Transmission device, transmission method, reception device, and reception method

Abstract

To allow subtitle bitmap data to be favorably superimposed onto video data on a receiving side.SOLUTION: A video stream having progressive video data is generated. A subtitle stream having progressive subtitle bitmap data is generated. A container which is of a prescribed format and includes the video stream and the subtitle stream is transmitted. For example, the progressive subtitle bitmap data divided into top-field subtitle bitmap data and bottom-field subtitle bitmap data or not divided is present in the subtitle stream.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present technology relates to a transmitting device, a transmitting method, a receiving device, and a receiving method, and more particularly to a transmitting device or the like that transmits subtitle bitmap data together with video data. [Background technology]

[0002] Conventionally, for example, in DVB (Digital Video Broadcasting) broadcasts, subtitle data has been transmitted as bitmap data (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-030180 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present technology is to enable the receiving side to successfully superimpose subtitle bitmap data onto video data. [Means for solving the problem]

[0005] The concept of this technology is as follows: a video encoding unit for generating a video stream having progressive video data; a subtitle encoding unit for generating a subtitle stream having progressive subtitle bitmap data; a transmitting unit for transmitting a container in a predetermined format including the video stream and the subtitle stream; Located in the transmitting device.

[0006] In the present technology, a video encoding unit generates a video stream having progressive video data, a subtitle encoding unit generates a subtitle stream having progressive subtitle bitmap data, and a transmission unit transmits a container in a predetermined format including the video stream and the subtitle stream.

[0007] For example, the subtitle stream may contain progressive subtitle bitmap data divided into top field subtitle bitmap data and bottom field subtitle bitmap data. In this case, the subtitle stream may contain a top field data block and a bottom field data block, and the top field subtitle bitmap data may be arranged in the top field data block, and the bottom field subtitle bitmap data may be arranged in the bottom field data block.

[0008] Also, for example, progressive subtitle bitmap data may be present in an unsplit state in the subtitle stream. In this case, for example, a top field data block and a bottom field data block may be present in the subtitle stream, and the unsplit progressive subtitle bitmap data may be arranged in the top field data block or the bottom field data block. Also, in this case, for example, progressive data blocks may be present in the subtitle stream, and the unsplit progressive subtitle bitmap data may be arranged in the progressive data block.

[0009] In this manner, in the present technology, progressive subtitle bitmap data is transmitted in conjunction with the transmission of progressive video data, so that the subtitle bitmap data can be successfully superimposed on the video data on the receiving side.

[0010] In addition, in the present technology, for example, the video data may have a first resolution, the subtitle bitmap data may have a second resolution lower than the first resolution, and an identification information inserting unit may be further provided that inserts identification information into a layer of the subtitle stream, the identification information instructing to superimpose the subtitle bitmap data on the video data after performing coordinate conversion and resolution conversion on the subtitle bitmap data. In this case, on the receiving side, based on the identification information, the subtitle bitmap data is superimposed on the video data after performing coordinate conversion and resolution conversion, and the superimposition of the subtitle bitmap data on the video data is performed satisfactorily.

[0011] Another concept of the present technology is a receiving unit for receiving a container in a predetermined format including a video stream having progressive video data and a subtitle stream having progressive subtitle bitmap data; a control unit for controlling a process of decoding the video stream to obtain the progressive video data, a process of decoding the subtitle stream to obtain the progressive subtitle bitmap data, and a process of superimposing the progressive subtitle bitmap data on the progressive video data to obtain video data for display. in the receiving device.

[0012] In the present technology, a receiving unit receives a container in a predetermined format including a video stream having progressive video data and a subtitle stream having progressive subtitle bitmap data. Then, a control unit controls a process of decoding the video stream to obtain progressive video data, a process of decoding the subtitle stream to obtain progressive subtitle bitmap data, and a process of superimposing the progressive subtitle bitmap data on the progressive video data to obtain video data for display.

[0013] For example, progressive subtitle bitmap data may exist in a subtitle stream divided into top field subtitle bitmap data and bottom field subtitle bitmap data, and the process of obtaining the progressive subtitle bitmap data may involve synthesizing the top field subtitle bitmap data and the bottom field subtitle bitmap data obtained by decoding the subtitle stream to obtain the progressive subtitle bitmap data.

[0014] Also, for example, a subtitle stream may include a top field data block and a bottom field data block, and the process of obtaining progressive subtitle bitmap data may obtain undivided progressive subtitle bitmap data inserted in the top field data block or the bottom field data block.

[0015] Also, for example, a progressive data block may exist in the subtitle stream, and in the process of obtaining progressive subtitle bitmap data, undivided progressive subtitle bitmap data inserted in the progressive data block may be obtained.

[0016] In this way, in the present technology, progressive subtitle bitmap data obtained by decoding the subtitle stream is superimposed on progressive video data to obtain video data for display, so that the subtitle bitmap data is successfully superimposed on the video data.

[0017] Another concept of the present technology is a video encoding unit for generating a video stream having video data at a first resolution; a subtitle encoding unit that generates a subtitle stream having subtitle bitmap data of a second resolution lower than the first resolution; a transmitting unit for transmitting a container in a predetermined format including the video stream and the subtitle stream; and an identification information inserting unit for inserting identification information into a layer of the subtitle stream, the identification information instructing that the subtitle bitmap data be superimposed on the video data after coordinate conversion and resolution conversion are performed on the subtitle bitmap data. Located in the transmitting device.

[0018] In the present technology, a video encoding unit generates a video stream having video data of a first resolution. A subtitle encoding unit generates a subtitle stream having subtitle bitmap data of a second resolution lower than the first resolution. Then, a transmission unit transmits a container in a predetermined format including the video stream and the subtitle stream. For example, the first resolution may be UHD resolution, and the second resolution may be HD resolution.

[0019] The identification information inserting unit inserts identification information into the layer of the subtitle stream, the identification information instructing to superimpose the subtitle bitmap data on the video data after performing coordinate conversion and resolution conversion on the subtitle bitmap data. For example, the device may further include a resolution information inserting unit that inserts information on a first resolution of the video data on which the subtitle bitmap data is superimposed into the layer of the container. For example, the identification information inserting unit may insert the identification information into a display definition segment. For example, the identification information inserting unit may insert a segment as the identification information into the subtitle stream. In this case, for example, the segment as the identification information may include information on the conversion magnification.

[0020] In this way, in the present technology, identification information is inserted into the layer of the subtitle stream, which instructs the subtitle bitmap data to be superimposed on the video data after the coordinate conversion and resolution conversion are performed on the subtitle bitmap data. Therefore, on the receiving side, the subtitle bitmap data is superimposed on the video data after the coordinate conversion and resolution conversion are performed on the basis of this identification information, and the subtitle bitmap data is successfully superimposed on the video data.

[0021] Another concept of the present technology is a receiving unit for receiving a container in a predetermined format including a video stream having video data in a first resolution and a subtitle stream having subtitle bitmap data in a second resolution lower than the first resolution; Identification information is inserted into a layer of the subtitle stream, the identification information instructing that the subtitle bitmap data is superimposed on the video data after being subjected to coordinate conversion and resolution conversion; The video data decoding device further includes a control unit for controlling a process of decoding the video stream to obtain the video data, a process of decoding the subtitle stream to obtain the subtitle bitmap data, and a process of superimposing the subtitle bitmap data on the video data after performing coordinate conversion and resolution conversion on the basis of the identification information to obtain video data for display. On the receiving device

[0022] In the present technology, a receiving unit receives a container in a predetermined format including a video stream having video data of a first resolution and a subtitle stream having subtitle bitmap data of a second resolution lower than the first resolution. Identification information is inserted into a layer of the subtitle stream, which indicates that the subtitle bitmap data is to be superimposed on the video data after coordinate conversion and resolution conversion.

[0023] The control unit controls a process of decoding the video stream to obtain video data, a process of decoding the subtitle stream to obtain subtitle bitmap data, and a process of superimposing the subtitle bitmap data on the video data after performing coordinate conversion and resolution conversion based on the identification information to obtain video data for display.

[0024] In this way, in the present technology, the subtitle bitmap data of the second resolution is subjected to coordinate conversion and resolution conversion, and then superimposed on the video data of the first resolution to obtain the video data for display. Therefore, the subtitle bitmap data is successfully superimposed on the video data. Effect of the Invention

[0025] According to the present technology, it is possible to satisfactorily superimpose subtitle bitmap data onto video data at the receiving side. Note that the effects described in this specification are merely examples and are not limiting, and additional effects may also be provided. [Brief description of the drawings]

[0026] [Figure 1] 1 is a block diagram showing an example of the configuration of a transmission / reception system according to an embodiment; [Diagram 2] FIG. 1 is a diagram illustrating methods 1 and 2 for transmitting progressive subtitle bitmap data. [Diagram 3] FIG. 13 is a diagram illustrating methods 3 and 4 for transmitting progressive subtitle bitmap data. [Figure 4] FIG. 13 is a diagram for explaining coordinate conversion and resolution conversion applied to HD resolution subtitle bitmap data to be superimposed on UHD resolution video data. [Diagram 5] FIG. 2 is a block diagram showing a configuration example of a transmission device. [Figure 6] FIG. 13 is a diagram showing an example of the structure of an object data segment. [Figure 7] FIG. 13 is a diagram showing an example of the structure of an object data segment and the contents of the main information in the example structure. [Figure 8] FIG. 13 is a diagram showing an example of the structure of a display definition segment and the contents of main information in the example structure. [Figure 9] This figure shows the correspondence between each value of "component_type", which is an important element of the component descriptor, and the subtitle bitmap data identified by it. [Figure 10] FIG. 2 is a diagram illustrating an example of the configuration of a transport stream TS. [Figure 11] FIG. 2 is a block diagram showing a configuration example of a receiving device. [Figure 12] 13 is a flowchart showing an example of processing in a coordinate / resolution conversion unit. [Figure 13] This figure shows an example of the structure of a rendering guide segment and the main information contained in that example structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, modes for carrying out the invention (hereinafter, referred to as "embodiments") will be described. The description will be made in the following order. 1. Embodiment 2. Variations

[0028] <1. Preferred embodiment> [Example of transmission and reception system configuration] 1 shows an example of the configuration of a transmission / reception system 10 according to an embodiment. The transmission / reception system 10 includes a transmission device 100 and a reception device 200.

[0029] The transmitting device 100 generates an MPEG2 transport stream TS as a container, and transmits this transport stream TS on broadcast waves or network packets. This transport stream TS includes a video stream having progressive video data (image data) at UHD resolution. Here, UHD resolution exceeds HD resolution and includes 4K resolution or 8K resolution.

[0030] This transport stream TS also includes a subtitle stream having progressive subtitle bitmap data (subtitle data) at HD resolution. In this embodiment, the progressive subtitle bitmap data is transmitted by any one of Method 1, Method 2, Method 3, and Method 4.

[0031] "Method 1 Explanation" Method 1 will now be described. In the case of method 1, progressive subtitle bitmap data exists in the subtitle stream in a state where it is divided into top field subtitle bitmap data and bottom field subtitle bitmap data.

[0032] Fig. 2(a) shows an outline of transmission according to Method 1. In this case, a top field data block and a bottom field data block exist in an ODS (Object_data_segment), which is an encoded subtitle transmission format in a subtitle stream. The subtitle bitmap data of the top field is arranged in the top field data block, and the subtitle bitmap data of the bottom field is arranged in the bottom field data block.

[0033] In this case, since subtitle bitmap data is placed in both the top field data block and the bottom field data block, the receiving side recognizes that progressive subtitle bitmap data is constructed by combining the subtitle bitmap data of both blocks.

[0034] At the receiving end, the top field subtitle bitmap data and the bottom field subtitle bitmap data are extracted from each block and combined to obtain progressive subtitle bitmap data for displaying subtitles. This progressive subtitle bitmap data is superimposed on the progressive video data to obtain the video data for display.

[0035] "Method 2 Explanation" Method 2 will now be described. In this method 2, progressive subtitle bitmap data exists in the subtitle stream in a unified state, that is, in an undivided state.

[0036] Fig. 2(b) shows an outline of transmission according to Method 2. In this case, a top field data block and a bottom field data block exist in ODS (Object_data_segment), which is the encoded subtitle transmission format in the subtitle stream. Undivided progressive subtitle bitmap data is placed in the top field data block. In this case, no subtitle bitmap data is placed in the bottom field data block.

[0037] In this case, since subtitle bitmap data is placed only in the top field data block and not in the bottom field data block, the receiving side recognizes that the progressive subtitle bitmap data is composed only of the subtitle bitmap data placed in the top field data block.

[0038] At the receiving end, the undivided progressive subtitle bitmap data is extracted from the top field data block and used as progressive subtitle bitmap data for subtitle display. This progressive subtitle bitmap data is superimposed on the progressive video data to obtain the video data for display.

[0039] "Method 3 Explanation" Method 3 will now be described. In the case of method 3, progressive subtitle bitmap data exists in the subtitle stream in a single, undivided state.

[0040] Fig. 3(c) shows an outline of transmission by Method 3. In this case, a top field data block and a bottom field data block exist in ODS (Object_data_segment), which is the encoded subtitle transmission format in the subtitle stream. And, undivided progressive subtitle bitmap data is placed in the bottom field data block. In this case, subtitle bitmap data is not placed in the top field data block.

[0041] In this case, since subtitle bitmap data is placed only in the bottom field data block and not in the top field data block, the receiving side recognizes that the progressive subtitle bitmap data is composed only of the subtitle bitmap data placed in the bottom field data block.

[0042] At the receiving end, the undivided progressive subtitle bitmap data is extracted from the bottom field data block and used as progressive subtitle bitmap data for subtitle display. This progressive subtitle bitmap data is superimposed on the progressive video data to obtain the video data for display.

[0043] "Method 4 Explanation" Method 4 will now be described. In the case of method 4, progressive subtitle bitmap data exists in the subtitle stream in a single, undivided state.

[0044] Fig. 3(d) shows an outline of transmission by Method 4. In this case, a progressive data block exists in ODS (Object_data_segment), which is the encoded subtitle transmission format in the subtitle stream. And the undivided progressive subtitle bitmap data is placed in the progressive data block.

[0045] In this case, since a progressive data block exists and subtitle bitmap data is placed in this block, the receiving side recognizes that the progressive subtitle bitmap data consists only of the subtitle bitmap data placed in the progressive data block.

[0046] At the receiving end, the undivided progressive subtitle bitmap data is extracted from the progressive data block, and this data is used as progressive subtitle bitmap data for displaying subtitles. This progressive subtitle bitmap data is superimposed on the progressive video data to obtain the video data for display.

[0047] Returning to Fig. 1, identification information is inserted into the layer of the subtitle stream to instruct the HD resolution subtitle bitmap data to be superimposed on the UHD resolution video data after coordinate conversion and resolution conversion. By performing coordinate conversion and resolution conversion on the HD resolution subtitle bitmap data in this way, it becomes possible to display the subtitle (subtitle) at the correct position on the UHD resolution video screen.

[0048] The receiving device 200 receives the transport stream TS transmitted from the transmitting device 100. The receiving device 200 decodes the video stream to obtain progressive video data at UHD resolution. The receiving device 200 also decodes the subtitle stream to obtain progressive subtitle bitmap data at HD resolution. In this case, the decoding process changes depending on the transmission method of the progressive subtitle bitmap data.

[0049] In the case of method 1, the receiving device 200 recognizes that since subtitle bitmap data is placed in both the top field data block and the bottom field data block, progressive subtitle bitmap data can be constructed by combining the subtitle bitmap data of both blocks.

[0050] In this case, the subtitle stream is decoded, the top field subtitle bitmap data is extracted from the top field data block, and the bottom field subtitle bitmap data is extracted from the bottom field data block. The top field subtitle bitmap data and the bottom field subtitle bitmap data are then combined to obtain progressive subtitle bitmap data.

[0051] In the case of method 2, since subtitle bitmap data is arranged only in the top field data block, the receiving device 200 recognizes that progressive subtitle bitmap data can be composed only of the subtitle bitmap data arranged in the top field data block. In this case, the subtitle stream is decoded and the subtitle bitmap data is extracted from the top field data block, thereby obtaining the progressive subtitle bitmap data.

[0052] In the case of method 3, since subtitle bitmap data is arranged only in the bottom field data block, the receiving device 200 recognizes that progressive subtitle bitmap data can be composed only of the subtitle bitmap data arranged in the bottom and top field data block. In this case, the subtitle stream is decoded and the subtitle bitmap data is extracted from the bottom field data block, thereby obtaining the progressive subtitle bitmap data.

[0053] In the case of method 4, the receiving device 200 recognizes that progressive subtitle bitmap data can be configured only by the subtitle bitmap data arranged in the progressive sub data block. In this case, the subtitle stream is decoded and the subtitle bitmap data is extracted from the progressive sub data block, thereby obtaining the progressive subtitle bitmap data.

[0054] In the layer of the subtitle stream, identification information is inserted to instruct the subtitle bitmap data of HD resolution to be subjected to coordinate conversion and resolution conversion and then superimposed on the video data of UHD resolution as described above. The receiving device 200 performs coordinate conversion and resolution conversion on the progressive subtitle bitmap data obtained as described above based on the identification information, and then superimposes the progressive video data to obtain the video data for display.

[0055] Figure 4(a) shows the case where the subtitle bitmap data is used as is without undergoing coordinate conversion or resolution conversion. In this case, HD resolution subtitles (subtitles) are superimposed (overlaid) on the UHD resolution video screen at the HD display position, and due to the difference in coordinate width between UHD and HD, the subtitles (subtitles) are not displayed in the correct position. Note that "R" indicates the reference point (origin). Also, "p0" indicates the upper left point, which is the start point of the region. "q0" indicates the lower right point, which is the end point of the region.

[0056] Figure 4(b) shows the case where the subtitle bitmap data is used after coordinate conversion and resolution conversion. In this case, the UHD resolution subtitles (subtitles) are superimposed (overlaid) on the UHD resolution video screen at the UHD display position, and the subtitles (subtitles) are displayed in the correct position.

[0057] In this case, the coordinates of the start point "p1" of the region are converted as p1(x, y) = p0(x, y) * N, and the coordinates of the end point "q1" of the region are converted as q1(x, y) = q0(x, y) * N. Here, "N" indicates the ratio between UHD resolution and HD resolution, and if the UHD resolution is 4K resolution, N = 2.

[0058] In this case, the "N" value is used to perform horizontal and vertical scaling processing on the subtitle bitmap data, and the HD resolution subtitle bitmap data is converted into UHD resolution subtitle bitmap data.

[0059] "Example of transmitting device configuration" 5 shows an example of the configuration of a transmission device 100. This transmission device 100 has a control unit 101, a camera 102, a video photoelectric conversion unit 103, an RGB / YCbCr conversion unit 104, a video encoder 105, a subtitle generation unit 106, a bitmap data generation unit 107, a subtitle encoder 108, a system encoder 109, and a transmission unit 110.

[0060] The control unit 101 includes a CPU (Central Processing Unit) and controls the operation of each unit of the transmission device 100 based on a control program. The camera 102 captures an image of a subject and outputs progressive video data (image data) at UHD resolution. The video photoelectric conversion unit 103 performs photoelectric conversion on the video data obtained by the camera 102 to obtain video data V1.

[0061] The RGB / YCbCr conversion unit 104 converts the video data V1 from the RGB domain to the YCbCr (luminance / chrominance) domain. The video encoder 105 performs encoding, such as MPEG4-AVC or HEVC, on the video data V1 converted to the YCbCr domain, and generates a video stream (PES stream) VS including the encoded video data.

[0062] A subtitle generation unit 106 generates text data (character code) DT as subtitle information. A bitmap data generation unit 107 inputs the text data DT generated by the subtitle generation unit 106 and generates progressive subtitle bitmap data at HD resolution. A subtitle encoder 108 converts the subtitle bitmap data and display control information into various segments, and generates a subtitle stream SS made up of PES packets with these segments arranged in the payload.

[0063] Progressive subtitle bitmap data is transmitted by using the object data segment (Object_data_segment) in any of the above-mentioned methods 1 to 4. Figures 6 and 7(a) show an example of the structure (Syntax) of an object data segment. Figure 7(b) shows the main information content (Semantics) in the example structure.

[0064] The 2-bit field of "object_coding_method" indicates whether the object type is bitmap data or text data. "00" indicates bitmap data, and "01" indicates text data. In this embodiment, in addition to "00" for interlaced video, "11" for progressive video is newly defined as a bitmap data.

[0065] When "object_coding_method" is "00", a 16-bit field "top_field_data_block_length" exists. Then, "pixel-data_sub-block()" blocks, that is, data blocks for the top field, exist repeatedly for the number indicated by "top_field_data_block_length".

[0066] When "object_coding_method" is "00", a 16-bit field "bottom_field_data_block_length" exists. Then, "pixel-data_sub-block()" blocks, that is, data blocks for the bottom field, exist repeatedly for the number indicated by "bottom_field_data_block_length".

[0067] The 8-bit field "8_stuff_bits" is a field for adding stuffing bits to make it 8 bits if 8-bit byte alignment is not performed.

[0068] When progressive subtitle bitmap data is transmitted by the above-mentioned first to third methods, "object_coding_method" is set to "00", and the data is arranged in the above-mentioned top field data block and / or bottom field data block.

[0069] That is, when transmitted using the first method, the progressive subtitle bitmap data is divided into top field subtitle bitmap data and bottom field subtitle bitmap data, the top field subtitle bitmap data is placed in a top field data block, and the bottom field subtitle bitmap data is placed in a bottom field data block.

[0070] When the second method is used, the progressive subtitle bitmap data is left unsplit, and the entire unsplit progressive subtitle bitmap data is placed in the top field data block. In this case, "bottom_field_data_block_length" is set to 0, indicating that no subtitle bitmap data is placed in the bottom field data block.

[0071] When the third method is used, the progressive subtitle bitmap data is left undivided, and the entire undivided progressive subtitle bitmap data is placed in the bottom field data block. In this case, "top_field_data_block_length" is set to 0, indicating that no subtitle bitmap data is placed in the top field data block.

[0072] Also, when "object_coding_method" is "11", there is a 16-bit field of "progressive_frame_data_block_length". And there are the same number of "pixel-data_sub-block()" blocks, that is, progressive data blocks, repeated as indicated by "progressive_frame_data_block_length". The 8-bit field of "8_stuff_bits" is a field for adding stuffing bits to make it 8 bits when 8-bit byte alignment is not performed.

[0073] When progressive subtitle bitmap data is transmitted by the above-mentioned fourth method, "object_coding_method" is set to "11" and the data is placed in the above-mentioned progressive data block. That is, the progressive subtitle bitmap data is placed in an undivided state, and the entire undivided progressive subtitle bitmap data is placed in the progressive data block.

[0074] Identification information instructing that HD resolution subtitle bitmap data be superimposed on UHD resolution video data after coordinate conversion and resolution conversion is included in the display definition segment (display_definition_segment).

[0075] Figure 8(a) shows an example of the structure (Syntax) of a display definition segment. Figure 8(b) shows the main information content (Semantics) in the example structure. The 1-bit field "display_window_flag" indicates whether or not a window is defined. "1" indicates that a window is defined. "0" indicates that a window is not defined.

[0076] When the 2-bit field of "display_rendering_type" is "11", it indicates that the display position of the subtitle (subtitle) is converted according to the video coordinates of the overlay display target. In other words, "11" of "display_rendering_type" is identification information that instructs to superimpose the HD resolution subtitle bitmap data on the UHD resolution video data after performing coordinate conversion and resolution conversion.

[0077] The 16-bit field of "display_width" and the 16-bit field of "display_height" indicate the resolution of the subtitle bitmap data. For example, "display_width" indicates 1920 when the resolution is HD resolution, and indicates 3820 when the resolution is 4K resolution included in UHD resolution. Also, for example, "display_height" indicates 1080 when the resolution is HD resolution, and indicates 2160 when the resolution is 4K resolution included in UHD resolution.

[0078] When "display_window_flag"="1", there are fields indicating the area of ​​the window, namely, a 16-bit field of "display_window_horizontal_position_minimum", a 16-bit field of "display_window_horizontal_position_maximum", a 16-bit field of "display_window_vertical_position_minimum", and a 16-bit field of "display_window_vertical_position_maximum".

[0079] The fields "display_window_horizontal_position_minimum" and "display_window_vertical_position_minimum" indicate the coordinates of the start point of the window. The fields "display_window_horizontal_position_maximum" and "display_window_vertical_position_maximum" indicate the coordinates of the end point of the window.

[0080] Returning to Fig. 5, the system encoder 109 generates a transport stream TS including the video stream VS generated by the video encoder 105 and the subtitle stream SS generated by the subtitle encoder 108. The transmitter 110 transmits this transport stream TS to the receiving device 200 via broadcast waves or net packets.

[0081] At this time, the system encoder 109 inserts resolution information of the video data on which the subtitle bitmap data is to be superimposed into a layer of the transport stream TS as a container. Specifically, the system encoder 109 inserts this resolution information into a component descriptor (Component_descriptor) in an event information table (EIT).

[0082] The important elements of this component descriptor are "stream_content" and "component_type". Figure 9 shows the relationship between each value of "component_type" and the subtitle bitmap data it identifies. When "stream_content" is "0x03", it indicates that it is a DVB subtitle.

[0083] For example, when "component_type" is "0x16", it indicates that it is a DVB subtitle for a UHD (Ultra High definition) monitor. Also, when "component_type" is "0x26", it indicates that it is a DVB subtitle for a UHD (Ultra High definition) monitor (for the hearing impaired). In this embodiment, "component_type" is set to "0x16" or "0x26", indicating that it is a DVB subtitle for a UHD resolution monitor. This indicates that the resolution of the video data on which the subtitle bitmap data is superimposed is UHD resolution.

[0084] "Example of Transport Stream TS Configuration" 10 shows an example of the structure of a transport stream TS. In this example, there is a PES packet "Video PES1" of a video stream identified by PID1. In addition, there is a PES packet "Subtitle PES2" of a subtitle stream identified by PID2.

[0085] The PES packets of the video stream contain the video coding stream, and the PES packets of the subtitle stream contain various segments including subtitle bitmap data and display control information.

[0086] The object data segment (ODS) containing the subtitle bitmap data has an "object_coding_method" field that indicates the object coding method. The display definition segment (DDS) has a "display_rendering_type" field that is set to "11" and serves as identification information that instructs the HD resolution subtitle bitmap data to be superimposed on the UHD resolution video data after coordinate conversion and resolution conversion.

[0087] The page composition segment (PCS) also has the fields "region_horizontal_address" and "region_vertical_address", which indicate the coordinates of the start position of the region, and the region composition segment (RCS) has the fields "region_width" and "region_height", which indicate the horizontal and vertical sizes of the region.

[0088] The transport stream TS also contains a PMT (Program Map Table) as PSI (Program Specific Information). The PSI is information that describes which program each elementary stream in the transport stream belongs to. The PMT contains a program loop that describes information related to the entire program.

[0089] The PMT also contains elementary stream loops that contain information related to each elementary stream. In this configuration example, there is a video elementary stream loop (video ES1 loop) that corresponds to the video stream, and a subtitle elementary stream loop (Subtitle ES2 loop) that corresponds to the subtitle stream.

[0090] In the video elementary stream loop (video ES1 loop), information such as stream type and PID (packet identifier) ​​corresponding to the video stream is placed, and a descriptor describing information related to the video stream is also placed. The value of "Stream_type" of this video stream is set to, for example, "0x24" which indicates an HEVC video stream, and the PID information indicates PID1 which is assigned to the PES packet "video PES1" of the video stream.

[0091] In the subtitle elementary stream loop (Subtitle ES2 loop), information such as stream type and PID (packet identifier) ​​corresponding to the subtitle stream is placed, and a descriptor describing information related to the subtitle stream is also placed. The value of "Stream_type" of this subtitle stream is set to a value indicating a private stream, for example, and the PID information indicates PID2 assigned to the PES packet "Subtitle PES2" of the subtitle stream.

[0092] The transport stream TS also includes an EIT (Event Information Table) as SI (Serviced Information) for managing events. Metadata for each program is described in this EIT. A component descriptor (Component_descriptor) having a "component_type" element (see FIG. 9) as resolution information of the video data is inserted under this EIT. In this embodiment, "component_type" is set to "0x16" or "0x26", which indicates that the subtitle is a DVB subtitle for a UHD resolution monitor, and therefore indicates that the resolution of the video data on which the subtitle bitmap data is superimposed is UHD resolution.

[0093] A stream identifier descriptor (Stream_identifier_descriptor) is inserted into the subtitle elementary stream loop (Subtitle ES2 loop). This descriptor associates this subtitle elementary stream loop with a component descriptor under the EIT using the component tag "Component_tag".

[0094] The operation of the transmitting device 100 shown in Fig. 5 will be briefly described. Progressive video data (image data) with UHD resolution captured by a camera 102 is supplied to a video photoelectric conversion unit 103. In the video photoelectric conversion unit 103, photoelectric conversion is performed on the video data to obtain video data V1.

[0095] The video data V1 obtained by the video photoelectric conversion unit 103 is converted from the RGB domain to the YCbCr (luminance / chrominance) domain by the RGB / YCbCr conversion unit 104, and then supplied to the video encoder 105. The video encoder 105 performs encoding processing such as MPEG4-AVC or HEVC on the video data V1, thereby generating a video stream (PES stream) VS including encoded video data.

[0096] The subtitle generating unit 106 generates text data (character code) DT as subtitle information. This text data DT is supplied to a bitmap data generating unit 107. The bitmap data generating unit 107 generates progressive subtitle bitmap data at HD resolution based on the text data DT.

[0097] This subtitle bitmap data is supplied to the subtitle encoder 108. The subtitle encoder 108 converts the subtitle bitmap data and display control information into various segments, and generates a subtitle stream SS made up of PES packets in whose payloads these segments are arranged.

[0098] The progressive subtitle bitmap data is transmitted by any of the methods 1 to 4 using the object data segment (ODS) (see Fig. 6 and Fig. 7). Also, in the display definition segment (DDS) (see Fig. 8), identification information ("display_rendering_type" = "11") is inserted, which instructs that the HD resolution subtitle bitmap data be superimposed on the UHD resolution video data after coordinate conversion and resolution conversion.

[0099] The video stream VS generated by the video encoder 105 is supplied to the system encoder 109. The subtitle stream SS generated by the subtitle encoder 108 is supplied to the system encoder 109. The system encoder 109 generates a transport stream TS including the video stream VS and the subtitle stream SS.

[0100] At this time, the system encoder 109 inserts into the event information table a component descriptor having resolution information (the "component_type" element) of the video data on which the subtitle bitmap data is to be superimposed.

[0101] The transport stream TS generated by the system encoder 109 is transmitted to the receiving device 200 via broadcast waves or network packets by the transmitting unit 110 .

[0102] "Example of receiving device configuration" 11 shows an example of the configuration of a receiving device 200. This receiving device 200 has a control unit 201, a receiving unit 202, a system decoder 203, a video decoder 204, a subtitle decoder 205, and a coordinate / resolution conversion unit 206. The receiving device 200 also has a video superimposition unit 208, a YCbCr / RGB conversion unit 209, an electro-optical conversion unit 210, a display mapping unit 211, a CE monitor 212, and a user operation unit 213.

[0103] The control unit 201 is configured with a CPU (Central Processing Unit) and controls the operation of each unit of the receiving device 200 based on a control program. The user operation unit 213 is a switch, a touch panel, a remote control transmission unit, etc., which allows a user such as a viewer to perform various operations.

[0104] The receiving unit 202 receives the transport stream TS transmitted by broadcast waves or network packets from the transmitting device 100. The system decoder 203 extracts the video stream VS and the subtitle stream SS from this transport stream TS.

[0105] The system decoder 203 also extracts various pieces of information inserted in the transport stream TS (container) and sends it to the control unit 201. This extracted information also includes a component descriptor having resolution information of the video data on which the subtitle bitmap data is superimposed. This allows the control unit 201 to recognize the resolution of the video data. Note that the resolution of the video data can also be recognized from information extracted by the video decoder 204.

[0106] The video decoder 204 performs a decoding process on the video stream VS extracted by the system decoder 203, and outputs progressive transmission video data V1 with UHD resolution. As described above, UHD resolution exceeds HD resolution and includes 4K resolution or 8K resolution.

[0107] In addition, the video decoder 204 extracts various information such as parameter sets and SEI messages inserted in each access unit constituting the video stream VS, and sends the extracted information to the control unit 201 .

[0108] The subtitle decoder 205 performs a decoding process on the subtitle stream SS to obtain progressive subtitle bitmap data at HD resolution. In this case, the decoding process differs depending on whether the progressive subtitle bitmap data is transmitted using method 1 to method 4.

[0109] For example, in the case of method 1, the top field subtitle bitmap data is extracted from the top field data block, and the bottom field subtitle bitmap data is extracted from the bottom field data block. The top field subtitle bitmap data and the bottom field subtitle bitmap data are then combined to obtain progressive subtitle bitmap data.

[0110] In the case of method 2, progressive subtitle bitmap data is obtained by extracting the subtitle bitmap data from the top field data block. In the case of method 3, progressive subtitle bitmap data is obtained by extracting the subtitle bitmap data from the bottom field data block. In the case of method 4, progressive subtitle bitmap data is obtained by extracting the subtitle bitmap data from the progressive field data block.

[0111] The subtitle decoder 205 also extracts various pieces of information inserted in the subtitle stream SS and sends it to the control unit 201. This extracted information includes identification information ("display_rendering_type"="11") that instructs the HD resolution subtitle bitmap data to be superimposed on the UHD resolution video data after coordinate conversion and resolution conversion. This extracted information also includes information such as the coordinates of the start position of the region, and the horizontal and vertical sizes of the region.

[0112] The coordinate / resolution conversion unit 206 performs coordinate conversion and resolution conversion on the progressive subtitle bitmap data obtained by the subtitle decoder 205 under the control of the control unit 201 based on the above-mentioned identification information (identification information that instructs the subtitle bitmap data in HD resolution to be subjected to coordinate conversion and resolution conversion and then superimposed on the video data in UHD resolution).

[0113] In this case, as shown in Fig. 4(b), the coordinates of the start point "p1" of the region are converted as p1(x, y) = p0(x, y) * N, and the coordinates of the end point "q1" of the region are converted as q1(x, y) = q0(x, y) * N. Here, "N" indicates the ratio between UHD resolution and HD resolution, and when UHD resolution is 4K resolution, N = 2.

[0114] In this case, the "N" value is used to perform horizontal and vertical scaling processing on the subtitle bitmap data, and the HD resolution subtitle bitmap data is converted into UHD resolution subtitle bitmap data.

[0115] 12 shows an example of processing in the coordinate / resolution conversion unit 206. Note that, here, related processing in the control unit 201 will also be described as processing in the coordinate / resolution conversion unit 206.

[0116] The coordinate / resolution conversion unit 206 starts processing in step ST1. Next, in step ST2, the coordinate / resolution conversion unit 206 detects the video picture frame, that is, the resolution of the video data. The information on the resolution of the video data can be detected from the video stream parameter set (SPS). Alternatively, the information on the resolution of the video data can also be detected from the "component_type" element of the component descriptor. In this embodiment, UHD resolution is detected.

[0117] Next, in step ST3, the coordinate / resolution conversion unit 206 detects the resolution of the subtitle bitmap data, that is, the display area of ​​the subtitle. The display area of ​​the subtitle (display_width, display_height) can be detected from the display definition segment (DDS). In this embodiment, it is detected as HD resolution.

[0118] Next, in step ST4, the coordinate / resolution conversion unit 206 determines whether or not the resolution of the video data is UHD resolution. When determining that the resolution is not UHD resolution, the coordinate / resolution conversion unit 206 ends the process in step ST5.

[0119] If it is determined that the resolution is UHD, the coordinate / resolution conversion unit 206 detects "display_rendering_type" in step ST6. Then, in step ST7, the coordinate / resolution conversion unit 206 determines whether "display_rendering_type" is "11". If it is determined that "display_rendering_type" is not "11", the coordinate / resolution conversion unit 206 ends the process in step ST5.

[0120] When it is determined that "display_rendering_type" is "11", in step ST8, the coordinate / resolution conversion unit 206 sets the position coordinate value of the region in the video image frame to a coordinate value obtained by multiplying the HD coordinate value from the HD display area starting point R by N (see FIG. 4(b)). In addition to converting the position coordinate value of the region, the resolution is converted from HD to UHD. Note that, for the subtitle data after the bitmap data has been output to the CLUT, a value indicating the mixing ratio at the time of video superimposition is processed so that it maintains the value specified by the CLUT even after the resolution conversion.

[0121] After the process of step ST8, the coordinate / resolution conversion unit 206 ends the process in step ST5.

[0122] Returning to FIG. 11, the video superimposing unit 208 superimposes the progressive subtitle bitmap data at UHD resolution obtained via the coordinate / resolution conversion unit 206 on the progressive video data V1 at UHD resolution obtained by the video decoder 204.

[0123] The YCbCr / RGB conversion unit 209 converts the progressive video data V1' with UHD resolution and superimposed subtitle bitmap data from the YCbCr (luminance / chrominance) domain to the RGB domain. The electro-optical conversion unit 210 applies electro-optical conversion characteristics corresponding to the photoelectric conversion characteristics applied to the transmission video data V1' converted to the RGB domain, thereby performing electro-optical conversion, thereby obtaining display video data for displaying an image.

[0124] The display mapping unit 211 adjusts the display brightness of the display video data according to the maximum brightness display capability of the CE monitor 212. The CE monitor 212 displays an image based on the display video data. The CE monitor 212 is configured with, for example, an LCD (Liquid Crystal Display), an organic EL display (organic electroluminescence display), or the like.

[0125] The operation of the receiving device 200 shown in Fig. 11 will now be briefly described. The receiving unit 202 receives the transport stream TS transmitted from the transmitting device 100 via broadcast waves or network packets. This transport stream TS is supplied to a system decoder 203. The system decoder 203 extracts a video stream VS and a subtitle stream SS from this transport stream TS.

[0126] Furthermore, the system decoder 203 extracts various pieces of information inserted in the transport stream TS (container) and sends the information to the control unit 201. This extracted information also includes a component descriptor having resolution information of the video data on which the subtitle bitmap data is superimposed.

[0127] The video stream VS extracted by the system decoder 203 is supplied to the video decoder 204. The video decoder 204 performs a decoding process on the video stream VS to obtain progressive video data V1 at UHD resolution. The video decoder 204 also extracts parameter sets and SEI messages inserted in each access unit constituting the video stream VS, and sends them to the control unit 201.

[0128] The subtitle stream SS extracted by the system decoder 203 is supplied to the subtitle decoder 205. In this subtitle decoder 205, the subtitle stream SS is subjected to a decoding process according to the transmission method (method 1 to method 4), and progressive subtitle bitmap data is obtained at HD resolution.

[0129] Furthermore, the subtitle decoder 205 extracts various pieces of information inserted in the subtitle stream SS and sends them to the control unit 201. This extracted information includes identification information ("display_rendering_type"="11") that instructs the HD resolution subtitle bitmap data to be superimposed on the UHD resolution video data after coordinate conversion and resolution conversion. This extracted information also includes information such as the coordinates of the start position of the region, and the horizontal and vertical sizes of the region.

[0130] The progressive subtitle bitmap data at HD resolution obtained by the subtitle decoder 205 is supplied to a coordinate / resolution conversion unit 206. The coordinate / resolution conversion unit 206 performs coordinate conversion and resolution conversion on this subtitle bitmap data so that it is correctly superimposed on the UHD resolution video data. The processing in the coordinate / resolution conversion unit 206 is performed under the control of the control unit 201, based on an instruction from the identification information ("display_rendering_type"="11").

[0131] The progressive video data V1 at UHD resolution obtained by the video decoder 204 is supplied to a video superimposition unit 208. Furthermore, the progressive subtitle bitmap data at UHD resolution, the display position of which has been corrected by the coordinate conversion obtained by the coordinate / resolution conversion unit 206, is supplied to the video superimposition unit 208. In the video superimposition unit 208, the subtitle bitmap data is superimposed on the video data V1.

[0132] The video data V1' on which the bitmap data is superimposed is supplied to a YCbCr / RGB conversion unit 209. In this YCbCr / RGB conversion unit 209, the video data V1' is converted from the YCbCr (luminance / chrominance) domain to the RGB domain, and is supplied to an electro-optical conversion unit 210. In the electro-optical conversion unit 210, electro-optical conversion is performed by applying electro-optical conversion characteristics corresponding to the photoelectric conversion characteristics applied to the video data V1', and display video data for displaying an image is obtained.

[0133] This display video data is supplied to a display mapping unit 211. In this display mapping unit 211, the display luminance adjustment is performed on the display video data in accordance with the maximum luminance display capability of the CE monitor 212. The display video data that has undergone this display luminance adjustment is supplied to the CE monitor 212. An image is displayed on the CE monitor 212 based on this display video data.

[0134] As described above, in the transmission / reception system 10 shown in Fig. 1, progressive subtitle bitmap data is transmitted in accordance with the transmission methods of Methods 1 to 4 along with the transmission of progressive video data. Therefore, the receiving side can successfully superimpose the subtitle bitmap data on the video data.

[0135] 1, identification information is inserted into the layer of the subtitle stream to instruct the subtitle bitmap data of HD resolution to be subjected to coordinate conversion and resolution conversion before being superimposed on the video data of UHD resolution. Therefore, on the receiving side, based on this identification information, the subtitle bitmap data is subjected to coordinate conversion and resolution conversion before being superimposed on the video data, and the subtitle bitmap data can be superimposed at the correct position on the video data of UHD resolution.

[0136] <2. Modifications> In the above embodiment, an example has been shown in which identification information ("display_rendering_type"="11") is inserted into the display definition segment (DDS) (see Figure 8) to instruct the subtitle bitmap data with HD resolution to be superimposed on the video data with UHD resolution after coordinate conversion and resolution conversion.

[0137] However, it is possible to achieve the same effect as this identification information by transmitting a newly defined segment. In this case, conventional receivers will ignore the newly defined segment, which has the effect of preventing conventional receivers from malfunctioning.

[0138] FIG. 13(a) shows an example structure (Syntax) of a rendering guide segment (Rendering_guide_segment) as a newly defined segment, and FIG. 13(b) shows the main information content (Semantics) in the example structure.

[0139] The 2-bit field "pixel_rendering_conversion_ratio" indicates the conversion magnification for adjusting the window area, which is the pasting position (image display area) for displaying subtitles described in the display definition segment (DDS), to the pixel coordinates of the video resolution of the overlay target. Here, the resolution of the subtitle is indicated by the elements "display_height" and "display_width" in the DDS. In addition, the starting point of the magnification calculation is the top-left position of the pasting position (window area).

[0140] "00" indicates normal magnification (subtitles are superimposed on the video in their original position). "01" indicates double magnification (subtitle paste position is doubled in both the horizontal and vertical directions and superimposed on the video). "10" indicates quadruple magnification (subtitle paste position is quadruple enlarged in both the horizontal and vertical directions and superimposed on the video). For example, if the subtitle resolution is an HD (1920x1080) screen frame and the resolution of the video to be superimposed is an UHD (3840x2160) screen frame, then "pixel_rendering_conversion_ratio" is set to "01", which will result in double magnification.

[0141] In the above embodiment, an example is shown in which the first resolution, which is the resolution of the video data, is UHD resolution, and the second resolution, which is the resolution of the subtitle bitmap data, is HD resolution. However, the present technology is not limited to this. For example, the first resolution may be 8K resolution, and the second resolution may be 4K resolution.

[0142] In the above embodiment, an example was shown in which the resolution of the video data is UHD resolution and the resolution of the subtitle bitmap data is HD resolution. If the resolution of the subtitle bitmap data is UHD resolution, the coordinate conversion and resolution conversion processes on the receiving side are not required. In that case, "display_rendering_type" is a different value instead of "11".

[0143] In addition, in the above embodiment, an example in which the container is an MPEG-2 TS has been shown, but the container of the present technology is not limited to an MPEG-2 TS, and can be similarly applied to other packets such as ISOBMFF and MMT.

[0144] The present technology can also be configured as follows. (1) a video encoding unit that generates a video stream having progressive video data; a subtitle encoding unit for generating a subtitle stream having progressive subtitle bitmap data; a transmitting unit for transmitting a container in a predetermined format including the video stream and the subtitle stream; Transmitting device. (2) In the subtitle stream, the progressive subtitle bitmap data exists in a state where it is divided into top field subtitle bitmap data and bottom field subtitle bitmap data. The transmitting device according to (1) above. (3) The subtitle stream includes a top field data block and a bottom field data block. The subtitle bitmap data of the top field is arranged in the data block for the top field, and the subtitle bitmap data of the bottom field is arranged in the data block for the bottom field. The transmitting device according to (2) above. (4) The subtitle stream contains the progressive subtitle bitmap data in an undivided state. The transmitting device according to (1) above. (5) The subtitle stream includes a top field data block and a bottom field data block. The undivided progressive subtitle bitmap data is arranged in the top field data block or the bottom field data block. The transmitting device according to (4) above. (6) The subtitle stream includes a progressive data block. The undivided progressive subtitle bitmap data is arranged in the progressive data block. The transmitting device according to (4) above. (7) the video data has a first resolution, and the subtitle bitmap data has a second resolution lower than the first resolution; The subtitle bitmap data may be subjected to coordinate conversion and resolution conversion before being superimposed on the video data. A transmitting device according to any one of (1) to (6). (8) a video encoding unit generating a video stream having video data; A subtitle encoding unit generates a subtitle stream having progressive subtitle bitmap data; The method includes a step of transmitting a container in a predetermined format including the video stream and the subtitle stream by a transmitting unit. Transmission method. (9) a receiving unit for receiving a container in a predetermined format including a video stream having progressive video data and a subtitle stream having progressive subtitle bitmap data; a control unit for controlling a process of decoding the video stream to obtain the progressive video data, a process of decoding the subtitle stream to obtain the progressive subtitle bitmap data, and a process of superimposing the progressive subtitle bitmap data on the progressive video data to obtain video data for display. Receiving device. (10) In the subtitle stream, the progressive subtitle bitmap data exists in a state where it is divided into top field subtitle bitmap data and bottom field subtitle bitmap data, In the process of obtaining the progressive subtitle bitmap data, the top field subtitle bitmap data and the bottom field subtitle bitmap data obtained by decoding the subtitle stream are synthesized to obtain the progressive subtitle bitmap data. The receiving device according to (9) above. (11) The subtitle stream includes a top field data block and a bottom field data block. In the process of obtaining the progressive subtitle bitmap data, the undivided progressive subtitle bitmap data inserted in the top field data block or the bottom field data block is obtained. The receiving device according to (9) above. (12) The subtitle stream includes a progressive data block. In the process of obtaining the progressive subtitle bitmap data, the undivided progressive subtitle bitmap data inserted in the progressive data block is obtained. The receiving device according to (9) above. (13) a receiving unit receiving a container in a predetermined format including a video stream having progressive video data and a subtitle stream having progressive subtitle bitmap data; The control unit has a step of controlling a process of decoding the video stream to obtain the progressive video data, a process of decoding the subtitle stream to obtain the progressive subtitle bitmap data, and a process of superimposing the progressive subtitle bitmap data on the progressive video data to obtain video data for display. Receiving method. (14) a video encoding unit for generating a video stream having video data at a first resolution; a subtitle encoding unit that generates a subtitle stream having subtitle bitmap data of a second resolution lower than the first resolution; a transmitting unit for transmitting a container in a predetermined format including the video stream and the subtitle stream; and an identification information inserting unit for inserting identification information into a layer of the subtitle stream, the identification information instructing that the subtitle bitmap data be superimposed on the video data after coordinate conversion and resolution conversion are performed on the subtitle bitmap data. Transmitting device. (15) The video data storing device further includes a resolution information inserting unit that inserts information on the first resolution of the video data on which the subtitle bitmap data is to be superimposed, into a layer of the container. The transmitting device according to (14) above. (16) The first resolution is UHD resolution and the second resolution is HD resolution. The transmitting device according to (14) or (15). (17) The identification information insertion unit Insert the above identification information into the display definition segment A transmitting device according to any one of (14) to (16). (18) The identification information insertion unit A segment serving as the identification information is inserted into the subtitle stream. A transmitting device according to any one of (14) to (16). (19) The above-mentioned segment as identification information includes information on the conversion rate. The transmitting device according to (18). (20) a video encoding unit generating a video stream having video data at a first resolution; a subtitle encoding unit generating a subtitle stream having subtitle bitmap data of a second resolution lower than the first resolution; a transmitting unit transmitting a container in a predetermined format including the video stream and the subtitle stream; The method includes a step of inserting, into a layer of the subtitle stream, identification information for instructing that the subtitle bitmap data is superimposed on the video data after coordinate conversion and resolution conversion by an identification information inserting unit. Transmission method. (21) A video stream having video data of a first resolution and a container having a predetermined format including a subtitle stream having subtitle bitmap data of a second resolution lower than the first resolution, Identification information is inserted into a layer of the subtitle stream, the identification information instructing that the subtitle bitmap data is superimposed on the video data after being subjected to coordinate conversion and resolution conversion; The video data decoding device further includes a control unit for controlling a process of decoding the video stream to obtain the video data, a process of decoding the subtitle stream to obtain the subtitle bitmap data, and a process of superimposing the subtitle bitmap data on the video data after performing coordinate conversion and resolution conversion on the basis of the identification information to obtain video data for display. Receiving device. (22) A method for providing a video stream having video data of a first resolution and a container having a predetermined format including a subtitle stream having subtitle bitmap data of a second resolution lower than the first resolution, the method comprising: Identification information is inserted into a layer of the subtitle stream, the identification information instructing that the subtitle bitmap data is superimposed on the video data after being subjected to coordinate conversion and resolution conversion; The method further includes a step of controlling a control unit to control a process of decoding the video stream to obtain the video data, a process of decoding the subtitle stream to obtain the subtitle bitmap data, and a process of superimposing the subtitle bitmap data on the video data after performing coordinate conversion and resolution conversion on the basis of the identification information to obtain video data for display. Receiving method.

[0145] The main feature of this technology is that progressive subtitle bitmap data is transmitted using various transmission methods in conjunction with progressive video data, enabling the receiving side to successfully superimpose the subtitle bitmap data onto the video data (see Figs. 2 and 3).

[0146] Another main feature of this technology is that it inserts identification information into the layer of the subtitle stream, which instructs the subtitle bitmap data in HD resolution to be subjected to coordinate transformation and resolution conversion before being superimposed on the video data in UHD resolution. Based on this identification information, the receiving side performs coordinate transformation and resolution conversion on the subtitle bitmap data before superimposing it on the video data, making it possible to superimpose the subtitle bitmap data on the UHD resolution video data in the correct position (see Figure 4). [Explanation of symbols]

[0147] 10. Transmitting and receiving system 100 Transmitting device 101...Control section 102 Camera 103 Video photoelectric conversion section 104 RGB / YCbCr conversion section 105...Video Encoder 106 Subtitle generation section 107 Bitmap data generator 108...Subtitle Encoder 109 System Encoder 110 Transmitter 200...Receiver error! The hyperlink reference is incorrect. 201... Control unit 202 Receiving unit 203 System Decoder 204: Video decoder 205...Subtitle Decoder 206 Coordinate / resolution conversion unit 208 Video overlay unit 209 YCbCr / RGB conversion section 210....Electro-optical conversion section 211 Display mapping section 212···CE Monitor 213 User operation section

Claims

1. a video encoding unit for generating a video stream having video data at a first resolution; a subtitle encoding unit that generates a subtitle stream having subtitle data in a second resolution different from the first resolution; a transmitter for transmitting a container including the video stream and the subtitle stream, The layer of the container has information about the resolution of the video data inserted therein; The subtitle stream includes type information of the subtitle data and display area information for displaying the subtitle data. Transmitting device.

2. The subtitle data constitutes progressive subtitle bitmap data. The transmitting device according to claim 1 .

3. a video encoding unit generating a video stream having video data at a first resolution; a subtitle encoding unit generating a subtitle stream having subtitle data in a second resolution different from the first resolution; A transmitting unit transmits a container including the video stream and the subtitle stream, The layer of the container has information about the resolution of the video data inserted therein; The subtitle stream includes type information of the subtitle data and display area information for displaying the subtitle data. Transmission method.

4. The subtitle data constitutes progressive subtitle bitmap data. The transmission method according to claim 3.

5. a receiving unit for receiving a container including a video stream having video data in a first resolution and a subtitle stream having subtitle data in a second resolution different from the first resolution; The layer of the container has information about the resolution of the video data inserted therein; the subtitle stream includes type information of the subtitle data and display area information for displaying the subtitle data, The video data decoding device further includes a control unit for controlling a process of decoding the video stream to obtain the video data, a process of decoding the subtitle stream to obtain the subtitle data, and a process of converting the resolution of the subtitle data based on the resolution information and then superimposing the subtitle data on the video data to obtain video data for display. Receiving device.

6. The control unit controls a process of performing electro-optic conversion on the video data to obtain the display video data.

6. The receiving device according to claim 5.

7. The control unit controls a process of performing a display luminance adjustment on the display video data.

7. The receiving device according to claim 6.

8. The subtitle data constitutes progressive subtitle bitmap data.

8. A receiving device according to claim 5.

9. The method includes a step of receiving a container including a video stream having video data in a first resolution and a subtitle stream having subtitle data in a second resolution different from the first resolution, the container including: The layer of the container has information about the resolution of the video data inserted therein; the subtitle stream includes type information of the subtitle data and display area information for displaying the subtitle data, The method further includes a step in which a control unit controls a process of decoding the video stream to obtain the video data, a process of decoding the subtitle stream to obtain the subtitle data, and a process of converting the resolution of the subtitle data based on the resolution information and then superimposing the subtitle data on the video data to obtain the video data for display. Receiving method.

10. The control unit includes a step of controlling a process of performing an electro-optical conversion on the video data to obtain the display video data. The receiving method according to claim 9.

11. The control unit includes a step of controlling a process of performing a display luminance adjustment on the display video data. The receiving method according to claim 10.

12. The subtitle data constitutes progressive subtitle bitmap data. A receiving method according to any one of claims 9 to 11.

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