Playback device, playback method, and program

Abstract

To make it possible to prevent an unnatural change in luminance during random access.SOLUTION: An information processing apparatus according to one aspect of the present technology is configured to generate dynamic metadata including information regarding luminance of a picture, and encode HDR video data such that the dynamic metadata is added to each picture serving as a random access point. For example, the dynamic metadata can be allowed to be added to a first picture of a GOP, the first picture serving as the random access point during fast-forward playback / rewind playback or cueing playback. The present technology can be applied to Blu-ray (R) Disc players.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] This technology is Playback device, playback method, and program Regarding this, it has been made possible to prevent unnatural brightness changes, especially during random access. Playback device, playback method, and program Regarding. [Background technology]

[0002] Ultra HD Blu-ray (registered trademark) Disc (UHD BD) is a BD standard that supports recording of HDR (High Dynamic Range) video, which is video with an expanded dynamic range. SDR (Standard Dynamic Range) video has a maximum brightness of 100 nits (100 cd / m 2 ), whereas the maximum brightness of HDR video exceeds that, for example, 10,000 nits.

[0003] Dynamic metadata, which is metadata containing luminance information for each picture (frame), is specified as metadata for HDR video streams in SMPTE ST 2094. When an HDR video stream with dynamic metadata added is played back, the dynamic metadata is transmitted from the player to the TV along with each picture.

[0004] On the TV side, if the maximum brightness of the display is lower than the brightness of the HDR video, processing is performed to compress the brightness of the HDR video based on the dynamic metadata transmitted from the BD player. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-139052 Summary of the Invention [Problem to be solved by the invention]

[0006] Random access may occur during HDR video playback. Random access refers to playback that jumps between sections, such as trick play, which involves fast-forwarding or rewinding at double speed, or chapter jumping. Random access occurs when a user commands trick play or chapter jumping.

[0007] Depending on the state of the picture to which a random access jumps, such as if dynamic metadata is not added, the brightness change may appear unnatural.

[0008] The present technology has been made in view of such circumstances, and is intended to prevent unnatural changes in brightness during random access. [Means for solving the problem]

[0009] An information processing device according to a first aspect of the present technology includes a generation unit that generates dynamic metadata including luminance information of a picture, and an encoding unit that encodes HDR video data by adding the dynamic metadata to each picture that serves as a random access point.

[0010] A playback device according to a second aspect of the present technology includes a playback unit that performs random access playback of a video stream to which dynamic metadata including picture brightness information has been added, and an output control unit that, when displaying predetermined information indicating that random access playback is being performed superimposed on the picture, adds metadata for random access playback to be used for adjusting brightness during random access playback to the picture at a random access point, and outputs the picture with the metadata for random access playback added to a display device.

[0011] In a first aspect of the present technology, dynamic metadata including luminance information of a picture is generated, and HDR video data is encoded by adding the dynamic metadata to each picture that serves as a random access point.

[0012] In a second aspect of the present technology, when random access playback of a video stream to which dynamic metadata including picture brightness information is added is performed, and predetermined information indicating that random access playback is being performed is displayed superimposed on the picture, metadata for random access playback used for adjusting brightness during random access playback is added to the picture at the random access point, and the picture with the metadata for random access playback added is output to a display device. [Effects of the Invention]

[0013] According to the present technology, it is possible to prevent unnatural changes in luminance during random access.

[0014] The effects described here are not necessarily limited to those described herein, and may be any of the effects described in this disclosure. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a playback system for HDR content. [Figure 2] FIG. 1 is a diagram illustrating an example of a tone curve used for luminance compression of HDR video. [Figure 3] FIG. 1 is a diagram showing dynamic metadata defined in SMPTE ST 2094-40. [Figure 4] FIG. 1 is a diagram showing the file structure of a BD. [Figure 5] FIG. 1 is a diagram illustrating an example of the structure of an AV stream. [Figure 6] FIG. 10 is a diagram illustrating an example of transmission of dynamic metadata. [Figure 7]FIG. 10 is a diagram showing an example of random access playback. [Figure 8] FIG. 10 is a diagram showing a display example during random access playback. [Figure 9] FIG. 1 is a diagram illustrating an example of a GOP that constitutes an HDR video stream. [Figure 10] FIG. 10 is a diagram showing an example of a management structure of an AV stream in the BD-ROM format. [Figure 11] FIG. 1 is a diagram showing the structure of a main path and a sub path. [Figure 12] FIG. 2 is a diagram illustrating an example of a file management structure. [Figure 13] FIG. 1 is a block diagram illustrating an example of the configuration of a recording device. [Figure 14] FIG. 14 is a block diagram showing an example of the functional configuration of a controller in FIG. 13. [Figure 15] FIG. 1 is a block diagram illustrating an example of the configuration of a playback device. [Figure 16] FIG. 1 is a block diagram showing an example of the configuration of a TV. [Figure 17] 10 is a flowchart illustrating a recording process of the recording device. [Figure 18] 10 is a flowchart illustrating a playback process of the playback device. [Figure 19] FIG. 1 is a diagram illustrating an example of an HDR video stream. [Figure 20] FIG. 10 is a diagram illustrating the syntax of Clip Information. [Figure 21] FIG. 10 is a diagram illustrating the syntax of CPI(). [Figure 22] FIG. 10 is a diagram illustrating the syntax of EP_map(). [Figure 23] A diagram showing the syntax of EP_map_for_one_stream_PID. [Figure 24] 10 is a flowchart illustrating a recording process of the recording device. [Figure 25] FIG. 10 is a diagram showing an example of metadata transmission during random access playback. [Figure 26] FIG. 10 is a diagram showing a display after luminance compression. [Figure 27] It is a block diagram showing a functional configuration example of the controller in FIG. 15. [Figure 28] It is a flowchart for explaining other playback processes of the playback device. [Figure 29] It is a flowchart for explaining the display process of the TV. [Figure 30] It is a diagram showing an example of random access playback. [Figure 31] It is a flowchart for explaining still another playback process of the playback device. [Figure 32] It is a diagram showing a configuration example of a playback system for HDR content. [Figure 33] It is a diagram showing another configuration example of the playback device. [Figure 34] It is a diagram showing a configuration example of another playback system for HDR content. [Figure 35] It is a block diagram showing a configuration example of a computer.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments for carrying out the present technology will be described. The description will be made in the following order. 1. Metadata for HDR video 2. Luminance change during random access playback 3. First Embodiment (Example of Encoding Restrictions) 4. Second Embodiment (Example of Using Default Metadata) 5. Configuration Example of Playback System 6. Other Examples

[0017] <<Metadata for HDR Video>> FIG. 1 is a diagram showing a configuration example of a playback system for HDR content.

[0018] 1 is configured by connecting a playback device 1 and a TV (television receiver) 2 with a cable conforming to a predetermined standard such as HDMI (registered trademark) (High-Definition Multimedia Interface) 2.0a or HDMI 2.1. The playback device 1 and TV 2 may also be connected via a wireless interface.

[0019] The playback device 1 is a device capable of playing HDR content, such as a UHD BD player. A BD on which HDR content is recorded is loaded into the drive of the playback device 1. The content played back by the playback device 1 includes audio data in addition to HDR video data.

[0020] TV2 has the function of receiving and displaying programs transmitted via broadcast waves or networks, as well as the function of displaying video input from an external source. The display device of TV2 is a display that supports HDR video with a brightness of over 100 nits.

[0021] Before starting transmission of HDR video, playback device 1 and TV 2 perform HDMI transmission configuration by sending and receiving information about their respective capabilities. For example, playback device 1 notifies TV 2 that it will transmit HDR video. TV 2 also notifies playback device 1 of the maximum brightness of TV 2's display.

[0022] After the transmission setup, the playback device 1 decodes the HDR video stream read from the BD and outputs each picture of the HDR video to the TV 2. The TV 2 receives each picture transmitted from the playback device 1 and displays it.

[0023] At this time, the TV 2 performs a process to adjust (compress) the brightness of the HDR video transmitted from the playback device 1 as appropriate, depending on the performance of the display. Brightness compression is performed when the brightness of the HDR video output by the playback device 1 is higher than the maximum brightness of the TV 2 display.

[0024] In the example of FIG. 1, the brightness of the HDR video output by the playback device 1 is 1000 nits, and the maximum brightness of the display of the TV 2 is 500 nits.

[0025] FIG. 2 is a diagram showing an example of a tone curve used for luminance compression of HDR video.

[0026] The horizontal axis in Figure 2 represents the brightness of the input signal, and the vertical axis represents the brightness of the output (display). For example, EOTF (Electro-Optical Transfer Function) processing using the PQ (Perceptual Quantization) curve specified in SMPTE ST 2084 is performed on the TV2 side, compressing the brightness of the HDR video so that it falls within the range of 500 nits, the maximum brightness of the display.

[0027] The point at which the expression of light and dark is no longer linear, indicated by the arrow in Figure 2, is called the knee point.

[0028] As described above, in the playback system of FIG. 1, if the display of the TV 2 does not have sufficient brightness for the brightness of the HDR video output by the playback device 1, brightness compression is performed on the TV 2 side.

[0029] Metadata including luminance information of the content is transmitted as auxiliary information for luminance compression from the playback device 1 to the TV 2. For example, dynamic metadata is transmitted from the playback device 1 to the TV 2.

[0030] Dynamic metadata is metadata that dynamically expresses content brightness information on a picture-by-picture basis, and is standardized as SMPTE ST 2094.

[0031] FIG. 3 is a diagram showing dynamic metadata defined in SMPTE ST 2094-40.

[0032] As shown in the first line of Figure 3, dynamic metadata describes information about windows set in a frame. A window is a rectangular area set within a frame. A maximum of three windows can be set within one frame.

[0033] The parameters shown on lines 2 to 14 are written for each window set in the frame.

[0034] Window size and window location indicate the size and location of the window.

[0035] The Internal Ellipse size and Internal Ellipse location indicate the size and position of the inner ellipse of the two ellipses set within the window. You can set an ellipse within the window and specify the brightness within the ellipse.

[0036] External Ellipse size and External Ellipse location indicate the size and location of the outer ellipse of the two ellipses set within the window.

[0037] The rotation angle indicates the tilt of the two ellipses set within the window.

[0038] The Overlap process option indicates how the pixels inside the ellipse are processed.

[0039] maxscl indicates the RGB value of the brightest pixel in the window.

[0040] average max rgb indicates the average of the largest values of R, G, and B for each pixel in the window.

[0041] Distribution max rgb percentages indicates the ranking of bright luminance in the window as a percentage.

[0042] Distribution max rgb percentiles indicates the ranking of brightest brightness in the window by rank (percentile).

[0043] Fraction bright pixels indicates the degree to which the maximum brightness value in the scene is displayed.

[0044] The knee point indicates the brightness value of the knee point described above.

[0045] Bezier curve anchors indicate brightness samples x,y beyond the knee point.

[0046] Color saturation weight indicates a value used to correct RGB values that change when luminance compression is performed on the target display.

[0047] Target System display max luminance indicates the luminance of the intended display. Target System display max luminance specifies that the content was created with the assumption that it will be displayed on this type of display.

[0048] Local display luminance indicates the maximum luminance value of each area when the display is divided into areas ranging from 2x2 to 25x25 vertically and horizontally.

[0049] Local mastering display luminance indicates the maximum luminance value of each area when the mastering display is divided into areas ranging from 2x2 to 25x25 in size.

[0050] In this way, in Dynamic metadata, the attributes of the frame (window within the frame) are indicated by the parameters on lines 1 to 15. Furthermore, the parameters on lines 16 and 17 indicate the attributes of the expected display, and the parameter on line 18 indicates the attributes of the display used to create the content.

[0051] FIG. 4 shows the file structure of a BD.

[0052] The optical disc 11 in FIG. 4 is a recording medium on which HDR video content is recorded in the BD format.

[0053] Details will be given later, but the STREAM directory set under the BDMV directory stores AV stream files with the m2ts extension.

[0054] An AV stream file is an MPEG-2 TS file obtained by multiplexing an HDR video stream, an audio stream, a subtitle stream, etc. using MPEG-2. In the example of Figure 4, the AV stream files "01000.m2ts", "02000.m2ts", and "03000.m2ts" are stored in the STREAM directory.

[0055] The HDR video stream is, for example, a High Efficiency Video Coding (HEVC) encoded stream. Dynamic metadata is included in the HDR video stream as an HEVC Supplemental Enhancement Information (SEI) message.

[0056] FIG. 5 is a diagram showing an example of the structure of the AV stream "03000.m2ts" enclosed in a frame F1 in FIG.

[0057] As shown in the top row of Fig. 5, the AV stream of "03000.m2ts" is made up of TS packets that store data for video, audio, subtitles, etc. Video TS packets are collected to make up the Video Elementary stream.

[0058] The Video Elementary stream is made up of a sequence of Access Units, with one Access Unit representing one picture of HDR video. Each Access Unit contains an AU delimiter followed by parameters such as SPS and PPS, as well as an SEI message, as shown in the box F11.

[0059] The SEI message includes the dynamic metadata described above. Note that the SEI message is followed by HDR video data as picture data.

[0060] In this way, in BD, dynamic metadata is included in the HDR video stream by being added to each picture, and is multiplexed together with the audio stream and the like.

[0061] It should be noted that pictures that make up an HDR video stream may include pictures to which no dynamic metadata has been added.

[0062] FIG. 6 is a diagram showing an example of transmission of dynamic metadata.

[0063] As shown in Fig. 6, the dynamic metadata is associated with each picture obtained by decoding the HDR video stream and transmitted from the playback device 1 to the TV 2. The TV 2 performs luminance compression on each picture based on the dynamic metadata transmitted together with the picture.

[0064] <<Brightness change during random access playback>> The playback device 1 has a function of performing random access playback, which is a playback method involving random access.

[0065] Random access means that, in the sequence of pictures constituting an HDR video stream, a picture to be played back jumps from a certain picture to another picture other than an adjacent picture.

[0066] Random access playback includes trick playback and cue playback. Trick playback refers to fast-forward playback or rewind playback at a specified speed, such as 5x or 8x. Cue playback refers to a playback method in which the program jumps to a picture with a chapter set or a picture a specified time later, and playback begins from that picture.

[0067] FIG. 7 shows an example of random access playback.

[0068] For example, a case will be described in which a cue playback command is issued when the picture to be played back becomes picture P1, and a jump is made from picture P1 to picture P2 as indicated by arrow A1 in FIG.

[0069] Before a cue playback command is issued, each picture before (to the left of) picture P1, along with the dynamic metadata added to each picture, is output to TV 2. Picture P1 is also output to TV 2 along with the dynamic metadata added to picture P1.

[0070] Furthermore, when cue playback is instructed, picture P2 is output together with metadata to be used for luminance compression of picture P2 on the TV 2 side. Here, as indicated by the bidirectional arrow, when picture P2 is a picture in a section to which no dynamic metadata is added, various types of metadata can be considered as the metadata to be output together with picture P2.

[0071] For example, it is conceivable that the dynamic metadata of the picture P1, which is the jump source picture, is output together with the picture P2 from the playback device 1 to the TV 2. In this case, the TV 2 performs luminance compression on the picture P2 based on the dynamic metadata of the picture P1.

[0072] It is also possible to output dynamic metadata of picture P3, which is the picture immediately before picture P2 and to which dynamic metadata is added, together with picture P2 from the playback device 1 to TV 2. In this case, TV 2 performs luminance compression of picture P2 based on the dynamic metadata of picture P3.

[0073] In either case, there is a possibility that brightness compression unintended by the HDR content producer will be applied to picture P2, the jump destination, which will result in picture P2 appearing differently from what the HDR content producer intended.

[0074] FIG. 8 shows an example of a display during random access playback.

[0075] The horizontal axis in Fig. 8 represents time. Pictures P11, P12, and P13 are transmitted in this order from playback device 1 to TV 2, where they are subjected to luminance compression.

[0076] In response to a user instruction to perform fast-forward playback at, for example, eight times the normal speed, OSD images p11, p12, and p13 are synthesized with the pictures P11, P12, and P13, respectively, in the playback device 1. In the example of Fig. 8, an image combining two triangular images representing fast-forward playback and a horizontally elongated band-shaped image containing the characters "eight times the normal speed" is displayed as the OSD image.

[0077] The same OSD image is displayed when rewind playback is instructed. Also, when start-to-start playback is instructed, an OSD image including the chapter number to jump to is displayed.

[0078] For example, it is assumed that the picture P12 is a picture that constitutes a scene with higher luminance than the pictures P11 and P13.

[0079] The luminance compression of picture P11 combined with OSD image p11 is performed based on tone curve C1 represented by dynamic metadata transmitted together with picture P11. The luminance compression of picture P12 combined with OSD image p12 is performed based on tone curve C2 represented by dynamic metadata transmitted together with picture P12. The luminance compression of picture P13 combined with OSD image p13 is performed based on tone curve C3 represented by dynamic metadata transmitted together with picture P13.

[0080] The tone curve C2 used to compress the luminance of picture P12, which constitutes a high-luminance scene, compresses luminance more strongly than the tone curve C1 used to compress the luminance of picture P11 and the tone curve C3 used to compress the luminance of picture P13. The luminance of OSD image p12 is also compressed more strongly than the luminance of the OSD images on pictures P11 and P13.

[0081] Therefore, when comparing the appearance of the OSD images of each picture after luminance compression, the OSD image p12 on the picture P12 is displayed with lower luminance than the OSD images on the pictures P11 and P13, as shown in Fig. 8. In Fig. 8, the OSD image p12 is shown in a lighter color, which indicates that it has lower luminance than the OSD images on the pictures P11 and P13.

[0082] When pictures P11 to P13 are displayed in order, the brightness of the OSD image is lowered by one step when picture P12 is displayed, and depending on the degree of brightness compression, the image may appear unnatural. For example, if there are successive scenes with large changes in brightness, the OSD image may appear to be flickering.

[0083] Thus, when performing random access playback of an HDR video stream including dynamic metadata, the appearance of the HDR video when the dynamic metadata is not added to the picture at the jump destination may become unnatural. In addition, the appearance of the OSD image displayed over the HDR video may become unnatural.

[0084] <<First Embodiment (Example of Encoding Restrictions)>> <Example of Always Adding Dynamic Metadata to the Picture at the Head of the GOP> FIG. 9 is a diagram showing an example of a GOP constituting an HDR video stream.

[0085] The HDR video stream recorded on the optical disk 11 is, for example, an encoded stream of HEVC (High Efficiency Video Coding) and is composed of pictures in GOP units. In the example of FIG. 9, GOP1 and GOP2 are shown.

[0086] Among the pictures constituting the HDR video stream, at least the picture P1 which is the picture at the head of GOP1 and the picture P2 which is the picture at the head of GOP2 have dynamic metadata added thereto. The pictures P1 and P2 which are the pictures at the head of the GOP in the display order are the pictures serving as random access points.

[0087] That is, the HDR video stream recorded on the optical disk 11 is a stream generated in accordance with the restriction that dynamic metadata is always added to the pictures at the random access points.

[0088] Fast forward playback and rewind playback are performed, for example, by sequentially playing only the pictures at the head of each GOP. The playback device 1 outputs the pictures at the head of each GOP serving as random access points to the TV2 together with the dynamic metadata added to the pictures at the head of each GOP.

[0089] Furthermore, the cue playback is performed by playing back from the first picture of a specific GOP. The playback device 1 outputs the first picture of a specific GOP, which serves as a random access point, to the TV 2 together with the dynamic metadata added to that picture.

[0090] On TV2, the luminance compression of the first picture of the GOP, which serves as a random access point, is performed based on the dynamic metadata transmitted along with the first picture of the GOP. By displaying the luminance-compressed picture, fast-forward playback, rewind playback, or cue playback is realized.

[0091] In this way, by ensuring that dynamic metadata is added to pictures at random access points, it is possible to prevent luminance compression of the jump destination picture from occurring in a manner unintended by the producer of the HDR content.

[0092] Although the HDR video stream recorded on the optical disc 11 is assumed to be an HEVC encoded stream, it may also be a stream generated by encoding using another method, such as AVC (H.264 / MPEG-4 AVC (Advanced Video Coding)).

[0093] AVC video streams contain units that make up the coding unit, such as CVS (Coded Video Sequence). AVC video streams are generated by encoding under the restriction that dynamic metadata must be added to the first picture of the CVS, which serves as a random access point.

[0094] Furthermore, an HDR video stream generated in accordance with the restriction that dynamic metadata must be added to pictures at random access points may be distributed via a network such as the Internet, rather than being recorded on the optical disc 11. The configuration of a system that distributes an HDR video stream generated in accordance with such restrictions will be described later.

[0095] <BDフォーマット> Here, the BD-ROM format will be explained.

[0096] Data management structure FIG. 10 is a diagram showing an example of the management structure of an AV stream in the BD-ROM format.

[0097] AV streams are managed using two layers: PlayList and Clip. AV streams may be recorded not only on the optical disc 11 but also in the local storage of the playback device 1.

[0098] A pair of one AV stream and its associated clip information is managed as a single object. The pair of an AV stream and clip information is called a clip.

[0099] An AV stream is expanded on a time axis, and the access point of each Clip is specified in a PlayList mainly by a timestamp. Clip Information is used to find the address in the AV stream where decoding should start.

[0100] A PlayList is a collection of playback sections of an AV stream. One playback section in an AV stream is called a PlayItem. A PlayItem is represented by a pair of IN and OUT points of the playback section on the time axis. As shown in Figure 10, a PlayList is made up of one or more PlayItems.

[0101] The first PlayList from the left in FIG. 10 is made up of two PlayItems, and these two PlayItems refer to the first and second halves of the AV stream contained in the Clip on the left, respectively.

[0102] The second PlayList from the left consists of one PlayItem, which references the entire AV stream contained in the Clip on the right.

[0103] The third PlayList from the left is made up of two PlayItems, and these two PlayItems reference a certain portion of the AV stream contained in the Clip on the left and a certain portion of the AV stream contained in the Clip on the right, respectively.

[0104] For example, if the left PlayItem included in the first PlayList from the left is specified as the playback target by the disc navigation program, the first half of the AV stream included in the left Clip referenced by that PlayItem is played back.

[0105] A playback path created in a PlayList by a sequence of one or more PlayItems is called a Main Path. A playback path created in a PlayList by a sequence of one or more SubPlayItems, which runs parallel to the Main Path, is called a Sub Path.

[0106] FIG. 11 is a diagram showing the structure of the Main Path and the Sub Path.

[0107] A PlayList has one Main Path and one or more Sub Paths. The PlayList in Fig. 11 has one Main Path and three Sub Paths made up of a sequence of three PlayItems.

[0108] An ID is assigned to each PlayItem that makes up the Main Path, in order from the beginning. IDs are also assigned to the Sub Paths, in order from the beginning: Subpath_id=0, Subpath_id=1, and Subpath_id=2.

[0109] In the example of Fig. 11, the Sub Path with Subpath_id=0 includes one SubPlayItem, the Sub Path with Subpath_id=1 includes two SubPlayItems, and the Sub Path with Subpath_id=2 includes one SubPlayItem.

[0110] An AV stream referenced by one PlayItem includes at least a video stream. The AV stream may or may not include one or more audio streams that are played at the same time (synchronized) with the video stream included in the AV stream.

[0111] The AV stream may or may not include one or more streams of bitmap subtitles (PG (Presentation Graphic)) that are played back in synchronization with the video stream included in the AV stream.

[0112] An AV stream may or may not include one or more IG (Interactive Graphic) streams that are played in synchronization with the video stream included in the AV stream file. IG streams are used to display graphics such as buttons that are operated by the user.

[0113] In the AV stream referenced by one PlayItem, a video stream and an audio stream, a PG stream, and an IG stream that are played in synchronization with the video stream are multiplexed.

[0114] Furthermore, one SubPlayItem references a video stream, audio stream, PG stream, etc. that is different from the AV stream referenced by the PlayItem.

[0115] In this way, AV streams are played back using PlayList and Clip Information. The playback control information used to manage the playback of AV streams, that is, the Index table, PlayList, and Clip Information, is referred to as Database information where appropriate.

[0116] Directory structure FIG. 12 is a diagram showing an example of the management structure of files recorded on the optical disc 11. As shown in FIG.

[0117] The files recorded on the optical disc 11 are managed hierarchically using a directory structure. One root directory is created on the optical disc 11.

[0118] The BDMV directory is placed under the root directory.

[0119] The BDMV directory contains an Index table file named "Index.bdmv" and a MovieObject file named "MovieObject.bdmv." The Index table file contains the index table.

[0120] Under the BDMV directory, a PLAYLIST directory, a CLIPINF directory, a STREAM directory, etc. are provided.

[0121] The PLAYLIST directory stores PlayList files that describe PlayLists. Each PlayList file is given a name that combines a five-digit number with the extension ".mpls." The three PlayList files shown in Figure 12 have the file names "00000.mpls," "00001.mpls," and "00002.mpls."

[0122] The CLIPINF directory stores Clip Information files. Each Clip Information file is named with a five-digit number and the extension ".clpi." The three Clip Information files in Figure 12 are named "01000.clpi," "02000.clpi," and "03000.clpi," respectively.

[0123] The STREAM directory stores the AV stream files described above. Each AV stream file is given a name that combines a five-digit number with the extension ".m2ts." The three AV stream files in Figure 12 are given the file names "01000.m2ts," "02000.m2ts," and "03000.m2ts," respectively.

[0124] A Clip Information file and an AV stream file that have the same five-digit number in their file names constitute a single Clip. When playing the AV stream file "01000.m2ts", the Clip Information file "01000.clpi" is used, and when playing the AV stream file "02000.m2ts", the Clip Information file "02000.clpi" is used.

[0125] <Configuration of each device> Recording device configuration FIG. 13 is a block diagram showing an example of the configuration of the recording device 3.

[0126] An optical disc 11, which is a BD as described above, is created in a recording device 3 shown in Fig. 13. The recording device 3 is a device used when authoring HDR content.

[0127] The recording device 3 is made up of a controller 21, an encoding processing unit 22, and a disk drive 23. A master video is input to the encoding processing unit 22.

[0128] The controller 21 is configured by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The controller 21 executes a predetermined program and controls the overall operation of the recording device 3.

[0129] The encoding processing unit 22 encodes the master video and generates an HDR video stream. Dynamic metadata, which is added to each picture when the HDR video stream is generated and encoded as an SEI message, is supplied from the controller 21.

[0130] The encoding by the encoding processing unit 22 is performed under the restriction that dynamic metadata must be added to the picture at the random access point.

[0131] The encoding processing unit 22 also generates an IG stream by encoding menu images, and generates a PG stream by encoding subtitle data, as appropriate. Information such as menu images and subtitle data is also input to the encoding processing unit 22.

[0132] The encoding processing unit 22 generates an AV stream that constitutes a Clip by multiplexing the HDR video stream, IG stream, and PG stream obtained by the encoding with an audio stream, etc. The encoding processing unit 22 outputs the generated AV stream to the disc drive 23.

[0133] The disc drive 23 records each file of the Database information supplied from the controller 21 and the AV stream file supplied from the encoding processing unit 22 onto the optical disc 11 in accordance with the directory structure of FIG.

[0134] FIG. 14 is a block diagram showing an example of the functional configuration of the controller 21.

[0135] The controller 21 implements a dynamic metadata generation unit 31, an encoding control unit 32, a database information generation unit 33, and a recording control unit 34. At least some of the functional units shown in Fig. 14 are implemented by the CPU of the controller 21 executing a predetermined program.

[0136] The dynamic metadata generation unit 31 sets the value of each parameter according to input by the content creator, and generates dynamic metadata. The dynamic metadata generation unit 31 outputs the generated dynamic metadata to the encoding control unit 32.

[0137] The encoding control unit 32 outputs the dynamic metadata generated by the dynamic metadata generation unit 31 to the encoding processing unit 22, and causes the encoding processing unit 22 to encode each picture of the HDR video. The encoding control unit 32 also causes the encoding processing unit 22 to encode menu data and subtitle data.

[0138] The Data Base information generation unit 33 generates Data Base information such as an Index table, PlayList, and Clip Information according to input from the content creator. The Data Base information generation unit 33 outputs a file of the generated Data Base information to the recording control unit 34. The Data Base information generated by the Data Base information generation unit 33 is supplied to the encoding control unit 32 as appropriate and used to control encoding.

[0139] The recording control unit 34 outputs the file of the Database information generated by the Database information generating unit 33 to the disc drive 23 and causes it to be recorded on the optical disc 11.

[0140] In this way, the recording device 3 functions as an information processing device that generates dynamic metadata and generates an HDR video stream by performing encoding in accordance with the restriction that dynamic metadata must be added to pictures at random access points.

[0141] ·Playback device configuration FIG. 15 is a block diagram showing an example of the configuration of the playback device 1.

[0142] The playback device 1 includes a controller 51 , a disk drive 52 , a memory 53 , a local storage 54 , a communication unit 55 , a decoding processing unit 56 , an operation input unit 57 , and an external output unit 58 .

[0143] The controller 51 is configured with a CPU, a ROM, a RAM, etc. The controller 51 executes a predetermined program and controls the overall operation of the playback device 1.

[0144] The disc drive 52 reads data recorded on the optical disc 11 and outputs it to the controller 51, the memory 53, or the decoding processing unit 56. For example, the disc drive 52 outputs Database information read from the optical disc 11 to the controller 51, and outputs the AV stream to the decoding processing unit 56.

[0145] The memory 53 stores data necessary for the controller 51 to execute various processes, such as programs executed by the controller 51.

[0146] The local storage 54 is configured by a recording medium such as a hard disk drive (HDD), a solid state drive (SSD), etc. The local storage 54 records streams downloaded from the server, etc.

[0147] The communication unit 55 is an interface for a wireless LAN, a wired LAN, etc. For example, the communication unit 55 communicates with a server via a network such as the Internet, and supplies data downloaded from the server to the local storage .

[0148] The decoding processing unit 56 decodes the HDR video stream multiplexed into the AV stream supplied from the disc drive 52, and outputs the HDR video data obtained by the decoding to the external output unit 58.

[0149] The decoding processing unit 56 also decodes the audio stream multiplexed into the AV stream, and outputs the audio data obtained by the decoding to the external output unit 58. Although the description has been mainly focused on video playback, the HDR content played back by the playback device 1 also includes audio data.

[0150] The operation input unit 57 is composed of input devices such as buttons and a touch panel, and a receiving unit that receives signals such as infrared rays transmitted from a remote controller. The operation input unit 57 detects user operations and supplies a signal indicating the content of the detected operation to the controller 51.

[0151] The external output unit 58 is an interface for external output such as HDMI. The external output unit 58 communicates with the TV 2 via an HDMI cable, acquires information about the performance of the display of the TV 2, and outputs the information to the controller 51. The external output unit 58 also receives HDR video data supplied from the decoding processing unit 56 and outputs the data to the TV 2.

[0152] TV configuration FIG. 16 is a block diagram showing an example of the configuration of the TV 2.

[0153] The TV 2 includes a controller 71 , an external input unit 72 , a signal processing unit 73 , a display 74 , a broadcast receiving unit 75 , a decoding processing unit 76 , and a communication unit 77 .

[0154] The controller 71 is configured with a CPU, a ROM, a RAM, etc. The controller 71 executes a predetermined program and controls the overall operation of the TV 2.

[0155] For example, the controller 71 manages information indicating the performance of the display 74. When HDMI transmission is set, the controller 71 outputs the information indicating the performance of the display 74 to the external input unit 72 and transmits it to the playback device 1.

[0156] Furthermore, the controller 71 controls the processing of HDR video by the signal processing unit 73. For example, the controller 71 causes the signal processing unit 73 to perform luminance compression of the HDR video based on dynamic metadata transmitted from the playback device 1 when playing back HDR content.

[0157] The external input unit 72 is an interface for external input such as HDMI. The external input unit 72 communicates with the playback device 1 via an HDMI cable, receives data of each picture of the HDR video transmitted from the playback device 1, and outputs the data to the signal processing unit 73. The external input unit 72 also receives dynamic metadata transmitted together with each picture of the HDR video, and outputs the data to the controller 71.

[0158] The signal processing unit 73 processes the HDR video supplied from the external input unit 72 and displays the image on the display 74. Under the control of the controller 71, the signal processing unit 73 appropriately compresses the luminance of the HDR video so that it fits within the range that the display 74 can display.

[0159] The signal processing unit 73 also performs processing such as displaying the video of the program on the display 74 based on the data supplied from the decoding processing unit 76 .

[0160] The display 74 is a display device such as an organic electroluminescence (EL) display or an LCD (Liquid Crystal Display). The display 74 displays HDR content images and program images based on the video signal supplied from the signal processing unit 73.

[0161] The broadcast receiving unit 75 extracts a broadcast signal of a predetermined channel from the signal supplied from the antenna, and outputs it to the decoding processing unit 76. The broadcast receiving unit 75 extracts the broadcast signal under the control of the controller 71.

[0162] The decoding processing unit 76 performs processing such as decoding on the broadcast signal supplied from the broadcast receiving unit 75 and outputs the video data of the program to the signal processing unit 73 .

[0163] The communication unit 77 is an interface for a wireless LAN, a wired LAN, etc. The communication unit 77 communicates with a server via the Internet.

[0164] <Operation of each device> Recording device operation The recording process of the recording device 3 will be described with reference to the flowchart of FIG.

[0165] The process in FIG. 17 starts, for example, when master video data is input.

[0166] In step S1, the dynamic metadata generating unit 31 of the controller 21 sets the values of each parameter according to input by the content creator, and generates dynamic metadata.

[0167] In step S2, the Data Base information generating unit 33 generates Data Base information such as a PlayList.

[0168] In step S3, the encoding processing unit 22, under the control of the encoding control unit 32, encodes the master video and generates an HDR video stream, under the restriction that dynamic metadata must be added to the first picture of the GOP, which is the random access point.

[0169] The encoding processing unit 22 also encodes menu images and subtitle data to generate an IG stream and a PG stream, and multiplexes the generated streams to generate an AV stream.

[0170] In step S4, the disc drive 23 generates the optical disc 11 by recording the Database information file supplied from the controller 21 and the AV stream file supplied from the encoding processing unit 22. Then, the process ends.

[0171] Through the above processing, the recording device 3 can generate an HDR video stream in which dynamic metadata is added to the first picture of a GOP that serves as a random access point, and provide HDR content that includes such an HDR video stream.

[0172] ·Playback device operation Next, the processing of the playback device 1 that plays back HDR content will be described with reference to the flowchart in FIG.

[0173] The process in FIG. 18 starts, for example, when the optical disc 11 is loaded into the disc drive 52 of the playback device 1 and playback of HDR content is instructed.

[0174] In step S11, the disc drive 52 reads from the optical disc 11 a file of Database information, including a PlayList file.

[0175] In step S12, the controller 51 analyzes the PlayList file and identifies the AV stream to be played back.

[0176] In step S13, the disc drive 52 reads from the optical disc 11 the file of the AV stream that includes the HDR video stream to be played back.

[0177] In step S14, the decoding processing unit 56 decodes the HDR video stream included in the AV stream supplied from the disc drive 52, and outputs the data of each picture to the external output unit 58. Dynamic metadata added to each picture is supplied from the decoding processing unit 56 to the controller 51.

[0178] In step S15, the external output unit 58 adds the dynamic metadata supplied from the controller 51 to each picture of the HDR video supplied from the decoding processing unit 56, and outputs the result to the TV 2. The TV 2 performs luminance compression on each picture based on the dynamic metadata, and displays the luminance-compressed picture.

[0179] In step S16, the controller 51 determines whether or not to perform random access playback. If it is determined in step S16 that random access playback is not to be performed, the process returns to step S15, and normal playback continues, in which each picture is played back in order.

[0180] On the other hand, if it is determined in step S16 that random access playback is to be performed, the process proceeds to step S 17. For example, if the user has instructed fast-forward playback / rewind playback or cue playback, it is determined in step S16 that random access playback is to be performed.

[0181] In step S17, the decoding processing unit 56 decodes the picture at the jump destination, which is a random access point. The picture decoded here is the picture at the head of the GOP, and Dynamic metadata is added thereto. The Dynamic metadata included in the SEI of the decoded picture is supplied to the controller 51.

[0182] In step S18, the external output unit 58 adds the Dynamic metadata supplied from the controller 51 to the picture at the random access point and outputs the result to the TV2.

[0183] Thereafter, the process returns to step S16, and the above processing is repeated. For example, when the random access playback instructed by the user is fast forward playback / rewind playback, the pictures at the heads of the respective GOPs are sequentially played back and output together with the Dynamic metadata. For example, when the playback of HDR content ends, the process of FIG. 18 ends.

[0184] As described above, since Dynamic metadata is always added to the picture at the random access point, it is possible to prevent the luminance compression of the picture at the jump destination from being performed in a form unintended by the producer of the HDR content even when performing random access playback.

[0185] <Example of always adding Dynamic metadata to the picture specified by the EP_map> The Clip Information, which is the Data Base information, includes information called EP_map that specifies the random access point.

[0186] The encoding of the HDR video data may be performed such that Dynamic metadata is always added to the picture at the random access point specified by the EP_map.

[0187] FIG. 19 is a diagram showing an example of an HDR video stream including pictures specified by the EP_map as random access points.

[0188] 19 describes information about entry points (random access points) EP entry1 and EP entry2. EP entry1 and EP entry2 are information that indicates the position on the HDR video stream represented by the PTS (Presentation Time Stamp) and SPN (Source Packet Number) of the entry point.

[0189] 19, picture P21 is specified by EP entry 1, and picture P22 is specified by EP entry 2. Of the pictures that make up the HDR video stream, dynamic metadata is added to at least picture P21 specified by EP entry 1 and picture P22 specified by EP entry 2.

[0190] For example, when an instruction is given to start playback from a specific entry point, the playback device 1 outputs the picture specified by the EP entry to the TV 2 together with the dynamic metadata added to that picture.

[0191] In the TV 2, the luminance compression of the picture specified by the EP entry is performed based on the dynamic metadata transmitted along with the picture. The picture after luminance compression is displayed, thereby realizing cue playback.

[0192] In this way, dynamic metadata may be added to the picture specified by the EP_map included in Clip Information, which is information in a file separate from the HDR video stream. This prevents luminance compression of the jump destination picture from being performed in a manner not intended by the producer of the HDR content.

[0193] Note that the playback device 1 may play back HDR content multiplexed in MP4 format.

[0194] HDR content multiplexed by MP4 includes an HDR video stream obtained by encoding HDR video data using a specified encoding method such as AVC or HEVC, and mfra (movie fragment random access box), which is playback control information for the HDR video stream.

[0195] The mfra contains information specifying random access points. Dynamic metadata is added to at least the pictures specified by the information included in the mfra among the pictures in the HDR video stream that make up the MP4 HDR content. This also prevents brightness compression of the jump destination picture from being performed in a way that the HDR content producer did not intend.

[0196] Such HDR content in MP4 format is also generated by an information processing device having a configuration similar to that shown in Figures 13 and 14. For example, the HDR video stream generated by the encoding processing unit 22 and the mfra generated by the Data Base information generation unit 33 are multiplexed according to the MP4 format to generate the HDR content.

[0197] <Clip InformationのEP_mapについて> 20 is a diagram showing the syntax of Clip Information. The main descriptions included in Clip Information will be described below.

[0198] As shown in FIG. 20, Clip Information includes descriptions of ClipInfo(), SequenceInfo(), ProgramInfo(), CPI(), ClipMark(), and ExtensionData().

[0199] ClipInfo() is a field in which information about the attributes of the AV stream that is played back using Clip Information is written.

[0200] SequenceInfo() is a field in which information about the sequence of source packets that make up the AV stream is written.

[0201] ProgramInfo() is a field in which information about the sequence of source packets that make up the program is written.

[0202] CPI() is a field in which information indicating the correspondence between time and position in the AV stream is written. EP_map is also written in CPI().

[0203] FIG. 21 is a diagram showing the syntax of CPI().

[0204] As shown in FIG. 21, CPI() describes CPI_type and EP_map().

[0205] If the value of CPI_type is 1, CPI() contains the information of EP_map.

[0206] FIG. 22 is a diagram showing the syntax of EP_map().

[0207] The stream_PID indicates the PID of the TS packet that stores the HDR video data.

[0208] The number_of_EP_coarse_entries indicates the number of EP-coarse-entries included in EP_map(). EP-coarse-entries are entry point information with low precision, such as in units of one second.

[0209] "number_of_EP_fine_entries" indicates the number of "EP-fine-entries" included in "EP_map()." "EP-fine-entry" is entry point information with higher precision than "EP-coarse-entry." An entry point is specified by a pair of "EP-coarse-entry" and "EP-fine-entry."

[0210] EP_map_for_one_stream_PID contains information about each EP-coarse-entries and EP-fine-entries.

[0211] FIG. 23 is a diagram showing the syntax of EP_map_for_one_stream_PID.

[0212] PTS_EP_coarse[i] represents the PTS (time) of the EP-coarse-entry.

[0213] SPN_EP_coarse[i] represents the source packet (position) on the HDR video stream that corresponds to PTS_EP_coarse[i].

[0214] PTS_EP_fine[i] represents the PTS of the EP-fine-entry.

[0215] SPN_EP_fine[i] represents a source packet on the HDR video stream corresponding to PTS_EP_fine[i].

[0216] When performing random access playback based on the EP_map, the playback device 1 analyzes the EP_map_for_one_stream_PID to identify the position in the HDR video stream of the source packet that stores the data of the picture that serves as the entry point. As described above, dynamic metadata is added to the picture at the entry point.

[0217] <Recording device operation> With reference to the flowchart in FIG. 24, the recording process of the recording device 3 for generating an HDR video stream by adding dynamic metadata to a picture at an entry point specified by the EP_map will be described.

[0218] The processing in Fig. 24 is similar to the processing described with reference to Fig. 17, except that the restrictions on the encoding of the master video are different. Duplicate descriptions will be omitted where appropriate.

[0219] That is, in step S31, the dynamic metadata generating unit 31 of the controller 21 sets the values of each parameter according to input by the content creator, and generates dynamic metadata.

[0220] In step S32, the Data Base information generator 33 generates Data Base information such as Clip Information describing a PlayList and an EP_map. The Data Base information generator 33 outputs information about each entry point (EP entry) described in the EP_map to the encoding control unit 32.

[0221] In step S33, the encoding processing unit 22, under the control of the encoding control unit 32, encodes the master video under the restriction that dynamic metadata must be added to the picture of the entry point specified by the EP_map, and generates an HDR video stream.

[0222] In step S34, the disc drive 23 generates the optical disc 11 by recording the Database information file supplied from the controller 21 and the AV stream file supplied from the encoding processing unit 22. Then, the process ends.

[0223] Through the above processing, the recording device 3 generates an HDR video stream in which dynamic metadata is added to pictures that are random access points specified by the EP_map, and can provide HDR content that includes such an HDR video stream.

[0224] <Modification> The above describes the case where dynamic metadata is added to the first picture of a GOP and the case where dynamic metadata is added to a picture specified by the EP_map, but these restrictions may be used in combination.

[0225] That is, it is possible to encode an HDR video stream by always adding dynamic metadata to both the first picture of a GOP and the picture specified by the EP_map.

[0226] If dynamic metadata is not attached to the jump destination picture, dynamic metadata attached to a picture near the jump destination picture may be transmitted from the playback device 1 to the TV 2 and used to compress the luminance of the jump destination picture.

[0227] <<Second embodiment (example using default metadata)>> <Example of using default metadata during random access playback> FIG. 25 is a diagram showing an example of metadata transmission during random access playback.

[0228] During random access playback, an OSD image representing the contents of random access playback is composited onto, for example, a jump destination picture in the playback device 1. The picture with the composited OSD image is output to the TV 2 together with default metadata, which is metadata for random access playback, as shown in Fig. 25, instead of dynamic metadata.

[0229] The default metadata has, for example, parameters similar to the parameters of the dynamic metadata described with reference to Fig. 3. For example, a fixed value is set for each parameter of the default metadata so that each type of OSD image is displayed at an appropriate brightness. The default metadata is prepared in advance in the playback device 1, for example, in a form stored in the memory 53 within the playback device 1.

[0230] FIG. 26 is a diagram showing a display after luminance compression.

[0231] For example, when a high-brightness scene is displayed as shown on the left side of Figure 26, if random access playback such as fast-forward playback is instructed, the default metadata is output to TV2 along with the jump destination picture onto which the OSD image is superimposed.

[0232] In the TV 2, the luminance of the picture onto which the OSD image has been combined is compressed based on the default metadata transmitted from the playback device 1, and the luminance of the HDR video is kept low as indicated by the tip of arrow A12. In other words, if the luminance after luminance compression using dynamic metadata is the original luminance of the HDR video as indicated by the tip of arrow A11, the HDR video displayed will be darker than the original luminance.

[0233] Since the metadata has a value set that is suitable for the OSD image, the brightness of the OSD image itself becomes suitable as indicated by the tip of arrow A12 by brightness compression using the default metadata.

[0234] In this way, during random access playback, default metadata is used to compress the brightness of the picture to which the jump is made, so the brightness of the OSD image for each picture becomes constant, preventing the OSD image from appearing to flicker.

[0235] ·Configuration and operation of playback device 27 is a block diagram showing an example of the functional configuration of the controller 51 when default metadata is transmitted during random access playback. The configuration of the playback device 1 is the same as the configuration in FIG.

[0236] The controller 51 implements a Database information analysis unit 101, an output control unit 102, and a default metadata generation unit 103. At least some of the functional units shown in Fig. 27 are implemented by the CPU of the controller 51 executing a predetermined program.

[0237] The Database information analysis unit 101 analyzes the Database information supplied from the disk drive 52, and outputs information indicating the analysis results to the output control unit 102 and the default metadata generation unit 103. The processing by the output control unit 102 and the default metadata generation unit 103 is performed by appropriately referring to the analysis results of the Database information.

[0238] The output control unit 102 controls the decoding processing unit 56 and the external output unit 58, thereby controlling the output of HDR video.

[0239] For example, the output control unit 102 causes the decoding processing unit 56 to decode the HDR video stream. The output control unit 102 also controls the external output unit 58 to add dynamic metadata to each picture obtained by decoding the HDR video stream and output the resulting picture.

[0240] When random access playback is instructed, the output control unit 102 causes the decoding processing unit 56 to decode the HDR video stream and composite an OSD image into the jump destination picture. The output control unit 102 also controls the external output unit 58 to add default metadata to the picture composited with the OSD image and output the composited picture.

[0241] The default metadata generation unit 103 generates default metadata by setting fixed values as the values of each parameter. The default metadata generation unit 103 has information on the fixed values to be set for each parameter. The default metadata generation unit 103 outputs the generated default metadata to the memory 53 for storage.

[0242] In this way, the default metadata may be generated within the playback device 1. Alternatively, the default metadata may be stored in the memory 53 at the time of manufacturing the playback device 1 or the like, and may be prepared in the playback device 1 in advance.

[0243] The user may be allowed to specify the value to be set for each parameter of the default metadata. In this case, the value of each parameter is set using, for example, a setting screen of the playback device 1.

[0244] Furthermore, the user may be allowed to select whether the TV 2 refers to or ignores the default metadata transmitted from the playback device 1. In this case, for example, a setting screen of the TV 2 is used to set whether to refer to or ignore the default metadata.

[0245] The values to be set for each parameter of the default metadata may be obtained from the server.

[0246] In this case, the server prepares information on values to be set for each parameter of the default metadata in association with, for example, the HDR content recorded on the optical disc 11. The default metadata generation unit 103 sets the values acquired from the server as the values of each parameter, thereby generating default metadata for the HDR content recorded on the optical disc 11.

[0247] Alternatively, the default metadata may be downloaded from a server. The downloaded default metadata received by the communication unit 55 is output to the memory 53 and stored therein.

[0248] Next, with reference to the flowchart in FIG. 28, a description will be given of the processing of the playback device 1 that plays back HDR content by transmitting default metadata during random access playback.

[0249] The processing in FIG. 28 is basically the same as the processing described with reference to FIG. 18, except that the metadata added to each picture when random access playback is instructed is different.

[0250] That is, in step S101, the disc drive 52 reads out from the optical disc 11 a file of Database information, including a PlayList file.

[0251] In step S102, the Database information analysis unit 101 of the controller 51 analyzes the PlayList file and identifies the AV stream to be played back.

[0252] In step S103, the disc drive 52 reads from the optical disc 11 the file of the AV stream that includes the HDR video stream to be played back.

[0253] In step S104, the decoding processing unit 56 decodes the HDR video stream included in the AV stream supplied from the disc drive 52, and outputs data of each picture to the external output unit 58. Dynamic metadata included in the HDR video stream is supplied from the decoding processing unit 56 to the controller 51.

[0254] In step S105, under the control of the output control unit 102, the external output unit 58 adds the dynamic metadata supplied from the output control unit 102 to each picture of the HDR video supplied from the decoding processing unit 56 and outputs the resulting picture to the TV 2.

[0255] In step S106, the controller 51 determines whether or not to perform random access playback. If it is determined in step S106 that random access playback is not to be performed, that is, that normal playback is to be performed, the process returns to step S105, and output of each picture of the HDR video continues.

[0256] On the other hand, if it is determined in step S106 that random access playback is to be performed, the process proceeds to step S 107. If fast-forward playback / rewind playback is instructed by the user, or if cue playback is instructed by the user, it is determined in step S106 that random access playback is to be performed.

[0257] In step S107, the decoding processing unit 56 decodes the jump destination picture, which is the random access point.

[0258] In step S108, the decoding processing unit 56 combines the OSD image with the picture of the jump destination.

[0259] In step S109, the external output unit 58 adds default metadata to the jump destination picture onto which the OSD image has been combined, and outputs the resultant picture. The default metadata to be output together with the jump destination picture is supplied from the output control unit 102 of the controller 51.

[0260] After that, the process returns to step S106, and the above processes are repeated. For example, if the random access playback instructed by the user is fast-forward playback / rewind playback, the first pictures of the GOPs are decoded in order, and the first picture of each GOP is output together with the default metadata.

[0261] TV operation Next, the display process of the TV2 will be described with reference to the flowchart of FIG.

[0262] 29 is performed when transmission of pictures obtained by decoding an HDR video stream starts. Dynamic metadata or default metadata is added to the pictures transmitted from the playback device 1.

[0263] In step S121, the external input unit 72 of the TV 2 receives the data of each picture of the HDR video transmitted from the playback device 1, and the dynamic metadata or default metadata transmitted together with the data.

[0264] If random access playback is not instructed, each picture and dynamic metadata are received here. If random access playback is instructed in the playback device 1, pictures with OSD images composited therewith and default metadata are received here.

[0265] Data for each picture received by the external input unit 72 is supplied to the signal processing unit 73 , and metadata (dynamic metadata or default metadata) is supplied to the controller 71 .

[0266] In step S122, the signal processing unit 73 performs luminance compression on each picture of the HDR video under the control of the controller 71. If the metadata transmitted with each picture is dynamic metadata, luminance compression is performed based on the dynamic metadata. Also, if the metadata transmitted with each picture is default metadata, luminance compression is performed based on the default metadata.

[0267] In step S123, the signal processing unit 73 displays the luminance-compressed picture on the display 74. The display of the HDR video, which is made up of such a series of processes, continues until the playback of the HDR content ends.

[0268] As described above, by performing luminance compression on the TV 2 based on the default metadata during random access playback, it is possible to prevent the OSD image combined with each picture from appearing to flicker.

[0269] <Example of using default metadata when there is no dynamic metadata at the jump destination> The default metadata is not necessarily used during random access playback, but may be used and transmitted to the TV 2 when dynamic metadata is not added to the jump destination picture.

[0270] FIG. 30 shows an example of random access playback.

[0271] For example, a case will be described in which a cue playback command is issued when the picture to be played back becomes picture P1, and a jump is made from picture P1 to picture P2 as indicated by arrow A1 in FIG.

[0272] In this case, the playback device 1 analyzes the picture P2 and detects whether dynamic metadata has been added. If the picture P2 is a picture in a section to which dynamic metadata has not been added, default metadata is used and output together with the picture P2.

[0273] For example, if dynamic metadata is added to picture P2, the dynamic metadata is output together with picture P2.

[0274] In this way, if dynamic metadata is added to the jump destination picture, the dynamic metadata may be transmitted, and if no dynamic metadata is added, default metadata may be transmitted.

[0275] Here, the processing of the playback device 1 that plays back HDR content will be described with reference to the flowchart in FIG.

[0276] The process in FIG. 31 is similar to the process in FIG. 28, except that the metadata to be transmitted to the TV 2 is switched depending on whether or not dynamic metadata is added to the jump destination picture.

[0277] That is, in steps S131 to S135, normal playback of HDR content is performed in the same manner as in steps S101 to S105 of FIG.

[0278] If it is determined in step S136 that random access playback is to be performed, then in step S137 the decoding processing unit 56 decodes the jump destination picture, which is the random access point.

[0279] In step S138, the decoding processing unit 56 combines the OSD image with the picture of the jump destination.

[0280] In step S139, the decoding processing unit 56 determines whether or not dynamic metadata has been added to the jump destination picture.

[0281] If it is determined in step S139 that dynamic metadata has not been added, then in step S140 the external output unit 58 adds default metadata to the jump destination picture onto which the OSD image has been combined, and outputs the picture.

[0282] On the other hand, if it is determined in step S139 that dynamic metadata has been added, then in step S141 the external output unit 58 adds dynamic metadata to the jump destination picture onto which the OSD image has been combined, and outputs the picture.

[0283] After the picture is output in step S140 or step S141, the process returns to step S136 and the above processing is repeated.

[0284] In this way, the default metadata may be used only when no dynamic metadata is added to the jump destination picture, and when dynamic metadata is added, the dynamic metadata may be transmitted to the TV 2. This allows the luminance compression of the jump destination picture to be performed as intended by the creator of the HDR content.

[0285] <<Playback system configuration example>> <First configuration example> Although the case where HDR content is recorded on the optical disc 11 has been described, as mentioned above, the above processing can also be applied when playing HDR content distributed via a network.

[0286] FIG. 32 is a diagram illustrating an example of the configuration of a playback system for HDR content.

[0287] The playback system in Fig. 32 is configured by connecting a playback device 1 and a content distribution server 301 via a network 302 such as the Internet. A TV 2 is connected to the playback device 1 via an HDMI cable or the like. Video of HDR content played back by the playback device 1 is displayed on the TV 2.

[0288] The content distribution server 301 is a server managed by a business that provides a distribution service for HDR content. The content distributed by the content distribution server 301 is HDR content.

[0289] Each HDR content is constructed by associating an HDR video stream file containing dynamic metadata with a playback control information file.

[0290] For example, when a user operates the playback device 1 to access the content distribution server 301, an HDR content selection screen is displayed on the TV 2. The user can select a desired HDR content and request the content distribution server 301 to start viewing.

[0291] When HDR content is selected, the content distribution server 301 transmits the selected HDR content to the playback device 1.

[0292] The playback device 1 receives the HDR content transmitted from the content distribution server 301, and plays back the HDR content by performing processing similar to the playback processing described above.

[0293] That is, dynamic metadata is transmitted from the playback device 1 to the TV 2 along with each picture obtained by decoding the HDR video stream, and luminance compression is performed based on the dynamic metadata.

[0294] Furthermore, when random access playback is instructed, dynamic metadata attached to the jump destination picture is transmitted along with each picture of the HDR video, and luminance compression is performed based on the dynamic metadata on the TV 2. Dynamic metadata is attached to the jump destination picture at the beginning of a GOP or a picture designated as an entry point by EP_map or the like.

[0295] Furthermore, if default metadata is prepared in the playback device 1, in response to an instruction for random access playback, the default metadata is transmitted along with the picture to be jumped to, and brightness compression is performed on the TV 2 based on the default metadata.

[0296] In this way, the content distribution server 301 may distribute HDR content including an HDR video stream in which dynamic metadata is always added to the first picture of a GOP or a picture specified as an entry point.

[0297] Furthermore, when random access playback of an HDR video stream that constitutes HDR content distributed by the content distribution server 301 is performed, default metadata may be output from the playback device 1 to the TV 2.

[0298] FIG. 33 is a diagram showing another example of the configuration of the playback device 1.

[0299] As shown in Fig. 33, the playback device 1 may be a so-called stick-type terminal. An HDMI terminal is provided on the housing of the playback device 1 shown in Fig. 33. The playback device 1 and TV 2 are connected by inserting the HDMI terminal provided on the housing into the HDMI terminal of the TV 2.

[0300] For example, the playback device 1 in Fig. 33 is provided with the components shown in Fig. 15 except for the disc drive 52. The playback device 1 plays back HDR content distributed by the content distribution server 301 by performing the same processing as described above.

[0301] In this way, various configurations can be adopted as the configuration of the playback device 1. For example, the functions of the playback device 1 may be installed in a portable terminal such as a smartphone or a tablet terminal, or the functions of the playback device 1 may be installed in a terminal such as a PC.

[0302] <Second configuration example> The functions of the playback device 1 may be incorporated into the TV 2.

[0303] FIG. 34 is a diagram illustrating an example of the configuration of another playback system for HDR content.

[0304] 34 is configured by connecting a TV 2 equipped with the functions of the playback device 1 and a content distribution server 301 via a network 302. Duplicate descriptions will be omitted where appropriate.

[0305] The TV 2 displays a selection screen for HDR content based on the information transmitted from the content distribution server 301.

[0306] When a predetermined HDR content is selected by the user, the content distribution server 301 transmits the selected HDR content to the TV 2.

[0307] The TV 2 receives the HDR content transmitted from the content distribution server 301 and plays back the HDR content.

[0308] That is, the TV 2 performs luminance compression for each picture of the HDR video based on the dynamic metadata.

[0309] Furthermore, when random access playback is instructed, the luminance compression of the jump destination picture is performed based on the dynamic metadata added to the jump destination picture.

[0310] Furthermore, if default metadata is prepared in the TV 2, when random access playback is instructed, the luminance compression of the jump destination picture is performed based on the default metadata.

[0311] In this way, the functions of the playback device 1 may be provided in the TV 2, and the above-described processing may be performed in the TV 2.

[0312] <<Other examples>> Although the recording medium for HDR content is an optical disc, it may be another recording medium such as a flash memory.

[0313] Although the processing performed on the video based on the dynamic metadata or default metadata is assumed to be luminance compression, luminance expansion may also be performed on the TV 2. In this case, information on the tone curve used for luminance expansion is described in the dynamic metadata or default metadata.

[0314] Although the video stream input to the playback device 1 is assumed to be a video stream encoded using a predetermined method, it is also possible to input an unencoded video stream composed of pictures with dynamic metadata added to the playback device 1.

[0315] <Example of computer configuration> The above-described series of processes can be executed by hardware or software. When the series of processes is executed by software, the program constituting the software is installed from a program recording medium into a computer incorporated in dedicated hardware or a general-purpose personal computer.

[0316] FIG. 35 is a block diagram showing an example of the hardware configuration of a computer that executes the above-described series of processes using a program.

[0317] A CPU (Central Processing Unit) 1001 , a ROM (Read Only Memory) 1002 , and a RAM (Random Access Memory) 1003 are interconnected by a bus 1004 .

[0318] An input / output interface 1005 is also connected to the bus 1004. An input unit 1006 including a keyboard, a mouse, etc., and an output unit 1007 including a display, a speaker, etc. are connected to the input / output interface 1005. Also connected to the input / output interface 1005 are a storage unit 1008 including a hard disk, a nonvolatile memory, etc., a communication unit 1009 including a network interface, etc., and a drive 1010 that drives removable media 1011.

[0319] In a computer configured as described above, the CPU 1001 performs the above-described series of processes by, for example, loading a program stored in the storage unit 1008 into the RAM 1003 via the input / output interface 1005 and the bus 1004 and executing the program.

[0320] The program executed by the CPU 1001 is installed in the storage unit 1008 by being recorded on, for example, a removable medium 1011 or provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital broadcasting.

[0321] The program executed by the computer may be a program that processes in chronological order according to the order described in this specification, or may be a program that processes in parallel or at the required timing, such as when called.

[0322] The embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present technology.

[0323] For example, this technology can be configured as cloud computing, in which a single function is shared and processed collaboratively by multiple devices via a network.

[0324] Furthermore, each step described in the above flowchart can be executed by one device, or can be shared and executed by multiple devices.

[0325] Furthermore, when one step includes multiple processes, the multiple processes included in that one step can be executed by one device or can be shared and executed by multiple devices.

[0326] In this specification, a system refers to a collection of multiple components (devices, modules (components), etc.), regardless of whether all the components are contained in the same housing. Therefore, multiple devices housed in separate housings and connected via a network, and a single device with multiple modules housed in a single housing, are both systems.

[0327] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0328] <Configuration combination example> The present technology can also be configured as follows.

[0329] (1) a generating unit for generating dynamic metadata including luminance information of a picture; an encoding unit that encodes HDR video data by adding the dynamic metadata to each picture that serves as a random access point; An information processing device comprising: (2) The encoding unit adds the dynamic metadata to the first picture of a GOP, using the picture as the random access point. The information processing device according to (1) above. (3) a generating unit that generates playback control information including information specifying the random access point, which is used for playing back the video stream obtained by performing the encoding; The encoding unit adds the dynamic metadata to a picture at the random access point specified by information included in the playback control information. The information processing device according to (1) above. (4) the information specifying the random access point is an EP_map included in Clip Information, which serves as the playback control information, and which is defined in the Blu-ray Disc format; The encoding unit adds the dynamic metadata to pictures at each entry point designated as the random access point in the EP_map. The information processing device according to (3) above. (5) the information specifying the random access point is a Movie Fragment Random Access Box as the playback control information, which is defined in the MP4 format; The encoding unit adds the dynamic metadata to the picture of each of the random access points specified by the Movie Fragment Random Access Box. The information processing device according to (3) above. (6) The information processing device generating dynamic metadata including luminance information for the picture; The HDR video data is encoded by adding the dynamic metadata to each picture that serves as a random access point. Information processing methods. (7) On the computer, generating dynamic metadata including luminance information for the picture; The HDR video data is encoded by adding the dynamic metadata to each picture that serves as a random access point. A program for executing a process. (8) The video stream generated by encoding HDR video data in such a way that dynamic metadata including luminance information is added to each picture that serves as a random access point is recorded. Recording medium. (9) a playback unit that performs random access playback of a video stream generated by encoding HDR video data in such a way that dynamic metadata including luminance information is added to each picture that serves as a random access point; an output control unit that outputs the picture at the random access point together with the dynamic metadata to a display device; A playback device comprising: (10) a playback unit for random access playback of a video stream to which dynamic metadata including picture luminance information is added; an output control unit that, when predetermined information indicating that random access playback is being performed is displayed superimposed on the picture, adds metadata for random access playback used for adjusting brightness during random access playback to the picture at the random access point, and outputs the picture to which the metadata for random access playback has been added to a display device; A playback device comprising: (11) The playback unit performs fast-forward playback or rewind playback at a predetermined speed as random access playback. The playback device according to (10) above. (12) The playback unit performs random access playback by starting playback. The playback device according to (10) or (11) above. (13) The playback device Random access playback of video streams with dynamic metadata including picture luminance information; When predetermined information indicating that random access reproduction is being performed is displayed superimposed on the picture, metadata for random access reproduction used for adjusting brightness during random access reproduction is added to the picture at the random access point; The picture to which the metadata for random access playback is added is output to a display device. How to play. (14) On the computer, Random access playback of video streams with dynamic metadata including picture luminance information; When predetermined information indicating that random access reproduction is being performed is displayed superimposed on the picture, metadata for random access reproduction used for adjusting brightness during random access reproduction is added to the picture at the random access point; The picture to which the metadata for random access playback is added is output to a display device. A program for executing a process. [Explanation of symbols]

[0330] 1 playback device, 2 TV, 3 recording device, 21 controller, 22 encoding processing unit, 23 disk drive, 31 dynamic metadata generation unit, 32 encoding control unit, 33 database information generation unit, 34 recording control unit, 51 controller, 52 disk drive, 53 memory, 54 local storage, 55 communication unit, 56 decoding processing unit, 57 operation input unit, 58 external output unit, 101 database information analysis unit, 102 output control unit, 103 default metadata generation unit

Claims

1. a playback unit for performing normal playback and random access playback of a video stream to which dynamic metadata including picture luminance information is added; an output control unit that, during normal playback of the video stream, outputs the picture to which the dynamic metadata has been added to a display device, and, when predetermined information indicating that random access playback is being performed is displayed superimposed on the picture during random access playback of the video stream, adds metadata for random access playback used for adjusting brightness during random access playback to the picture at a random access point, and outputs the picture to which the metadata for random access playback has been added to the display device; A playback device comprising:

2. The playback unit performs fast-forward playback or rewind playback at a predetermined speed as random access playback. The playback device according to claim 1 .

3. The playback unit performs random access playback by starting playback. The playback device according to claim 1 .

4. The playback device outputting the picture to which the dynamic metadata including the luminance information of the picture has been added to a display device during normal playback of the video stream to which the dynamic metadata has been added; When predetermined information indicating that random access playback is being performed is displayed superimposed on the picture during random access playback of the video stream, metadata for random access playback used for adjusting brightness during random access playback is added to the picture at the random access point, and the picture to which the metadata for random access playback has been added is output to the display device. How to play.

5. On the computer, outputting the picture to which the dynamic metadata including the luminance information of the picture has been added to a display device during normal playback of the video stream to which the dynamic metadata has been added; When predetermined information indicating that random access playback is being performed is displayed superimposed on the picture during random access playback of the video stream, metadata for random access playback used for adjusting brightness during random access playback is added to the picture at the random access point, and the picture to which the metadata for random access playback has been added is output to the display device. A program for executing a process.

Images