the communication transceiver unit 41, access units, PES packets for each component such as video and audio, and control information and clock information input from the control unit 51 are demultiplexed using a specific multiplexing method and then transmitted to the cooperation terminal. Examples of the multiplexing method include MP4, MPEG2-TS, MPEG-DASH, and MMT.

[0115] (8) In the first embodiment, it is assumed that the communication content is delayed by a certain time with respect to the broadcast content. However, it is also conceivable that the broadcast content is delayed with respect to the communication content. In this case, the presentation of the broadcast content becomes one pattern of normal presentation, and the presentation of the communication content becomes two patterns of normal presentation and delayed presentation. Except for this point, it is possible to apply substantially the same content as the synchronous presentation method and the synchronous presentation notification in the synchronous presentation method described in the first embodiment and the supplement to the first embodiment.

[0116] In the first embodiment, it is assumed that the communication content is delayed by a certain time with respect to the broadcast content. However, for example, due to the influence of transmission jitter in the communication transmission path, when the delay time of the communication content with respect to the broadcast content is not constant, the buffer is appropriately controlled to perform synchronous presentation of the broadcast content and the communication content.

[0117] (9) In the first embodiment, the transition from the broadcast ON / communication OFF state to the broadcast ON / communication ON state has been described. However, there is also a transition from the broadcast ON / communication ON state to the broadcast ON / communication OFF state.

[0118] In the transition from this broadcast ON / communication ON state to the broadcast ON / communication OFF state, when switching the presentation of the broadcast content from delayed presentation to normal presentation, the occurrence of discontinuous presentation of the broadcast content or the occurrence of partial omission of the presentation of the broadcast content may occur.

[0119] Therefore, the receiving device 1 may perform synchronous presentation notification including the occurrence of discontinuous presentation of the broadcast content, the occurrence of partial omission of the presentation of the broadcast content, etc. to the viewer.

[0120] Note that the control unit 51 determines the content, timing, or period of the synchronous presentation notification and instructs the content generation unit 31. Then, the content generation unit 31 executes the notification of the content instructed at the instructed timing or period.

[0121] (10) In the first embodiment, the case where broadcast content and communication content are presented synchronously using FIG. 1 has been described, but the present invention is not limited to this, and for example, the following may be applicable.

[0122] When transmitting one content via two different transmission paths, the configuration of the receiving device can be, for example, the configuration shown in FIG. 9 in which the content received from the two transmission paths is synchronized and decoded by one decoder unit. However, in FIG. 9, the configuration units that perform substantially the same processing as the configuration units in FIG. 1 are given the same reference numerals.

[0123] In the receiving device 1A shown in FIG. 9, the decoder unit 14A takes the outputs of the buffer 13 and the buffer 22 as inputs, decodes the input data from each, and outputs the decoded data to the content generation unit 31A. The content generation unit 31A takes the output of the decoder unit 14A as an input, and generates presentation content of the service according to the instructions of the control unit 51 using the input data.

[0124] When transmitting the main video using broadcast and transmitting the extended information using communication, the configuration of the receiving device can be, for example, the configuration shown in FIG. 10 in which the main video is decoded by one decoder unit and the main video and the extended video are decoded by another decoder unit. However, in FIG. 10, the configuration units that perform substantially the same processing as the configuration units in FIG. 1 are given the same reference numerals.

[0125] In the receiving device 1B shown in FIG. 10, the decoder unit 14B takes the output of the buffer 13 as an input, decodes the input data, and outputs the decoded data to the content generation unit 31B. The content generation unit 31B takes the output of the decoder unit 14B as an input, generates presentation content such as non-extended video according to the instructions of the control unit 51 using the input data, and outputs the generated content to the presentation unit 5.

[0126] The decoding unit 23B takes the outputs of the buffer 13 and the buffer 22 as inputs, decodes the input data, and outputs it to the content generation unit 32B. The content generation unit 32B takes the outputs of the decoding unit 14B and the decoding unit 23B as inputs, generates presentation content such as an extended video in accordance with the instructions of the control unit 51 using the input data from each, and outputs it to the presentation unit 5B.

[0127] In any of the cases of FIGS. 9 and 10, it is possible to apply substantially the same content as the synchronization presentation method and the synchronization presentation notification in the synchronization presentation method described in the first embodiment and the supplement of the first embodiment.

[0128] (11) Even if there is a time difference in reception between broadcasting and communication, depending on the content, there may be no need to synchronize between broadcasting and communication, and there is also an option not to perform synchronization control between broadcasting and communication. In this case, the control unit 51 may be configured to determine whether to perform synchronization control between broadcasting and communication.

[0129] The necessity of synchronization may be determined by the receiving device, or a delay tolerance may be defined for each content, and a broadcaster or an operator related to the broadcaster or another operator may transmit it to the receiving device using broadcasting or communication. The delay tolerance includes methods such as sending by AIT, sending within an application that can be specified by AIT, control information (SI) of a broadcast signal, and the like.

[0130] (12) The buffer configuration in the receiving device 1 described with reference to FIGS. 1 and 2 in the first embodiment is an example, and the buffer having the same function as the first embodiment is not limited to this configuration.

[0131] For example, it is desirable to place the buffer at the position where the memory size can be minimized. Also, in Embodiment 1, buffers are provided for each function such as a PES buffer, a synchronization buffer, and a reorder buffer, but it is not limited to this, and a single buffer may be provided with multiple functions. Further, the memory allocation that the buffer allocates to each function may be dynamic, or a plurality of functions may be realized by sharing the memory.

[0132] The same can be said for the receiving apparatuses 1A and 1B described with reference to FIGS. 9 and 10.

[0133] (13) In Embodiment 1, the synchronization control between broadcasting and communication has been described, but the cooperating systems are not limited to the cooperation between broadcasting and communication, and may be the cooperation between broadcasting and broadcasting, the cooperation between communication and communication, or the cooperation of signals based on three or more transmission paths.

[0134] (14) In Embodiment 1, the packet configuration defined in the MPEG2-TS system has been used for the description, but the multiplexing method is not particularly limited. Examples of the multiplexing method include MP4, RTP widely used in streaming, MMT, and the like.

[0135] (15) In the broadcast communication cooperation service, a service in which a receiving apparatus and a content presentation apparatus which is a communication terminal such as a smartphone or a tablet cooperate has also been proposed.

[0136] In this case, synchronization control between the content presented by the receiving apparatus 1 and the content presented by the content presentation apparatus is necessary.

[0137] As an example of such a service, there is one in which broadcast content is presented by the receiving apparatus and communication content is presented by the content presentation apparatus.

[0138] However, the services in which the receiving device and the content presentation device cooperate are not limited to this. For example, (A) a service in which communication content is presented on the receiving device and broadcast content is presented on the content presentation device, (B) a service in which a part of the broadcast content and a part of the communication content are presented on the receiving device and a part of the communication content is presented on the content presentation device, (C) a service in which a part of the broadcast content is presented on the receiving device and a part of the broadcast content and the communication content are presented on the content presentation device, (D) a service in which a part of the communication content is presented on the receiving device and a part of the communication content and the broadcast content are presented on the content presentation device, (E) a service in which a part of the broadcast content and the communication content are presented on the receiving device and the broadcast content is presented on the content presentation device, and (F) a service in which a part of the broadcast content and a part of the communication content are presented on the receiving device and a part of the broadcast content and a part of the communication content are presented on the content presentation device, etc.

[0139] In order to achieve synchronization control between broadcast and communication between the receiving device and the content presentation device, it is necessary to notify the other party, as necessary, of control information such as AIT related to synchronization, PTS or DTS, or the delay time between broadcast and communication, the synchronization presentation method, and the synchronization presentation notification.

[0140] When receiving broadcast on the receiving device and receiving communication on a tablet terminal which is a cooperation terminal, and synchronizing them with each other, it is necessary to notify the receiving device of the PTS of the cooperation terminal.

[0141] Also, when transmitting the broadcast content or communication content received by the receiving device to the linked terminal, by transmitting the data after the synchronization control is performed by the receiving device, the burden on the hardware and software of the linked terminal can be reduced. At this time, the receiving device calculates the delay time generated in the communication between the receiving device and the content presentation device, and considers both the delay time of the reception time of the communication content with respect to the reception time of the broadcast content and the delay time generated in the communication between the receiving device and the content presentation device, and controls the output timing of the PES packets from the PES buffer 71 in the buffer 13 and the PES buffer 71 in the buffer 22.

[0142] In any case, the control unit 51 determines the synchronization presentation method, the content and timing or period of the synchronization presentation notification, instructs the content generation unit, and at the same time notifies the determined content to the linked terminal via the communication transceiver unit 41.

[0143] (16) Depending on the type of application and content, there are many use cases and synchronization presentation methods for synchronizing communication and broadcast for presentation.

[0144] The control unit 51 has a function of providing a plurality of synchronization presentation methods and a function of controlling the presentation method related to the synchronization presentation according to the synchronization presentation method, and presents a plurality of synchronization presentation methods selectable according to the application and content to the viewer.

[0145] The viewer selects from among the plurality of selectable synchronization presentation methods by operating using the input interface. Then, the selected content is input to and set by the control unit 51. Note that a series of operations related to the setting are performed in conjunction with the control unit 51, the operation input unit 42, the content generation unit 31, and the presentation unit 5.

[0146] An example of the setting menu is shown in FIG. 11.

[0147] In the example of FIG. 11, as a menu for broadcast communication linkage, animation setting and synchronization presentation method setting can be performed.

[0148] In the animation setting, for example, in the screen transition of synchronous presentation, the animation can be set when connecting two discontinuous videos.

[0149] In the synchronous presentation method setting, settings related to the synchronous presentation method can be made. Fig. 12 shows an example of the setting screen for the synchronous presentation method. In the synchronous presentation method setting, for example, in addition to the receiver delegation mode, the broadcasting station delegation mode, the manual mode, and OFF (no synchronous presentation), the viewer can select from the synchronous presentation methods (Type1, Type2) that can be presented to the viewer.

[0150] When the viewer selects the broadcasting station delegation mode, the control unit 51 executes the synchronous presentation method described in the AIT only when the synchronous presentation method is set in the AIT.

[0151] When the viewer selects the receiver delegation mode, the control unit 51 selects from the synchronous presentation methods that can be presented to the viewer or the synchronous presentation method described in the AIT, and executes the selected synchronous presentation method. Note that the selection of the synchronous presentation method may be performed dynamically.

[0152] In addition to specifying the synchronous presentation method in the AIT, there are a method of specifying within an application that can be identified by the AIT and a method of specifying using the control information (SI, etc.) of the broadcast signal.

[0153] When the viewer selects the manual mode, a manual setting screen as shown in FIG. 13 appears. In the example of the manual setting screen in FIG. 13, the viewer can set the delay time between -MAX seconds and +MAX seconds within -10 seconds to +10 seconds. The MAX value of the delay time is determined by the control unit 51 based on the size of the content data, the size of the buffer, etc. Also, the synchronization delay time calculated from the PTS is displayed as a recommended value. Further, the viewer can change the setting of the delay time by moving the position of the black arrow painted black in the figure. Also, the viewer can return the delay time to the recommended value determined by the control unit 51 by pressing the recommended value button. Also, the viewer can set the delay time to 0 (switch to normal presentation without delay) by pressing the reset button.

[0154] When the viewer performs an operation to change the setting of the delay time, a control signal indicating the delay time is output to the control unit 51. The control unit 51 controls the buffer based on the control signal to adjust the delay.

[0155] (17) The function of the control unit 51 described in this embodiment may be implemented as software or as an application. Also, a part of the function can be packaged as an API (Application Programming Interface).

[0156] (Knowledge 2 on which the invention is based) The receiving device described in Patent Document 3 receives broadcast content from a digital broadcast signal and receives communication content linked to the broadcast content from a communication network. Then, the receiving device delays the presentation of the broadcast content based on the difference between the PTS of the broadcast content and the PTS of the communication content.

[0157] By the way, in a communication network such as the Internet, jitter occurs in the transmission path, so it is necessary to compensate for jitter on the receiving side. For this reason, a digital buffer for compensating jitter is required for a receiving device for communication. On the other hand, a digital buffer is not required for a receiving device for broadcasting. A receiving device as a broadcast-communication cooperative receiving device that links broadcasting and communication includes a digital buffer for communication, and further includes a delay buffer for realizing a buffer delay corresponding to the buffer delay of the digital buffer for broadcasting, and it is necessary to match the playback times of communication and broadcasting.

[0158] As described above, the receiving device described in Patent Document 3 synchronizes broadcast content and communication content based on the difference between the PTS of the broadcast content and the PTS of the communication content. If a large-capacity buffer is used for synchronization, it becomes possible to compensate for jitter without underflow or overflow.

[0159] However, if the buffer capacity is increased, there is a problem that the End-to-End delay increases. In conventional broadcast receiving systems, it has been required to minimize the End-to-End delay, and even if there is sufficient surplus memory in the receiving device, it is not realistic to use all the memory for jitter compensation, and it is desirable to use the minimum necessary memory. Also, when a system decoder model for guaranteeing buffer management during synchronous playback and decoding of the receiving device is defined, it is necessary to guarantee the operation of the receiving device using a buffer of a predetermined size.

[0160] In a receiving device as a broadcast-communication cooperative receiving device, when controlling a digital buffer using a buffer of a predetermined size, underflow and overflow are likely to occur, and for example, further buffering of communication content is required as a countermeasure against underflow. When using the receiving device described in Patent Document 3, the delay time of the delay buffer for broadcasting is dragged by the control of the digital buffer, and overflow or underflow occurs in the delay buffer for broadcasting, which affects the viewing of the content and makes it difficult to guarantee the operation of the broadcast receiver.

[0161] Therefore, the inventors have considered a technical solution to this problem, and as a result of this consideration, embodiments based on the solution obtained by the inventors will be described below.

[0162] (Embodiment 2) FIG. 14 is a block diagram showing the configuration of a receiving apparatus 100 which is a broadcast communication cooperation receiving apparatus according to Embodiment 2 of the present invention.

[0163] The receiving apparatus 100 includes a digital broadcast receiving unit 111, a separation unit 112, a delay buffer 113, a separation buffer 114, a decoding unit 115, a communication transmission / reception unit 121, a separation unit 122, a digital buffer 123, a separation buffer 124, a decoding unit 125, a content generation unit 131, a control management unit 141, and a control unit 151.

[0164] The digital broadcast receiving unit 111 takes as input a digital broadcast signal received by an external broadcast antenna 3. Then, the digital broadcast receiving unit 111 selects a desired channel from the digital broadcast signal, performs demodulation processing, error correction processing, etc. on the digital broadcast signal of the selected desired channel, generates a transport stream, and outputs it to the separation unit 112.

[0165] The separation unit 112 separates the transport stream generated by the digital broadcast receiving unit 111 into video data, audio data, subtitle data, etc., and outputs it to the delay buffer 113. Also, the separation unit 112 acquires various control information included in the transport stream, outputs the PCR to the control unit 151, and outputs control information including information related to the type and control of the content to the control management unit 141.

[0166] The delay buffer 113 is a buffer for realizing a buffer delay corresponding to the buffer delay of the digital buffer 123. The delay buffer 113 adjusts the delay of content data for each component such as video data and audio data output from the separation unit 112 according to the input / output timing instructed from the control unit 151, and outputs it to the separation buffer 114.

[0167] The separation buffer 114 stores video data, audio data, etc. output from the delay buffer 113, and based on timestamp information such as DTS obtained from the PES header of the PES packet, it outputs the elementary stream (ES) for each component such as video and audio to the decoding unit 115 in access unit units with their output timings aligned. Also, the separation buffer 114 outputs timestamp information such as DTS obtained from the PES header to the control unit 151. Note that the separation buffers 114 and 124 have the same function as the Elementary Stream Buffer in the MPEG2 system.

[0168] The decoding unit 115 decodes the access units for each component such as video and audio output from the separation buffer 114 and outputs them to the content generation unit 131.

[0169] The communication transceiver unit 121 acquires AV content from a content server provided by an operator related to the broadcaster or another operator via a communication network, and outputs the acquired AV content to the separation unit 122. The AV content provided by the communication operator includes file data, video data, audio data, etc.

[0170] The separation unit 122 separates the AV content input from the communication transceiver unit 121 into video data, audio data, etc., and outputs them to the digital buffer 123. Also, the separation unit 122 outputs control information including information related to the type and control of the content included in the AV content to the control management unit 141.

[0171] The digital buffer 123 is a buffer for absorbing jitter due to the transmission path. The digital buffer 123 adjusts the delay of the content data for each component such as video data and audio data output from the separation unit 122 at the input / output timing instructed by the control unit 151 and outputs them to the separation buffer 124.

[0172] The separation buffer 124 stores video data, audio data, etc. output from the digital buffer 123, and based on timestamp information such as DTS obtained from the PES header of the PES packet, outputs elementary streams for each component such as video and audio to the decoding unit 115 in access unit units with their output timings aligned. Also, the separation buffer 124 outputs timestamp information such as DTS obtained from the PES header to the control unit 151.

[0173] The decoding unit 125 decodes access units for each component such as video and audio output from the separation buffer 124 and outputs them to the content generation unit 131.

[0174] The content generation unit 131 generates presentation content using the content data of each component (video, audio, subtitles, etc.) output from the decoding unit 115 and the content data of each component (video, audio, and subtitles, etc.) output from the decoding unit 125. The presentation content generated by the content generation unit 131 is output to an external presentation unit 5 and presented by the presentation unit 5.

[0175] The control management unit 141 determines the control methods for the delay buffer 113 and the digital buffer 123 based on the type of content and control-related information included in the control information, and the states of the delay buffer 113 and the digital buffer 123, and instructs the control unit 151 of the determined control methods. Note that the control management unit 141 will be described later with reference to FIG. 15.

[0176] The control unit 151 generates a reference clock signal using the PCR output from the separation unit 112. This generated reference clock signal is used for controlling the output timings of each buffer.

[0177] The control unit 151 controls the delays of the delay buffer 113 and the digital buffer 123 based on the timestamp information such as DTS output from the separation buffer 114, the timestamp information such as DTS output from the separation buffer 124, and the control method determined by the control management unit 141.

[0178] Hereinafter, a configuration example of the control management unit 141 will be described with reference to FIG. 15.

[0179] FIG. 15 is a block diagram showing a configuration example of the control management unit 141 in FIG. 14.

[0180] The control management unit 141 includes a control information extraction unit 171, a buffer management unit 172, a monitoring unit 173, and a control method determination unit 174.

[0181] The control information extraction unit 171 extracts information related to the content type and control from the input control information, and outputs the extracted information related to the content type and control to the control method determination unit 174. However, as information related to the content type and control, for example, there is information related to the accuracy required for content synchronization, information related to the allowable end-to-end delay time of the broadcast content, and the like. Note that control information such as information related to the content type and control is multiplexed and transmitted on the transmission side, for example. When using the MPEG2-TS method as the multiplexing method, the control information is composed of PSI, SI, sections, etc. constituted by descriptors, tables, etc.

[0182] The buffer management unit 172 manages the buffer size, buffer occupancy, and delay time (the time from input to output in the buffer) for each of the delay buffer 113 and the digital buffer 123, and calculates the size of the available surplus buffer based on these.

[0183] For example, the buffer management unit 172 can always monitor the input clock and output clock, and calculate the delay time and buffer occupancy in each of the digital buffer 123 and the delay buffer 113.

[0184] Further, the buffer management unit 172 can calculate the buffer occupancy in each of the digital buffer 123 and the delay buffer 113 by multiplying the average bit rate by the delay time in the buffer.

[0185] In addition, if there is a buffer memory shared by the delay buffer 113 and the digital buffer 123 other than those, the buffer management unit 172 may dynamically determine the buffer size including the available memory therein.

[0186] The monitoring unit 173 constantly monitors the possibility of underflow and the possibility of overflow in the digital buffer 123, and notifies the monitoring result to the control method determination unit 174.

[0187] Here, an example of the monitoring process performed by the monitoring unit 173 in the second embodiment will be described.

[0188] The monitoring unit 173 monitors the buffer occupancy of the digital buffer 123.

[0189] Then, when the buffer occupancy of the digital buffer 123 is less than a predetermined first threshold, the monitoring unit 173 turns on the underflow flag assuming that there is a possibility of underflow. On the other hand, when the buffer occupancy of the digital buffer 123 is equal to or greater than the predetermined first threshold, the monitoring unit 173 turns off the underflow flag assuming that there is no possibility of underflow.

[0190] Also, when the buffer occupancy of the digital buffer 123 exceeds a predetermined second threshold, the monitoring unit 173 turns on the overflow flag assuming that there is a possibility of overflow. On the other hand, when the buffer occupancy of the digital buffer 123 is equal to or less than the predetermined second threshold, the monitoring unit 173 turns off the overflow flag assuming that there is no possibility of overflow.

[0191] The monitoring unit 173 constantly performs the above operations.

[0192] When there is a possibility of underflow or overflow, the control method determination unit 174 determines the control methods for the delay buffer 113 and the digital buffer 123 based on the surplus buffer size, End-to-End delay, content type, control-related information, etc., and notifies the control unit 151 of the determined control methods. The operation of the control method determination unit 174 will be described later with reference to FIG. 17 in more detail.

[0193] FIG. 16 is a flowchart showing an example of the initial operations of the delay buffer 113 and the digital buffer 123 after the start of broadcast communication reception by the receiving device 100 in FIG. 14. However, in the flowchart of FIG. 16, it is assumed that underflow and overflow do not occur in the delay buffer 113 and the digital buffer 123. In FIG. 16, the communication-related processes are shown on the left side of the figure, and the broadcast-related processes are shown on the right side of the figure.

[0194] The receiving device 100 starts receiving the broadcast (step S101) and starts receiving the communication (step S102).

[0195] After the start of communication reception, the digital buffer 123 starts buffering communication data under the control of the control unit 151 (step S103). The control unit 151 controls the start of buffering of the delay buffer 113 in accordance with the start of buffering of the digital buffer 123, and the delay buffer 113 starts buffering broadcast data under the control of the control unit 151 (step S104).

[0196] The control unit 151 determines whether the buffering amount of the digital buffer 123 has reached the initial buffering amount, that is, whether the initial buffering of the digital buffer 123 is completed (step S105). Until it is determined that the initial buffering of the digital buffer 123 is completed (S105: No), the initial buffering of the digital buffer 123 and the delay buffer 113 is performed, and the process of step S105 is performed.

[0197] When it is determined that the initial buffering of the digital buffer 123 is completed (S105: Yes), the control unit 151 controls the start of the delayed output of the data in the digital buffer 123 and the delay buffer 113. The digital buffer 123 starts the delayed output of the communication data under the control of the control unit 151 (step S106), and the delay buffer 103 starts the delayed output of the broadcast data under the control of the control unit 151 (step S107).

[0198] As described above, according to the operation of the digital buffer 123, the delay buffer 113 is operated, and the initial operation is completed.

[0199] However, the initial buffering amount of the digital buffer 123 is, for example, a value obtained by multiplying the assumed time of the jitter to be compensated by the average bit rate.

[0200] The output of the normal broadcast data before starting the delayed output may start after waiting for the completion of the initial buffering of the digital buffer 123, or may start without waiting for the completion of the initial buffering of the digital buffer 123.

[0201] When starting the output of the digital buffer 123, communication data synchronized with the broadcast data is output based on the time difference calculated from the timestamp information of the broadcast data and the communication data.

[0202] In addition, in FIG. 16, it was described that the size of the delay buffer 113 has a sufficient size to delay the broadcast. However, if the delay buffer 113 is likely to overflow before starting the delayed output of the broadcast data, it is necessary to appropriately process it at that time.

[0203] FIG. 17 is a flowchart showing an example of the control method determination operation by the control method determination unit 174 in FIG. 14. However, at the start of the flowchart in FIG. 17, it is assumed that the digital buffer 123 and the delay buffer 113 are in a steady state where they are synchronized.

[0204] The control method determination unit 174 determines whether the underflow flag based on the result of monitoring the digital buffer 123 by the monitoring unit 173 is ON or OFF (step S151). If the underflow flag is OFF, that is, when there is no possibility of underflow occurring in the digital buffer 123 (S151: OFF), the control method determination unit 174 determines whether the overflow flag based on the result of monitoring the digital buffer 123 by the monitoring unit 173 is ON or OFF (step S152).

[0205] If the overflow flag is OFF, that is, when there is no possibility of overflow occurring in the digital buffer 123 (S152: OFF), the process returns to the process of step S151.

[0206] If the overflow flag is ON, that is, when there is a possibility of overflow occurring in the digital buffer 123 (S152: ON), the control method determination unit 174 determines the process for overflow as the control method (for example, the process of skipping the output of the digital buffer 123) and instructs the control unit 151. The control unit 151 receives this instruction and executes the process for overflow on the digital buffer 123 (step S153).

[0207] If the underflow flag is ON, that is, when there is a possibility of underflow occurring in the digital buffer 123 (S151: ON), the control method determination unit 174 determines whether there is a margin in the digital buffer 123 (step S154). The determination in step S154 is made, for example, that there is a margin in the digital buffer 123 when the surplus buffer size of the digital buffer 123 calculated in the buffer management unit 172 is equal to or greater than a predetermined value.

[0208] If it is determined that there is no margin in the digital buffer 123 (S154: No), the process proceeds to the process of step S162.

[0209] On one hand, when it is determined that there is margin in the digital buffer 123 (S154: Yes), the control method determination unit 174 determines whether there is margin in the delay buffer 113 (step S155). The determination in step S155 is made, for example, when the surplus buffer size of the delay buffer 113 calculated by the buffer management unit 172 is equal to or greater than a predetermined value, it is determined that there is margin in the delay buffer 113.

[0210] When it is determined that there is no margin in the delay buffer 113 (S155: No), the process proceeds to the process of step S162.

[0211] When it is determined that there is margin in the delay buffer 113 (S155: Yes), the control method determination unit 174 instructs the control unit 151 to perform additional buffering of the digital buffer 123, and the control unit 151 receives this instruction and performs control to stop the output of the digital buffer 123 and perform additional buffering. The digital buffer 123 receives the control by the control unit 151, stops the output, and performs additional buffering (step S156).

[0212] The control method determination unit 174 determines whether the additional buffering of the digital buffer 123 is completed (step S157). Whether the additional buffering is completed is determined, for example, based on the result of monitoring the digital buffer 123 by the monitoring unit 173. When it is determined that the occupancy of the digital buffer is sufficient and the possibility of the digital buffer underflowing again is low, it is determined that the additional buffering is completed.

[0213] When it is determined that the additional buffering of the digital buffer 123 is not completed (S157: No), the process returns to the process of step S154.

[0214] When it is determined that the additional buffering of the digital buffer 123 is completed (S157: Yes), the control method determination unit 174 determines whether it is necessary to delay the broadcast (step S158). The determination in step S158 determines that there is no need to delay the broadcast, for example, when the information related to the accuracy required for content synchronization does not require synchronization.

[0215] When it is determined that there is no need to delay the broadcast (S158: No), the control method determination unit 174 determines the control method that does not perform the delay control of the delay buffer 113 as the control method, and notifies the control unit 151 of the determined control method. The control unit 151 does not perform the delay control of the delay buffer 113 upon receiving this notification, and the delay buffer 113 outputs the broadcast data without delaying it (step S159).

[0216] When it is determined that it is necessary to delay the broadcast (S158: Yes), the control method determination unit 174 determines whether the actual end-to-end delay time is within the allowable range by using the information related to the allowable end-to-end delay time of the broadcast content (step S160). The information related to the allowable end-to-end delay time of the broadcast content can be obtained, for example, by specifying the allowable end-to-end delay time of the content on the transmission side, transmitting it as a control signal using the broadcast, and the receiving device receiving the broadcast signal and obtaining the information related to the allowable end-to-end delay time of the broadcast content from the control signal.

[0217] When it is determined that the end-to-end delay time is not within the allowable range (S160: No), the process proceeds to the process of step S162.

[0218] When it is determined that the end-to-end delay time is within the allowable range (S160: Yes), the control method determination unit 174 determines that the control method is to perform delay control of the delay buffer 113, and notifies the control unit 151 of the determined control method. The control unit 151 performs delay control of the delay buffer 113 in response to this notification, and the delay buffer 113 performs a delay output operation of the broadcast data (step S161). Note that the delay amount in the delay buffer 113 in the delay control can be calculated by using the input / output counter of the digital buffer 123 and the input / output counter of the delay buffer 113.

[0219] In step S162, the control method determination unit 174 determines that synchronization between broadcasting and communication is impossible. Then, the control method determination unit 174 determines that the control method is to independently control the digital buffer 123 and the delay buffer 113 so as to guarantee only the reception operation of the broadcast, and notifies the control unit 151 of the determined control method. The control unit 151 independently controls the digital buffer 123 and the delay buffer 113 in response to this notification (step S162).

[0220] (Supplement of Embodiment 2) The supplement of Embodiment 2 will be described below.

[0221] (1) In Embodiment 2, when there is a delay difference due to the transmission path between broadcasting and communication, the configuration of the receiving apparatus can be the configuration shown in FIG. 18. However, in FIG. 18, the same reference numerals are given to the configuration units that perform substantially the same processing as the configuration units in FIG. 14.

[0222] The receiving apparatus 100A in FIG. 18 has a configuration in which a synchronization buffer 191 is added between the delay buffer 113 and the separation buffer 114, and a synchronization buffer 196 is added between the digital buffer 123 and the separation buffer 124, with respect to the receiving apparatus 100 in FIG. 14.

[0223] The control unit 151 controls the output timings of the synchronization buffer 191 and the synchronization buffer 196 so that synchronization is achieved between the broadcast data and the communication data, using the timestamp information such as DTS from the separation buffer 114 and the timestamp information such as DTS from the separation buffer 124.

[0224] (2) Even when there is a possibility of an underflow or an overflow occurring in the digital buffer 123, it is not always necessary to control the delay buffer 113.

[0225] (3) The mechanism for determining the control method described in the second embodiment can be used when various underflow avoidance methods and overflow avoidance methods are employed.

[0226] (4) In the second embodiment, when a buffer size for guaranteeing the operation of the buffer is defined in advance, the surplus buffer size may be calculated using the defined buffer size.

[0227] When it is impossible to control the digital buffer 123 and the delay buffer 113 with the defined buffer size, it may not be necessary to guarantee the reception operation related to communication.

[0228] When control is impossible with the defined buffer size, a message indicating that may be presented to, for example, the presentation unit 5.

[0229] When control is impossible with the defined buffer size, information indicating that may be fed back to the transmission side using the communication means.

[0230] Information related to the transmission path such as the actual jitter time and the delay time between broadcast and communication may be fed back to the transmission side using the communication means.

[0231] (5) When synchronization between broadcast and communication cannot be guaranteed, it is preferable to perform control that prioritizes the operation of the receiving device related to broadcast.

[0232] When synchronization between broadcasting and communication cannot be guaranteed, while monitoring the digital buffer 123, by appropriately controlling the digital buffer 123 and the delay buffer 113, the operation of the receiving device related to broadcasting is guaranteed.

[0233] (6) As a result of controlling the digital buffer 123, there is also an option to change the communication content into data with less delay and less jitter. In this case, the communication transceiver 121 notifies the content server to that effect and acquires data with less jitter. Thereby, it becomes possible to provide a stable service to the viewer.

[0234] It is also assumed that it may be necessary to change the acquisition method of the broadcast content along with the change in the acquisition of the communication content. In this case, the control management unit 141 changes the acquisition method of the broadcast content.

[0235] (7) On the transmission side, control information indicating the quality of the transmission path may be multiplexed and transmitted as a signaling message, and the receiving device may determine or limit the control method based on the transmitted quality. For example, when the maximum delay time assumed in the communication transmission path is signaled from the transmission side as a control signal indicating the quality of the transmission path, the receiving device may determine whether to receive the communication content or whether to synchronously reproduce the broadcast content and the communication content by comparing it with the buffer size of the receiving device.

[0236] On the transmission side, control information indicating the recommended control method may be multiplexed and transmitted as a signaling message, and the receiving device may operate based on the transmitted recommended control method.

[0237] On the transmission side, the jitter time that the transmission side can guarantee the operation, as well as the information on the buffer sizes of the digital buffer 123 and the delay buffer 113, may be multiplexed and transmitted as a signaling message.

[0238] (8) The accuracy required for content synchronization is, for example, for one content relative to the other content: (A) no synchronization required, (B) synchronization accuracy within 10 seconds is required, (C) synchronization accuracy within 1 second is required, (D) synchronization accuracy at the frame level is required, etc.

[0239] The receiving device 100 can freely determine a control method related to synchronization and jitter so as to satisfy the accuracy required for content synchronization. Therefore, it is also possible to select a control method according to the specifications and capabilities of the receiving device. For example, if frame-level synchronization is required, the high-precision delay buffer 113 is controlled in accordance with the digital buffer 123. Also, if synchronization is not required, it is also possible to make a selection not to control the delay buffer 113 in accordance with the control of the digital buffer 123. Instead of notifying the minimum required synchronization accuracy, the recommended synchronization accuracy may be transmitted.

[0240] It is also possible for the receiving device to determine the synchronization accuracy according to the content of the content and determine the control method. For example, in the case of video and subtitles as the content, if there is no problem for viewing the subtitles, the synchronization accuracy may be reduced for control.

[0241] (9) The transmitting side may transmit control information as to whether one content can be decoded alone or cannot be decoded alone. For example, if the broadcast cannot be decoded alone, it is essential to synchronize the broadcast and the communication. On the other hand, if the broadcast can be decoded alone, when synchronization is impossible, it is also possible to select to display only the broadcast content.

[0242] (10) The transmitting side may define an acceptable jitter and digital buffer amount and transmit them as control signals.

[0243] The content producer may determine, for example, to "force" or "not force" the synchronization accuracy, and the transmitting side may transmit this information.

[0244] (11) It is preferable that the control information can be acquired before the start of decoding.

[0245] As information that can be acquired before the start of decoding, for example, when using MMT (MPEG Media Transport) as a multiplexing method, it may be described in CI (Composition Information), or may be described in MPT (MMT Packege Table) together with a list of Assets. Also, in the case of MPEG2-TS, it may be control information such as PMT (Program Map Table), and in the case of using MPEG-DASH (Dynamic Adaptive Streaming over HTTP), it may be described in MPD (Media Presentation Description). In the case of other multiplexing systems, any program information that can be acquired by the receiving apparatus before the start of decoding is acceptable.

[0246] The control information is transmitted from either or both of broadcasting and communication, and the control management unit 141 acquires and analyzes the control information before the start of decoding, and determines the control methods for the digital buffer 123 and the delay buffer 113.

[0247] (12) A buffer size for compensating for jitter and the synchronization between broadcasting and communication may be specified in advance, and further, constraint conditions for compensating operations within the specified buffer size may be specified, and based on the specifications, operations of the buffer such as countermeasures against underflow and overflow may be determined.

[0248] The total size of the digital buffer, the delay buffer, and the synchronization buffer may be specified, and the specifications for compensating operations within the total size may also be used.

[0249] (13) The configurations of the receiving apparatuses 100 and 100A whose configurations are shown in FIGS. 14 and 18 may be modified to be decoded by one decoding unit described with reference to FIG. 9, or may be modified to include, for example, two content generation units described with reference to FIG. 10.

[0250] (14) The functions described in Embodiment 2 and the supplement to Embodiment 2 may be realized by hardware, or may be realized by software. Further, part of them may be realized by hardware and part of them may be realized by software.

[0251] (15) Before decoding content for which jitter and synchronization between broadcast and communication have been completed, it may be transmitted to a cooperation device such as a tablet.

[0252] (16) Part of the functions described in Embodiment 2 and the supplement to Embodiment 2 may be realized not only as a receiving device but also as part of the function of a relay station.

[0253] (17) The control results of the digital buffer 123 and the delay buffer 113 (for example, an error message such as "Synchronization between broadcast and communication is impossible") may be presented to the viewer or may be recorded as a report.

[0254] (18) The buffer configuration in the receiving device 100 described with reference to FIG. 14 in Embodiment 2 is an example, and the buffer is not limited to this configuration as long as it has the same function as Embodiment 2.

[0255] For example, it is desirable to arrange the buffer at a position where the memory size can be minimized. Further, in Embodiment 2, buffers are provided for each function such as the delay buffer 113, the separation buffer 114, the digital buffer 123, and the separation buffer 124, but the present invention is not limited to this, and a single buffer may be provided with a plurality of functions. Further, the memory allocation that the buffer allocates to each function may be dynamic, or a plurality of functions may be realized by sharing the memory.

[0256] The same can be said for the receiving device 100A described with reference to FIG. 18.

[0257] In Embodiment 2, MPEG2-TS was taken as an example for the multiplexing method, but the multiplexing method is not particularly limited. Examples of the multiplexing method include MP4, RTP widely used in streaming, MMT, etc.

[0258] (Others) The contents described in Embodiment 1 and the supplement to Embodiment 1 may be appropriately combined.

[0259] The contents described in Embodiment 2 and the supplement to Embodiment 2 may be appropriately combined.

[0260] The contents described in Embodiment 1 and the supplement to Embodiment 1 and the contents described in Embodiment 2 and the supplement to Embodiment 2 may be appropriately combined.

[0261] The contents described in Embodiment 1 and the supplement to Embodiment 1 may be applied to the contents described in Embodiment 2 and the supplement to Embodiment 2, and the contents described in Embodiment 2 and the supplement to Embodiment 2 may be applied to the contents described in Embodiment 1 and the supplement to Embodiment 1.

[0262] <<Summary>> Summarize the receiving apparatus, receiving method, and their effects according to the embodiments and modification examples.

[0263] (1) The first receiving apparatus includes: a first buffer that accumulates and outputs a first signal received via a first transmission path that does not require jitter compensation; a second buffer that accumulates and outputs a second signal received via a second transmission path that requires jitter compensation; a control management unit that monitors whether an underflow may occur in the second buffer, and determines a control method for the first buffer and the second buffer based on the surplus buffer size of the first buffer and the surplus buffer size of the second buffer when an underflow may occur; and a control unit that controls the first buffer and the second buffer based on the control method for the first buffer and the second buffer determined by the control management unit.

[0264] The first receiving method is a receiving method performed in a receiving apparatus including a first buffer that accumulates and outputs a first signal received via a first transmission path that does not require jitter compensation, and a second buffer that accumulates and outputs a second signal received via a second transmission path that requires jitter compensation. The method monitors whether an underflow may occur in the second buffer, and when an underflow may occur, determines a control method for the first buffer and the second buffer based on the surplus buffer size of the first buffer and the surplus buffer size of the second buffer, and controls the first buffer and the second buffer based on the determined control method for the first buffer and the second buffer.

[0265] According to these, it is possible to improve the quality of services for the first signal that does not require jitter compensation and the second signal that requires jitter compensation.

[0266] (2) In the second receiving apparatus, in the first receiving apparatus, the control management unit further determines the control method based on control information related to the accuracy required for synchronization between the first signal and the second signal.

[0267] (3) In the third receiving apparatus, in the first receiving apparatus, the control management unit further determines the control method based on information related to the allowable End-to-End delay time of the first signal.

[0268] (4) The fourth receiving apparatus includes a first buffer that accumulates and outputs a first signal received from a first transmission path, a second buffer that accumulates and outputs a second signal received from a second transmission path, a control unit that performs synchronization control of the first buffer and the second buffer related to synchronization between the first signal and the second signal based on time information included in the first signal and time information included in the second signal, and a notification unit that performs notification related to synchronization in response to the synchronization control by the control unit.

[0269] The second receiving method is a receiving method performed in a receiving apparatus including a first buffer that accumulates and outputs a first signal received from a first transmission path and a second buffer that accumulates and outputs a second signal received from a second transmission path. Based on the time information included in the first signal and the time information included in the second signal, synchronization control of the first buffer and the second buffer related to the synchronization of the first signal and the second signal is performed, and notification related to synchronization is performed according to the synchronization control.

[0270] According to these, it becomes possible to reduce the sense of strangeness and discomfort given to the viewer when synchronizing the first signal and the second signal.

[0271] (5) In the fifth receiving apparatus, the control unit performs the synchronization control based on the input content by the viewer.

[0272] According to this, the synchronization of the first signal and the second signal can be made in accordance with the viewer's wishes.

[0273] (Embodiment 3) In the embodiments described so far, the case where the receiving apparatus does not select communication content, such as the acquisition of multicast-streamed communication content, has been described as an example. In Embodiment 3, an example of synchronously presenting the communication content selected by the receiving apparatus with the broadcast content will be described.

[0274] Note that in the following Embodiment 3, when simply described as a "receiving apparatus", any of the receiving apparatuses described in FIGS. 1, 9, 10, and 14 may be adopted for this "receiving apparatus". The same applies to the description of components included in the receiving apparatus, such as the "control unit".

[0275] [Overview] The following describes the outline of the operations performed by the receiving device and the server according to Embodiment 3. Note that the server is an example of a transmitting device. In the following Embodiment 3, when the description refers to functions that can be realized in both the communication server and the broadcast server as the "server", it may be a communication server or a broadcast server. · The server includes information on whether the communication protocol is multicast and whether the content is live in the control information and transmits it. The receiving device determines whether it can acquire communication content at an arbitrary time based on whether the control information and the acquired content are in the communication server. · When the receiving device can acquire communication content at an arbitrary time, it determines the time and acquisition timing of the communication content to be acquired and acquires it from the server. · When the receiving device can acquire communication content at an arbitrary time, it pre-buffers the communication content. Also, the server notifies the timing of pre-buffering and the like as control information or an event, and the receiving device starts pre-buffering at the notified time. · The receiving device determines whether the broadcast content and the communication content can be synchronously reproduced based on the buffer state, the type of content, the state of the transmission path, etc. When there is a possibility that synchronous reproduction becomes impossible, the receiving device controls the buffer or makes a determination based on the acquisition of the communication content and performs control based on the determination. · The server signals as control information the accuracy required for synchronizing the broadcast content and the communication content and the allowable time difference in content presentation. The receiving device controls the presentation method and the buffer based on the control information. · The server signals as control information the accuracy required for synchronizing the broadcast content and the communication content and the allowable time difference in content presentation, and instructs the communication server to acquire the communication content to be acquired based on the control information.

[0276] [Details] The following describes the details of the operations performed by the receiving device and the server according to Embodiment 3.

[0277] For example, in a progressive download method such as MPEG-DASH, it is conceivable that content of different qualities is selected according to the communication environment. Also conceivable are cases where data for a desired time is selected and acquired from segmented data, or cases where communication content acquired using a protocol such as RTSP in a streaming service is selected.

[0278] In the example of MPEG-DASH, for one video content, a plurality of video data with different image sizes and encoding speeds are prepared on the server, and the video data is divided into segments. Also, the MPD describes information about the video data stored on the server.

[0279] Therefore, the receiving device acquires and analyzes the MPD from the server, determines the data to be acquired in consideration of the capabilities of the receiving device and the state of the transmission path for communication, and requests it from the server. Then, the receiving device acquires the determined desired video data from the server using the HTTP protocol.

[0280] By the way, in the broadcast communication cooperation service in Embodiment 3, it is desirable that the receiving device acquires communication content in an appropriate manner according to the broadcast service (broadcast content) and performs synchronized playback. Therefore, in Embodiment 3, the receiving device acquires control information related to the acquisition of communication content, acquires control information related to broadcast communication cooperation, and acquires communication content according to the broadcast service.

[0281] In order to provide a broadcast communication cooperation service, the transmitting side can include in the control information related to broadcast communication cooperation information indicating whether information on the transmission method of communication content, information related to the service of communication content, information on whether time information related to the acquisition of communication content is included, time information or timing information related to the acquisition of communication content, or location information of communication content. Hereinafter, each piece of information will be described.

[0282] The transmission method of communication content is, for example, the MPEG-DASH method, the MMT method, the RTP method, etc. When the transmission method of communication content is included in the control information related to broadcast-communication cooperation, the receiving device acquires the transmission method of communication content from the control information related to broadcast-communication cooperation, and acquires the communication content by a receiving method corresponding to the transmission method.

[0283] Information related to the service of communication content is, for example, information indicating VOD, streaming, or live, etc.

[0284] The information indicating whether time information related to the acquisition of communication content is included is, for example, information indicating that the time information related to the start of acquisition of communication content or the timing information is described in the control information. As the timing information, there is timing information such as an event message, for example.

[0285] When the receiving device determines that the control information includes time information related to the acquisition of communication content, the receiving device acquires the time information, controls the acquisition of communication content, or selects the communication content to be acquired. Further, when the control information includes information indicating that an event message has been transmitted, the receiving device monitors the event message and controls the acquisition of communication content according to the event.

[0286] The time information related to the acquisition of communication content is information for specifying the acquisition timing of communication content necessary for playing back the communication content in synchronization with the broadcast content to the receiving device.

[0287] Note that the receiving device does not necessarily need to acquire the content based on the time information related to the acquisition of communication content. The determination of whether to acquire the content based on the time information may be controlled by transmitting a control signal so that the broadcasting station can specify it, or the receiving device may make the determination by itself. Further, such a determination may be made by the viewer.

[0288] The time information or timing information related to the acquisition of communication content is specifically the following information. · Time information or timing information related to the start of acquisition of communication content (information indicating the time or timing at which the acquisition of communication content should start in order to synchronize with broadcast content) · Time information or timing information related to the completion of acquisition of communication content (information indicating the time or timing at which the acquisition of communication content should be completed in order to synchronize with broadcast content) · Time information or timing information related to the playback of communication content (information indicating the time or timing at which the communication content should be played back in order to synchronize with broadcast content) · Time information or timing information indicating the time when the acquisition of communication content becomes possible Note that these time information may be absolute times such as NTP, or relative times with respect to the reference time of the broadcast signal (such as PCR or NTP). Also, as time information related to the acquisition of communication content, timing information such as an event message may be transmitted.

[0289] The location information of communication content is, for example, information indicating the storage location of the communication content.

[0290] Note that the control information may include the following information in addition to the above information.

[0291] For example, it may include information indicating the switching from a program (program) for only broadcast to a program for broadcast-communication cooperation, or time information indicating the time when the program for broadcast-communication cooperation starts. The program for broadcast-communication cooperation is, for example, a program that synchronously plays back broadcast and communication, but may also be a program that does not synchronously play back broadcast and communication.

[0292] Also, when switching from a program with only broadcasting to a program with broadcast communication cooperation, before the switch, it is possible to notify the receiving side in advance that the program with broadcast communication cooperation will start or the time information when the program with broadcast communication cooperation starts, and to transmit the program information of the next program in advance to instruct pre-buffering of communication content. As a result, the receiving device can pre-acquire program information from a time before the start of the broadcast program, start acquiring communication content, and perform pre-buffering, enabling smooth synchronized playback of the program with broadcast communication cooperation.

[0293] Also, when the state such as the combination of transmission paths constituting the program changes, information indicating that the state will change in advance or information indicating the time when the state changes may be included in the control information. For the transmission of these information, EIT may be used, or these information may be described in the information of the next program by setting the current next indicator of PMT to '0' and transmitted as program information.

[0294] Also, these information may be described in AIT and transmitted. For example, in the hybrid cast specification, it is assumed that a descriptor ait identifier info() indicating that AIT (application control information) is included in the descriptor of the PMT information of the next program is described. In such a case, the AIT of the next program may be transmitted in advance during the broadcast of the current program. Specifically, a flag indicating whether it has been transmitted in advance may be stored in the descriptor, or information that can identify whether it is the AIT related to the current program or the AIT related to the next program information may be described inside the AIT.

[0295] In addition, the control information may include information indicating that the communication server is in a state where it can provide communication content. Such information is, in other words, information (acquisition information) indicating that the communication content can be acquired. Further, the control information may include time information at which the communication content becomes available. Such time information is, in other words, information (acquisition information) indicating that the communication content can be acquired after the timing by notifying the timing. Further, the control information may indicate acquisition information of a plurality of communication contents, or may indicate a list of communication contents that the communication server can provide.

[0296] The control information related to broadcast-communication cooperation may be described in program information based on the broadcast transmission method as a descriptor, or may be described in program information based on the communication transmission method. Further, the control information related to broadcast-communication cooperation may be described in other forms of program information. The control information related to broadcast-communication cooperation may be described in any one of these program informations, or may be described in a plurality of program informations.

[0297] Here, a supplement to the program information will be given.

[0298] The program information is described in the PMT when using MPEG2-TS, for example, but may be described in the MPT when using the MMT method, or may be described in the MPD in the case of MPEG-DASH. Further, the program information is described in application control information (Application Information Table) used in hybrid cast or the like, and may be transmitted as a section or transmitted by a data carousel.

[0299] The program information is transmitted using at least one or more of a plurality of transmission paths such as broadcast and communication. For example, there may be a case where program information based on the communication transmission method is transmitted using broadcast.

[0300] Note that information indicating that the program information includes control information related to broadcast-communication cooperation may be described in the program information, or the program information may include information indicating location information where control information related to broadcast-communication cooperation is included.

[0301] Hereinafter, specific examples in the case where control information related to broadcast-communication cooperation is described in program information as a descriptor will be described.

[0302] When the broadcast content is transmitted using the MPEG2-TS format and the communication content is transmitted using MPEG-DASH, the descriptor corresponding to the control information may be described in the PMT transmitted by broadcast or in the MPD transmitted by communication. Also, the descriptor corresponding to the control information may be described in both the PMT and the MPD, the MPD may be transmitted by broadcast, or the PMT may be transmitted by communication.

[0303] [Example of content acquisition operation] Next, the communication content acquisition operation of the receiving device according to Embodiment 3 will be described using a flowchart. FIG. 19 is a flowchart showing an example of the communication content acquisition operation of the receiving device according to Embodiment 3. Note that the flowchart of FIG. 19 is premised on the state where communication content can be acquired at an arbitrary time (the state where transmission preparation of communication content is ready).

[0304] First, the control unit (receiving device) determines an acquisition method for communication content based on the transmission method of the communication content, information on the service of the communication content, etc. (step S201).

[0305] Next, based on the acquisition method of the communication content determined in step S201, the control unit acquires control information related to broadcast, control information related to communication, control information related to broadcast-communication cooperation, etc., starting from the program information serving as an entry (step S202).

[0306] Next, the control unit acquires information for acquiring the following communication content (step S203). · The control unit acquires content information prepared on the server from the control information related to communication. For example, in the case of MPEG-DASH's MPD, the content information includes the image size of video data, the encoding rate of video data, and the time information of video data, etc. · The control unit acquires information on the quality of the communication transmission path from the communication transceiver unit 21. · The control unit acquires the capabilities of the receiving device necessary for playing back the content.

[0307] Note that when only communication content is played back in the receiving device, the control unit can determine the communication content based on the information for acquiring the above communication content. However, in order to synchronously play back broadcast content and communication content in a broadcast communication cooperation service, the control unit further acquires information related to the playback of broadcast content (step S204), and determines communication content suitable for synchronous playback of broadcast content.

[0308] Information related to the playback of broadcast content includes, for example, the presentation time or decoding time of broadcast content such as PTS and DTS, the state of buffers such as the delay buffer and digital buffer in the receiving device (buffer size, buffer usage amount, overflow, underflow, etc.), the End-to-End delay amount, etc.

[0309] Note that in step S203 above, the receiving device may acquire time information or timing information related to the acquisition of the above communication content (information indicating the timing related to the acquisition of communication content). Also, in step S203 above, the receiving device may acquire information indicating that the acquisition of communication content is possible (information indicating that the communication content is ready on the server). These information (information related to the acquisition of communication content, that is, acquisition information) are received through broadcast in Embodiment 3, but may also be received by communication.

[0310] With such acquired information, the receiving device can appropriately acquire communication content in response to the reception of broadcast content. Further, by the receiving device acquiring communication content according to the acquired information, it is possible to reduce the possibility of discontinuities such as skipping and stopping occurring in the presentation of the broadcast, which is the main content, and ensure stable broadcast viewing.

[0311] Next, based on the information acquired in steps S203 and S204, the control unit selects communication content suitable for synchronous playback with the broadcast content, and acquires the selected communication content from the server (step S205).

[0312] Then, the control unit synchronously plays back the broadcast content and the communication content by appropriately controlling the buffer according to the acquired communication content (step S206). Note that the broadcast content is received, for example, in step S206. The method of controlling the buffer here has been described in Embodiments 1 and 2, so the description is omitted.

[0313] Supplementary details of the processing in step S205 are described below. In step S205, specifically, the control unit acquires the time stamp of the broadcast content and selects communication content that can be synchronously played back with the broadcast content. Then, the control unit requests the selected communication content from the server and acquires it.

[0314] Also, during the synchronous playback of the broadcast content and the communication content, it is conceivable that the state of the buffer is monitored, and it is determined that synchronous playback cannot be continued due to buffer overflow, underflow, etc. In such a case, the control unit can also continue synchronous playback by controlling the acquisition of the communication content. Here, the control of the acquisition of the communication content means controlling (temporarily stopping, fast-forwarding, rewinding, etc.) the acquisition of the content.

[0315] In addition, the control unit can also continue synchronous playback by acquiring content with different playback times from the server. Acquiring content with different playback times means, for example, skipping the acquisition of communication content and acquiring communication content with a later playback time, or rewinding the acquisition of communication content and acquiring communication content with an earlier playback time. Such control is effective when changes occur in jitter, delay, etc. of the transmission path.

[0316] [Operation example in steady state] Next, a synchronous playback operation including acquisition of communication content in a steady state where the digital buffer and the delay buffer are synchronized will be described with reference to FIG. 20. FIG. 20 is a flowchart showing an example of a synchronous playback operation including acquisition of communication content.

[0317] In step S162 of FIG. 17 described in Embodiment 2, when it is determined that synchronous playback of broadcast content and communication content is difficult, control is performed to guarantee only the broadcast reception operation. In contrast, in the flowchart of FIG. 20, the difference is that even when it is determined that synchronous playback of broadcast content and communication content is difficult, an attempt is further made to acquire communication content for which synchronous playback is possible.

[0318] In the steady state, the control unit (or control management unit) monitors buffers (such as a delay buffer, a digital buffer, and a synchronization buffer) in the receiving device. Then, based on the state of the buffer, it is determined whether synchronous playback of broadcast content and communication content is difficult (step S251).

[0319] If it is determined in the buffer control that synchronous playback of broadcast communication is difficult due to overflow, underflow, etc. (S251: Yes), the control unit selects the communication content to be acquired based on the operation flow of acquiring communication content shown in FIG. 19 (step S252).

[0320] Next, the control unit determines whether it is possible to synchronously play the broadcast content and the selected communication content (step S253). If it is determined that synchronous playback of the broadcast content and the selected communication content is possible (S253: Yes), the control unit acquires the selected communication content (step S254), returns to the steady state, and the processing after step S251 is performed on the side.

[0321] On the other hand, if it is determined in step S253 that synchronous playback is not possible (S253: No), buffer control is performed to guarantee only the broadcast reception operation (step S255).

[0322] [Operation Example 1 Regarding Pre-Buffering] In the broadcast communication cooperation service, in order to perform highly accurate synchronous playback of broadcast content and communication content, it is advisable to acquire the communication content in advance and perform synchronous playback with the broadcast content. Thereby, smooth synchronous playback is possible without delaying the broadcast content.

[0323] Hereinafter, an example in which the broadcast communication cooperation service is started during the program will be described. FIG. 21 is a flowchart showing an example of the operation in which the broadcast communication cooperation service is started during the program.

[0324] First, the control unit selects a broadcast program (broadcast station), receives and analyzes program information corresponding to the service ID of the selected program (step S300). The program information is, for example, a PMT if it is in the MPEG2-TS format.

[0325] Next, the control unit analyzes the program information and determines whether the selected program is related to the broadcast communication cooperation service (step S301). If the program information does not describe that it is a broadcast communication cooperation service (S301: No), the control unit receives only the broadcast content (step S307) and plays the broadcast content (step S308).

[0326] When it is described in the program information that it is a broadcast communication cooperation service (S301: Yes), the control unit determines whether there is information on the start time (information related to the acquisition of communication content) in the descriptor regarding the acquisition start time of the communication content (step S302). When there is information on the start time (S302: Yes), the control unit acquires that time. Note that the control unit also acquires the location information of the communication content at this time. Then, the control unit calculates the acquisition start time of the communication content based on the acquired information (if necessary), and starts acquiring the communication content at the calculated time (step S303).

[0327] For example, when the acquisition start time of the communication content is indicated by the PCR reference time information of the broadcasting station, the control unit starts acquiring the communication content when the PCR time reproduced by the receiving device matches the PCR time indicated by the start time information.

[0328] Also, for example, when the acquisition start time of the communication content is described as T seconds before the start of the broadcast program, the control unit calculates T seconds before the start time of the broadcast program and starts acquiring the communication content at that time.

[0329] Note that in step S303, a step for determining whether the communication content can be acquired may be provided. Whether the communication content can be acquired may be determined by an inquiry from the receiving device to the server, or may be determined by the descriptor of the program information or the transmission of an event message from the server. Also, whether the communication content can be acquired may be determined by the transmission of time information indicating that the acquisition of the communication content is possible.

[0330] In step S302, when there is no information on the acquisition start time of communication content (S302: No), the control unit starts acquiring communication content triggered by an input from the viewer such as a user interface input (step S306). In this case, the control unit may start acquiring the content at a predetermined time, or may calculate the acquisition time of the communication content and then start the acquisition.

[0331] Note that the communication content acquired in advance in step S303 or step S306 is buffered in a memory (buffer) or the like, and is output after waiting for the reception of the broadcast content and the arrival of the synchronous playback time.

[0332] Subsequent to step S303, the control unit receives the broadcast content (step S304) and performs synchronous playback of the broadcast content and the communication content (step S305).

[0333] Note that even when it is determined in step S302 that there is information on the acquisition start time of the communication content, a determination step may be provided to determine whether to acquire the communication content in advance based on the playback ability of the receiving device, buffer performance, etc.

[0334] Note that the descriptor including the control information (here, the information on the acquisition start time of the content) described in the example of FIG. 21 may be described in the same program information or in different program information. Among a plurality of transmission paths for broadcasting and communication, it may be transmitted through at least one or more transmission paths. When transmitted through different transmission paths, information indicating the location of the program information is described in the program information serving as an entry.

[0335] Also, in the example of FIG. 21, the control information is described as a descriptor, but the control information may be transmitted as an event message.

[0336] In the example of FIG. 21, the broadcast communication cooperation service is started during the broadcast program. However, when the broadcast communication cooperation service is started from the beginning of the next broadcast program, it is necessary to acquire communication content before the start of the next broadcast program. In this case, program information of the next program is transmitted while the previous program is being provided.

[0337] When the receiving apparatus receives the program information of the next program, it determines whether it is possible to pre-acquire the communication content of the next program, and pre-acquires the communication content. At this time, since the previous program information includes information indicating the start of the provision of the next program information and location information, the receiving apparatus may recognize the existence of the communication content and start acquiring the program information.

[0338] [Operation Example 2 Regarding Pre-Buffering] Regarding the buffering operation of communication content, the hybrid broadcast specifications standardized by the IPTV Forum and ARIB will be described as an example. FIG. 22 is a flowchart showing an example of the buffering operation of communication content. In the example of FIG. 22, the information on the acquisition start time of communication content is notified as an event using the control code of AIT.

[0339] First, the control unit selects a broadcast program (broadcast station), receives and analyzes the PMT of the selected program (step S351). Next, the control unit determines whether there is a descriptor ait_identifier_info() indicating that AIT is transmitted in the PMT (step S352). If there is no descriptor, that is, if AIT is not transmitted (S352: No), the control unit receives only the broadcast content (step S353) and reproduces the received broadcast content (step S354).

[0340] If there is a descriptor (S352: Yes), the control unit starts acquiring and monitoring AIT (step S355). Specifically, the control unit analyzes AIT and acquires the location information of the application included in AIT, the acquisition start time information of the communication content, and the location information.

[0341] Subsequently, the control unit monitors the application control code of the AIT (step S356), and monitors the application pre-acquisition flag (PREFECH command in the hybrid broadcast specification), that is, determines the presence or absence of the application pre-acquisition flag (step S357).

[0342] If there is an application pre-acquisition flag (S357: Yes), the control unit pre-acquires the application (step S360) and returns to the process of step S356. If there is no application pre-acquisition flag (S357: No), the control unit monitors the communication content pre-acquisition flag (PREBUFFER command in the hybrid broadcast specification), that is, determines the presence or absence of the communication content pre-acquisition flag (step S358). Note that in step S355, if there is no information on the acquisition start time of the communication content, the monitoring of the communication content pre-acquisition flag in step S358 may not be performed.

[0343] If there is a communication content pre-acquisition flag (S358: Yes), the control unit pre-acquires the communication content from the server and buffers it, and returns to the process of step S356. If there is no communication content pre-acquisition flag (S358: No), the control unit monitors the application execution flag (AUTOSTART command in the hybrid broadcast specification), that is, determines the presence or absence of the application execution flag (step S359).

[0344] Until the application execution flag is set in step S359 (S359: No), the processes of steps S356 to S358, S360, and S361 are repeated. When the application execution flag is set (S359: Yes), the control unit acquires the application from the location specified by the location information described in the AIT (step S362). At this time, if the application has been pre-acquired in step S360, the process here is skipped.

[0345] Subsequently, the control unit executes the application (step S363) and acquires communication content from the location specified by the location information of the communication content (step S364). At this time, if the communication content has been acquired in advance in step S361, the processing here is skipped.

[0346] Finally, the control unit receives the broadcast content (step S365) and synchronously plays back the broadcast content and the communication content (step S366).

[0347] Note that the operations related to the application and communication content described in the operation example of FIG. 22 may be realized as one application or may be divided into a plurality of applications. For example, the acquisition of communication content may be executed as part of one application, or an application for performing the acquisition operation of communication content and an application for performing the playback operation of communication content may be provided separately and each may be executed. In this case, the application for performing the acquisition operation of communication content is started first, and the application for playing back the communication content is started at another timing.

[0348] Also, the location information of the communication content may be described in the AIT or may be acquired inside the application.

[0349] Also, the location information of the communication content may be acquired by executing an application for acquiring only program information from the communication transmission path.

[0350] Also, information indicating whether the communication content can be acquired and information indicating whether the communication content can be played back may be acquired by an API or the like.

[0351] Also, the information on the acquisition start time of the communication content is not limited to the control code of the AIT, and may be described in the control information or may be determined by the presence or absence of other control information.

[0352] [Modification of Embodiment 3] Note that the functions (operations) described in the above Embodiment 3 may be implemented by software or by hardware. Also, a part of the functions may be implemented as an API, and a configuration may be such that the functions can be controlled from an application. Further, an API capable of acquiring information obtained by the functions and information indicating the state of the functions may be implemented, and a configuration may be such that information can be acquired from an application.

[0353] Here, the state of the function is, for example, the exclusive amount of a buffer (delay buffer, digital buffer), the End-to-End delay time, the state of the application, the acquisition state of communication content, and the like.

[0354] Note that when it is determined that the program being played is not a live program but a recorded program, the receiving apparatus may acquire information from the server as to whether an application or communication content is valid. If the application or communication content is not valid, the receiving apparatus may prohibit acquisition / execution of the application and acquisition of the communication content.

[0355] Also, in such a case, application control information for recording / playback, pre-acquisition information of communication content for recording / playback, etc. may be separately prepared in the server, and in the case of recording / playback, the information for live broadcast may not be used, and the information for recording / playback may be acquired from the server.

[0356] Also, in the above Embodiment 3, an example in which content is acquired mainly based on the acquisition start time of communication content has been described. However, the acquisition completion time of the communication content may be specified, and the receiving apparatus may determine the acquisition start time of the communication content in consideration of the time required for communication transmission and transmission delay. Also, when control of an application and acquisition of communication content are performed through a cooperation terminal such as a tablet, the time required for acquisition of the communication content may be determined in consideration of the transmission delay between the cooperation terminals.

[0357] (Supplement to Embodiment 3) [Supplement 1: Acquisition of Communication Content] The acquisition of communication content described with reference to FIGS. 19 and 20 will be described in more detail.

[0358] In a broadcast communication cooperation service, information necessary for determining each control method of delay control, synchronization control, and acquisition control of communication content includes control information signaled from the transmission side, the state of the receiving device, and the state of the transmission path. The receiving device can acquire these pieces of information as necessary. Further, the receiving device can also detect changes in information and states by monitoring the following information and states.

[0359] The flow related to the acquisition of information and states corresponds to steps S201 to S204 in FIG. 19. Examples of the control information, the state of the receiving device, and the state of the transmission path are as follows.

[0360] (1) Examples of the control information related to broadcast communication cooperation include the following information (for example, stored in a meta file such as a PMT in the MPEG-2TS format or an MPT in the MMT format). · Information indicating whether it is a broadcast communication cooperation program · Information indicating the type of the broadcast communication cooperation program · Information indicating that it is scalable-encoded content and that one of the base layer data and the enhancement layer data is transmitted by broadcast and the other is transmitted by communication · Information indicating that a program to which a rainfall attenuation countermeasure (when the broadcast transmission path deteriorates due to rainfall attenuation, switching to communication content instead) is applied · Other information indicating that it is multi-view, multi-audio, or targeted advertising · Information indicating whether a broadcast program can be decoded alone · Information indicating the accuracy of synchronization required for decoding and presenting broadcast content and communication content. This information indicates, for example, that high-precision synchronization at the frame level is required, or that presentation is possible even asynchronously. · Information indicating whether the broadcast content and the communication content are to be synchronized · Information indicating whether the timelines are synchronized · Information indicating whether it is a live video or a non-live video · Information indicating that the broadcast content is delayed with respect to the communication content, or that the communication content is delayed with respect to the broadcast content. Note that this information may indicate the amount of delay assumed based on the line design of the broadcasting station, rather than the delay of an individual receiving device · Information indicating the allowable End-to-End delay in the presentation of the broadcast program · Information for notifying in advance that the control information will change

[0361] (2) As information related to the communication means, the following information is exemplified. Note that the information related to the communication means is stored, for example, in the MPD in MPEG-DASH or the metadata file in the IPTVF VOD specification · Information indicating the communication protocol (e.g., http, rtsp, etc.) · Information indicating that it is unicast (TCP), multicast (UDP), or unicast (UDP)

[0362] (3) As information related to the communication content, the following information is exemplified. Note that the information related to the communication content is stored, for example, in the MPD in MPEG-DASH or the metadata file in the IPTVF VOD specification · Information indicating the attributes of the communication content · The expiration date of the content · The viewing restriction (CAS) of the content · The type of the content (resolution, transmission rate) · Whether the communication content at any time can be pre-acquired

[0363] (4) As the state of the broadcast transmission path, the state of the communication transmission path, and the state of the delay, the following parameters are exemplified. Note that these parameters are acquired by the receiving device · The state of the communication path · Jitter, QoS, RTT ·End-to-End delay ·Transmission rate (bandwidth) Delay difference between broadcast and communication (broadcast first? communication first?)

[0364] (5) As for the state of the buffer, the following parameters are exemplified. These parameters are acquired by the receiving device. ·Buffer capacity ·Buffer occupancy ·Buffer delay amount

[0365] (6) As for the specifications or capabilities of the receiving device, the following parameters are exemplified. These parameters are acquired by the receiving device. ·Specifications ·Number of decoders ·Compatible browsers ·Version information, etc.

[0366] (7) As for the information related to the delay control, synchronization control, and content acquisition control method, "information indicating whether to issue a control instruction" is exemplified. This information is stored in a meta file such as PMT in the MPEG-2TS format or MPT in the MMT format, for example.

[0367] In the information indicating whether to issue a control instruction, for example, it is specified that the broadcasting station instructs the control method, the receiving device determines the control method, or the user determines the control method by user settings.

[0368] When the broadcasting station instructs the control method, the broadcasting station instructs, for example, whether to synchronously present the broadcast content and the communication content, and whether to pre-buffer the communication content. When instructing pre-buffering, the broadcasting station signals time information and timing information.

[0369] When the user determines the control method by user settings, the user settings include settings that follow the instructions of the broadcasting station, settings left to the receiving device, and manual settings by the user, etc.

[0370] [Supplementary Note 2: Determination of Whether Communication Content Can Be Acquired at Any Time] So far, the cases where communication content can be acquired at any time and where it cannot have been described respectively. Here, the receiving device may determine whether the communication content can be acquired at any time, and determine the control content based on the determination result.

[0371] Whether communication content can be acquired at any time can be determined, for example, by control information signaled from the transmission side.

[0372] 1. Dependent on the communication method Based on whether the communication method in the broadcast communication cooperation service is unicast or multicast, determination is possible. For example, in the case of multicast, it is determined that the communication content cannot be acquired at any time.

[0373] 2. Content-dependent It is possible to signal whether the communication content among the broadcast communication cooperation content can be acquired at any time, and make a determination based on the signaled information. Based on the signaled information, for example, the determination is made as follows. 2-1. The communication content cannot be acquired at any time 2-2. All the communication content is prepared on the server and can be acquired at any time 2-3. It is unknown whether the communication content can be acquired at any time (for example, in the case of a live video, etc.).

[0374] In the cases of the above 1, 2-1, and 2-2, since the receiving device can make a determination by analyzing the control information signaled on the transmission side, basically, the control content can be determined without inquiring the server. Note that even in these cases, if the determination by analyzing the control information is impossible, the control content is determined by inquiring the server. Figure 23 is a flowchart showing an example of the determination of whether communication content can be acquired at any time.

[0375] As shown in FIG. 23, the receiving device first analyzes the control information transmitted from the server and determines whether the communication content can be acquired at an arbitrary time (step S401). If the determination based on the analysis of the control information is possible (S402: Yes), the control content is determined based on the determination result (step S404). If the determination based on the analysis of the control information is not possible (S402: No), a determination based on an inquiry to the server is made (step S403), and the control content is determined based on the determination result (step S404).

[0376] When it is determined that the communication content cannot be acquired at an arbitrary time, for example, using the methods described in Embodiment 1 and Embodiment 2, buffer control of the receiving device is performed to control the delay and synchronous presentation between the broadcast content and the communication content.

[0377] When it is determined that the communication content can be acquired at an arbitrary time, for example, by using the method described in Embodiment 3 to control the buffer of the receiving device and the acquisition of the communication content, delay control between the broadcast content and the communication content is performed, or the broadcast content and the communication content are presented synchronously.

[0378] When the determination is 2-3 as described above, specifically, the server signals whether the broadcast content is a live video, and this is the case when it is determined that the content is a live video.

[0379] Here, when the broadcast content is a live video, it is highly likely that the communication content is not prepared in the server, but there may also be cases where it is prepared in the server. Therefore, whether it can actually be acquired is determined by the receiving device making an inquiry to the server.

[0380] Incidentally, the server may signal whether the live video has been delayed in the broadcast. This is because when the live video has not been delayed, it is highly likely that the communication content has not been prepared on the server, and when the broadcast has been delayed, the communication content may have been prepared on the server. In this case, the server may signal information on the degree of delay of the broadcast.

[0381] Incidentally, the actual time taken to acquire the communication content in the receiving device depends on the bandwidth of each communication line, the capabilities of the receiving device, the CPU usage, the buffer size, etc. Therefore, in the case of the above 2-3, the transmitting side (server) may signal whether the communication content can be acquired at an arbitrary time in the environment assumed by the transmitting side, and guarantee the acquisition of the communication content on the receiving side.

[0382] Here, the environment assumed by the transmitting side is, for example, an environment determined based on the minimum buffer size, communication line bandwidth, and CPU capabilities defined by the standard.

[0383] The determination of whether the communication content can be acquired at an arbitrary time has been described above. However, it may also be determined whether the communication content can be acquired at an arbitrary time for the broadcast content. For example, in the case of a live video, the acquisition period may be limited, such as whether the communication content at a time a predetermined time after the broadcast content can be acquired.

[0384] [Supplementary Note 3: Operations When Delay Presentation of Broadcast Content is Not Allowed] The operations in the case where the communication content can be acquired at an arbitrary time and the case where there is a possibility that the communication content can be acquired at an arbitrary time, and where the delay presentation of the broadcast content is not allowed (prohibited) will be described below.

[0385] During the provision of a broadcast communication cooperation service, delaying the presentation of broadcast content, which is the main content, will make viewers feel uncomfortable and will not result in a stable broadcast service. Therefore, the control under the condition that the presentation of broadcast content should not be delayed in the broadcast communication cooperation service will be described.

[0386] Note that, as described above, whether the acquisition of communication content at an arbitrary time is possible may be determined based on control information or by actually making an inquiry to the server. Also, in the following description, it is assumed that the communication content to be synchronized with the broadcast content changes over time (a plurality of communication contents exist for each time).

[0387] FIG. 24 is a flowchart showing an example of the operation when the delayed presentation of broadcast content is not permitted.

[0388] First, the receiving device acquires the delay time between the communication content and the broadcast content (step S451). The delay time (delay difference) between the broadcast content and the communication content can be acquired by the receiving device as described above. Then, the receiving device determines whether the communication content is delayed with respect to the broadcast content (step S452).

[0389] If the communication content is delayed with respect to the broadcast content (S452: Yes), since the broadcast content cannot be delayed, the receiving device acquires the communication content at a later time (step S453). That is, the receiving device skips the frame of the communication content.

[0390] Here, the receiving device determines whether it is possible to acquire the communication content at the desired time (step S457). If it is possible to acquire the communication content at the desired time (S457: Yes), that is, if the communication content at a later time is also the communication content at the desired time, the receiving device acquires the communication content at a later time and synchronously presents the broadcast content and the acquired communication content (step S459).

[0391] If the desired communication content cannot be obtained within the desired time (S457: No), synchronous presentation is not possible. Therefore, the receiving apparatus determines whether the decoding and presentation accuracy of the broadcast content and the communication content is acceptable, and if it is not acceptable, presents only the broadcast content (step S458).

[0392] If the decoding and presentation accuracy is acceptable, the decoding and presentation of the broadcast content and the decoding and presentation of the communication content are independently controlled (step S458). For example, when the communication content is subtitles attached to the broadcast content, since highly accurate synchronization is not considered necessary, it may be acceptable to present the broadcast content and the communication content without synchronization.

[0393] Specifically, the case where the decoding and presentation accuracy is acceptable means that the time difference between the reproduction timing of the communication content and the reproduction timing of the broadcast content is within a predetermined allowable range. Also, the case where the decoding and presentation accuracy is not acceptable means that the time difference between the reproduction timing of the communication content and the reproduction timing of the broadcast content is outside the predetermined allowable range.

[0394] On the other hand, when the broadcast content is delayed with respect to the communication content (S452: No), the receiving apparatus determines whether there is sufficient capacity in the delay buffer of the communication content (whether the remaining capacity is less than a predetermined value) (step S454).

[0395] If there is no margin in the buffer capacity (S454: No), the receiving device acquires communication content at a time earlier than the currently acquired communication content (step S455). Then, if it is possible to acquire the communication content at the desired time (S457: Yes), the receiving device acquires the communication content at the desired time and synchronously presents the broadcast content and the acquired communication content (step S459). Note that, in this case, usually the desired communication content can be acquired. If it is not possible to acquire the communication content at the desired time, since synchronous presentation is not possible, the receiving device presents only the broadcast content, or independently controls the decoding and presentation of the broadcast content and the decoding and presentation of the communication content (step S458).

[0396] If there is margin in the buffer capacity (S454: Yes), the communication content is buffered and delayed (step S456), and by matching the presentation time to the broadcast content, the broadcast content and the communication content are synchronously presented (step S459).

[0397] Note that if the polarity of the delay time difference between the broadcast content and the communication content is inverted or may be inverted, a change in state is detected, and based on the detection result, the control of 1-1 and 1-2 is performed.

[0398] Note that in the flowchart of FIG. 24 above, steps S454 and S456 may be omitted. That is, even if there is margin in the buffer capacity, communication content at an earlier time may be acquired. In this case, if the broadcast content is delayed with respect to the communication content (S452: No), the receiving device acquires communication content at a time earlier than the currently acquired communication content (step S455).

[0399] Next, the acquisition request for communication content from the server of the receiving device performed in step S453, step S455, etc. will be described.

[0400] When the receiving device acquires communication content from the server, it makes a request for acquiring the communication content by specifying the timing of acquiring the communication content and the time of the communication content to be acquired (for example, PTS, etc.).

[0401] If the server has the communication content at the specified time, it transmits the communication content to the receiving device. Also, if the server does not have the communication content at the time specified by the receiving device, it notifies the receiving device that there is no communication content.

[0402] Here, when there is no communication content at the time specified by the receiving device, the server may transmit the communication content at the latest time to the receiving device instead of the communication content at the specified time. Also, the server may transmit the communication content at the time closest to the instructed communication content (the previous time or the next time) to the receiving device. Also, a combination of the above notification and the transmission of alternative communication content may be made.

[0403] Note that when there is no communication content at the time specified by the receiving device, the server may transmit the communication content to the receiving device based on the instruction of the receiving device.

[0404] By the way, when the receiving device specifies the communication content to be requested in a function in the acquisition request for the communication content, as arguments, the time of the communication content to be requested and the operation instruction when there is no content are stored.

[0405] Here, the operation instruction does not necessarily have to be included in the acquisition request. After the determination of the operation when the receiving device determines that synchronous presentation is impossible (step S458), an operation instruction when there is no communication content may be given based on the determined operation.

[0406] Specifically, for example, when the decoding and presentation accuracy of broadcast content and communication content is acceptable, the receiving device issues an instruction to request acquisition of communication content at an alternative time, and decodes and presents the broadcast content and the communication content independently. Also, for example, when the decoding and presentation accuracy of the broadcast content and the communication content is unacceptable, the receiving device issues an instruction indicating that it may not transmit the communication content, and presents only the broadcast content.

[0407] Also, when there is no communication content at the time specified by the receiving device, or when there is no random access point at that time, the receiving device may request acquisition of the communication content closest to the communication content at the specified time (the communication content at the previous time or the next time).

[0408] Next, the presentation control of the broadcast content and the communication content performed in step S458, step S459, etc. will be described.

[0409] (1) Until the preparation for presenting the communication content is complete During the time until the preparation for presenting the communication content is complete, when accuracy is required for the decoding and presentation of the broadcast content and the decoding and presentation of the communication content, the receiving device presents only the broadcast content. When accuracy is not required for the decoding and presentation of the broadcast content and the decoding and presentation of the communication content, the receiving device decodes and presents the broadcast content and the communication content independently.

[0410] (2) After the preparation for presenting the communication content is complete When only the broadcast content was presented in the above (1) (when the presentation of the communication content was stopped), the receiving device starts synchronous presentation of the broadcast content and the communication content.

[0411] On the one hand, in the above (1), when the broadcast content and the communication content are independently decoded and presented, if the broadcast content is delayed, the communication content is skipped and the broadcast content and the communication content are presented synchronously. When the communication content is delayed and the communication content was being presented in the above (1), the receiving device presents the communication content traced back (or continuously) from the communication content presented in the above (1).

[0412] In addition, in the presentation of the content, a message indicating the state (for example, a message indicating whether the broadcast content and the communication content are being presented synchronously or the broadcast content is being presented alone) may be presented to the user.

[0413] In addition, when the communication content can be acquired earlier than the broadcast content, the server may signal whether the communication content may be presented earlier than the broadcast content. When the communication content may be presented earlier, the receiving device presents the communication content immediately after the completion of the preparation for presenting the communication content. When the communication content may not be presented earlier, the receiving device buffers the communication content until the preparation for presenting the broadcast content is completed, and presents the broadcast content and the communication content synchronously after the completion of the preparation for presenting the broadcast content.

[0414] [Supplement 4: Method for setting the delay time on the transmission side] When delaying the broadcast content, a method for setting the delay amount of the broadcast content by the transmitting station (transmitting device) will be described. The broadcast content is transmitted from the transmitting station to a plurality of receiving devices, but the capabilities of the receiving devices and the communication bandwidth differ for each device. For this reason, it is difficult to guarantee that all receiving terminals can receive the broadcast content with a delay.

[0415] Therefore, in order to change the delay amount according to the receiving device, the transmitting station may be configured to be able to switch between a plurality of delay modes. Here, in the transmitting station, for example, a plurality of delay modes with different assumed communication transmission speeds are provided.

[0416] Specifically, at the transmitting station, a first mode assuming a high transmission speed such as an optical line and a second mode assuming a medium transmission speed such as CATV or ADSL are provided.

[0417] The delay amount is determined based on, for example, the following formula.

[0418] Delay amount = Minimum buffer size defined by the standard / Transmission speed assumed in each mode

[0419] The transmitting station may signal the above-described delay amount and delay mode to the broadcast signal. In this signaling, the delay amount and the delay mode are stored in the PMT in MPEG-2 TS, the MPT in the MMT method, etc. As a result, the receiving device can control the receiving device based on the signaled delay amount and delay mode.

[0420] Note that based on the signaled delay amount and the actual delay amount, if it is determined that the actual delay amount is larger than expected, the receiving device may increase the allocation of the resources (CPU speed and communication transmission speed) of the receiving device for communication.

[0421] Also, for example, when the receiving device cannot handle the signaled delay amount, only the broadcast content is preferentially presented.

[0422] In addition, it is conceivable to perform simulcast using both broadcast communication-linked content and content of only normal broadcast for the same content such as baseball and soccer. In such a case, the transmitting station may delay-transmit the broadcast-only content together with the broadcast communication-linked content to be delay-transmitted, or may transmit it as it is without delay-transmission.

[0423] Also, in simulcast, the transmitting station may signal information indicating whether each content has been transmitted with a delay, or whether there is a delay difference and information on each delay difference.

[0424] [Supplementary Note 5: Configuration of Transmitting Device] Here, a supplementary note is made about the transmitting device (specifically, a server) used by the transmitting station (broadcasting station). FIG. 25 is a block diagram showing the configuration of the transmitting device. FIG. 26 is a flowchart showing an example of the operation of the transmitting device. Note that FIG. 26 is a flowchart of the operation of the transmitting device corresponding to the flowchart of FIG. 19.

[0425] As shown in FIG. 25, the transmitting device 300 includes an encoding unit 301, a multiplexing unit 302, and a transmitting unit 303. Note that the components of the transmitting device 300 are specifically realized by a microcomputer, a processor, a dedicated circuit, or the like.

[0426] The transmitting unit 303 transmits information for acquiring communication content to the receiving device corresponding to step S203 in FIG. 19 described above (step S501). Here, an example of the information for acquiring communication content is the acquisition information described above. That is, the transmitting unit 303 transmits information for synchronizing and reproducing the communication content transmitted by communication with the broadcast content transmitted by broadcast, and information related to the acquisition of the communication content through broadcast.

[0427] Specifically, the multiplexing unit 302 packetizes the encoded acquisition information output from the encoding unit 301, and the transmitting unit 303 transmits the acquisition information packetized by the multiplexing unit 302 through broadcast.

[0428] Next, the transmitting unit 303 transmits broadcast content to the receiving device corresponding to step S206 in FIG. 19 described above (step S502).

[0429] Specifically, the multiplexing unit 302 packetizes the encoded broadcast content output from the encoding unit 301, and the transmission unit 303 transmits the broadcast content packetized by the multiplexing unit 302 through broadcasting.

[0430] In this way, when the acquisition information is transmitted, the receiving device can appropriately acquire the communication content in response to the reception of the broadcast content. Further, when the receiving device acquires the communication content according to the acquisition information, it is possible to reduce the possibility of discontinuities such as skipping and stopping in the presentation of the broadcast, which is the main content, and ensure stable broadcast viewing.

[0431] (Summary of Embodiment 3) A receiving method according to an aspect of the present invention is a receiving method in a broadcast communication cooperation service, which receives broadcast content transmitted by broadcasting, and synchronizes communication content transmitted by communication with the received broadcast content for reproduction. Information related to the acquisition of the communication content, that is, acquisition information, is received through broadcasting, and the communication content is acquired based on the received acquisition information.

[0432] Such a receiving method is shown in the flowchart of FIG. 19 and the like. According to such a receiving method, the communication content can be appropriately acquired in response to the reception of the broadcast content. Further, by acquiring the communication content according to the acquisition information, it is possible to reduce the possibility of discontinuities such as skipping and stopping in the presentation of the broadcast, which is the main content, and ensure stable broadcast viewing.

[0433] Note that the broadcast content and the communication content typically constitute one piece of content (the content presented in one presentation unit). For example, when the broadcast content is video, the subtitles displayed corresponding to the video shown by the broadcast content are the communication content. Also, in scalable encoding, for example, each frame constituting a 60fps video is the broadcast content, and each frame for constituting a 120fps video by being added to the broadcast content is the communication content. Further, there may be a case where the broadcast content is the main video and the communication content is an advertisement (CM).

[0434] That is, the above-mentioned "synchronization" means adjusting the time difference between the playback timing of the broadcast content and the playback timing of the communication content to a predetermined time difference (a time difference within a predetermined range) in order to play one piece of content composed of the broadcast content and the communication content.

[0435] Also, the acquisition information may be information indicating the timing related to the acquisition of the communication content.

[0436] In this way, by specifying the timing related to the acquisition of the communication content from the transmission side (server), a reception method is realized in which the communication content can be appropriately acquired in response to the reception of the broadcast content.

[0437] Also, the acquisition information may be information indicating the timing at which the acquisition of the communication content should be started in order to play the communication content in synchronization with the received broadcast content.

[0438] Also, the acquisition information may be information indicating the timing at which the acquisition of the communication content should be completed in order to play the communication content in synchronization with the received broadcast content.

[0439] Alternatively, the acquired information may be information indicating the timing at which the reproduction of the communication content should be started in order to reproduce the communication content in synchronization with the received broadcast content.

[0440] Alternatively, the acquired information may be information indicating that the acquisition of the communication content will be possible after the timing by notifying the timing.

[0441] As described above, various modes of timing related to the acquisition of communication content can be considered.

[0442] Further, the timing at which the acquisition of the communication content is started may be calculated based on the received acquired information, and the acquisition of the communication content may be started at the calculated timing.

[0443] Such a reception method is shown in step S303 and the like of the flowchart in FIG. 21. That is, when the content acquisition start time is not directly specified, the content acquisition start time may be calculated on the receiving side. In addition, in order to calculate the acquisition start time with higher accuracy, the information described in the third embodiment above, such as the capabilities of the receiving device, the state of the transmission path for communication, and the transmission delay, may be further used.

[0444] Alternatively, the acquired information may be information indicating that the acquisition of the communication content is possible.

[0445] Further, the acquired communication content may be reproduced in synchronization with the received broadcast content.

[0446] If the acquisition of the communication content fails, only the broadcast content among the broadcast content and the communication content may be reproduced.

[0447] Such a receiving method is shown in step S255 of FIG. 20, step S308 of FIG. 21, step S458 of FIG. 24, and the like. In this way, when synchronization cannot be achieved, only the broadcast content is played, thereby realizing a broadcast communication cooperation service that is less likely to give viewers a sense of discomfort.

[0448] Also, when the acquired communication content cannot be synchronized with the received broadcast content for playback, (1) when the time difference between the playback timing of the communication content and the playback timing of the broadcast content is within a predetermined allowable range, the communication content and the broadcast content are played, and (2) when the time difference is outside the predetermined allowable range, only the broadcast content among the broadcast content and the communication content may be played.

[0449] Such a receiving method is shown in step S458 of FIG. 24 and the like. In this way, within an allowable range, the broadcast content and the communication content may be played without being synchronized.

[0450] Also, a transmission method according to an aspect of the present invention is a transmission method in a broadcast communication cooperation service, and transmits, through a broadcast, acquisition information which is information for synchronizing communication content transmitted by communication with broadcast content transmitted by broadcast for playback and which is information related to acquisition of the communication content.

[0451] Such a transmission method is shown in a flowchart shown in FIG. 26 and the like. According to such a transmission method, on the receiving side, the communication content can be appropriately acquired in response to reception of the broadcast content, and on the receiving side, the possibility of discontinuities such as skipping and stopping occurring in the presentation of the broadcast, which is the main content, can be reduced, and stable broadcast viewing can be ensured.

[0452] Also, a receiving apparatus according to one aspect of the present invention is a receiving apparatus used for a broadcast communication cooperation service, which receives broadcast content transmitted by broadcast, and synchronizes communication content transmitted by communication with the received broadcast content for reproduction, and is information related to acquisition of the communication content. The receiving apparatus includes a broadcast receiving unit that receives acquisition information, which is information related to acquisition of the communication content, through broadcast, and a communication unit that acquires the communication content based on the received acquisition information.

[0453] Here, the broadcast receiving unit corresponds to the digital broadcast receiving unit shown in FIGS. 1, 9, 10, 14, etc., and the communication unit corresponds to the communication transceiver unit shown in FIGS. 1, 9, 10, 14, etc.

[0454] Also, a transmitting apparatus according to one aspect of the present invention is a transmitting apparatus used for a broadcast communication cooperation service, which includes a transmitting unit that transmits, through broadcast, acquisition information, which is information related to acquisition of communication content and is information for synchronizing communication content transmitted by communication with broadcast content transmitted by broadcast for reproduction.

[0455] Here, the transmitting unit corresponds to the transmitting unit shown in FIG. 25.

[0456] Note that these general or specific aspects may be implemented by a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM. Further, these general or specific aspects may be implemented by any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0457] (Other Embodiments) Although Embodiments 1 to 3 have been described above, the present invention is not limited to the above embodiments.

[0458] For example, in Embodiment 3, the broadcast content is transmitted by broadcasting, and the communication content is transmitted by communication. However, other information (for example, control information) may be transmitted by either broadcasting or communication if possible.

[0459] In each of the above embodiments, each component may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

[0460] Also, each component may be a circuit. These circuits may form one circuit as a whole or may be separate circuits. Also, each of these circuits may be a general-purpose circuit or a dedicated circuit.

[0461] For example, in each of the above embodiments, a process executed by a specific processing unit may be executed by another processing unit. Also, the order of a plurality of processes may be changed, or a plurality of processes may be executed in parallel.

[0462] As described above, the receiving device (receiving method) and the transmitting device (transmitting method) according to one or more aspects have been described based on the embodiments. However, the present invention is not limited to these embodiments. As long as the gist of the present invention is not deviated from, various modifications conceived by those skilled in the art applied to these embodiments or forms constructed by combining components in different embodiments may also be included within the scope of one or more aspects.

Industrial Applicability

[0463] The receiving method of the present invention can be used in a broadcast-communication cooperation service as a receiving method capable of appropriately acquiring communication content in response to the reception of broadcast content.

Explanation of Signs

[0464] 1, 1A, 1B, 100, 100A Receiver 3 Broadcast Antenna 5, 5B Presentation Unit 11, 111 Digital Broadcast Receiver 12, 112, 122 Separation Unit 13, 22 Buffer 14, 14A, 14B Decoder 21, 41, 121 Communication Transceiver 23, 23B, 115, 125 Decoder 31, 31A, 31B, 32B, 131 Content Generator 42 Operation Input Unit 51, 151 Control Unit 71 PES Buffer 72 Synchronization Buffer 103, 113 Delay Buffer 114, 124 Separation Buffer 123 Digital Buffer 141 Control Management Unit 171 Control Information Extraction Unit 172 Buffer Management Unit 173 Monitoring Unit 174 Control Method Determination Unit 191, 196 Synchronization Buffer 300 Transmitter 301 Encoder 302 Multiplexer 303 Transmitter

Claims

Claim 1 Receiving broadcast content transmitted by broadcast, Information for reproducing communication content transmitted by communication in association with the received broadcast content, the acquisition information which is information related to the acquisition of the communication content, the location information indicating the storage location of the communication content, information indicating whether there is communication content to be associated with the broadcast content, and information indicating the type of the communication content are received through the broadcast, Acquiring the communication content based on the received acquisition information and the received location information, The received acquisition information includes information indicating the expiration date of the communication content Receiving method.

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