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

Abstract

To satisfactorily superimpose subtitle bitmap data on video data on a reception side.SOLUTION: To generate a video stream having progressive video data. A subtitle stream having progressive subtitle bitmap data is generated. A container in a predetermined format including a video stream and a subtitle stream is transmitted. For example, in the subtitle stream, the progressive subtitle bitmap data exists in a state of being divided into the top-field subtitle bitmap data and the bottom-field subtitle bitmap data, or in a non-divided state.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] Japanese Patent Application Laid-Open No. 2011-030180 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: a video encoding unit that generates a video stream having progressive video data; a subtitle encoding unit that generates 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 this 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 top field data blocks and bottom field data blocks, with the top field subtitle bitmap data arranged in the top field data blocks and the bottom field subtitle bitmap data arranged in the bottom field data blocks.

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

[0009] In this way, 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] Note that the present technology may further include, for example, an identification information inserting unit that inserts, into a layer of the subtitle stream, identification information that instructs the subtitle bitmap data to be superimposed 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 this identification information, the subtitle bitmap data is superimposed on the video data after performing coordinate conversion and resolution conversion on the subtitle bitmap data, thereby successfully superimposing the subtitle bitmap data on the video data.

[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 that controls 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; It is in the receiving device.

[0012] In this 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, and 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, the subtitle stream may contain progressive subtitle bitmap data 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 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 subtitle stream may have a progressive data block, and the process of obtaining progressive subtitle bitmap data may obtain undivided progressive subtitle bitmap data inserted in the progressive data block.

[0016] In this way, in this technology, progressive subtitle bitmap data obtained by decoding a subtitle stream is superimposed on progressive video data to obtain video data for display, thereby ensuring good superimposition of the subtitle bitmap data on the video data.

[0017] Another concept of the present technology is a video encoding unit that generates 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 transmitter for transmitting a container in a predetermined format including the video stream and the subtitle stream; an identification information inserting unit that inserts 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 being subjected to coordinate conversion and resolution conversion; Located in the transmitting device.

[0018] In this technology, a video encoding unit generates a video stream having video data at a first resolution. A subtitle encoding unit generates a subtitle stream having subtitle bitmap data at a second resolution lower than the first resolution. Then, a transmitting 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 a layer of the subtitle stream, instructing the subtitle bitmap data to be superimposed on the video data after coordinate conversion and resolution conversion. 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 to be superimposed into a 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 serving as identification information into the subtitle stream. In this case, for example, the segment serving as identification information may include information on the conversion ratio.

[0020] In this way, in this technology, identification information is inserted into a layer of a subtitle stream, instructing that the subtitle bitmap data be superimposed on the video data after being subjected to coordinate conversion and resolution conversion. Therefore, on the receiving side, the subtitle bitmap data is superimposed on the video data after being subjected to coordinate conversion and resolution conversion based on 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 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 the layer of the subtitle stream, the identification information instructing that the subtitle bitmap data be superimposed on the video data after being subjected to coordinate conversion and resolution conversion; The video data decoding device further includes a control unit that controls 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 subtitle bitmap data based on the identification information to obtain video data for display. On the receiving device

[0022] In this technology, a receiving unit receives a container in a predetermined format including a video stream having video data at a first resolution and a subtitle stream having subtitle bitmap data at a second resolution lower than the first resolution. Identification information is inserted into a layer of the subtitle stream, indicating that the subtitle bitmap data should 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, thereby ensuring good superimposition of the subtitle bitmap data on the video data. [Effects of the Invention]

[0025] According to the present technology, it is possible to successfully superimpose subtitle bitmap data onto video data on the receiving side. Note that the effects described in this specification are merely examples and are not intended to be limiting, and additional effects may also be provided. [Brief explanation 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; [Figure 2] FIG. 10 is a diagram illustrating methods 1 and 2 for transmitting progressive subtitle bitmap data. [Figure 3] FIG. 10 is a diagram illustrating methods 3 and 4 for transmitting progressive subtitle bitmap data. [Figure 4] FIG. 10 is a diagram illustrating coordinate conversion and resolution conversion applied to HD resolution subtitle bitmap data superimposed on UHD resolution video data. [Figure 5] FIG. 2 is a block diagram illustrating an example of the configuration of a transmitting device. [Figure 6] FIG. 10 is a diagram showing an example of the structure of an object data segment. [Figure 7] This figure shows an example of the structure of an object data segment and the contents of the main information in that example structure. [Figure 8] FIG. 10 is a diagram showing an example of the structure of a display definition segment and the contents of the main information in that example structure. [Figure 9] This figure shows the correspondence between each value of "component_type," an important element of the component descriptor, and the subtitle bitmap data identified by it. [Figure 10] FIG. 1 is a diagram illustrating an example of the configuration of a transport stream TS. [Figure 11] FIG. 2 is a block diagram illustrating an example of the configuration of a receiving device. [Figure 12] 10 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 structure. DETAILED DESCRIPTION OF THE INVENTION

[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. 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 via broadcast waves or network packets. This transport stream TS includes a video stream with 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 with 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 Description" Method 1 will now be described. In this method 1, progressive subtitle bitmap data exists in the subtitle stream, divided into top field subtitle bitmap data and bottom field subtitle bitmap data.

[0032] Figure 2(a) shows an overview of transmission using Method 1. In this case, the ODS (Object_data_segment), which is the coded subtitle transmission format in the subtitle stream, contains a top field data block and a bottom field data block. The top field subtitle bitmap data is placed in the top field data block, and the bottom field subtitle bitmap data is placed 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 then 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 single, undivided state.

[0036] Figure 2(b) shows an overview of transmission using Method 2. In this case, the ODS (Object_data_segment), which is the coded subtitle transmission format in the subtitle stream, contains a top field data block and a bottom field data block. 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] On the receiving side, 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 then superimposed on the progressive video data to obtain the video data for display.

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

[0040] Figure 3(c) shows an overview of transmission using Method 3. In this case, the ODS (Object_data_segment), which is the coded subtitle transmission format in the subtitle stream, contains a top field data block and a bottom field data block. Undivided progressive subtitle bitmap data is placed in the bottom field data block. In this case, no subtitle bitmap data is 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] On the receiving side, 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 then superimposed on the progressive video data to obtain the video data for display.

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

[0044] Figure 3(d) shows an overview of transmission using Method 4. In this case, a progressive data block exists in the ODS (Object_data_segment), which is the coded subtitle transmission format in the subtitle stream. 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 is composed only of the subtitle bitmap data placed in the progressive data block.

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

[0047] Returning to Figure 1, identification information is inserted into the subtitle stream layer to instruct the HD resolution subtitle bitmap data to be superimposed on the UHD resolution video data after undergoing 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 subtitles (captions) 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 varies depending on the transmission method of the progressive subtitle bitmap data.

[0049] In the case of method 1, since subtitle bitmap data is placed in both the top field data block and the bottom field data block, the receiving device 200 recognizes that 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, and top field subtitle bitmap data is extracted from the top field data block, and bottom field subtitle bitmap data is extracted from the bottom field data block.The top field subtitle bitmap data and 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 blocks, the receiving device 200 recognizes that progressive subtitle bitmap data can be constructed only from the subtitle bitmap data arranged in the top field data blocks. In this case, the subtitle stream is decoded and the subtitle bitmap data is extracted from the top field data blocks, 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, receiving device 200 recognizes that progressive subtitle bitmap data can be constructed only from the subtitle bitmap data arranged in the bottom and top field data blocks. 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 constructed using only the subtitle bitmap data arranged in the progressive data block. In this case, the subtitle stream is decoded and the subtitle bitmap data is extracted from the progressive data block, thereby obtaining the progressive subtitle bitmap data.

[0054] The subtitle stream layer contains identification information that instructs the receiver 200 to perform coordinate conversion and resolution conversion on the HD resolution subtitle bitmap data before superimposing it on the UHD resolution video data, as described above. The receiver 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 resulting progressive subtitle bitmap data on the progressive video data to obtain video data for display.

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

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

[0058] In this case, the value of "N" is used to perform horizontal and vertical scaling 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 transmitting device 100. This transmitting 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 transmitting unit 110.

[0060] The control unit 101 is configured with 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 encodes the video data V1 converted to the YCbCr domain using, for example, MPEG4-AVC or HEVC, 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 using the object data segment (Object_data_segment) by one of the above 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) of 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 indicator.

[0065] When "object_coding_method" is "00", there is a 16-bit field "top_field_data_block_length". Then, there are the same number of "pixel-data_sub-block()" blocks, i.e., the top field data blocks, repeated as 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, the number of "pixel-data_sub-block()" blocks, i.e., bottom field data blocks, is repeated as 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 it is not byte-aligned to 8 bits.

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

[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, and 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 transmitted using the second method, the progressive subtitle bitmap data is left undivided, and the entire undivided 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 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 "progressive_frame_data_block_length". And there are the same number of "pixel-data_sub-block()" blocks, i.e., progressive data blocks, repeated as indicated by "progressive_frame_data_block_length". The 8-bit field "8_stuff_bits" is a field for adding stuffing bits to make it 8 bits when 8-bit byte alignment is not achieved.

[0073] When progressive subtitle bitmap data is transmitted using the fourth method, "object_coding_method" is set to "11" and the data is placed in the 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 that instructs HD resolution subtitle bitmap data to 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) of that structure example. 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 (caption) is converted to match the video coordinates of the overlay display target. In other words, "11" of "display_rendering_type" is identification information that instructs that the HD resolution subtitle bitmap data be subjected to coordinate conversion and resolution conversion before being superimposed on the UHD resolution video data.

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

[0078] When "display_window_flag"="1", there are fields that indicate the window area: a 16-bit field for "display_window_horizontal_position_minimum", a 16-bit field for "display_window_horizontal_position_maximum", a 16-bit field for "display_window_vertical_position_minimum", and a 16-bit field for "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] 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 network packets.

[0081] At this time, the system encoder 109 inserts resolution information of the video data onto which the subtitle bitmap data is to be superimposed into the layer of the transport stream TS serving 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 correspondence between each value of "component_type" and the subtitle bitmap data it identifies. Note that when "stream_content" is "0x03," it indicates 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" for a video stream identified by PID1. In addition, there is a PES packet "Subtitle PES2" for a subtitle stream identified by PID2.

[0085] The PES packets of the video stream contain the video encoding 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," which is identification information that indicates that the HD resolution subtitle bitmap data should be superimposed on the UHD resolution video data after undergoing 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] The video elementary stream loop (video ES1 loop) contains information such as the stream type and PID (packet identifier) ​​for each video stream, as well as a descriptor describing information related to that video stream. The value of "Stream_type" for this video stream is set to "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] The subtitle elementary stream loop (Subtitle ES2 loop) contains information such as the stream type and PID (packet identifier) ​​for each subtitle stream, as well as a descriptor describing information related to that subtitle stream. The value of "Stream_type" for this subtitle stream is set to a value indicating a private stream, for example, and the PID information indicates the 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. This EIT describes metadata for each program. A component descriptor (Component_descriptor) having a "component_type" element (see FIG. 9) as resolution information for the video data is inserted under this EIT. In this embodiment, "component_type" is set to "0x16" or "0x26," which indicates 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 the 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) at UHD resolution captured by the camera 102 is supplied to the video photoelectric conversion unit 103. The video photoelectric conversion unit 103 performs photoelectric conversion 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 and 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 the 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 which these segments are arranged in the payload.

[0098] The progressive subtitle bitmap data is transmitted using one of methods 1 to 4 in the object data segment (ODS) (see Figures 6 and 7). In addition, the display definition segment (DDS) (see Figure 8) contains identification information ("display_rendering_type" = "11") that instructs the HD resolution subtitle bitmap data to be superimposed on the UHD resolution video data after undergoing 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 a broadcast wave or a network packet 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 superimposing 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 that has resolution information for 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 the 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 at UHD resolution. As described above, UHD resolution exceeds HD resolution and includes 4K resolution or 8K resolution.

[0107] The video decoder 204 also extracts various pieces of information, such as parameter sets and SEI messages, inserted in each access unit that makes up the video stream VS, and sends the extracted information to the control unit 201 .

[0108] The subtitle decoder 205 decodes 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, top field subtitle bitmap data is extracted from the top field data block, and bottom field subtitle bitmap data is extracted from the bottom field data block. The top field subtitle bitmap data and 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 HD resolution subtitle bitmap data to be superimposed on UHD resolution video data after coordinate conversion and resolution conversion. This extracted information also includes information such as the coordinates of the region start position 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 HD resolution subtitle bitmap data to be subjected to coordinate conversion and resolution conversion before being superimposed on the UHD resolution video data).

[0113] In this case, as shown in Figure 4(b), the coordinates of the region start point "p1" are converted as p1(x, y) = p0(x, y) * N, and the coordinates of the region end point "q1" 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 value of "N" is used to perform horizontal and vertical scaling 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. Information about the resolution of the video data can be detected from the video stream parameter set (SPS). Alternatively, information about 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, i.e., the subtitle display area. The subtitle display area (display_width, display_height) can be detected from the display definition segment (DDS). In this embodiment, HD resolution is detected.

[0118] Next, in step ST4, the coordinate / resolution conversion unit 206 determines whether the resolution of the video data is UHD resolution. If it is determined 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] If it is determined that "display_rendering_type" is "11", the coordinate / resolution conversion unit 206 sets the position coordinate value of the region in the video picture frame to a coordinate value obtained by multiplying the HD coordinate value from the HD display area origin R by N in step ST8 (see FIG. 4(b)). In addition, in conjunction with the conversion of the position coordinate value of this 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, the value representing 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 onto the progressive video data V1 at UHD resolution obtained by the video decoder 204.

[0123] The YCbCr / RGB converter 209 converts the progressive video data V1' at UHD resolution, on which the subtitle bitmap data is superimposed, from the YCbCr (luminance / chrominance) domain to the RGB domain. The electro-optical converter 210 applies electro-optical conversion characteristics corresponding to the applied photoelectric conversion characteristics 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 the system decoder 203. The system decoder 203 extracts the video stream VS and the subtitle stream SS from this transport stream TS.

[0126] The system decoder 203 also extracts various pieces of information inserted in the transport stream TS (container) and sends them to the control unit 201. This extracted information also includes a component descriptor that has resolution information for 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 at HD resolution is obtained.

[0129] The subtitle decoder 205 also extracts various pieces of information inserted in the subtitle stream SS and sends the extracted information 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 region start position 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 the 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 can be correctly superimposed on the UHD resolution video data. The processing in this coordinate / resolution conversion unit 206 is performed under the control of the control unit 201, based on instructions 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, whose display position has been corrected by the coordinate conversion obtained by the coordinate / resolution conversion unit 206, is supplied to the video superimposition unit 208. The video superimposition unit 208 superimposes the subtitle bitmap data on the video data V1.

[0132] The video data V1' on which the bitmap data has been 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 on the video data V1' by applying electro-optical conversion characteristics corresponding to the photoelectric conversion characteristics applied thereto, 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 brightness of the display video data is adjusted in accordance with the maximum brightness display capability of the CE monitor 212. The display video data that has undergone this display brightness 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 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 at HD resolution to be subjected to coordinate conversion and resolution conversion before being superimposed on the video data at UHD resolution. Therefore, on the receiving side, the subtitle bitmap data is subjected to coordinate conversion and resolution conversion based on this identification information before being superimposed on the video data, and the subtitle bitmap data can be superimposed at the correct position on the video data at UHD resolution.

[0136] <2. Modifications> In the above embodiment, an example was shown in which identification information ("display_rendering_type"="11") is inserted into the display definition segment (DDS) (see Figure 8) to instruct HD resolution subtitle bitmap data to be superimposed on UHD resolution video data 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] Figure 13(a) shows an example of the structure (Syntax) of a rendering guide segment (Rendering_guide_segment) as a newly defined segment, and Figure 13(b) shows the main information content (Semantics) of that structure example.

[0139] The 2-bit field "pixel_rendering_conversion_ratio" indicates the conversion magnification factor for adjusting the window area, which is the 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 subtitle resolution is indicated by the "display_height" and "display_width" elements in the DDS. The starting point for magnification calculation is the top-left position of the window area.

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

[0141] In addition, in the above-described embodiment, an example is shown in which the first resolution, which is the resolution of video data, is UHD resolution, and the second resolution, which is the resolution of subtitle bitmap data, is HD resolution. However, the present technology is not limited to this. For example, it is also possible that the first resolution is 8K resolution and the second resolution is 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, coordinate conversion and resolution conversion processing are not required on the receiving side. In that case, "display_rendering_type" will be a different value instead of "11."

[0143] In addition, in the above-described embodiment, an example was shown in which the container was an MPEG-2 TS. However, 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 that generates 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 top field data block, and the subtitle bitmap data of the bottom field is arranged in the bottom field data block. 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 contains 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 stream layer further includes an identification information inserting unit that inserts identification information, which instructs the subtitle bitmap data to be superimposed on the video data after coordinate conversion and resolution conversion are performed on the subtitle bitmap data, into the subtitle stream layer. The 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 generating a subtitle stream having progressive subtitle bitmap data; a transmitting unit transmitting a container in a predetermined format including the video stream and the subtitle stream; Sending 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 that controls 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 combined 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 includes steps 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 that generates 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 transmitter for transmitting a container in a predetermined format including the video stream and the subtitle stream; an identification information inserting unit that inserts 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 being subjected to coordinate conversion and resolution conversion; Transmitting device. (15) The video encoding device further includes a resolution information inserting unit that inserts information about the first resolution of the video data onto which the subtitle bitmap data is 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) above. (17) The identification information insertion unit Insert the above identification information into the display definition segment The 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. The transmitting device according to any one of (14) to (16). (19) The segment as the above-mentioned identification information includes information on the conversion rate. The transmitting device according to (18) above. (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; an identification information inserting unit 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 being subjected to coordinate conversion and resolution conversion; Sending 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, comprising: a receiving unit for receiving 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 the layer of the subtitle stream, the identification information instructing that the subtitle bitmap data be superimposed on the video data after being subjected to coordinate conversion and resolution conversion; The video data decoding device further includes a control unit that controls 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 subtitle bitmap data based on the identification information to obtain video data for display. Receiving device. (22) A method for transmitting 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, the method comprising: receiving, by a receiving unit, a container of a predetermined format including the 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 the layer of the subtitle stream, the identification information instructing that the subtitle bitmap data be superimposed on the video data after being subjected to coordinate conversion and resolution conversion; The method further includes a control step of 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 subtitle bitmap data based on 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 along with progressive video data, enabling the receiving side to successfully superimpose the subtitle bitmap data onto the video data (see Figures 2 and 3).

[0146] Another key feature of this technology is that it inserts identification information into the subtitle stream layer, 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, thereby enabling the subtitle bitmap data to be superimposed 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 unit 102···Camera 103 Video photoelectric conversion unit 104 RGB / YCbCr conversion section 105...Video Encoder 106 Subtitle generator 107 Bitmap data generator 108···Subtitle Encoder 109 System Encoder 110 Transmitter 200 Receiving device 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 Electrical-optical conversion unit 211 Display mapping section 212···CE Monitor 213 User operation unit

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 of 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 display position information 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 at a second resolution different from the first resolution; a transmitting unit 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 display position information and display area information for displaying the subtitle data. Sending 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 display position information and display area information for displaying the subtitle data; The video data decoding device further includes a control unit that 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 video data for display. Receiving device.

6. The control unit controls a process of performing electro-optical 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 adjusting the display brightness of the display video data.

7. The receiving device according to claim 6.

8. The subtitle data constitutes progressive subtitle bitmap data.

8. The receiving device according to claim 5, wherein the receiving device is a receiving unit.

9. a receiving unit 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 display position information 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 controls a process of performing electro-optical conversion on the video data to obtain the video data for display. The receiving method according to claim 9.

11. The control unit controls a process of adjusting the display brightness of 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.

Images