Packet Synchronization Control Device, Packet Synchronization Reproduction Device, Packet Synchronization Control Method, Packet Synchronization Reproduction Method, and Program

Abstract

To provide a packet synchronization control device that contributes to synchronizing data and time information by sharing time difference information when sharing data with sequential numbers and time information between multiple districts.SOLUTION: A packet synchronization control device includes a reference time management unit that manages reference time, a district time management unit that manages a district time, a corrected time information generation unit that generates first corrected time information on the basis of the reference time and the district time, and a packet generation unit that receives first data, and the packet generation unit generates a first packet including first correction time information and the first data, the first corrected time information includes a district time, a first corrected time that is the difference between the reference time and the district time, a difference time for the first data, and a sequence number of the first data, and the difference time for the first data is zero.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a packet synchronization control device, a packet synchronization playback device, a packet synchronization control method, a packet synchronization playback method, and a program.

Background Art

[0002] Regarding the control of the playback time of transmitted data, there are the following documents.

[0003] Patent Document 1 relates to a communication device that performs communication with time synchronization based on PTP (Precision Time Protocol).

[0004] Patent Document 2 relates to a real-time transport protocol RTP packet transmission method in which a GCS AS (Group Communication Service Application Server) or a BM-SC (Broadcast-Multicast Service Centre) provides UE with synchronization source information of the GCS AS and synchronization source information of the BM-SC, whereby the UE can continuously receive RTP packets.

[0005] Patent Document 3 relates to a data transmission control method that measures the transmission time (delay time) of stream data, calculates the difference from the maximum delay time, and each receiving side adjusts the output timing of the stream data according to the difference, so that the stream data is output from the transmitting side at the same timing at the receiving sides among a plurality of locations.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The following analysis is provided by the present inventor.

[0008] RTP (Real-time Transport Protocol) packets are often used when handling continuous data such as audio and video. Usually, RTP packets are used as the payload of UDP packets, and a timestamp and a sequence number are added as the header information of the RTP packets.

[0009] In addition, as a requirement specific to broadcast content, there is a need to synthesize or process video / audio data (RTP packets) generated by different equipment from multiple different locations and play them synchronously. Since the timestamp of the RTP packet may be used as the synchronization reference in some cases, synchronization of the RTP packet timestamp at multiple locations is required. Also, since the broadcast system operates 24 hours a day, the timestamp standards at different locations may deviate even after synchronization correction, and periodic correction is necessary.

[0010] A timestamp based on the data transmission area is attached to the RTP packet. There are the following first problem and second problem with respect to the RTP packet.

[0011] The first problem is that when the time on the receiving side is different from that on the sending side, it is difficult to execute RTP packets at the expected time. This is because although the timestamp in the header information of the RTP packet can define the execution time of the packet data, the execution time is defined by the sending side, so the time on the sending side is the reference. Therefore, it is important to synchronize the times of related regions such as the sending region and the receiving region. Usually, the reference time is distributed to the related regions, and a time correction operation to adjust the time is performed in each region. For example, the timestamps are synchronized based on NTP (Network Time Protocol) or PTP (Precision Time Protocol).

[0012] The second problem is that the time correction for synchronizing the times of the above-mentioned related regions makes it impossible to maintain the continuity of the data in the order of the sequence numbers. This is because when the time correction is performed, there may be a case where the timestamp width between the sequence numbers changes significantly from the sampling time on the receiving side.

[0013] The data of the RTP packet is expected to be used in the order of the sequence numbers. The sequence numbers are maintained continuously both on the sending side and the receiving side during normal operation (note that the processing in case of digit overflow needs to be the same). To maintain the continuity of the data, the data can be processed based on the sequence numbers. However, when there is an instruction to process based on time, the following problems occur.

[0014] First, as described above, if there is a time difference between the region where the execution instruction is issued (sending region) and the region where the instruction is executed (receiving region), the instruction will not be executed at the expected time. However, if a time correction process to align the times is performed in both regions, then due to this time correction, the sequence number may jump, or the sequence number may go backward, making it impossible to maintain the continuity of the data.

[0015] FIG. 29 is a diagram showing an example of duplicate execution of packets when performing correction processing of regional time. (1) shows the regional time at point A where the packet is transmitted (hereinafter referred to as the transmitting point A), the sequence number of the transmitted packet, and the timestamp of the transmitted packet.

[0016] (2) shows the execution when no correction of the regional time is performed at point Z where the packet is received (hereinafter referred to as the receiving point Z). When the receiving point Z receives a received packet with a sequence number of 1 and a timestamp of 10 at a regional time of 8, it shows that when the regional time becomes 10, the packet with a timestamp of 10 and a sequence number of 1 is executed.

[0017] (3) shows the execution when the regional time is corrected at the receiving point Z. Similar to (2), assume that the receiving point Z receives a received packet with a sequence number of 1 and a timestamp of 10 at a regional time of 8. Then, it shows the case where the regional time of the receiving point Z is corrected to 10 when the regional time of the receiving point Z is 14. When the regional time before the correction process becomes 10, the packet with a timestamp of 10 and a sequence number of 1 has already been executed. However, due to the correction of the regional time, the regional times 10 and 12 of the receiving point Z appear again, and the packet with a timestamp of 10 and a sequence number of 1 that has already been executed and the packet with a timestamp of 12 and a sequence number of 2 will be executed again.

[0018] In this way, due to time correction, the sequence number may jump, the sequence number may go backward, and the continuity of data may not be maintained.

[0019] The present invention aims to provide a packet synchronization control device, a packet synchronization reproduction device, a packet synchronization control method, a packet synchronization reproduction method, and a program that contribute to enabling synchronization of data and time information by sharing differential time information when sharing data having a consecutive number and time information among a plurality of regions.

Means for Solving the Problem

[0020] According to a first aspect of the present invention, a reference time management unit that manages a reference time, a local time management unit that manages local time, a correction time information generation unit that generates first correction time information based on the reference time and the local time, including a packet generation unit that receives first data, the packet generation unit generates a first packet including the first correction time information and the first data, the first correction time information includes the local time, a first correction time that is a difference between the reference time and the local time, a difference time with respect to the first data, and a sequence number of the first data, and the difference time with respect to the first data is zero, and a packet synchronization control device can be provided.

[0021] According to a second aspect of the present invention, further including a packet processing unit that extracts second data, a second correction time, and a sequence number of the second data from a second packet received from another packet synchronization control device, the first correction time information further includes a difference time with respect to the second data and the sequence number of the second data, the difference time with respect to the second data is a difference between the first correction time and the second correction time, and the difference time with respect to the second data is positive when the second correction time is greater than the first correction time, the first packet further includes the second data, a packet synchronization control device according to the first aspect can be provided.

[0022] According to a third aspect of the present invention, a reference time management unit that manages a reference time, a received local time management unit that manages received local time, a received correction time generation unit that generates a received correction time that is a difference between the reference time and the received local time, A packet processing unit that receives a first packet including first data transmitted from a packet synchronization control device and extracts first correction time information from the first packet; including a packet execution unit; The first correction time information includes the local time, a first correction time that is the difference between the reference time and the local time, a differential time with respect to the first data, and a sequence number of the first data. The differential time with respect to the first data is zero. The packet execution unit can provide a packet synchronization playback device that determines the execution time of the first data from the received local time, the received correction time, the local time, the first correction time, the differential time with respect to the first data, the sampling time of the first data, and the sequence number of the first data.

[0023] According to a fourth aspect of the present invention, a reference time management unit that manages a reference time, a received local time management unit that manages a received local time, a received correction time generation unit that generates a received correction time that is the difference between the reference time and the received local time, a packet processing unit that receives a first packet including first data and second data transmitted from a packet synchronization control device and extracts first correction time information from the first packet, including a packet execution unit; The first correction time information includes the local time, a first correction time that is the difference between the reference time and the local time, a differential time with respect to the first data and a differential time with respect to the second data, the sequence number of the first data, and the sequence number of the second data. The differential time with respect to the first data is zero. The differential time with respect to the second data is the difference between the first correction time and a second correction time with respect to the second data. The packet execution unit can provide a packet synchronous playback device that determines the execution times of the first data and the second data from the reception area time, the reception correction time, the area time, the first correction time, the differential time for the first data and the differential time for the second data, the sequence number of the first data and the sequence number of the second data, and the sampling time.

[0024] According to a fifth aspect of the present invention, a reference time management unit that manages a reference time, An area time management unit that manages area time, A correction time information generation unit that generates first correction time information based on the reference time and the area time, In a packet synchronous control device including a packet generation unit that receives first data, The packet generation unit has a step of generating a first packet including the first correction time information and the first data, The first correction time information includes the area time, a first correction time that is a difference between the reference time and the area time, a differential time for the first data, and a sequence number of the first data. The differential time for the first data is zero. A packet synchronous control method can be provided. This method is associated with a specific machine, namely a computer that performs the packet synchronous control method.

[0025] According to a sixth aspect of the present invention, a reference time management unit that manages a reference time, A reception area time management unit that manages reception area time, A reception correction time generation unit that generates a reception correction time that is a difference between the reference time and the reception area time, A packet processing unit that receives a first packet including first data transmitted from a packet synchronous control device and extracts first correction time information from the first packet, In a packet synchronous playback device including a packet execution unit, The first correction time information includes the local time, a first correction time that is the difference between the reference time and the local time, a difference time for the first data, and a sequence number of the first data. The difference time for the first data is zero. The packet execution unit can provide a packet synchronization playback method including the step of determining the execution time of the first data from the received local time, the received correction time, the local time, the first correction time, the difference time for the first data, the sampling time of the first data, and the sequence number of the first data. This method is associated with a specific machine, namely a computer that performs the packet synchronization playback method.

[0026] According to a seventh aspect of the present invention, a reference time management unit that manages a reference time, a local time management unit that manages local time, a correction time information generation unit that generates first correction time information based on the reference time and the local time, a computer in the packet generation unit of a packet synchronization control device including a packet generation unit that receives first data, is caused to execute a process of generating a first packet including the first correction time information and the first data, The first correction time information includes the local time, a first correction time that is the difference between the reference time and the local time, a difference time for the first data, and a sequence number of the first data, and the difference time for the first data is zero, and a program can be provided.

[0027] According to an eighth aspect of the present invention, a reference time management unit that manages a reference time, a received local time management unit that manages received local time, a received correction time generation unit that generates a received correction time that is the difference between the reference time and the received local time, a packet processing unit that receives a first packet including first data transmitted from a packet synchronization control device and extracts first correction time information from the first packet. including a packet execution unit, The first correction time information includes the local time, a first correction time that is the difference between the reference time and the local time, a difference time for the first data, and a sequence number of the first data. The difference time for the first data is zero, for the computer in the packet execution unit of the packet synchronous playback device. A program can be provided that causes the computer to execute a process of determining the execution time of the first data from the received local time, the received correction time, the local time, the first correction time, the difference time for the first data, the sampling time of the first data, and the sequence number of the first data.

[0028] These programs can be recorded on a computer-readable storage medium. The storage medium can be non-transient such as a semiconductor memory, a hard disk, a magnetic recording medium, an optical recording medium, etc. The present invention can also be embodied as a computer program product.

Advantages of the Invention

[0029] According to the present invention, it is possible to contribute to making it possible to synchronize data and time information by sharing difference information of time when sharing data having a serial number and time information among a plurality of regions, and to provide a packet synchronization control device, a packet synchronous playback device, a packet synchronization control method, a packet synchronous playback method, and a program.

Brief Description of the Drawings

[0030]

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Embodiments for Carrying Out the Invention

[0031] First, an overview of an embodiment of the present invention will be described with reference to the drawings. Note that the reference numerals attached to the drawings in this overview are for convenience and are attached to each element as an example to assist understanding, and are not intended to limit the present invention to the illustrated embodiments. Also, the connection lines between the blocks in the drawings and the like referred to in the following description include both bidirectional and unidirectional ones. The one-way arrow schematically shows the flow of the main signal (data) and does not exclude bidirectionality.

[0032] FIG. 1 is a diagram showing an example of the configuration of a packet synchronization control device according to an embodiment of the present invention. The packet synchronization control device 100 according to an embodiment of the present invention shown in FIG. 1 is assumed to be arranged at point A. Referring to FIG. 1, the packet synchronization control device (point A) 100 includes a reference time management unit 110 that manages the reference time, a local time management unit 120 that manages the local time of point A, a correction time information generation unit 130 that generates correction time information of point A based on the reference time and the local time of point A, and an RTP packet generation unit 140 that receives data 1 and data 2 of point A. Note that the received data is not limited to two, and one or any number of data can be received. When the entire system including the packet synchronization control device (point A) 100 and the packet synchronization playback device (point Z) 500 described later is started up, the timestamp (local time) of the packet synchronization control device (point A) 100 and the received local time of the packet synchronization playback device 500 are synchronized with the reference time distributed from the reference time synchronization source. Thereafter, until each device is reset or the entire system is reset, each timestamp (local time) is not reset by the reference time, but is updated by counting up with the clock installed in each device.

[0033] When the RTP packet generation unit 140 generates an RTP packet, the RTP header unit 150 sets information indicating X:1 and PT:xx (correction information) in the RTP header.

[0034] The RTP packet generation unit 140 generates an RTP packet including the correction time information of point A, data 1, and data 2. The IP packet construction unit 160 adds a UDP header and an IP header to the RTP packet generated by the RTP packet generation unit 140, and outputs IP packet 1 in which the RTP packet is arranged. In one embodiment of the present invention, a configuration in which data 1 and data 2 are input to the packet synchronization control device is described, but it is not intended to be limited to two data, and one or any number of data can be received.

[0035] The correction time information of point A includes the local time (timestamp) of point A, the correction time of point A which is the difference between the reference time and the local time of point A, the difference time for data 1 and data 2, and the sequence numbers of data 1 and data 2, and the difference time for data 1 and data 2 is zero.

[0036] Next, with reference to FIGS. 2 to 4, the configuration of IP packet 1 will be described. FIG. 2 is a diagram showing an example of the schematic configuration of IP packet 1 according to an embodiment of the present invention. IP packet 1 includes an IP header 10, a UDP header 20, and an RTP packet 50, and the RTP packet 50 includes an RTP header 30 and a coded data section 40.

[0037] FIG. 3 is a diagram showing an example of the schematic configuration of the RTP header 30 according to an embodiment of the present invention. The RTP header 30 includes a Version (V) (2 bits), a Padding (P) (1 bit), an Extension bit (X) (1 bit), a Contributing Source count (CC) (4 bits), a Marker (M) (1 bit), a Payload Type (PT) (7 bits), a Sequence Number (16 bits), a Timestamp (32 bits), a Synchronization Source (SSRC) identifier (32 bits), and a CSRC identifier. Note that the CSRC identifier does not exist when CC is zero.

[0038] The RTP header 30 of the RTP packet 50 according to an embodiment of the present invention is configured to have correction information in the code data section 40 designated as the extension area of the RTP packet by specifying X = 1 (extension) and PT = xx (code representing correction information). In each of the following embodiments of the present invention, data is transmitted using a correction information packet that includes correction time information and correction information including, for example, video and audio data in the code data section 40 of the RTP packet. The data included in the packet is assumed to include data sampled at a predetermined sampling time (sampling interval). For example, in the case of audio, audio data sampled at a predetermined sampling frequency is arranged in each packet. Similarly, for video, video data sampled at a predetermined sampling frequency is arranged in each packet, but it may be configured such that video file format data including not only video data but also text characters such as audio and subtitles is arranged over several packets.

[0039] FIG. 4 is a diagram showing an example of the schematic configuration of the code data section 40 of the RTP packet 50 according to an embodiment of the present invention. When X = 1 (extension) and PT = xx (code representing correction information) are specified in the RTP header 30, the code data section 40 is used as the extension area.

[0040] Next, the correction time information generation unit 130 of the packet synchronization control device (location A) 100 according to an embodiment of the present invention will be described. FIG. 5 is a diagram showing an example of the schematic configuration of the correction time information generation unit of the packet synchronization control device according to an embodiment of the present invention. Referring to FIG. 5, the correction time information generation unit 130 includes a correction time generation unit 131, a difference time generation unit 132, a sequence number generation unit 133, a format number / data PT generation unit 134, a maximum CH (channel) number generation unit 135, and a control information generation unit 136.

[0041] The correction time generation unit 131 generates the correction time of location A, which is the difference between the reference time managed by the reference time management unit 110 and the local time of location A managed by the local time management unit 120. The differential time generation unit 132 generates the differential time of location A, which is the difference between the correction time of location A and the correction time of location A. Therefore, the differential time of location A is zero.

[0042] The sequence number generation unit 133 generates sequence numbers for Data 1 and Data 2. The sequence numbers generated are the same as the sequence numbers in the RTP header 30. The initial value of the sequence number may be, for example, zero, or it may be another value. For the packets following the packet with the initial value of the sequence number, the sequence numbers are sequentially incremented. When the sequence number reaches the maximum value, it returns to zero and starts counting up from zero. The format number / data PT generation unit 134 generates the format number / data PT for Data 1 and Data 2, and the maximum CH (channel) number generation unit 135 generates the maximum channel number of the transmission data. The control information generation unit 136 generates control information for Data 1 and Data 2. With the control information generation unit 136, control instructions and data can be arranged in the same packet, and control instructions can be issued for each sequence number. By synthesizing control instructions for a plurality of consecutive sequences, it is also possible to issue long control instructions.

[0043] FIG. 6 is a diagram showing an example of the schematic configuration of correction time information and each channel data according to an embodiment of the present invention. Referring to FIG. 6, the coded data portion 40 of the RTP packet 50 includes correction time information, channel CH01 data, and channel CH02 data. The correction time information includes "Location A: Local Time" (timestamp), CH00 including "Location A: Correction Time (32 bits / signed)", CH number including "Maximum number of channels of transmission data", format including "Format number / Data PT", CH01 including "Control information (Data 1: Valid)", "Data 1 (Location A) differential time (lower 16 bits / signed)", and "Data 1 sequence number", and CH02 including "Control information (Data 2: Valid)", "Data 2 (Location A) differential time (lower 16 bits / signed)", and "Data 2 sequence number".

[0044] Next, a packet synchronous playback device (Location Z) 500 according to an embodiment of the present invention will be described. FIG. 7 is a diagram showing an example of the schematic configuration of the packet synchronous playback device according to an embodiment of the present invention. The packet synchronous playback device (Location Z) 500 according to the embodiment of the present invention shown in FIG. 7 is assumed to be arranged at a location Z different from Location A. Referring to FIG. 7, the packet synchronous playback device 500 includes a reference time management unit 510 that manages a reference time, a received local time management unit 520 that manages a received local time, a received correction time generation unit 530 that generates a received correction time that is a difference between the reference time and the received local time, an IP packet reception unit 540 that receives an IP packet 1 including Data 1 and Data 2 transmitted from the packet synchronous control device 100 described in FIG. 1, and an RTP packet processing unit 550 that extracts correction time information of Location A from the received IP packet 1, and an RTP packet execution unit 560. The RTP packet processing unit 550 sends the received Data 1, Data 2, and correction time information to the RTP packet execution unit 560.

[0045] The correction time information of Location A includes the local time (timestamp) of Location A, the correction time of Location A which is the difference between the reference time and the local time of Location A, the differential time of Location A for Data 1 and Data 2, and the sequence numbers of Data 1 and Data 2. The differential time of Location A for Data 1 and Data 2 is zero.

[0046] The RTP packet execution unit 560 determines the execution times of Data 1 and Data 2 from the received local time of Location Z, the received correction time of Location Z, the local time of Location A, the correction time of Location A, the differential time of Location A for Data 1 and Data 2, the sampling times of Data 1 and Data 2, and the sequence numbers of Data 1 and Data 2, and executes Data 1 and Data 2. The operation of executing Data 1 and Data 2 is meant to, for example, play back video and audio from Data 1 and Data 2 and output the video / audio 570.

[0047] As an example, the RTP packet execution unit 560 determines the execution time of the data as follows. When the received local time of Location Z is ahead of the reference time, the received correction time of Location Z is set to be positive, for example. When the local time of Location A is ahead of the reference time, if the correction time of Location A is set to be positive, for example, Received local reference time of Location Z = Received local time of Location Z - Received correction time of Location Z Transmission local start time of Location A for Data 1 and Data 2 = Local time of Location A when the sequence numbers of Data 1 and Data 2 are at the initial values (for example, zero) - Correction time of Location A - Differential time of Location A (note that the differential time of Location A for Data 1 and Data 2 is zero) Execution time of Data 1 and Data 2 = Transmission local start time of Location A for Data 1 and Data 2 + Sampling time × Sequence numbers of Data 1 and Data 2 In the case of The RTP packet execution unit 560 executes Data 1 and Data 2 when the received local reference time of Location Z reaches the execution times of Data 1 and Data 2.

[0048] In addition, when the sequence numbers of Data 1 and Data 2 become zero after reaching the maximum value, Offset value = Sampling time × Maximum value of sequence number is added to the execution times of Data 1 and Data 2. In the above, for example, if the value assumed to be positive is made negative, in the above equations, the corresponding subtraction is made an addition.

[0049] Therefore, according to one embodiment of the present invention, when sharing data having a serial number and time information among a plurality of regions, it contributes to making it possible to synchronize data and time information by sharing time difference information, and a packet synchronization control device, a packet synchronization reproduction device, a packet synchronization control method, a packet synchronization reproduction method, and a program can be provided.

[0050] [First Embodiment] Next, a first embodiment of the present invention will be described with reference to the drawings. FIG. 8 is a diagram showing an outline of the relationship of each point in the first embodiment of the present invention. Referring to FIG. 8, point B and point C generate RTP packets from the data at each point, and construct IP packets by adding a UDP header and an IP header to the RTP packets, and transmit them to point A. Point A generates RTP packets from the data at point A and the data stored in the RTP packets in the IP packets sent from points B and C, and constructs IP packets by adding a UDP header and an IP header to the RTP packets, and transmits them to point Z. Point Z that has received the IP packet executes the data of points A, B, and C sent by the IP packet. Note that points A, B, C, and Z are all different points.

[0051] FIG. 9 is a diagram showing an outline of distributing a reference time to each point in the first embodiment of the present invention. The reference time is distributed to points A, B, C, and Z.

[0052] FIG. 10 is a diagram showing an example of a schematic configuration of connections at each of points A, B, C, and Z according to the first embodiment of the present invention. Data 1 to data 4 are input to the packet synchronization control device (point A) 101 at point A, data 5 and data 6 are input to the packet synchronization control device (point B) 102 at point B, and data 7 and data 8 are input to the packet synchronization control device (point C) 103 at point C. The packet synchronization control device (point A) 101 is connected to the packet synchronization control device (point B) 103 via the L3SW200. The L3SW200 is connected to the L3SW201 via the network 400, and the packet synchronization reproduction device (point Z) 104 at point Z is connected to the L3SW201. Also, the reference time is distributed from the reference time synchronization source 300 to the time servers 301 and 302, and the time servers 301 and 302 distribute the reference time to the L3SW200 and the L3SW201, respectively.

[0053] First, when the entire system shown in FIG. 10 is started, the packet synchronization control devices 101, 102, 103 at points A, B, and C, and the packet synchronization reproduction device 104 at point Z synchronize their own time stamps (local time) and received local times with the reference time by the time servers 301 and 302 synchronized with the reference time synchronization source 300. After synchronization, until each device is reset or a system reset is applied, the time stamps and received local times are not reset based on the reference time, but are updated by counting up by the clocks mounted on each device.

[0054] FIG. 11 is a diagram showing an example of the schematic configuration of the first embodiment of the present invention. The RTP header 30 of the RTP packet 50 in the first embodiment of the present invention is configured to have correction time information in the coded data part 40 of the RTP packet by designating X = 1 (extension) and PT = xx (code representing correction information), and data is transmitted using a correction time information packet having correction time information. Referring to FIG. 11, in the first embodiment of the present invention, data 5 and data 6 input to the packet synchronization control device (location B) 102 at location B and data 7 and data 8 input to the packet synchronization control device (location C) 103 at location C are sent to location A by IP packets 2 and 3 including RTP packets. At location A, together with data 1 to data 4 input to location A, data 5 and data 6 and data 7 and data 8 included in IP packets 2 and 3 are multiplexed into one RTP packet, and an IP packet 1 including this RTP packet is transmitted to the packet synchronization playback device (location Z) 501 at location Z via L3SW200, IP line 1 of network 400, and L3SW201. This is an embodiment in which the packet synchronization playback device (location Z) 501 at location Z plays back data 1 to data 8. Note that the packet synchronization control device (location A) 101 is connected by L3SW200, a signal line for inputting IP packets 2 and 3, and a signal line for outputting IP packet 1, but this shows a functional connection. As shown in FIG. 10, the packet synchronization control device (location A) 101 and L3SW200 may be connected by one bidirectional connection line.

[0055] FIG. 12 is a diagram showing the transmission signal of the packet synchronization control device (location A) in the first embodiment of the present invention in chronological order. Referring to FIG. 12, for IP packet 1, it shows the coded data part 40, that is, the correction time information and the data of each channel. Sequence numbers 0 to 4 correspond to the sequence numbers included in the correction time information. The packet synchronization control device (location A) 101 multiplexes the correction time information and the data from CH01 to CH08, that is, data 1 to data 8, in the coded data part 40 of the RTP packet and transmits it as IP packet 1.

[0056] FIG. 13 is a diagram showing an example of a schematic configuration of a packet synchronization control device (at point B) according to the first embodiment of the present invention. In FIG. 13, components denoted by the same reference numerals as those in FIG. 1 represent the same components. Referring to FIG. 13, a packet synchronization control device (at point B) 102 receives data 5 and data 6 by an RTP packet generation unit 140. The operation of generating an RTP packet including data 5 and data 6 and outputting an IP packet 2 is the same as the operation of generating an RTP packet including data 1 and data 2 and outputting an IP packet 1 in FIG. 1. In the first embodiment of the present invention, the correction time information of the IP packet 2 is referred to as second correction time information. The second correction time information includes a second correction time and a second sequence number for data 5 and data 6. In the first embodiment of the present invention, a configuration in which data 5 and data 6 are input to the packet synchronization control device 102 is described, but it is not intended to be limited to two pieces of data, and one or more arbitrary numbers of data can be received.

[0057] FIG. 14 is a diagram showing an example of a schematic configuration of the correction time information generated by a packet synchronization control device (at point B) 102 according to the first embodiment of the present invention and each channel data. In FIG. 14, CH01 data corresponds to data 5 described in FIG. 13, and CH02 data corresponds to data 6 described in FIG. 13.

[0058] FIG. 15 is a diagram showing an example of a schematic configuration of a packet synchronization control device (at point C) according to the first embodiment of the present invention. In FIG. 15, components denoted by the same reference numerals as those in FIG. 1 represent the same components. Referring to FIG. 15, a packet synchronization control device (at point C) 103 receives data 7 and data 8 at an RTP packet generation unit 140. The operation of generating an RTP packet including data 7 and data 8 and outputting an IP packet 3 is the same as the operation of generating an RTP packet including data 1 and data 2 and outputting an IP packet 1 in FIG. 1. In the first embodiment of the present invention, the correction time information of the IP packet 3 is referred to as third correction time information. The third correction time information includes a third correction time and a third sequence number for data 7 and data 8. In the first embodiment of the present invention, a configuration in which data 7 and data 8 are input to the packet synchronization control device (at point C) 103 is described, but it is not intended to be limited to two pieces of data, and one or any number of pieces of data can be received.

[0059] FIG. 16 is a diagram showing an example of a schematic configuration of correction time information generated by a packet synchronization control device (at point C) 103 according to the first embodiment of the present invention and each channel data. In FIG. 16, CH01 data corresponds to data 7 described in FIG. 15, and CH02 data corresponds to data 8 described in FIG. 15.

[0060] FIG. 17 is a diagram showing an example of a schematic configuration of a packet synchronization control device (location A) 101 according to the first embodiment of the present invention. In FIG. 17, components denoted by the same reference numerals as those in FIG. 1 represent the same components. Referring to FIG. 17, the packet synchronization control device (location A) 101 receives data 1 to data 4 from the RTP packet generation unit 140. The operation of generating an RTP packet including data 1 to 4 and outputting IP packet 1 is the same as the operation of generating an RTP packet including data 1 and data 2 and outputting IP packet 1 in FIG. 1. In the first embodiment of the present invention, the correction time information of IP packet 1 is referred to as first correction time information. The first correction time information includes the first correction time and the first sequence number for data 1 to data 4. Note that, in the first embodiment of the present invention, a configuration in which data 1 to data 4 are input to the packet synchronization control device (location A) 101 is described, but it is not intended to be limited to four pieces of data, and one or more arbitrary numbers of data can be received.

[0061] Referring to FIG. 17, the packet synchronization control device (location A) 101 further includes an IP packet receiving unit 170 and an RTP packet processing unit 180.

[0062] The RTP packet processing unit 180 extracts data 5, data 6, data 7, data 8, the correction times of location B and location C included in the second correction time information and the third correction time information, and the sequence numbers of data 5, data 6, data 7, and data 8 from IP packet 2 and IP packet 3 received by the IP packet receiving unit 170 from the packet synchronization control devices 102 and 103.

[0063] Note that the data of IP packet 2 and IP packet 3 preferably multiplexes data corresponding to the time obtained by adjusting the difference from the time stamp of IP packet 1 by the second difference time and the third difference time described later into packet 1. However, if the data includes a time stamp in units of data, since it is possible to adjust the difference from the time stamp of IP packet 1 by the second difference time and the third difference time described later on the playback side, this is not the case.

[0064] The first correction time information further includes a second difference time for data 5 and data 6, a second sequence number of data 5 and data 6, a third difference time for data 7 and data 8, and a third sequence number of data 5 and data 6.

[0065] The second difference time for data 5 and data 6 is the difference between the first correction time and the second correction time. The second difference time for data 5 and data 6 is, for example, positive when the second correction time is greater than the first correction time. The third difference time for data 7 and data 8 is the difference between the first correction time and the third correction time. The third difference time for data 7 and data 8 is, for example, positive when the second correction time is greater than the first correction time. Note that it is preferable to multiplex data corresponding to a time obtained by adjusting the difference from the time stamp of IP packet 1 by the above-described second difference time and third difference time into packet 1 for the data of IP packet 2 and IP packet 3. However, when the data includes a time stamp in data units, since it is possible to adjust the difference from the time stamp of IP packet 1 by the above-described second difference time and third difference time on the playback side, this is not the case.

[0066] IP packet 1 further includes data 5, data 6, data 7, and data 8.

[0067] FIG. 18 is a diagram showing an example of a schematic configuration of a correction time information generation unit 130 of a packet synchronization control device (location A) 101 according to a first embodiment of the present invention. In FIG. 18, components denoted by the same reference numerals as those in FIG. 5 represent the same components. The correction time information generation unit 130 of the packet synchronization control device (location A) 101 according to the first embodiment of the present invention generates first correction time information.

[0068] Referring to FIG. 18, the second and third correction times of point B and point C included in the second and third correction time information extracted from the IP packet 2 and the IP packet 3 are input to the differential time generation unit 132 by the RTP packet processing unit 180, and the difference from the first correction time is taken to generate the above-mentioned second differential time and third differential time. In addition to generating sequence numbers for data 1 and data 2, the sequence number generation unit 133 generates the same sequence numbers as the sequence numbers included in the second and third correction time information extracted from the IP packet 2 and the IP packet 3 as the respective sequence numbers for data 5 and data 6, and data 7 and data 8. Further, in addition to generating control information for data 1 and data 2, the control information generation unit generates the same control information as the control information included in the second and third correction time information extracted from the IP packet 2 and the IP packet 3 as the respective control information for data 5 and data 6, and data 7 and data 8. Other operations of the correction time information generation unit 130 are the same as the operations of the correction time information generation unit 130 described with reference to FIG. 5.

[0069] FIG. 19 is a diagram showing an example of the schematic configuration of the first correction time information generated by the packet synchronization control device (point A) 101 according to the first embodiment of the present invention and each channel data. Referring to FIG. 19, the coded data part 40 of the RTP packet shown in FIG. 19, which includes the first correction time information and CH01 (data 1) to CH08 (data 8) described with reference to FIGS. 11 to 18, is generated.

[0070] Next, the operation of receiving the IP packet 1 output by the packet synchronization control device (point A) 101 and executing each data included in the coded data part 40 of the RTP packet will be described. The operation of executing each data is meant to reproduce video and audio from each data of video and audio, for example.

[0071] FIG. 20 is a diagram showing an example of the schematic configuration of a packet synchronization playback device (location Z) 501 according to the first embodiment of the present invention. The packet synchronization playback device (location Z) 501 according to the first embodiment of the present invention is assumed to be arranged at location Z. Referring to FIG. 20, the packet synchronization playback device (location Z) 501 according to the first embodiment of the present invention includes a reference time management unit 510 that manages a reference time, a reception area time management unit 520 that manages the reception area time of location Z, a reception correction time generation unit 530 that generates a reception correction time which is the difference between the reference time and the reception area time of location Z, an IP packet reception unit 540 that receives an IP packet 1 including data 1 to data 4, data 5 and 6, and data 7 and 8 transmitted from the packet synchronization control device (location A) 101 shown in FIG. 17, and an RTP packet processing unit 550 that extracts first correction time information from the received IP packet 1, and an RTP packet execution unit 560. The RTP packet processing unit 550 sends the received data 1 to data 8 and the correction time information to the RTP packet execution unit 560.

[0072] The first correction time information includes the area time of location A, a first correction time which is the difference between the reference time and the area time of location A, a first difference time for data 1 to data 4, a second difference time for data 5 and data 6, a third difference time for data 7 and data 8, a sequence number of data 1 to data 4, a sequence number of data 5 and data 6, and a sequence number of data 7 and data 8. The difference time for data 1 to data 4 is zero. The difference time for data 5 and data 6 is the difference between the first correction time and a second correction time for data 5 and data 6. The difference time for data 7 and data 8 is the difference between the first correction time and a third correction time for data 7 and data 8.

[0073] The RTP packet execution unit 560 determines the execution times of Data 1 to Data 4, Data 5 and Data 6, and Data 7 and Data 8 from the reception area time at point Z, the reception correction time at point Z, the area time at point A, the correction time at point A, the differential times for Data 1 to Data 4, the differential time for Data 5 and Data 6, the differential time for Data 7 and Data 8, the sequence numbers of Data 1 to Data 4, the sequence numbers of Data 5 and Data 6, the sequence numbers of Data 7 and Data 8, and the sampling time of the data, and executes Data 1 to Data 4, Data 5 and Data 6, and Data 7 and Data 8. The operation of executing each of Data 1 to Data 4, Data 5 and Data 6, and Data 7 and Data 8 is meant to, for example, play back video and audio from each piece of data and output the video / audio 570.

[0074] As an example, the RTP packet execution unit 560 determines the execution time of the data as follows. · When the reception area time at point Z is ahead of the reference time, the reception correction time is made positive, for example. · When the area time at point A is ahead of the reference time, the correction time at point A is made positive, for example. · The second differential time is made positive, for example, when the second correction time is greater than the first correction time. · The third differential time is made positive, for example, when the third correction time is greater than the first correction time. · Reception area reference time at point Z = Reception area time at point Z - Reception correction time at point Z · Transmission area start time at point A for Data 1 to Data 4 = First area time at point A when the sequence number at the head of Data 1 to Data 4 is the initial value - First correction time at point A - First differential time at point A · Execution time of Data 1 to Data 4 = Transmission area start time at point A for Data 1 to Data 4 + Sampling time × Sequence number of Data 1 to Data 4 · Transmission area start time at point B for Data 5 and Data 6 = First area time when the sequence number at the head of Data 5 and Data 6 is the initial value - First correction time - Second differential time · Execution time of data 5 and data 6 at point B = Transmission area start time of data 5 and data 6 + Sampling time × Sequence number of data 5 and data 6 · Transmission area start time of data 7 and data 8 at point C = First area time when the first sequence number of data 7 and data 8 is the initial value - First correction time - Third difference time · Execution time of data 7 and data 8 at point C = Transmission area start time of data 7 and data 8 + Sampling time × Sequence number of data 7 and data 8 When it is set as follows, When the reception area reference time becomes the execution time of data 1 to data 4, the RTP packet execution unit 560 executes data 1 to data 4, When the reception area reference time becomes the execution time of data 5 and data 6, the RTP packet execution unit 560 executes data 5 and data 6, When the reception area reference time becomes the execution time of data 7 and data 8, the RTP packet execution unit 560 executes data 7 and data 8, When the sequence number of the first data becomes zero after reaching the maximum value, Offset value = Sampling time × Maximum value of sequence number Add it to the execution time of data 1 to data 4, When the sequence number of data 5 and data 6 becomes zero after reaching the maximum value, Offset value = Sampling time × Maximum value of sequence number Add it to the execution time of data 5 and data 6, When the sequence number of data 7 and data 8 becomes zero after reaching the maximum value, Offset value = Sampling time × Maximum value of sequence number Add it to the execution time of data 7 and data 8. In the above, for example, when a positive value is set to a negative value, in the above formulas, the corresponding subtraction is changed to addition.

[0075] According to the first embodiment of the present invention, (1-1) There is no need to replace the time stamp of the data every time a location is passed through. Since the difference from the reference time is attached as the correction time, the time stamp can continue to be used as the time in the transmission area as it is. (1-2) Since the receiving side can perform data playback processing based on the sequence number, even if the reference time is corrected, it is not a process of aligning the internal time of the receiving side with the time stamp, so the sequence number does not move forward or backward or jump. (1-3) Since the control instruction and the data can be arranged in the same packet, there is no deviation between the data and the control. Since control instructions can be given for each sequence number, the control operation on the receiving side is easy. Also, since control information can be included in the correction time information, it is possible to determine and process control instructions in units of reproduced data. Also, since the RTP packet is a continuous signal, it is also possible to issue a long control instruction by synthesizing control instructions for a plurality of consecutive sequences.

[0076] Therefore, according to the first embodiment of the present invention, when sharing data having a serial number and time information among a plurality of regions, it contributes to making it possible to synchronize the data and the time information by sharing the time difference information, and a packet synchronization control device, a packet synchronization playback device, a packet synchronization control method, a packet synchronization playback method, and a program can be provided.

[0077] [Second Embodiment] Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 21 is a diagram showing an example of the schematic configuration of the second embodiment of the present invention. In FIG. 21, components denoted by the same reference numerals as in FIG. 11 represent the same components. Referring to FIG. 21, in the second embodiment of the present invention, the first correction time information of the IP packet 1 of the second embodiment of the present invention is the same as the first correction time information of the IP packet 1 in the first embodiment of the present invention. However, the data 5, data 6, data 7, and data 8 sent to the packet synchronization control device (location A) 101 by the IP packet 2 and the IP packet 3 are not multiplexed into the IP packet 1. This is an embodiment in which the IP packet 2 and the IP packet 3 are each transmitted to the packet synchronization playback device (location Z) 502.

[0078] When location A includes the data 1 (CH01) to data 4 (CH04) input to location A, the local time of location A for data 1 to data 4, the first correction time, the first difference time, the first sequence number, the second difference time for data 5 and data 6 described in the first embodiment, the second sequence number of data 5 and data 6, and the third difference time for data 7 and data 8, and the third sequence number of data 5 and data 6, the first correction time information is transmitted by the IP packet 1 via the L3SW200, the IP line 1 of the network 400, and the L3SW201 to the packet synchronization playback device (location Z) 501 at location Z. This is an embodiment in which the packet synchronization playback device (location Z) 501 at location Z plays back the data 1 to data 4.

[0079] Regarding data 5 and data 6, and data 7 and data 8, the IP packet 2 including the RTP packet transmitted from location B and the IP packet 3 including the RTP packet transmitted from location C are each transmitted to the packet synchronization playback device (location Z) 501 at location Z via the L3SW200, the IP lines 2 and 3 of the network 400, and the L3SW201. This is an embodiment in which the packet synchronization playback device (location Z) 501 at location Z plays back the data 5 and data 6, and the data 7 and data 8.

[0080] FIG. 22 is a diagram showing a transmission signal of the packet synchronization control device (point A) 101 according to the second embodiment of the present invention in chronological order. Referring to FIG. 22, for the IP packet 1, the coded data section 40, that is, the correction time information and the data of each channel are shown, and the sequence numbers 0 to 4 correspond to the sequence numbers included in the correction time information. The packet synchronization control device (point A) 101 multiplexes the first correction time information and the data from CH01 to CH04, that is, the data 1 to data 4, into the coded data section 40 of the RTP packet and transmits it as the IP packet 1.

[0081] FIG. 23 is a diagram showing an example of a schematic configuration of the first correction time information and each data generated by the packet synchronization control device (point A) 101 according to the second embodiment of the present invention. Referring to FIG. 23, the coded data section 40 of the RTP packet shown in FIG. 2, which includes the first correction time information and CH01 (data 1) to CH04 (data 4), is generated.

[0082] Next, the operation of receiving the IP packet 1 output by the packet synchronization control device (point A) 101, the IP packet 2 output by the packet synchronization control device (point B) 102, and the IP packet 3 output by the packet synchronization control device (point B) 102 and executing each data included in the coded data section 40 of each RTP packet will be described. Note that the operation of executing each data is meant to reproduce video and audio from each data of video and audio, for example.

[0083] FIG. 24 is a diagram showing an example of the schematic configuration of a packet synchronization reproduction apparatus (location Z) 502 according to the second embodiment of the present invention. In FIG. 24, components denoted by the same reference numerals as those in FIG. 20 of the first embodiment of the present invention represent the same components. The packet synchronization reproduction apparatus (location Z) 502 receives IP packet 1, IP packet 2, and IP packet 3. Data 1 to data 4 of IP packet 1 are executed by the RTP packet execution unit 560 based on the reference time, the reception area time at location Z, and the first correction time information, in the same manner as described with reference to FIG. 20 of the first embodiment of the present invention. Also, for data 5 and data 6, and data 7 and data 8 of IP packet 2 and IP packet 3, they are executed by the RTP packet execution unit 560 based on the reference time, the reception area time at location Z, and the first correction time information of IP packet 1, in the same manner as described with reference to FIG. 20.

[0084] Note that since IP packet 2 and IP packet 3 each include second correction time information and third correction time information, the RTP packet execution unit 560 can execute data 5 and data 6, and data 7 and data 8 based on the second correction time information and the third correction time information respectively, without referring to the first correction time information of IP packet 1, as described in an embodiment of the invention with reference to FIG. 7.

[0085] According to the second embodiment of the present invention, (2-1) If there is correction time information and original data, data reproduction is possible on the receiving side. Therefore, data from other locations such as location B and location C can be sent to the receiving side via a different route and utilized. When the data is not sent together, the bandwidth from the transmitting side to the receiving side can be reduced. (2-2) Data from other locations such as location B and location C can be sent to the receiving side via a different route. Therefore, either one of the (coded data) of that channel can be used as backup data. This leads to an improvement in data reliability from the transmitting side to the receiving side. (2-3) The data at other locations can be sent to the receiving side via a different route. Therefore, the (coded data) of that channel CH can reduce the bandwidth and be used as emergency backup data. This leads to an improvement in data reliability from the transmitting side to the receiving side. (2-4) Since RTP packets are priority packets with guaranteed bandwidth, it is possible to reduce troubles caused by the control signal not reaching. This leads to an improvement in the reliability of the entire system.

[0086] As described above, according to the second embodiment of the present invention, when sharing data with consecutive numbers and time information among multiple regions, it contributes to making it possible to synchronize data and time information by sharing time difference information. A packet synchronization control device, a packet synchronization playback device, a packet synchronization control method, a packet synchronization playback method, and a program can be provided.

[0087] [Third Embodiment] Next, the third embodiment of the present invention will be described with reference to the drawings. The third embodiment of the present invention is an embodiment in which, in the second embodiment of the present invention, the first correction time information transmitted via the IP line 1 by the IP packet 1 is transmitted via the IP line 4 by an IP packet 4 different from the IP packet 1.

[0088] FIG. 25 is a diagram showing an example of the schematic configuration of the third embodiment of the present invention. In FIG. 25, components denoted by the same reference numerals as in FIG. 21 represent the same components. Referring to FIG. 25, in the third embodiment of the present invention, the packet synchronization control device (Location A) 101 of the second embodiment of the present invention described with reference to FIG. 21 further outputs an IP packet 4 different from the IP packet 1, which includes only the first correction time information transmitted via the IP line 1 by the IP packet 1. The IP packet 4 is transmitted to the packet synchronization playback device (Location Z) 503 at Location Z via the L3SW200, the IP line 4 of the network 400, and the L3SW201.

[0089] FIG. 26 is a diagram showing the transmission signals of the packet synchronization control device (location A) 101 according to the third embodiment of the present invention in chronological order. Referring to FIG. 26, for the IP packet 4, it includes the first correction time information included in the IP packet 1. The first correction time information of the IP packet 1 is the same as the first correction time information of the IP packet 1 by the packet synchronization control device (location A) according to the first embodiment of the present invention described with reference to FIG. 19.

[0090] Next, the operation of receiving the IP packet 1 and the IP packet 4 output by the packet synchronization control device (location A) 101, the IP packet 2 output by the packet synchronization control device (location B) 102, and the IP packet 3 output by the packet synchronization control device (location B) 102 and executing each data included in the coded data part 40 of each RTP packet will be described. The operation of executing each data is meant to reproduce video and audio, for example, from each data of video and audio.

[0091] FIG. 27 is a diagram showing an example of the schematic configuration of the packet synchronization playback device (location Z) 503 according to the third embodiment of the present invention. In FIG. 27, the components denoted by the same reference numerals as in FIG. 24 indicate the same components. The packet synchronization playback device (location Z) 503 receives the IP packet 1, the IP packet 2, the IP packet 3, and the IP packet 4. The data 1 to data 4 of the IP packet 1 are executed by the RTP packet execution unit 560 in the same manner as described with reference to FIG. 20 of the first embodiment or FIG. 24 of the second embodiment of the present invention based on the reference time, the reception area time at location Z, and the first correction time information included in the IP packet 4. Also, for the data 5 and data 6, and the data 7 and data 8 of the IP packet 2 and the IP packet 3, they are executed by the RTP packet execution unit 560 in the same manner as described with reference to FIG. 20 of the first embodiment or FIG. 24 of the second embodiment of the present invention based on the reference time, the reception area time at location Z, and the first correction time information of the IP packet 1.

[0092] Note that data 1 to data 4, data 5 and data 6, and data 7 and data 8 included in IP packet 1, IP packet 2, and IP packet 3 can be executed by the RTP packet execution unit 560 respectively, without using the first correction time information included in IP packet 4, as described in the second embodiment of the present invention.

[0093] As described above, according to the third embodiment of the present invention, when sharing data having a serial number and time information among a plurality of regions, it contributes to making it possible to synchronize data and time information by sharing difference information of time, and it is possible to provide a packet synchronization control device, a packet synchronization reproduction device, a packet synchronization control method, a packet synchronization reproduction method, and a program.

[0094] As described above, each embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiments, and further modifications, substitutions, and adjustments can be made without departing from the basic technical idea of the present invention. For example, the network configuration shown in each drawing, the configuration of each element, and the expression form of the message are examples for helping the understanding of the present invention, and are not limited to the configurations shown in these drawings. Also, "A and / or B" is used to mean at least either A or B.

[0095] Also, the procedures shown in the first to second embodiments described above can be realized by a program that causes a computer (9000 in FIG. 28) that functions as the packet synchronization control device or the packet synchronization reproduction device of the present invention to realize the functions of the packet synchronization control device or the packet synchronization reproduction device. Such a computer is exemplified by a configuration including a CPU (Central Processing Unit) 9010, a communication interface 9020, a memory 9030, and an auxiliary storage device 9040 in FIG. 28. That is, the CPU 9010 in FIG. 28 may execute a control program of the packet synchronization control device or the packet synchronization reproduction device and perform an update process of each calculation parameter held in the auxiliary storage device 9040 or the like.

[0096] The memory 9030 is a RAM (Random Access Memory), a ROM (Read Only Memory), or the like.

[0097] That is, each part (processing means, function) of the packet synchronization control device or the packet synchronization reproduction device shown in the first to third embodiments described above can be realized by a computer program that causes the processor of the computer to execute each of the above-described processes using its hardware.

[0098] Finally, the preferred forms of the present invention will be summarized. [First Form] (Refer to the packet synchronization control device according to the first aspect) [Second Form] (Refer to the packet synchronization control device according to the second aspect) [Third Form] (Refer to the packet synchronization reproduction device according to the third aspect) [Fourth Form] (Refer to the packet synchronization reproduction device according to the fourth aspect) [Fifth Form] When the received area time is ahead of the reference time in the packet synchronization reproduction device described in the third aspect, the received correction time is set to positive, When the area time is ahead of the reference time and the first correction time is set to positive, Received area reference time = the received area time - the received correction time Transmission area start time of the first data = the area time when the sequence number of the first data is the initial value - the first correction time - the differential time for the first data Execution time of the first data = the transmission area start time of the first data + the sampling time × the sequence number of the first data If it is preferable that the packet execution unit executes the first data when the received area reference time becomes the execution time of the first data. [Sixth Form] When the received area time is ahead of the reference time, the received correction time is set to positive, When the area time is ahead of the reference time, the first correction time is set to positive, Regarding the differential time for the second data, when the second correction time is greater than the first correction time, it is set to positive, Received area reference time = the received area time - the received correction time Transmission area start time of the first data = the area time when the sequence number at the head of the first data is the initial value - the first correction time - the differential time for the first data Execution time of the first data = the transmission area start time of the first data + the sampling time × the sequence number of the first data Transmission area start time of the second data = the area time when the sequence number at the head of the second data is the initial value - the first correction time - the differential time for the second data Execution time of the second data = the transmission area start time of the second data + the sampling time × the sequence number of the second data When it is set as above, When the received area reference time becomes the execution time of the first data, the packet execution unit executes the first data, It is preferable that when the received area reference time becomes the execution time of the second data, the packet execution unit executes the second data. [Seventh embodiment] (Refer to the packet synchronization control method according to the fifth perspective above) [Eighth embodiment] (Refer to the packet synchronization reproduction method according to the sixth perspective above) [Ninth embodiment] (Refer to the program according to the seventh perspective above) [Tenth embodiment] (Refer to the program according to the eighth perspective above) Note that the above-described seventh and ninth forms can be developed into the second form. Also, the above-described eighth and tenth forms can be developed into the fifth form.

[0099] Note that each disclosure of the above patent documents is incorporated herein by reference. Within the scope of the entire disclosure of the present invention (including the claims), further modifications and adjustments of the embodiments or examples can be made based on its basic technical idea. Also, within the scope of the disclosure of the present invention, various combinations or selections of various disclosure elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible. That is, the present invention naturally includes all the disclosures including the claims, and various deformations and corrections that could be made by those skilled in the art according to the technical idea. In particular, regarding the numerical ranges described in this document, any numerical value or small range included within the range should be construed as specifically described even without separate description.

Explanation of Reference Numerals

[0100] 10 IP header 20 UDP header 30 RTP header 40 Encoded data section 50 RTP packet 100 Packet synchronization control device (Location A) 101 Packet synchronization control device (Location A) 102 Packet synchronization control device (Location B) 103 Packet synchronization control device (Location C) 104 Packet synchronous playback device (Location Z) 110 Reference time management unit 120 Local time management unit 130 Correction time information generation unit 131 Correction time generation unit 132 Difference time generation unit 133 Sequence number generation unit 134 Format number / data PT generation unit 135 Maximum CH (channel) number generation unit 136 Control Information Generation Unit 140 RTP Packet Generation Unit 150 RTP Header Unit 160 IP Packet Composition Unit 170 IP Packet Reception Unit 180 RTP Packet Processing Unit 200, 201 L3SW (Layer 3 Switch) 300 Reference Time Synchronization Source 301, 302 Time Server 400 Network 500 Packet Synchronized Playback Device (Location Z) 501, 502, 503 Packet Synchronized Playback Device (Location Z) 510 Reference Time Management Unit 520 Received Area Time Management Unit 530 Received Correction Time Generation Unit 540 IP Packet Reception Unit 550 RTP Packet Processing Unit 560 RTP Packet Execution Unit 570 Video and Audio Output 9000 Computer 9010 CPU 9020 Communication Interface 9030 Memory 9040 Auxiliary Storage Device

Claims

1. A reference time management unit for managing a reference time, A local time management unit for managing a local time, A correction time information generation unit for generating first correction time information based on the reference time and the local time, including a packet generation unit for receiving first data, The packet generation unit generates a first packet including the first correction time information and the first data, The first correction time information includes the local time, a first correction time which is a difference between the reference time and the local time, a difference time for the first data which is a difference between the first correction time and the first correction time, and a sequence number of the first data, and the difference time for the first data is zero, further including a packet processing unit for extracting second data, a second correction time which is a difference between the reference time and the local time of the area of another packet synchronization control device, and a sequence number of the second data from a second packet received from another packet synchronization control device, The first correction time information further includes a difference time for the second data and a sequence number of the second data, The difference time for the second data is a difference between the first correction time and the second correction time, and the difference time for the second data is positive when the second correction time is greater than the first correction time, The first packet further includes the second data, A packet synchronization control device.

2. A reference time management unit for managing a reference time, A received local time management unit for managing a received local time, A received correction time generation unit for generating a received correction time which is a difference between the reference time and the received local time, receiving a first packet including first data and second data transmitted from the packet synchronization control device according to Claim 1, and extracting first correction time information from the first packet; a packet processing unit, including a packet execution unit, The packet execution unit determines the execution times of the first data and the second data from the received area time, the received correction time, the area time, the first correction time, the differential time for the first data and the differential time for the second data, the sequence number of the first data and the sequence number of the second data, and the sampling time. A packet synchronous playback device.

3. When the received area time is ahead of the reference time, the received correction time is set to positive, When the area time is ahead of the reference time, the first correction time is set to positive, The differential time for the second data is set to positive when the second correction time is greater than the first correction time, Received area reference time = the received area time - the received correction time Transmission area start time of the first data = the area time when the sequence number at the head of the first data is the initial value - the first correction time - the differential time for the first data Execution time of the first data = the transmission area start time of the first data + the sampling time × the sequence number of the first data Transmission area start time of the second data = the area time when the sequence number at the head of the second data is the initial value - the first correction time - the differential time for the second data Execution time of the second data = the transmission area start time of the second data + the sampling time × the sequence number of the second data When it is set as follows, When the received area reference time becomes the execution time of the first data, the packet execution unit executes the first data, When the received area reference time becomes the execution time of the second data, the packet execution unit executes the second data. The packet synchronous playback device according to claim 2.

4. a reference time management unit that manages a reference time; A local time management unit that manages local time, A correction time information generation unit that generates first correction time information based on the reference time and the local time, A packet generation unit that receives first data, In a packet synchronization control device including a packet processing unit, The packet generation unit has a step of generating a first packet including the first correction time information and the first data, The first correction time information includes the local time, a first correction time that is the difference between the reference time and the local time, a difference time for the first data that is the difference between the first correction time and the first correction time, and a sequence number of the first data. The difference time for the first data is zero. The packet processing unit extracts second data, a second correction time that is the difference between the reference time and the local time of the area of another packet synchronization control device, and a sequence number of the second data from a second packet received from another packet synchronization control device. The first correction time information further includes a difference time for the second data and a sequence number of the second data. The difference time for the second data is the difference between the first correction time and the second correction time. The difference time for the second data is positive when the second correction time is greater than the first correction time. The first packet further includes the second data, a packet synchronization control method.

5. A reference time management unit that manages a reference time, A received local time management unit that manages a received local time, A received correction time generation unit that generates a received correction time that is the difference between the reference time and the received local time, Receives a first packet including first data and second data transmitted from the packet synchronization control device according to claim 1, and extracts first correction time information from the first packet, a packet processing unit In a packet synchronous playback device including a packet execution unit, The packet execution unit includes a step of determining execution times of the first data and the second data from the received area time, the received correction time, the area time, the first correction time, the differential time with respect to the first data, the differential time with respect to the second data, the sampling time of the first data, the sequence number of the first data, and the sequence number of the second data. A packet synchronous playback method.

6. A reference time management unit for managing a reference time, An area time management unit for managing an area time, In a computer in a packet synchronous control device including a correction time information generation unit that generates first correction time information based on the reference time and the area time, A process of receiving first data, Execute a process of generating a first packet including the first correction time information and the first data, The first correction time information includes the area time, a first correction time that is a difference between the reference time and the area time, a differential time with respect to the first data that is a difference between the first correction time and the first correction time, and a sequence number of the first data. The differential time with respect to the first data is zero. Execute a process of extracting second data, a second correction time that is a difference between the reference time and the area time of the area of the other packet synchronous control device, and a sequence number of the second data from a second packet received from another packet synchronous control device. The first correction time information further includes a differential time with respect to the second data and a sequence number of the second data. The differential time with respect to the second data is a difference between the first correction time and the second correction time. The differential time with respect to the second data is positive when the second correction time is greater than the first correction time. The first packet further includes the second data. A program.

7. A reference time management unit that manages a reference time, A received area time management unit that manages a received area time, A received correction time generation unit that generates a received correction time which is a difference between the reference time and the received area time, A packet processing unit that receives a first packet including first data and second data transmitted from the packet synchronization control device according to claim 1, and extracts first correction time information from the first packet, A program for causing a computer in a packet synchronous reproduction device including a packet execution unit to execute a process of determining execution times of the first data and the second data from the received area time, the received correction time, the area time, the first correction time, a difference time with respect to the first data, a difference time with respect to the second data, a sampling time of the first data, a sequence number of the first data, and a sequence number of the second data.

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