JP2020017996A - Video reproduction device, video recording device, and video recording medium - Google Patents

Abstract

To provide a video reproduction device, a video recording device, and a video recording medium for enhancing responsiveness during special reproduction.SOLUTION: A video recording/playback device 100 comprises: a tuner-modulator section 11; a multiplexing/demultiplexing section 21; decode sections 31, 32, 33, and 34; and a recording/reproducing control section 41. The tuner-modulator section 11 receives broadcast waves Ba. The multiplexing/demultiplexing section 21 demultiplexes multiplexed streams Sm of the broadcast waves Ba. The decode sections 31, 32, 33, and 34 decompress compressed data of the demultiplexed multiplexed streams Sm. The recording/reproducing control section 41 collects video data or control information for recording from the data decompressed in the decode sections 31, 32, 33, and 34. When recording video data contained in the broadcast waves Ba using an MMT system, the video recording/playback device 100 records as video data made by coupling packet data.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a video playback device, a video recording device, and a video recording medium.

  2. Description of the Related Art In recent years, with the advance of video compression technology or broadcast wave modulation technology, introduction of a new television broadcast system is being considered in each country. The new scheme improves transmission efficiency. For this reason, it is possible to broadcast a higher quality video using the same radio band as before. It is also possible to broadcast a video of the same quality as before in a narrower radio band. With the introduction of new methods, cooperation with networks is being considered. In addition, applications and contents that are stored and operated in the receiver are also being studied.

  A system for recording a television broadcast is closely related to a normal television broadcast system. When a new television broadcasting system is adopted, a program in the new television broadcasting system cannot be recorded as it is. Therefore, when the television broadcasting system is changed, it is necessary to change the recording system to a system corresponding to the new broadcasting system.

  In particular, when a replaceable recording medium is used, it is necessary to consider compatibility with other playback devices. The exchangeable recording medium is, for example, a DVD (registered trademark: Digital Versatile Disc) or a Blu-ray disc (registered trademark: BLU-RAY DISC).

  With the currently adopted recording method, it is difficult to record a new television broadcasting method as it is. For this reason, a recording system compatible with a new television broadcasting system is required.

  For example, Patent Literature 1 describes a recording method of a television broadcast using the BDAV method, a method of dividing and recording large-capacity recording data, and a method of accessing large-capacity recording data. It also describes a method of storing compressed video data and audio data in an MPEG2TS for recording. It also describes a method of receiving a television broadcast transmitted by MPEG2TS and recording it in MPEG2TS format.

WO 2006/030767 (0021 stage to 0105 stage, FIGS. 1 to 21)

  When playing back a disc on which a high-quality 8K video broadcast is recorded, if special playback such as fast forward is performed, there is a problem that it takes time to display an image for one frame.

  The present invention has been made in view of these problems, and has as its object to improve responsiveness during special reproduction.

A video playback device according to the present invention is a video playback device that plays back recorded data in which a broadcast stream is recorded, wherein the recorded data includes video information including an I picture, and a start position of the I picture. A first time table, a second time table indicating a start position of a plurality of slice segments constituting the I picture, and continuity information indicating continuity of video scenes included in the video information, When fast-forwarding playback of the recording data, if the continuity information indicates that the continuity information is continuous, one of the plurality of slice segments constituting the I picture is played back, and When the continuity information indicates discontinuity, all the slice segments constituting the I picture are reproduced. Features.
A video recording apparatus according to the present invention is a video recording apparatus that records a broadcast stream on a recording medium, records the broadcast stream including video information including an I picture, and sets a start position of the I picture. A first time table is generated and recorded on a recording medium, and a second time table indicating start positions of a plurality of slice segments constituting the I picture is generated and recorded on a recording medium, and is included in the video information. The continuity information indicating the continuity of the video scene is generated and recorded on a recording medium, and when the broadcast stream is fast-forward reproduced, if the continuity information indicates that the continuity is continuous, the I picture is A case where one of the plurality of slice segments constituting the slice segment is reproduced and the continuity information indicates that the continuity information is discontinuous It is characterized by reproducing all of said slice segments constituting the I-picture.
A video recording medium according to the present invention is a video recording medium for recording a broadcast stream reproduced by a video reproduction device, wherein the broadcast stream including video information including an I picture, and the start of the I picture A first time table indicating a position, a second time table indicating a start position of a plurality of slice segments constituting the I picture, continuity information indicating continuity of video scenes included in the video information, Is recorded, and when the video playback device performs fast-forward playback of the broadcast stream, the video playback device determines whether the continuity information indicates that the continuity information is continuous or discontinuous. If the information indicates that it is continuous, the slice segment of one of the plurality of slice segments constituting the I picture Play the, when said continuity information indicates that it is a discontinuous, characterized in that it is used in the process of reproducing all of the slice segments constituting the I-picture.

  The video reproduction device, the video recording device, and the video recording medium according to the present invention can improve responsiveness during special reproduction.

1 is a configuration diagram of a video recording / reproducing device 100 according to Embodiment 1. It is a figure explaining a demultiplexing procedure. FIG. 3 is a diagram illustrating a logical structure of data. It is a schematic diagram at the time of combining and recording TLV packet. FIG. 4 is a conceptual diagram illustrating packet selection and time synchronization. FIG. 3 is a diagram illustrating a synchronization method using an MPU time stamp descriptor in the MMTP method. 9 is a flowchart illustrating a procedure for creating a time table. FIG. 5 is a diagram showing a time table that can be searched for at times in frame units. FIG. 3 is a diagram illustrating a synchronization method using an MPU time stamp descriptor in the MMTP method. FIG. 4 is an explanatory diagram when stream data is recorded as a BMFF. FIG. 14 is an explanatory diagram of demultiplexing by MPT in the MMTP method according to the second embodiment. FIG. 4 is an explanatory diagram of a relationship between a time table and video data. It is an example of the MPT data structure in the MMTP method. FIG. 4 is an explanatory diagram of alignment when focusing on an image. FIG. 14 is a schematic diagram of a video stream according to Embodiment 3. FIG. 4 is a diagram illustrating division of an image. FIG. 4 is a diagram illustrating division of an image. It is a figure of a time table corresponding to a division slice segment. It is a figure which shows the correspondence between each item of a time table and data. FIG. 3 is an explanatory diagram of fast-forward playback. FIG. 11 is an explanatory diagram of fast-forward playback according to Modification 1. FIG. 9 is an explanatory diagram of an image update order. FIG. 9 is an explanatory diagram of an image update order. FIG. 14 is a diagram of a time table according to a second modification. FIG. 3 is an explanatory diagram of fast-forward playback. FIG. 4 is an explanatory diagram of a time table (TMSN). FIG. 9 is an explanatory diagram of an effect of a scene continuity number. 9 is a flowchart of a display screen update using a scene continuity number. FIG. 9 is an explanatory diagram of an effect of priority slice information. 9 is a flowchart of a display screen update using priority slice information.

  2. Description of the Related Art As one of the ways to enjoy a television broadcast, recording (recording) a television broadcast program and reproducing and viewing the program at a later date has conventionally been performed. There are roughly two ways to enjoy recording. One is called "time shift". In the time shift, when the program cannot be watched during the broadcast time, the program is recorded and the program is reproduced later. Others are called "archives." The archive is for recording and storing programs. Therefore, the recorded program can be viewed at any time.

  In the case of using the time shift, the use is often ended in a short period after recording the program. On the other hand, when using an archive, a program is often recorded and stored for a long time before use.

  In addition to television broadcasting, recording of images taken by users themselves is also performed. Video data captured by a home video camera or the like is recorded and stored on an optical disk or a hard disk.

  Recently, video collected by a network or the like is sometimes recorded. In addition to recording at home, recorded images are also used in museums, museums, or digital signage. “Digital signage” is an advertising medium that displays video or information using a flat display or a projector by utilizing digital technology for display and communication.

  Commercial contents such as a movie include a read-only DVD or a Blu-ray disc on which the content is recorded. In recent years, in addition to optical discs containing packages, services for contents downloaded via a network have been increasing.

  The format for recording broadcast content may be different from the format for recording commercially available content. For example, in the case of a Blu-ray disc, two types of formats are defined. First, BDAV is a format for recording broadcasted content. BDAV can record broadcast waves as they are. Second, BDMV is a format for commercially available content. BDMV has an advanced playback control function. AVCHD is used when recording video on an HDD or a memory card used in a camera or the like. AVCHD is modified based on BDMV.

  In television broadcasting, the introduction of the Ultra Hi-Vision system corresponding to 4K video having a resolution four times that of the conventional system is scheduled. Also, broadcasting of higher quality 8K video is being studied. Similarly, in North America and Europe, the introduction of new television broadcasting schemes is being considered, each extending the current broadcasting scheme.

  Although there are differences between regions, the conventional television broadcasting system employs MPEG2 or AVC (h.264) as a video compression system. Also, the conventional television broadcasting system has adopted MPEG2TS as a multiplexing system. MPEG2TS presupposes a single transmission path called broadcasting, and is a form in which a broadcasting station collectively transmits video or audio. In MPEG2TS, a fixed-length packet system with a synchronization mark is used as a transmission unit. For this reason, a method of recording MPEG2TS is often adopted as a recording method.

  On the other hand, in many new television broadcasting systems, there are many standards that adopt MPEG2, AVC or HEVC (h.265) as a video compression system. HEVC (High Efficiency Video Coding) has a compression efficiency that is four times that of MPEG2 and twice that of AVC when compared with the same image quality. HEVC is a compression technology required for a new television broadcasting system aiming at higher image quality or narrower band.

  In addition, the new television broadcasting system places importance on compatibility with network technology. Therefore, in a new television broadcasting system, adoption of MMT (MPEG Media Transport) as a multiplexing system is being studied. The MMT is a system capable of providing information through a plurality of transmission paths, and separately transmits video or audio, and a receiver can select and receive them. Further, the MMT employs a variable length packet. Further, a method of changing a video stream to be reproduced according to a reception state is also being studied.

  As described above, it is difficult to record a new television broadcast system as it is in the currently used recording system. For this reason, a recording system compatible with a new television broadcasting system is required.

  Here, when making a new recording method, several approaches are conceivable.

  First, there is a method of completely converting a new broadcasting system into a video of a conventional system and recording it. In this case, there is no need to change the recording method, and compatibility with the conventional reproducing apparatus can be maintained. However, it cannot take advantage of new methods such as high image quality.

  Secondly, there is a method in which the video and audio, which are the center of the information of the television broadcast, are converted into a new system and recorded by following the conventional recording system as much as possible. In this case, the advantages of the new system can be obtained for video and audio. However, subtitles or data broadcasting cannot be enjoyed.

  Third, there is a method of recording program data of a new broadcasting method as it is. Except for external services such as network services, many of the benefits of the new method can be used.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a video recording / reproducing device 100 according to Embodiment 1. The video recording / reproducing device 100 is also described below as the recording / reproducing device 100. The video recording / reproducing device 100 and the recording / reproducing device 100 are the same device.

  The video recording / reproducing apparatus 100 includes a tuner / demodulator 11, a demultiplexer 21, and a recording / reproducing controller 41. In the following embodiments, a recording and playback device will be described, but a recording device that does not include a playback portion can be used.

  The video recording / reproducing apparatus 100 includes a video decoding unit 32, an audio decoding unit 31, a subtitle decoding / rendering unit 33, or a data broadcasting / EPG processing unit. The decoding unit includes a video decoding unit 32, an audio decoding unit 31, a subtitle decoding / rendering unit 33, or a data broadcasting / EPG processing unit.

  In addition, the video recording / reproducing device 100 can include a built-in recording device 51 or an optical disk drive 52.

  Further, the video recording / reproducing apparatus 100 can include an external input unit 12 or a network unit 13. The external input unit 12 and the network unit 13 have a function of receiving an external signal input. The tuner / demodulator 11 also has a function of receiving an external signal input.

<Configuration of video recording / reproducing device 100>
The tuner / demodulation unit 11 receives the broadcast wave Ba. Then, the tuner / demodulation unit 11 demodulates the received broadcast wave Ba. The external input unit 12 receives data from an external device Ei. The external device is, for example, a recording device such as a video camera. The “data” includes video data, audio data, caption data, data of data broadcasting, control information, and the like.

  The network unit 13 receives data from the network Ne. The network Ne is a computer network or a communication network capable of exchanging signals, data, or information by connecting a plurality of computers or electronic devices, for example.

  The demultiplexing unit 21 demultiplexes the multiplexed stream Sm. That is, the demultiplexing unit 21 separately extracts various data from the multiplexed stream Sm.

  The audio decoder 31 expands the compressed audio data. The audio decoding unit 31 expands the compressed audio data included in the elementary stream Se.

  The video decoding unit 32 decompresses the compressed video data. The video decoding unit 32 decompresses the compressed video data included in the elementary stream Se.

  The subtitle decoding / rendering unit 33 decompresses the compressed subtitle data. The subtitle decoding / rendering unit 33 decompresses the compressed subtitle data included in the elementary stream Se.

  The data broadcast / EPG processing unit 34 expands the data of the compressed data broadcast. The data broadcast / EPG processing unit 34 expands the compressed data broadcast data included in the elementary stream Se.

  The recording and reproduction control unit 41 collects recording video data, audio data, control information, and the like. The recording / reproduction control unit 41 converts the collected data into a data format for recording.

  The built-in recording device 51 is a recording device provided in the video recording / reproducing device 100. The internal recording device 51 is, for example, a hard disk drive, a volatile memory, a nonvolatile memory, or the like.

  The optical disk drive 52 records data on the optical disk 53. The optical disk drive 52 reads data from the optical disk 53. The optical disk 53 is, for example, a Blu-ray disk or a DVD.

<Data processing flow when data is not recorded>
First, a flow of displaying a broadcast program on a television without recording it will be described. That is, the process from reception of a broadcast wave to output of video and audio will be described using a broadcast wave as an example. The television is the display device Dd and the audio device Es in FIG.

  The external input signal includes a broadcast wave Ba received by an antenna, a video signal from a video camera (external device Ei) or the like, a video signal from a video playback device or the like, or video data from a network Ne. The user selects an input unit using a remote controller (remote controller) or operation buttons. The input unit is the tuner / demodulation unit 11, the external input unit 12, the network unit 13, or the like. The remote control is a remote control device operated by a user.

  In the case of the broadcast wave Ba, a broadcast station or a program is set. In the case of the network Ne, a data acquisition destination or access information to data is set. It is assumed that the video service that the user wants to view or the video service that the user wants to record is specified. Also, it is assumed that the video service that the user wants to view or the video service that the user wants to record is in a receivable state.

  The broadcast wave Ba received by an antenna or the like is input to the tuner / demodulator 11. The tuner / demodulation unit 11 extracts the radio wave of the designated broadcast station from the broadcast wave Ba. Then, the tuner / demodulation unit 11 demodulates the broadcast wave Ba by a specified demodulation method. Then, the tuner / demodulation unit 11 extracts digital data from the broadcast wave Ba.

  Here, the extracted digital data is a multiplexed stream Sm obtained by multiplexing video data, audio data, caption data, control information, and the like. Also, a plurality of programs may be stored together in one multiplexed stream Sm.

  The “stream” represents data having a time flow or data transmitted in a form having a time flow. For example, the stream is a video stream in the case of video data, and is an audio stream in the case of audio data. Other examples include a subtitle stream, a multiplexed stream, a received stream, a data stream, and the like.

  The multiplexed stream Sm is extracted by the tuner / demodulator 11. The multiplexed stream Sm extracted by the tuner / demodulation unit 11 is sent to the demultiplexing unit 21. The demultiplexing unit 21 separately extracts various data or various control information from the multiplexed stream Sm. The data is, for example, data that directly constitutes a program. The data is, for example, a video stream, an audio stream, or a subtitle stream. The data is, for example, a data broadcast program or data stored in the multiplexed stream Sm.

  Various data (elementary stream Se) demultiplexed are compressed data.

  The video stream is compressed video data. The video decoding unit 32 decompresses the compressed video data. The expanded video data is output as a video from the display device Dd or the like. The display device Dd is, for example, a television.

  Similarly, the audio stream is compressed audio data. The audio decoder 31 expands the compressed audio data. The expanded sound data is output as sound from the sound device Es. The sound device Es is, for example, a television.

  When output from the display device Dd or the audio device Es, the video data Di1 and the audio data Ds are buffered and synchronized (not shown). As a result, no shift occurs between the video and the audio. The output timing of the video data and the audio data is a timing designated or calculated from control information or a system clock.

  The subtitle stream is compressed subtitle data. The subtitle decoding / rendering unit 33 decompresses the compressed subtitle data. The subtitle decoding / rendering unit 33 interprets the expanded subtitle data. The subtitle decoding / rendering unit 33 visualizes the interpreted subtitle data. The imaged subtitle data is synthesized with video data or audio data at a specified timing. The combined subtitle data is output as a video from the display device Dd or the like.

  The data broadcast stream is compressed data. The data broadcast / EPG processing unit 34 expands the data of the compressed data broadcast. The data broadcast / EPG processing unit 34 combines the expanded video data and the expanded audio data at the designated timing. The synthesized video data and audio data are output as video and audio from a television or the like.

  The video recording / reproducing apparatus 100 outputs the broadcast wave Ba thus received as synchronized video and audio.

<Recording data>
Next, recording this video data will be considered.

  The recording / reproduction control unit 41 collects recording video data, audio data, control information, and the like in the flow from the reception of the broadcast wave Ba to the display of the video. The collected data is converted to a data format for recording. The data converted into the data format for recording is recorded on the optical disk 53 or the like through the built-in recording device 51 or the optical disk drive 52.

  Various combinations of positions where the recording / reproduction control unit 41 extracts the video data or the audio data can be considered. However, in order to facilitate the explanation, the explanation is simplified to the following three paths (A) to (C). The three paths are (A) extraction in the state of the multiplexed stream Sm, (B) extraction in the state of the demultiplexed elementary stream Se, and (C) the state in which video and audio are expanded (video data Di1).

  Hereinafter, (A) and (B) will be described.

{(A-1) Recording of data in the state of multiplexed stream Sm (1)}
Consider data extraction in the state of a multiplexed stream and recording on a Blu-ray disc (optical disc 53). The data is extracted using the path (A) in FIG.

  For example, in the case of a conventional broadcasting system of the Japanese system, the multiplexed stream Sm extracted from the tuner / demodulator 11 is a data in which a video signal compressed in the MPEG2 format is stored in a multiplexed stream of MPEG2TS. It is.

  An MPEG2TS broadcast stream employs fixed-length packets of 192 bytes. By combining these packets in the order of reception, a data file for a recording format can be created. The data file created in this way is called a stream file.

  A plurality of programs are multiplexed in an actually broadcasted stream. A process of extracting a target program from the program is required. However, the description is omitted here.

  First, the case of the BDAV format of a Blu-ray disc will be described.

  In the case of the Blu-ray Disc BDAV format, a clip file, a playlist file, an info file, and the like are required in addition to the stream file. A clip file is a file in which detailed information for accessing data in a stream file is recorded. The playlist file manages time-series information. The time-series information is, for example, information such as a start point and an end point of one program or switching of a playback stream. The info file manages information of the entire disc such as a list of reproducible programs.

  These pieces of information are created from management information in the stream, reservation information set by the user, management information obtained from the tuner / demodulation unit 11, and the like. These are described in detail in Patent Document 1, for example.

  Next, the case of a new broadcasting system in Japan will be described.

  This is described in, for example, "Advanced High Bandwidth Satellite Digital Broadcasting Operational Regulations, Version 1.1 NEXTVF TR-004" (published March 30, 2016, Part I, Part II, Chapter V by the Japan Broadcasting Services Advancement Association). Pp. 2-31 to 2-40, and FIG. 5-1).

  This method supports 4K and 8K high-resolution video. Also, this method supports color gamut and luminance gamut expansion. This system employs HEVC as a video compression system. This method employs a combination of MMT and TLV as a multiplexing method.

  MMT and TLV are designed in consideration of compatibility with IP packets used in a network. TLV is a transmission method using broadcast waves of IP packets. The MMT defines a method for transferring video data using IP packets and its data format. The IP packet employs a variable length packet. For this reason, MMT and TLV also employ variable length packets.

  A demultiplexing procedure in this method will be described with reference to FIG. FIG. 2 is a diagram illustrating a demultiplexing procedure.

  In FIG. 2, the horizontal direction indicates the order of data reception. That is, in the direction of the horizontal axis Ha, the data is arranged in the order of reception. It is described from left to right in the order of reception. The direction of the vertical axis Va indicates the flow of data processing. That is, in the direction of the vertical axis Va, the order of extracting data by packet analysis is shown. In the range of the vertical axis Va1, the multiplexing of the multiplexed stream Sm is released. In the range of the vertical axis Va2, the multiplexing of the elementary stream Se is released.

  The data of the TLV packet is obtained by demodulating the broadcast wave Ba. The TLV packet contains information on broadcasting. The information on the broadcast is, for example, a broadcast identifier, a channel, a broadcast station name, an IP address, a port number, or information on a radio wave to be used. The “radio wave to be used” is a terrestrial wave, a BS broadcast, a CS broadcast, or the like. “Information on radio waves to be used” includes the form of broadcast, modulation method, frequency, deflection direction or turning direction, and the like.

  Payload refers to the data portion in data transmission. That is, the payload corresponds to the entire data to be transmitted excluding management information for transmission processing. The management information is, for example, a header or metadata.

  The TLV (Type-Length-Value) is a format for collectively expressing the type, length, and value of information. UDP (User Datagram Protocol) is a protocol that operates in the transport layer of a protocol higher than IP. UDP operates by bridging the network layer IP with the protocol above the session layer. MMTP (registered trademark) is a multimedia multiplexing transmission protocol.

  The tuner / demodulator 11 extracts broadcast station information, IP address information, or port number information from the TLV packet. The tuner / demodulation unit 11 extracts a necessary IP packet using the information of the IP address. Next, the tuner / demodulation unit 11 extracts a UDP packet using the information of the port number.

  At this point, the tuner / demodulator 11 has demultiplexed the broadcast wave Ba sent from the broadcast station. Then, the tuner / demodulation unit 11 extracts the data of the UDP packet. The tuner / demodulator 11 removes the UDP header from the UDP packet. Then, the tuner / demodulation unit 11 extracts the UDP payload from the UDP packet. Thereby, the tuner / demodulation unit 11 can extract the MMTP packet from the UDP packet.

  According to a new broadcasting standard in Japan, one MMTP packet is stored in one UDP / IP packet. Further, one UDP / IP packet is stored in one TLV packet. Therefore, in the packet transmitting the MMTP after separating the control data, the MMTP packet is extracted by simply removing the TLV header, the IP header, and the UDP header from the TLV packet.

  At the time when the broadcast wave Ba has been extracted as an MMTP packet, the multiplexing of the broadcast wave Ba sent from the broadcast station has been released. However, the broadcast wave Ba may be multiplexed as a series of MMTP packets in which a plurality of programs are put together. In that case, in order to take out only a target program, control information is first taken out, and an MMTP packet is selected and taken out according to the description of the control information.

  One of the control signals sent as the MMTP packet is a PLT (Package List Table). When all information is transmitted by broadcast waves, the “packet_id” specified by “MMT_general_location_info” in the PLT is referred to. The MMTP packet is filtered using the “packet_id”. As a result, it is possible to select the MMTP packet including the management information of the target program. The “target program” is a program to be viewed.

  When acquiring program management information from the network, the IP address and port number described in “MMT_general_location_info” are specified. Alternatively, “MMT_general_location_info” specifies a program acquisition destination by a URL.

  Next, data including MPT (MMT_Package_Table) is extracted from the selected MMTP packet. The MPT describes a combination of assets such as video, audio, or subtitles that constitute a target program, and an acquisition source. The acquisition source of each asset is indicated by “packet_id” or network information by “MMT_general_location_info”. Here, the network information is an IP address, a port number, or a URL.

  In this way, the control data indicated by the PLT and the assets constituting the program indicated by the MPT are filtered by, for example, “packet_id”. Thus, the MMTP packet of the target program can be extracted.

  In the process of extracting the MMTP packet or the MMTP payload from the TLV packet, attention is focused on one packet. The packet header is stripped. However, the data in the packet does not change. However, packets are actually selected and classified based on the control information and the contents of the packet header at each stage.

[Recording without using standard format]
As one method of recording a program, for example, a method of recording a received broadcast packet as it is will be described.

  FIG. 4 is a schematic diagram when TLV packets are combined and recorded.

  In the example shown in FIG. 4, at the time of the TLV packet, the multiplexing of the multiplexed stream Sm sent from the broadcasting station is released. The TLV packets of the program are combined as they are. The combined TLV packets make up a file.

  FIG. 4 shows TLV packets TP-0, TP-1, TP-2, and TP-3. “−0” or the like indicates the order in which the TLV packets TP are received. For example, the TLV packet TP-0 is the first TLV packet TP received. The horizontal axis Ha represents the order of reception.

  The TLV packets TP-1, TP-2, and TP-3 received after the TLV packet TP-0 are connected behind the first received TLV packet TP-0. Then, the combined TLV packets TP-0, TP-1, TP-2, TP-3 are recorded. The TLV packet TP employs a variable length packet.

  Since data is received in packet units, the head of the packet is clear at the time of reception. However, when one file is created by combining with other packets, it is necessary to determine the head position of each packet.

  The first method is to create a list of the start position of a packet as a management file Af at the time of recording.

  This is because the head position of the packet in the file is known at the time of recording the packet. In this case, a list of the start position of the packet may be created in association with the packet number or the like.

  In the second method, data is read from the beginning of a file, and if there is leading data Hm, it is determined to be the beginning of the TLV packet TP. Then, the data combined with the TLV packet TP is read.

  In the TLV packet TP, a fixed value “0x7F” is stored in the first byte to identify the head of the packet. After the first byte, 1-byte data indicating the packet type is stored. After that, 2-byte data indicating the data length is stored.

  Here, the head data Hm of the TLV packet TP is a fixed value “0x7F”.

  When the fixed value “0x7F” (the leading data Hm) is read, the data read immediately before is interpreted as the TLV packet TP and the processing is performed.

  The fixed value “0x7F” is not a special value. The fixed value “0x7F” also exists in the data. Therefore, there is a possibility of reading from the wrong position. Even in this case, it is checked whether there is any contradiction as the data of the TLV packet TP. Alternatively, after reading the data of the data length, it is checked whether or not the head of the next data is a fixed value “0x7F” every time. As a result, packets can be read at the correct data breaks.

  In this example, a method of recording a TLV packet has been described. However, another method of recording a UDP / IP packet can be adopted. In addition, a method of recording the MMTP packet as it is can be adopted.

  However, the reason for selecting the TLV packet is that a fixed byte for identification is prepared at the head of the TLV packet, and the identification of the packet is relatively easy.

  In another method of recording a packet, a mark for identification may not be inserted. Therefore, a method of independently inserting an identifier can also be adopted. In the case of a UDP / IP packet, for example, a method of using IP address information as a mark for identification can be adopted. The IP address information does not change during the same program.

{(A-2) Recording of data in state of multiplexed stream Sm (2)}
The MPT is stored in an MMTP packet and transmitted. MPT contains control information. The demultiplexing unit 21 sorts the packet based on the information described in the MPT. The information described in the MPT is, for example, packet ID information included in the MMTP header. Thus, the demultiplexing unit 21 can individually extract video information, audio information, and the like. Then, the demultiplexing unit 21 can demultiplex the multiplexed stream Sm.

  The MFU is stored in the MMTP packet. A plurality of MFUs may be stored in one MMTP packet. Further, one MFU may be stored in one MMTP packet. One MFU may be stored in a plurality of MMTP packets.

  The MFU of the video data or the MFU of the audio data included in the MMTP is a processing unit called an access unit (hereinafter, referred to as an AU) or a NAL unit. The NAL (Network Abstraction Layer) unit is data obtained by further dividing the AU.

  When video data is stored directly in the MFU, a case where an AU is stored and a case where a NAL unit is stored are defined. However, a new broadcasting method in Japan adopts a method of storing in a NAL unit. Therefore, in the following description, it will be described as being stored as a NAL unit.

  FIG. 2 shows a case where the NAL unit is directly stored in the MFU. The NAL units include a VCL-NAL unit containing only video data and a non-VCL-NAL unit containing management information without containing video data (VCL: Video Coding Layer).

  For a non-VCL-NAL unit, control information is obtained by removing the NAL header.

  When the VCL-NAL unit removes the NAL header, the divided video data is extracted. By combining these divided video data, one frame of compressed video data is obtained.

  Normally, a NAL unit handles a plurality of NAL units including management information and video data for one frame as a set, and is called an AU. In the case of video data, the AU includes video data. Then, the demultiplexing unit 21 can reconstruct the ES (elementary stream).

  The AU of video data is basically a video unit for one frame. The video unit for one frame is a unit expressing a picture. The video device displays the picture as a moving image by displaying the picture while sequentially switching the picture in time series. However, there are several types of dependencies with the frames before and after.

  One is called an I picture. An I picture can reproduce one picture only with this data.

  Others are called P pictures or B pictures. These data are dependent on other pictures. Therefore, a P picture and a B picture cannot alone reproduce one picture. The P picture and the B picture can reproduce the picture by referring to other pictures. The P picture refers to one other picture. The B picture refers to two other pictures.

  In a television broadcast or a video recording / reproducing device, it is required that the program can be viewed from the middle of the program. In addition, a television broadcast or a video recording / reproducing device or the like is required to be capable of random access. Therefore, it is inconvenient if the picture to be referred to is wide.

  Therefore, a certain amount of time or the number of frames is treated as one set. In this set of data, a reference picture is defined so as to be completed.

  This set of data is called a GOP (Group Of Pictures). A GOP includes at least one I picture. When viewing from the middle of a program, even if the acquired stream data starts from an incomplete position where the video cannot be reproduced, the video can be reproduced and displayed from the beginning of the next GOP.

  For example, a new broadcasting system in Japan requires a GOP to be created in about 0.5 seconds for 2K broadcasting and about 1 second in 4K broadcasting. Thus, even when the power of the television is turned on or when the channel is switched, an image can be displayed in one to two seconds.

  When the video is switched over the entire screen, it is more efficient to divide GOPs before and after the switching. For example, the efficiency such as the compression ratio or the image reproduction is improved. When the entire screen is switched, for example, the scene is switched. Therefore, the GOP length is not a fixed value but is operated flexibly. That is, the GOP length is changed according to the situation.

  In communication or Internet distribution, a GOP in a unit longer than a new broadcasting system in Japan may be used.

  When reproducing the recorded video, the video is accessed from the beginning of the GOP including the frame to be displayed. This enables smooth random access. When fast-forwarding or the like, only I pictures can be displayed for each GOP. A GOP is a unit of a group of video data that can be reproduced as a moving image. GOP is a unit indicating a position where reproduction is possible. GOP is a unit indicating a position where random access is possible.

  When receiving the broadcast wave Ba, a PLT (Package List Table) is received. PLT is one of the control signals sent as MMTP packets.

  When all the information is transmitted by the broadcast wave Ba, the “packet_id” specified by “MMT_general_location_info” in the PLT is referred to. Then, the MMTP packet is filtered by the “packet_id”. As a result, it is possible to select the MMTP packet including the management information of the target program.

  When acquiring the management information of the program from the network Ne, the acquisition source of the program is specified by the IP address and the port number described in “MMT_general_location_info”. Alternatively, the acquisition source of the program is specified by the URL described in “MMT_general_location_info”.

  Next, data including MPT (MMT_Package_Table) is selected from the selected MMTP packets. The MPT describes a combination of assets such as video, audio, and subtitles that constitute a program, and an acquisition source. The acquisition source of each asset is indicated by “packet_id” described in “MMT_general_location_info” or network information. The network information is an IP address and a port number. Alternatively, the network information is a URL.

  For assets that need to be synchronized in time, such as video, audio, and subtitles, an MPU time stamp descriptor and an MPU extension time stamp descriptor are defined for each asset.

  As the acquisition destination of the asset and the like, a case where the asset is transmitted by being included in the broadcast wave Ba and a case where the asset is acquired from the network Ne are defined. However, for the sake of simplicity of description, a case where the broadcast wave Ba is transmitted and included in the broadcast wave Ba will be described as an example.

  The new Japanese broadcasting system employs a system in which video data and audio data are stored in a MFU directly and transmitted. Further, in the new Japanese broadcasting system, the data from the MMTP packet with “RAP_flag” added to immediately before the MMTP packet with “RAP_flag” added is treated as one data set. Then, the one set of data is handled as an MPU. “RAP_flag” indicates a start point of data that can be randomly accessed.

  By examining the presence or absence of “RAP_flag” of the MMTP packet, these can be identified as belonging to the same MPU. Alternatively, these can be identified as belonging to the same MPU by “MPU_sequence_number” of the MMTP packet. Here, the MPU in this usage is temporarily referred to as a “stream transmission unit MPU”.

  The “stream transmission unit MPU” is headed by data that can be randomly accessed. For this reason, from the viewpoint of video, it is a GOP unit. That is, the “stream transmission unit MPU” can be considered as a group of MMTP packets constituting one GOP from the viewpoint of MMTP.

  The above-mentioned MPU time stamp descriptor and MPU extension time stamp descriptor provide information on the time to be synchronized in association with the “stream transmission unit MPU”.

  In the MPU time stamp descriptor, the timing at which the MPU such as video or audio is reproduced first in each MPU is indicated by the time in NTP (Network Time Protocol) format. NTP is a protocol for properly synchronizing the time between computers with a system clock built in the computer via a network.

  In the MPU extension time stamp descriptor, the reproduction timing is described as a relative time in the MPU for each AU (frame in the case of video) in each MPU. The relative time in the MPU is a difference from the head in the AU or a difference from the immediately preceding AU. "Difference" refers to the difference between two values. For example, here, the two values are time.

  With these descriptions, a combination of video, audio, subtitles, and the like can be specified. Then, it is possible to reproduce the video, audio, subtitles, and the like while synchronizing with time.

  In television broadcasting, PLT and MPT are retransmitted at a relatively short cycle so that a program can be displayed in a short time after the television is turned on. In the case of the new Japanese broadcast scheme, PLT and MPT are sent every 100 ms.

  The method of recording a file in which the TLV packet, the TCP packet, and the MMTP packet are combined has been described. Alternatively, a method of recording a file in which a TLV packet, a UDP packet, and an MMTP packet are combined has been described.

  However, in this state, information on the reproduction time, information indicating the position where random access is possible, and the like are dispersedly recorded in various places in the file. This is not suitable for accessing information. Further, since the same information is recorded many times, it is redundant.

  This information is recorded in a distributed manner because in broadcasting, it is necessary to arrange the information in a short time and start displaying the program, regardless of the point in time at which reception of the program starts. For this reason, information is distributed to various places in the stream. Also, in broadcasting, it is not necessary to consider recording and random access.

  When the recorded program is viewed, a search for a scene, a search or editing of a scene, and a connection between videos are performed. Therefore, random access is required. Therefore, information necessary for random access is created independently at the time of recording information or after recording information.

  Data generation for random access will be described with reference to FIG. 5, FIG. 6, and FIG.

  Here, an example will be described in which video data including video or audio is created as a file combined with MMTP packets. However, the same applies to the case where TLV or UDP / IP packets are used.

  FIG. 5 is a conceptual diagram illustrating packet selection and time synchronization. What is represented by a square is an MMTP packet.

  In FIG. 5, the horizontal direction indicates the order of data reception. That is, in the direction of the horizontal axis Ha, the data is arranged in the order of reception. It is described from left to right in the order of reception.

  “RAP_flag” is set in the packet of the video MMTP packet described as “R”. And it includes the head of the GOP.

  In FIG. 5, the arrows drawn from the MPT indicate the relationship in which the MPU time stamp descriptor of the MPT determines the playback time of each MPU.

  For example, MPT-0 that appears first specifies “packet_ID” as a video asset. In FIG. 5, as an example, the MPT-0 specifies the reproduction time stamps of the MPU-v0 and the MPU-v1. The MPU is composed of a plurality of MMTP packets.

  Also, the same MPT-0 specifies “packet_ID” as a voice asset. In FIG. 5, as an example, the MPT-0 specifies reproduction time stamps of the MPU-a0 and the MPU-a1. Note that the number of audio MPUs is not limited to one for one MMTP packet. Further, the audio MPU does not always appear at the same frequency as the video MPU. However, one MMTP packet is one audio MPU for drawing. In addition, the frequency of appearance of the video MPU and the frequency of appearance of the audio MPU are approximately the same.

  In FIG. 5, three flows of audio, video and control information are written. However, actually, the video recording / reproducing apparatus 100 receives the data in a mixed state as one data flow.

  A state in which such different types of information are mixed as one piece of data is called multiplexed. From the multiplexed state, a target data flow (stream) can be extracted and separated using “packet_ID”, various flags or various identifiers. “Packet_ID”, various flags or various identifiers are added to each MMTP packet. Extracting target data from the multiplexed data is called demultiplexing.

  An MMTP packet containing the MPT is extracted from the multiplexed data of the target program. Then, the MPT is extracted from the MMTP packet. In the MPT, a list of various assets constituting the program and a method of obtaining the list are stored.

  For example, it is possible to know the type of video and “packet_ID” that stores the data. In addition, it is possible to know the type of voice and “packet_ID” storing the data. With these “packet_IDs”, the received MMTP packets are selected or classified. With these, video data or audio data constituting a program can be individually taken out. That is, the multiplexing can be released.

  One of the purposes of the container format is to collectively multiplex different data into a set to facilitate handling. The container format is, for example, MMT or MPEG2TS.

  In FIG. 5, the received stream data is divided into three streams: an MPT stream, a video stream, and an audio stream.

  Another purpose of the container format is to reproduce these data in time. That is, another purpose of the container format is to reproduce these data in synchronization.

  In FIG. 5, when MPT-0 is received, asset information such as video or audio constituting the program can be obtained. Further, time stamp information is described for each of these assets. The time stamp information is information indicating the timing of video display or audio reproduction. The time stamp information is described in the MPT. The time stamp information is the reproduction time for the number of the “stream transmission unit MPU” for each asset.

  For example, for a video, the reproduction time of the first frame of MPU-v0 and the reproduction time of the first frame of MPU-v1 are described in MPT-0. The reproduction time of the first frame of each of MPU-v1 and MPU-v2 is described in MPT-1.

  Similarly, for audio, the reproduction time of MPU-a0 and the reproduction time of MPU-a1 are described in MPT-0. Further, in MPT-1, the reproduction time of MPU-a1 and the presentation time of MPU-a2 are described.

  Here, for the sake of explanation, it has been described that each asset has two time stamps of “stream transmission unit MPU”. However, in practice, more timestamps can be provided.

  In this way, the reproduction time of the “stream transmission unit MPU” can be designated by the MPU. Then, the video and the audio can be reproduced in synchronization. Although not described here, the same applies to subtitles.

  The case of recording such information will be described with reference to FIG. FIG. 6 is a diagram illustrating a synchronization method using an MPU time stamp descriptor in the MMTP method. FIG. 6 shows an asset table, a time table, and a data file. The upper part of the data file is the head of the data.

  In the data file, MMTP packets constituting the program are sequentially recorded. When MMTP packets are simply recorded in the order of reception, video data, audio data, control information, and the like are recorded in a mixed state. Here, for the sake of explanation, it is described in a form in which each “stream transmission unit MPU” is summarized.

  For example, “MPT-0” is MPT. And the order in which they were received is given. Since the order of “MPT-0” is “0”, it indicates that it was received first.

  For example, “MPU-v0” is an MMTP packet selected as a video stream. The MMTP packet is treated as an MPU in which a plurality of MMTP packets are put together. And the order in which they were received is given. Since the order of “MPU-v0” is “0”, it indicates that it has been received first.

  For example, “MPU-a0” is an MMTP packet selected as an audio stream. The number of audio MPUs is not limited to one for one MMTP packet. Further, the audio MPU does not always appear at the same frequency as the video MPU. However, for the sake of simplicity, it is assumed that audio MPUs occur at the same frequency as video MPUs. Also, one MPU for voice is provided for one MMTP packet.

  The packet described as “R” in the data file has “RAP_flag” set. And it includes the head of the GOP. Therefore, the video can be efficiently reproduced by starting to read the data from the packet.

  Also, discarding incomplete data is reduced. The video data forms a GOP. For this reason, if the data of the leading I-picture part is missed, dozens of subsequent pictures cannot be reproduced as video. If the first data of the GOP is missed, the read data is discarded while waiting for the next GOP. Such discarding of data can be reduced. Such discarding of data causes display delay at the time of cueing or random access. Therefore, smooth reproduction can be achieved by reducing data discarding.

  As described above, the data file thus recorded is not suitable for random access.

  First, the video data is variable length data. For this reason, it is not possible to specify where the data for reproducing the target video exists. Second, a packet in which “RAP_flag” is set cannot be directly called.

  Therefore, a search table for random access is prepared.

  “Packet_id” is stored in the asset table of FIG. By using “packet_id”, necessary assets can be extracted from MMTP packets in the data file.

  The time table stores the recording position in the file of the packet including “RAP_flag”. Then, the designated reproduction time of the “stream transmission unit MPU” including this packet is stored. These pieces of information are arranged in chronological order of the reproduction time.

  The contents of the asset table and the time table can be created, for example, from information described in the MPT and information recorded on the video recording / reproducing apparatus 100.

  A case where reproduction is performed at a predetermined time will be described.

  For example, in FIG. 6, when displaying the video from the time “0: 0: 1.00”, first, the time in the time table is searched. Then, "25000000", which is the position on the file, is read from the column where the times match.

  Therefore, data is read from the data file at the position "25000000". Then, data reproduction processing is performed. Thereby, data can be reproduced from the designated position.

  The data file is a state in which video data, audio data, or other data is mixed in packet units. However, by classifying packets with reference to the asset table or the MPT, it is possible to separate and reproduce video data or audio data.

  There is a case where the same time as the time to start the reproduction does not exist in the time table. In this case, from the times described in the time table, the one closest to the time at which the reproduction is to be started is selected, and the data is reproduced therefrom.

  For example, when “0: 0: 1.70” is designated as the reproduction start time, “0: 0: 1.50” and “0: 0: 2.00” described in the time table "0: 0: 1.50", which is close to the designated time, is selected. Then, the data is reproduced from the position "33000000" on the data file.

  The position on the data file is, for example, a position in byte units from the head of the file. Alternatively, the position on the data file is, for example, a position in block units. Alternatively, the position on the data file is, for example, a position in sector units.

  The case of special reproduction will be described. The trick play is, for example, fast forward or rewind. For example, in the case of fast-forward, the time table is sequentially read, and the file is read from the designated position. Then, when the data for one frame is reproduced, the process moves to the next time position. As a result, data can be reproduced in fast forward.

  FIG. 7 is a flowchart showing a procedure for creating a time table.

  In the Japanese broadcasting system, the MPT is retransmitted every 100 ms. If one GOP is 0.5 seconds, MPT is received five times during that time. One GOP is one “stream transmission unit MPU”.

  Also, it is allowed to store 15 time stamps in one asset of one MPT. That is, the time stamps are transmitted in duplicate.

  In step S7001, an MMTP packet is extracted when receiving stream data. When the MMTP packet includes the MPT, the time stamp processing is performed.

  In step S7002, the MPT is extracted from the MMTP packet. Then, a combination of the sequence number of the “stream transmission unit MPU” and the time stamp information for each asset is extracted.

  In step S7003, the duplication of the time stamp information is removed. As described above, this is because the time stamp information is transmitted in duplicate. At this point, a sequence number of the “stream transmission unit MPU” and a list of time stamps indicating the reproduction time are obtained.

  Although not included in this flowchart, MMTP packets containing video data or audio data in parallel are sequentially recorded as data files on the built-in recording device 51 or the optical disk 53. Then, the position on the data file is known at the time of recording.

  In step S7004, when recording the MMTP packet in which “RAP_flag” is set, the position of the packet in the file and the sequence number of the “stream transmission unit MPU” to which the MMTP packet belongs are extracted. In the list of time stamps, information on the position recorded on the file is added to the time stamp information having the same sequence number of “stream transmission unit MPU”.

  In step S7005, it is confirmed whether these processes have been completed. If the processing has not been completed, "no" is selected, and the flow advances to step S7001. When the process is completed, “yes” is selected, and the process proceeds to step S7006.

  In step S7006, the created data is written to the built-in recording device 51 or the optical disk 53.

  In this way, a time table can be created.

  Here, random access is realized using the time stamp information of the MPU time stamp descriptor set for each GOP. The GOP is a “stream transmission unit MPU”. Therefore, the position where data reproduction can be started is in GOP units. That is, the reproduction position can be specified only in units of 0.5 seconds or 1 second. For example, in the case of cueing, fast-forwarding or rewinding by specifying time, such accuracy is sufficient.

  However, when editing or the like is performed after recording on the built-in recording device 51 or the optical disk 53, the position specification in GOP units is not sufficient. For example, there are cases where different positions of the same program are combined and played back continuously, or where different programs are combined and played back continuously. With such a combination, a favorite scene collection or the like can be created.

  Therefore, the MPU extension time stamp descriptor in the MPT is used.

  FIG. 8 is a diagram showing a time table that can be searched at a time of a frame unit.

  The time table shown in FIG. 8 is a time table obtained by expanding a normal time table so that a search can be performed at a time of a frame unit. The time table shown in FIG. 8 has information on a reproduction time, a data position on a file, and an AU number.

  The AU number indicates the AU number of the data belonging to the same “stream transmission unit MPU”. In the case of video data, AU corresponds to a picture. However, for decoding efficiency, the order of the AUs in the GOP does not always match the display order of the pictures.

  In this time table, they are arranged in the order of the reproduction time. Therefore, the AU numbers are different. That is, the AU numbers are not arranged in order.

  In the MPU extension time stamp descriptor, a reproduction time is given to an AU in each “stream transmission unit MPU” as a difference from an AU displayed first. Alternatively, in the MPU extension time stamp descriptor, an interval of a reproduction time is given to an AU in each “stream transmission unit MPU”.

  Therefore, the playback time of each AU can be calculated from the playback time of the MPU time stamp descriptor and the difference time between the MPU extension time stamp descriptor. Alternatively, the reproduction time of each AU can be calculated from the reproduction time of the MPU time stamp descriptor and the interval between the reproduction times of the MPU extended time stamp descriptor.

  Note that, in FIG. 8, for the sake of explanation, an example is shown in units of 1/100 second.

  In the MPU extended time stamp descriptor, a number for dividing one second is defined as a time scale. The playback time of each AU is described using this time scale. The frame rate used for video is 60 frames per second or 24 frames per second. If one frame is expressed in fractional seconds, an error occurs because it is not divisible. For this reason, a time scale is used. Therefore, a value using this time scale can be adopted in the time column for each frame of the time table.

  Even if it is desired to start reproducing data from the middle of the GOP, decoding is always performed from the beginning of the GOP. Therefore, the data reading start position is the same in the same “stream transmission unit MPU”.

  An example of a case where data is reproduced using this time table will be described.

  When the search is performed by designating the time “00: 00: 01.04”, there is no picture corresponding to this time. For this reason, reproduction is performed from the immediately preceding picture "00: 00: 01.03".

  Referring to the time table, this picture is the AU with the AU number 2 of the “stream transmission unit MPU” starting from the position “25000000” on the file. That is, the AU of this picture is the third AU.

  Therefore, reading is started from the position "25500000" on the file and decoding is started. Decoding of the first AU is completed, and picture data is created. After this, the created picture is not displayed. Then, the subsequent AU having only the difference information is decoded. Then, after the decoding of the third AU is completed, the reproduction is started from the video of the third AU. In this way, data (video) can be reproduced from the middle of the GOP.

  In this example, reproduction is performed using one time table having detailed information. However, for example, in the case of the above-described fast-forward playback, it is not always an efficient method. Therefore, a method of performing a search in two stages of a standard time table and a detailed time table may be adopted.

  In a new broadcasting system in Japan, the MPU extended time stamp descriptor specifies a playback interval between AUs. The interval is 1/60 second or 1/120 second. This interval is variable. However, the same frame rate is used in a program. Therefore, the reproduction time of each frame can be obtained by calculation without using a detailed time table.

  In this case, the search is performed using the time table for each “stream transmission unit MPU” shown in FIG. Then, the “stream transmission unit MPU” including the time at which the reproduction is to be started is specified. Then, a difference between the reproduction time and the time at which reproduction is desired to be started is obtained. From the time difference and the frame rate, it is possible to determine the number of the picture in the display order within the “stream transmission unit MPU”.

  If there is no frame at the designated time, the frame is set to the frame immediately before or immediately after the designated time in display order. That is, the frame immediately before or immediately after the designated time is adopted.

  As described above, the order of the AUs and the order of the picture playback times are different. However, decoding starts from the head of the “stream transmission unit MPU”. Then, decoding of the picture having the calculated reproduction order is completed. Playback starts from the decoded picture. This makes it possible to perform cueing with the accuracy of a picture unit.

  Here, when the time table described above is created as a separate file for recording, it is not necessary to record a time stamp in a data file for recording program contents.

  The MPT includes control information other than the time stamp. For example, the MPT includes asset information and the like. The time stamp is, for example, an MPU time stamp descriptor or an MPU extended time stamp descriptor. That is, the MPT includes control information other than the time stamp, such as asset information, in addition to the MPU time stamp descriptor or the MPU extended time stamp descriptor.

  However, such information is not of a nature that is changed during the program. For this reason, by recording at one place in a separate file or the like, the recording of MPT itself can be omitted. For example, in FIG. 6, management information (Packet_id) is held as an asset table.

  When the MPT is stored alone in the MMTP packet, it is not necessary to record the MMTP packet storing the MPT when recording the MMTP packet in the data file.

  When the MPT is stored in the MMTP packet together with other management information, the MMTP packet is reconfigured with the management information excluding the MPT. Then, the reconstructed MMTP packet can be recorded.

  The MPU time stamp descriptor or the MPU extended time stamp descriptor is data having a high degree of duplication during broadcasting. Therefore, if it can be omitted, the data size to be recorded can be reduced.

  In the above description, it was not necessary to record the MPT. However, it may be more convenient to record the MPT together with the MMTP packet including a stream such as a video stream or an audio stream.

  For example, when decoding processing is performed using an LSI in which the demultiplexing unit 21 and the decoding units 31, 32, 33, and 34 are integrated, data including MPT is input to the demultiplexing unit 21. Thus, demultiplexing, decoding, and synchronization can be performed collectively.

  Also, when performing cueing in units of frames, if there is an MPT before or at the beginning of the "stream transmission unit MPU", referring to this MPT, the reproduction time in units of frames is determined before starting reproduction. You can search for the beginning. The MPT may be near the head of the “stream transmission unit MPU”.

  Also in this case, it is not necessary to record all the MPTs transmitted from the television station. Processing can also be performed by recording only a part of the MPT.

  FIG. 9 is a diagram illustrating a synchronization method using an MPU time stamp descriptor in the MMTP method. In FIG. 9, the MPT is stored immediately before the “stream transmission unit MPU”. The time table indicates the position of the MPT, not the head position of the “stream transmission unit MPU”.

  In a conventional Blu-ray disc recording method, “EP_map” is stored in a clip file as information corresponding to these time tables. However, the “EP_map” has a structure based on an MPEG2TS having a fixed-length packet and a time stamp for each packet. Therefore, it cannot be applied to MMT data as it is.

  Therefore, the above-mentioned time table is used instead of “EP_map”. Thus, when MMT data is recorded on a Blu-ray disc, data access can be facilitated.

  In this example, a description has been given of combining and recording MMTP packets. However, it is also possible to combine and record the packets in the respective states of the TLV packet, the IP packet and the UDP packet. In addition, it is also possible to extend the time table and record each asset. That is, it is possible to search for the reading start position of the video data or the audio data. Then, the data is combined and recorded as a list of MFUs.

[When recording using standard format]
In the MMT, the storage format is defined separately from the transmission format as described above. In the storage format of the MMT, data is stored based on the BMFF (ISO / IEC 14496-12 ISO Base Media File Format) format. In this case, the data layout has the logical structure shown in FIG. FIG. 3 is a diagram showing a logical structure of data.

  This block of data is called an MPU. This MPU is different from the aforementioned “stream transmission unit MPU”. Here, it is tentatively called a “program storage MPU”. The “program storage MPU” is stored and managed as a normal file.

  The structure of the "program storage MPU" will be described using the logical structure of FIG.

  The MPU metadata includes file management data, asset information, various parameters or hint information, and the like. The asset information is information for managing a combination of video data and audio data. The various parameters are parameters for setting the operation mode and the like of the decoder. The hint information is information for reconstructing the MMTP packet from the MFU stored in the MPU file.

  Movie fragment metadata is information for accessing video data, audio data, and the like delimited by the playback time. The movie fragment metadata is information for reproducing video data, audio data, or the like.

  Actual video data and audio data are stored as a list of MFUs. One piece of movie fragment metadata and a block of MFU managed by it are collectively called a movie fragment. Generally, a plurality of movie fragments constitute one content. In network streaming or the like, one fragment generally consists of 10 to 15 seconds.

  When the MPU metadata and the movie fragment metadata are transmitted in a broadcast wave Ba or the like, an MPU can be configured using these. PLT, MPT, other control information, or various header information until the MFU is extracted are redundant and need not be recorded.

  On the other hand, in the new Japanese broadcasting scheme proposal, MPU metadata and movie fragment metadata are not transmitted at the time of broadcasting. Therefore, PPU information, MPT information, and various types of header information are combined to independently create MPU metadata and the like.

  It is considered that the above storage format is also used for recording on the optical disc 53. The optical disk 53 can read data stored physically continuously at a relatively high speed. However, reading data at a position distant in the diameter direction on the optical disc 53 involves a head seek, so that it takes time to read the data. That is, in the optical disc 53, if data that is likely to be used before and after is arranged in a continuous area or a close position on the disc 53, the data can be read out more efficiently.

  When data is recorded in the data arrangement with the logical structure shown in FIG. 3 as it is, MPU metadata, movie fragment metadata and MFU are stored in a distributed manner as a physical arrangement. MPU metadata is data necessary for reproduction. The MFU stores video data. Therefore, due to the characteristics of the optical disk, the data arrangement with the logical structure shown in FIG. 3 is disadvantageous.

  In many file systems, the logical structure and physical arrangement of stored data can be managed separately. The same applies to the UDF used in Blu-ray discs.

  Accordingly, the MPU metadata and the movie fragment data are collectively recorded in the physical arrangement with the logical structure as specified.

  The data structure shown in the physical arrangement of FIG. 3 is an example in which management information is collectively arranged as a physical data arrangement on an optical disk. With such a data arrangement, the MPU metadata and the movie fragment metadata can be read at once.

  Here, the “data structure” indicates a structure viewed from a higher level than the file system. For example, a logical data structure, a data arrangement in a directory or one file, and the like. On the other hand, “data arrangement” indicates an arrangement viewed from a lower level than the file system. For example, a physical data layout is used. It is composed of blocks linked by a file name and a file name, or link information between blocks indicating data connection. In this case, a block is a set of data managed in association with a physical location on the disk. Other names may be used depending on the file system.

  The data arrangement shown in the physical arrangement in FIG. 3 reduces the number of head seeks. The data arrangement shown in the physical arrangement of FIG. 3 can reduce the time required for starting reproduction and the time required for random access.

  It is also conceivable to simply give a copy of the management information to another file without considering the logical structure and the physical arrangement separately. The additional clip file shown in FIG. 3 is an example of such a case. In this case, for example, additional information or the like for facilitating random access can be added to the file.

  In the example shown so far, the example of the data structure using the fragment has been described. However, when transmission in units of fragments is not assumed, recording in a data structure without movie fragment metadata is also possible.

  In the BMFF file format, management information and stream data are collectively recorded in the same file. On the other hand, in a conventional Blu-ray disc recording method, management information and stream data are separately managed.

  This is because it is suitable for the device of the optical disc to read the management information collectively, set the device according to the data to be reproduced, and then reproduce the stream data. The management information and the stream information are recorded on the optical disc in different areas. Also, this is because the management data is double-recorded on the optical disk and used as backup data in preparation for damage to the optical disk. This backup data is recorded at a remote position on the optical disk.

  The management data in the BMFF is information managed mainly by a clip file in a Blu-ray disc. Therefore, when recording as a BMFF, the management data portion of the program is referred to from another file on the file system. That is, apparently, the management data portion of the program can be a separate file.

  FIG. 10 is an explanatory diagram when stream data is recorded as a BMFF.

  FIG. 10 shows an example in which stream data is recorded as BMFF.

  As a physical arrangement, the management data is recorded in a management data area on the optical disk 53. The stream data portion is recorded in a stream data area on the optical disc 53.

  When accessing this data as a stream file, the file system associates the management data portion with the stream data portion so that it can be logically viewed as one BMFF file.

  On the other hand, when accessing this data as a clip file, which is management data of a Blu-ray disc, only the management data portion of the BMFF file is made to appear as a file. A clip file is management data of a Blu-ray disc.

  With such an arrangement, a BMFF format file can be created as a standard recording format of MMT. In addition, a data format compatible with the Blu-ray disc management method can be used.

  If the header portion of the data recorded as the BMFF can be referred to as another file in this manner, it is advantageous in data management on the optical disc 53. Also, it becomes easy to create backup data of the management data.

  For example, when video data is taken out by a PC or the like, if a BMFF file is copied, it can be copied as a BMFF file containing both management information and stream data. On the other hand, when making a backup of the management information in the optical disk, if a copy is made from the BMFFCLIP file, only the management data portion that needs to be backed up can be copied.

  Further, the management data portion of the BMFF can be stored in another area of the optical disk 53 where the management data is stored, in accordance with the format of the optical disk storing the management data and the stream data separately. Therefore, the amount of head seek when preparing for reproduction can be reduced.

{(B) Recording of Data in Demultiplexed Elementary Stream Se State}
In the above-described example, the method of converting the received data into the storage format while partially demultiplexing the received data has been described. The received data is data received from the broadcast wave Ba, the external device Ei, the network Ne, or the like.

  However, when the demultiplexing unit 21 is made as hardware, it can be extracted and recorded in an ES (Elementary stream) state separated into video or audio. Note that the ES is shown as an elementary stream Se in FIG.

  ES is a stream of compressed video data or a stream of audio data. The ES is divided for each unit. Here, the “unit” is a meaningful unit for processing. This unit is, for example, a picture or NAL in the case of video data. This unit is, for example, a block in the case of audio data.

  In the following, the video recording format will be described using ISO BMFF as an example.

  In a method of recording data in a multiplexed state in the BMFF, data for managing data having a time flow is called a track.

  In the above-described method of recording in a state where multiplexing is not released, there is one track. This is, for example, a state in which video data and audio data are multiplexed, so that data having a time flow is one of the multiplexed streams Sm. The multiplexed stream Sm is represented as a list of MFUs.

  On the other hand, in the state of the elementary stream Se, for example, the video data and the audio data exist as separated ES stream data. Therefore, a track for video data and a track for audio data are separately created. The track of the video data and the track of the audio data are recorded in an area for storing management data in the data file. Then, the video data and the audio data are stored in an area for storing the media data.

  Each track indicates a playback time. Each track indicates the position of an area for storing media data corresponding to the playback time. The media data is video data, audio data, or the like.

  Then, the video data and the audio data are associated with each other in a time-synchronized state. Similarly, subtitles and the like are also related, including display timing.

  In the new Japanese broadcasting scheme proposal, combinations of video, audio, subtitles, and the like used in a program are indicated in the MTP of the MMTP packet. The display timing or reproduction timing of video, audio, subtitles, or the like is indicated in the MTP of the MMTP packet. Further, in the MTP of the MMTP packet, the storage position of data such as video, audio, or subtitles is shown.

  When transmitting a data file or the like (such as a part of a data broadcast) constituting a program by MMT, one file is stored in one MPU. This MPU is called a “data element MPU”. Then, this one “data element MPU” is divided and sent as MMTP as MFU. In this case, an MPU header or MPU metadata is also sent at the same time.

  Also, for stream data such as video or audio, the data element MPU is not used to avoid overhead. Instead, the AU or NAL is put directly into the MFU and sent by MMTP.

  However, in the time management of the new Japanese broadcasting scheme proposal, the MPU is configured in units of random access flags. The time is specified for the MPU. Therefore, there is no problem as a unit for specifying time as long as the unit is 0.5 seconds to 1 second in one GOP. In this case, no MPU header or MPU metadata is sent. As described above, a set of a set of MMTP packets separated by the random access flag is herein temporarily referred to as a “stream transmission unit MPU”.

  Also, the multiplexed data is received and recorded in a file. The data structure used for recording in this file is also MPU. For example, when recording in a file, one MPU can be used for the entire program. Here, the MPU in this usage is temporarily referred to as a “program storage MPU”. Also, recording can be performed in units of stream transmission units MPU. In this case, the number of MPU files becomes enormous. Also, the stream transmission unit MPU can be bundled and stored in the MPU. Here, the MPU in which the stream transmission unit MPUs are bundled is temporarily referred to as a “program storage MPU”.

  In the case of a new broadcasting system in Japan, a “stream transmission unit MPU” is configured in GOP units. The “MPU time stamp descriptor” in the MPT specifies the display time of the first frame. The time here is the NTP time. The “extended time stamp descriptor” specifies the display time of the subsequent frame in the GOP. The display time of the subsequent frame is indicated by a difference from the display time of the first frame.

  In a state where the multiplexing has been released and the elementary stream Se has been extracted, the MPT has been removed. Therefore, it is necessary to create and record management information such as tracks by combining the MPT and other control information. The track is data management information having a time flow. The data having a time flow is, for example, video data or audio data. The track includes a data type, a reproduction time, a pointer to a recording position of actual data, and the like. These data can be created in the same procedure as the above-described time table creation.

  In the track, the data extraction position can be specified in minute time units. Therefore, the video data and the audio data can be mixed and arranged in the order of the reproduction time or the order of the decode time. By adopting such a structure, video data and audio data that need to be reproduced at the same time can be extracted while suppressing head seek.

  In this way, a program transmitted by MMT can be recorded as a file in the BMFF format.

Embodiment 2 FIG.
In the second embodiment, MMTP packets are sequentially recorded. The MMTP packet is obtained by selecting a received broadcast at a program level.

  The data transmitted from one transmitter is designed so that a plurality of programs from a plurality of broadcasting stations can be multiplexed. Therefore, when a user watches or records a specific program, it is necessary to separate at a broadcast station level and at a program level.

  Here, it is assumed that the separation up to the program level has been completed, and MMTPs constituting one program to be recorded are sequentially extracted and recorded. In this state, data multiplexing is partially released. That is, the multiplexing is released up to the program unit. However, individual video, audio, subtitle streams, or control data constituting a program are multiplexed.

  FIG. 11 is an explanatory diagram for explaining demultiplexing by MPT in the MMTP method. FIG. 12 is an explanatory diagram illustrating the relationship between the time table and the video data. FIG. 13 is a diagram illustrating an example of the structure of MPT data in the MMTP method. FIG. 14 is an explanatory diagram for explaining the alignment in a case where an image is mainly considered.

  The MMT stream shown in FIG. 11 is an example of an MMTP packet sequence forming a program. In the MMT stream, for example, video, audio, subtitles, and the like are multiplexed one by one. In an actual broadcast, a plurality of videos, sounds, subtitles, and the like may be multiplexed.

  Video, audio, subtitles, and the like are elements that constitute a program. Elements that make up these programs are called assets. The MMT stream is multiplexed in units of MMTP packets. For this reason, the service information packet and the asset data packet are mixed in the MMT stream.

  The service information packet is a control signal for the multiplexed stream. The service information is, for example, control information for separating video, audio, or subtitles. The service information is control information for synchronously reproducing video, audio, and subtitles. The service information is information for displaying the name of each asset.

  The asset data packets constitute, for example, video, audio, and subtitle assets. In the second embodiment, these packets are sequentially recorded on a recording medium. Here, for simplicity, these packets constituting the MMT stream are sequentially recorded as a file.

  As shown in FIG. 11, the MMT stream includes a control packet SI (MPT), a video packet V, a video packet V (RAP), an audio packet A, and a caption packet T. The control packet SI (MPT) is a control packet with an MPT. The control packet SI (MPT) is a type of service information. The video packet V (RAP) is a video packet with a RAP flag.

  Actually, many types of control packets SI are transmitted. However, here, for ease of explanation, attention is paid to MPT. According to the broadcasting standard, MPT is to be transmitted periodically at intervals of about 100 ms.

  When sequentially reproducing the MMT stream from the beginning, data is sequentially extracted from the beginning of the file in which the MMT stream is recorded. Then, the data can be reproduced by sequentially sending the MMT stream to the demultiplexing unit 21. For example, the multiplexed stream Sm shown in FIG.

  The demultiplexing unit 21 sequentially analyzes the received data. Upon receiving the data packet including the MPT, the demultiplexing unit 21 extracts information used for demultiplexing and timing for displaying a video from the description of the MPT. Then, the demultiplexing unit 21 sets the demultiplexing unit 21 and the decoding units 31, 32, 33, and 34.

  FIG. 13 shows an example of data described in the MPT. The data shown in FIG. 13 is based on ARIB standard STD-B60. For example, in the MPT, information for extracting a plurality of assets is described. Each asset obtains information for acquiring data and information for separating data by the identification information in the MMT. The identification information in the MMT is, for example, location information (MMT_general_location_info ()).

  Further, although omitted in FIG. 13, detailed information of the stream of each asset can be obtained from the information of the component descriptor. Based on this information, various multiplexed streams are separated and reproduced as shown in FIG.

  Also when recording a broadcast, the data of the MMT stream in FIG. 11 is sequentially recorded in a file. Then, the data of the MMT stream is sequentially taken out from the head of the file and reproduced. In this case, the MMT packet does not necessarily need to be the MMT packet itself. The data may be recorded in a state where the data inside the MMT packet is extracted. Conversely, it may be recorded in a state of an IP packet or a state of a TLV packet.

  Next, consider random access. Here, a time designation jump will be described as an example. However, the same applies to chapter search and fast forward rewind.

  The operation of random access will be described with reference to FIG. The time table TM is data for associating time information on a program with a reproduction position corresponding to the time information. Here, the reproduction position is described as an offset from the head of the file in which the data of the MMT stream is recorded. However, a sector address or a block address may be used as the reproduction position.

  Using this time table TM, data is taken out from the reproduction position corresponding to the time and reproduced. Thus, a time designation jump can be performed. That is, it is possible to perform reproduction with a specified time.

  Normally, video data is configured in GOP units. The GOP is obtained by, for example, compressing a video of about 0.5 to 1 second at a time. The GOP includes, for example, several tens of images. One GOP includes one to a plurality of complete images and several tens of difference images. The GOP is efficient because it includes a compressed difference image.

  Also, the order of display and the order of decoding do not always correspond. Therefore, even if it is desired to reproduce the data in the middle of the GOP, it is necessary to decode the data from the beginning of the GOP. Therefore, in the MMTP packet, a RAP flag can be added to the head of the GOP. The RAP flag is a flag indicating that random access is possible. In FIG. 12, the position of the packet with the RAP flag is stored in the time table as the head of the GOP. This realizes random access.

  Image data that can reproduce a complete image from one image data is called an I picture. One I picture always exists in one GOP. However, a plurality of I pictures may exist in one GOP. Of the I pictures, the I picture that is decoded first in a GOP is called an IRAP because of the dependency on other images. By reproducing from this I picture, the subsequent image data can be displayed correctly.

  The RAP flag of the MMTP packet is attached to the head packet or control packet of the IRAP image data. Image data composed of difference data from one I picture is called a P picture. By synthesizing the I picture of the reference destination and the image data of the P picture, the image of the P picture can be reproduced. Image data that can reproduce an image with reference to a plurality of other images is called a B picture.

  As with video data, audio data also has the concept of the head of one block of data. Then, a RAP flag is added to the head of the audio data. However, for the sake of simplicity, the audio data packet is also separated here by the GOP of video data.

  The operation of the random access shown in FIG. 12 will be considered in correspondence with the reading at the packet level shown in FIG.

  The information on the reproduction position is extracted from the time table TM. Then, the packet is taken out from the position P1 of the MMT stream in FIG. 11 and reproduced. The position P1 is the position of the first video packet V (RAP). At this point, the MPT information has not been obtained. For this reason, it is not possible to separate video, audio, and subtitles in units of assets.

  The control packet SI (MPT) is read out at the position P2 by sequentially reading out. Thereby, a parameter for separating the asset is obtained. That is, video, audio, subtitles, and the like can be separated.

  At this time, if the data from the position P1 to the position P2 cannot be separated and is not read as a result, the data at the head of the GOP will be lost. Then, this GOP cannot be decoded.

  After the position P3, decoding is possible because there is MPT information already acquired at the position P2. Position P3 is the head of the next GOP after position P1. Therefore, the reproduction may be performed from the next GOP instead of the GOP from which reproduction is originally desired.

  In the case of chapter search or fast-forward in the same program, if the asset information of the MPT used for reproduction matches the asset information of the MPT of the jump destination, the process starts from the position P1 which is the head of the jump destination. It is possible to reproduce from a GOP. However, when a program is reproduced with a commercial (CM) or a change in the program interposed, there is no guarantee that the MPT before the jump and the MPT after the jump have the same asset. Alternatively, when editing is performed by connecting different recorded programs, there is no guarantee that the MPT before jumping and the MPT after jumping have the same asset.

  Also, when an asset is changed, the proposed broadcasting standard requires that the MPT be updated 0.5 seconds before the actual data is reproduced. This takes time, for example, in setting a filter for separating assets. Further, it takes time to perform a mute process when the sound is switched. Further, it takes time to perform a mute process when the video is switched. For this reason, even if the MPT is changed at a timing immediately before the actual data is switched, there is a possibility that the processing for switching or muting the filter may not be performed in time.

  This is the same for random access. Even if the MPT can be obtained immediately at the jump destination, the processing system cannot be switched in time, and the first GOP may not be displayed correctly. Alternatively, it is necessary to delay the display in order to secure the time required for data switching. Here, the “processing system” is, for example, the demultiplexing unit 21 and the decoding units 31, 32, 33, and 34.

  Therefore, in the second embodiment, as shown in FIG. 12, first, the MPT information is stored in the time table TM. When a jump is performed by designating a time, the information of the MPT is set in the demultiplexing unit 21 and the decoding units 31, 32, 33, and 34. Thereafter, the data at the position where the reproduction is started is read.

  In this way, the processing system (the demultiplexing unit 21 and the decoding units 31, 32, 33, 34, etc.) can be switched in parallel with the preparation for reading data such as a seek. Then, the time required for data switching can be reduced.

  In this example, the MPT itself is stored in the time table TM. As another method, information for separating the assets described in the MPT and the time at which the display of the GOP is started are stored in the time table TM. The time at which the display of the GOP is started may be used as the time in the time table TM. As described above, there is a method of extracting asset information and storing it in the time table TM.

  As another method, the MPT or asset information is recorded in another table. Then, there is a method in which the time table TM has a reference to the corresponding MPT information or asset information. In addition, there is a method of preparing another time table that can be searched at the same time, instead of referencing, and recording MPT or asset information there. The MPT stores the display start time of a plurality of GOPs. Some or all of them may be stored in the time table TM.

  Similarly, even when the control of the television is changed by the HDR parameter or the like, it may take time to change the luminance of the backlight or the setting of the driving voltage of the liquid crystal. In that case, the HDR parameters and the like are stored in the time table TM. This makes it possible to control the television in advance. FIG. 12 shows a metadata area of the time table TM as an example of an area for storing these parameters.

  When performing special reproduction, there is a case where only an IRAP image (IRAP picture) is reproduced in a GOP and other images are not displayed. The trick play is, for example, fast forward or rewind. The IRAP image is the first image in decoding order. The IRAP image is also placed at the head of the GOP in the order of data arrangement. That is, the IRAP image is located at the head of the GOP. Also, an IRAP image does not depend on other images. Therefore, the IRAP image can be decoded independently. In this case, the position of the IRAP image can be read from the time table TM.

  However, it is more convenient to know the end of the IRAP image in order to skip the reading efficiently. Therefore, the size of the IRAP image or the end of the IRAP image is stored in the time table TM. As a result, trick play can be performed efficiently. In FIG. 12, the IRAP size column of the time table TM is shown as an example of an area for storing this data.

  When image data constituting a video is recorded as a slice, it may be better to access the data in slice units. “Slice” means that the image data is divided in a decodable state. When considered for special reproduction, for example, there is a method of reproducing only a specific slice of an IRAP image in a GOP and not displaying other slices. The trick play is, for example, fast forward or rewind.

  In this case, the position and size of each of the data and the slice of the IRAP image at the head of the GOP are stored in the time table TM, so that the special reproduction can be performed efficiently. Although not shown in FIG. 12, for example, the data can be stored by expanding the IRAP size column of the time table TM.

  In order to smoothly perform fast-forward and rewind, a non-IRAP I-picture or a non-IRAP P-picture included in a GOP may be displayed in addition to an IRAP image. In this case, the start position, size, or end position of each of the I picture and the P picture is stored in the time table TM. This makes it possible to perform trick play efficiently.

  Although not shown in FIG. 12, for example, these data can be stored by expanding the IRAP size column of the time table TM. Alternatively, a table indicating the position, size, or end position for an I picture or a P picture is separately prepared. The time table TM can also store a reference to this table.

  Next, storage of the MMT stream according to the second embodiment in a disk device such as an HDD or an optical disk will be considered.

  Many disk formats use fixed-size data blocks as access units. This access unit is called a sector, block, cluster, page, or the like. Here, it is simply called a “block”. For example, according to the Blu-ray Disc standard, 6144 Byte is called an aligned unit and is handled as one recording unit. In the Blu-ray Disc standard and the UDF standard, 2048 bytes per block is often used. UDF (Universal Disk Format) is a file system for optical disks.

  In the case of performing random access, efficient access can be achieved by aligning data boundaries with this block. In addition, not only the structure of the disk device but also a block size may be determined as an encryption unit, for example. Even in this case, it is efficient if data can be accessed in accordance with a block boundary as a unit of access. Determining the data size or data storage position in consideration of such access efficiency and the like is called alignment.

  When recording a transport stream (TS), 32 TS packets are connected to form 6144 bytes of data. The TS packet is 192 bytes. This allows efficient recording in three blocks of the UDF. One block of the UDF is 2048 bytes. The MMTP packet is a variable length packet. For this reason, it is not possible to simply match the block boundaries with the number of packets.

  As shown in FIG. 12, when performing random access, it is desirable to efficiently access the head of the GOP. However, when reproducing from any image in the GOP, it is necessary to read data from the head of the GOP. Therefore, recording is performed in GOP units in accordance with block boundaries.

  FIG. 14A shows an example of a file recording an MMT stream in which the GOP is set as a unit of data access and the head of the GOP is an integral multiple of the block size.

  FIG. 14A shows a part of data of a file in which an MMT stream is recorded. The left side of FIG. 14A corresponds to the front of the file, and the right side corresponds to the back of the file. The packets of the MMT stream are sequentially recorded, for example, from left to right in FIG. FIG. 14A shows only a part of the recorded data. In practice, this data structure is repeatedly recorded.

  A symbol Bb in FIG. 14A indicates a block boundary. “N1”, “n2”, “n3”, “n4”, “n5” and “nm” indicate integers. “M” is a positive integer. “×” indicates multiplication. Therefore, “block × n” indicates that the data is an integral multiple of the block size.

  When the alignment is performed so that the head of the GOP is at the boundary of the block, the data size of the GOP is not always an integral multiple of the block size. Therefore, padding (Pad) in FIG. 14 is used. "Padding" is to intentionally create an invalid area in order to align data. There are several types of padding. For example, one method is to record data indicating invalidity. In addition, there is a method of managing an invalid data area by the OS or the file system.

  In the example of FIG. 14A, the blocks are aligned on a GOP basis. Therefore, random access in GOP units can be efficiently performed. In this example, only the video data is described. However, actually, as shown in FIG. 11, video data, audio data, subtitle data, and the like are multiplexed and mixed.

  Therefore, when the stream data is divided at the break position of the video data, the audio data other than the video or the subtitle data is not always divided at the appropriate break position. Therefore, at the time of random access, there is a possibility that audio or subtitles will be reproduced with a delay. Usually, even if the reproduction of audio or subtitles is delayed, there is no problem as long as there is no deviation from the video. For this reason, here, other data is also handled as a set of data based on the video delimiter position.

  FIG. 14B shows an example of a file in which an MMT stream aligned in image units is recorded. In FIG. 14B, the combination of the picture (AU) and padding is an integral multiple of the block. In this case, efficiency is high when access in units of images is required.

  AU is one type of meaningful chunk of compressed data. In the case of image (picture) data, it is one image. That is, the AU is one of an IRAP picture, an I picture, a P picture, and a B picture.

  In FIG. 14B, all alignments are performed in image units. However, what is important at the time of random access is the IRAP picture. An IRAP picture is placed at the beginning of a GOP. Therefore, it is possible to perform alignment separately into two, that is, an IRAP picture and a group of other pictures.

  In FIG. 14C, the alignment is performed with the head of the IRAP picture, the head of the I picture, and the head of the P picture as block boundaries. FIG. 14C illustrates an I picture as “I”, a P picture as “P”, and a B picture as “B”. In the case of fast-forwarding or rewinding, efficiency is high when not only an IRAP picture but also an I picture or a P picture is used. In FIG. 14C, alignment is performed at the head of an IRAP picture, the head of a P picture, or the head of a non-IRAP I picture. However, the alignment at the head of the P picture or the head of the I picture may be omitted.

  FIG. 14D shows an example of a file in which an MMT stream in which alignment is set in consideration of access in slice units is recorded. When the video has a slice configuration, access can be efficiently performed in slice units.

  In FIG. 14D, non-VCL data is described at the beginning of image (picture) data. The non-VCL data is parameters such as AUD, VPS or SPS. Subsequent slices # 1 to # 4 are VCL data. VCL data is compressed image data.

  Even when decoding is performed in units of slices, non-VCL data is required when decoding each slice. For example, when decoding slice # 2, non-VCL data and data of slice # 2 are combined and decoded. Therefore, here, alignment is performed for the non-VCL data and slice # 1 to slice # 4.

  In practice, non-VCL data is often very small compared to each slice. Before decoding slice # 1, non-VCL data is required. For this reason, it is conceivable to perform alignment of the non-VCL data and slice # 1 collectively.

  Alignment in slice units does not necessarily need to be performed for all pictures. For example, it is conceivable to use only the IRAP picture for alignment in slice units. This is because the IRAP picture has a large size and is used for random access.

  A method of performing alignment in units of MMTP packets is also conceivable. The data amount of the MMTP packet differs depending on the standard. For example, the maximum value of the MMTP packet in the proposed broadcasting standard is about 1500 bytes.

  For example, when alignment is performed assuming a 2048-byte block, the amount of padding in the entire data amount becomes large. Then, the recording efficiency deteriorates.

  On the other hand, access in packet units can be performed efficiently. That is, the alignment in MMTP packet units is suitable for temporary data storage when data processing in packet units is required. Data processing in packet units is performed, for example, at the time of recording / reproduction or editing.

  By using the time table TM and the alignment, it is possible to efficiently reproduce the data with the specified time.

  The Blu-ray disc has a correspondence table (EP map, EP_map) as a mechanism corresponding to the time table TM of the second embodiment. This EP map indicates the reproduction position by the system clock and the position of the TS packet. The reproduction position is a position for reading a PTS (display start time) and its data.

  The EP map is used for jumping at a specified time, random access, or reproduction using a playlist. The random access is, for example, fast forward or rewind. The play list is a list in which the reproduction portions and the reproduction order of the stream are determined.

  In the EP map of the Blu-ray disc, the data format of the time and the reproduction position is different from the case of the MMT. However, the mechanism for acquiring the data of the reproduction position by designating the time is the same concept as when using the time table TM described in the second embodiment.

  By making the time table TM similar in structure to the EP map, it is possible to record and reproduce MMT-format broadcasts on a Blu-ray disc without significantly changing these playback mechanisms.

  For example, the time format of the reproduction of the MMT is the absolute time (world time) at the time of broadcasting. On the other hand, in the EP map of the Blu-ray disc, the relative time using the internal clock is used. Therefore, the notation of the time in the time table TM is converted to the notation of the relative time. Alternatively, data for conversion between the absolute time and the relative time is separately provided. Alternatively, the playback time information used on the Blu-ray disc is changed to an absolute time format.

Embodiment 3 FIG.
In a new broadcasting system in Japan, the multiplexing system and the encoding system have been changed. In Japan's new broadcasting system, the transmission rate has also been raised. For example, according to ARIB TR B-39, a transmission rate of 35 Mbps is assumed for 4K broadcasting, and a transmission rate of 100 Mbps is assumed for 8K broadcasting.

  On the other hand, with a BDXL (registered trademark) disk currently on the market, the transmission rate of the optical disk is around 140 Mbps.

  Therefore, when reproducing a disk on which 8K broadcast is recorded, normal reproduction has no problem and can be reproduced. However, when special playback such as fast-forwarding is performed on a disc on which 8K broadcast is recorded, there is a problem that it takes time to display an image for one frame.

  Japanese Patent Application Laid-Open No. 2000-125259 discloses that a recording area of a recording medium is divided into a predetermined data size, a stream is decoded at the time of recording, and a TS packet including PCT (picture type code) indicating an I picture is And a pointer indicating the start address of the sector is registered in a table provided on the recording medium. Then, special playback operations such as fast forward and fast rewind using the recording medium recorded in this way read a pointer address from a pointer table, reproduce only one I picture from a sector indicated by the pointer, and thereafter successively. It describes that the sectors indicated by the pointer are sequentially reproduced.

  As described above, when performing special reproduction such as fast forward, a method of reproducing only an I picture is often adopted. The I picture is at a random access point in the video stream. In normal fast-forward (FF, Fast Forward), all I-pictures are displayed according to the fast-forward speed. In double speed fast forward (FF × 2), one I picture is skipped and displayed. In the case of triple-speed fast-forward (FF × 3), two I pictures are skipped and displayed. In this way, the reproduction speed at the time of fast forward is adjusted.

  However, when the ratio of the I pictures in the GOP is large, it takes time to read the I pictures, and the update interval of the image (I picture) becomes long.

  The video playback device according to Embodiment 3 can shorten the read time of an I picture and the update interval of an image (I picture) during special playback.

  In the conventional fast-forward reproduction, the position of a reproducible I picture on a disk is managed in a table. Then, I-picture data is sequentially read out using the table.

  In the case of an optical disc, when the read position is changed, it takes time to move the head. The moving time of the head is called a seek time.

The update interval of the fast-forward image on the screen is represented by the following equation 1.
Update interval = seek time + read time of I picture data + decode time (1)

  In the 4K / 8K broadcast, the size of the I picture is larger than that in the conventional 2K broadcast. Therefore, when the size of the I picture is large, it takes time to read the I picture, and the update interval of the image (I picture) becomes long.

  Also, when the difference between the data rate of the video stream and the maximum reading speed from the disk is small, the reading time of the I picture becomes longer, and the image update interval becomes longer. For example, when a broadcast stream of 100 Mbps is read from an optical disk having a maximum read speed of 140 Mbps, it can be read only at a speed of 1.4 times.

  As described above, when 4K / 8K video is recorded on the optical disc, the update interval of the image at the time of special reproduction becomes longer than before. On the other hand, when playing back a video recorded with a broadcast, special playback operations such as fast forward are often performed. When the user specifies a target scene, it is desirable that the image update interval be short.

  If the image update interval is long, it becomes difficult for the user to find the target scene when searching for a scene using fast forward.

  In the third embodiment, it is an object to provide a video playback device that can easily find a target scene and has good operability during special playback such as fast-forward playback.

  From the user's point of view, the update interval of the image at the time of fast forward is arranged. For example, consider fast-forwarding in which a video whose original playback time is 100 seconds is played back in 10 seconds. Here, it is tentatively called 10-times fast forward.

  Normally, the user checks the video being fast-forwarded and cancels the fast-forward when a target scene appears. That is, the normal reproduction speed is restored. At the time of fast-forward playback, the displayed video is intermittent. However, it is easier for the user to recognize the scene to be displayed, with less temporal information missing. Further, after the fast-forward operation is completed, the shift of the position at which the fast-forward is released and the normal playback is returned can be reduced.

  For example, consider fast forward at 10 times speed. If the update interval of the fast-forwarding image is 1 second, one frame is displayed for 10 seconds of the normal reproduction time. On the other hand, if the update interval of the fast-forwarding image is 0.5 seconds, one frame is displayed for the normal reproduction time of 5 seconds.

  At the time of fast-forward playback, in order for the user to find a target scene, it is advantageous that the number of frames (images) extracted from the normal playback time is large. In this way, operability can be improved by displaying many images during fast-forward playback. That is, operability can be improved by shortening the update interval.

  In 4K / 8K broadcasting, a stream format having a plurality of slice segments is defined assuming divisional decoding.

  For example, when one image is divided into four parts, the image is divided into two parts in the vertical and horizontal directions (hereinafter also referred to as a cross-shaped) to create a four-part image. Alternatively, one image is divided into four in the vertical direction (hereinafter also referred to as a character shape). Then, decoding can be performed independently for each slice segment. This is a consideration for decoding 4K video using four 2K decoders and decoding 8K video using four 4K decoders.

  When a broadcast stream having these plurality of slice segments is recorded on an optical disc, if data can be read out in units of slice segments, it is possible to reproduce only some of the slice segments.

  If this is used during special playback, the updated image will be part of the image displayed in normal playback. However, the “I-picture data read time” in equation (1) can be reduced to a quarter. And the update interval of the image at the time of special reproduction can be shortened.

  FIG. 15 is a schematic diagram of a video stream according to Embodiment 3.

  As the multiplexing method, both the TS method and the MMT method can be considered. However, in FIG. 15, unique header information and the like are omitted. Also, padding and the like are omitted.

  In the case of broadcasting, one GOP can include up to about 60 frames (image or picture). One GOP includes at least one I picture. In particular, an I picture that is a starting point at the time of decoding is called an IRAP picture (IRAP picture). In the data order, the IRAP picture is usually arranged at the head of the GOP.

  An I picture (including an IRAP picture), a B picture, and a P picture each represent a frame (image or picture).

  The I picture indicates an independent image that can be decoded independently. On the other hand, B pictures and P pictures are dependent on other pictures. The B picture and the P picture are difference data from other images. Therefore, the B picture and the P picture cannot be decoded alone.

  In the GOP, a dependency between images is completed in the GOP. That is, all images in the GOP constitute a set of data that can be decoded.

  When one image is composed of a plurality of slice segments, each image is composed of a parameter set and a plurality of slice segments. By combining the parameter set and one slice segment, the slice segment is a unit that can be decoded. In FIG. 15, only the IRAP picture is described in a slice segment structure. However, the B picture and the P picture can have the same structure.

  When decoding is performed in parallel using four decoders, data is extracted for each slice segment. Then, a parameter set is added to each data. Thereafter, by giving each data to each decoder, one image can be decoded in a divided state. When displaying images, individually decoded images are combined and displayed as one image.

  FIG. 16 shows an example in which the image is divided into four in the vertical and horizontal directions (a cross-shaped). At the upper left of the image, the image of slice # 1 is displayed. At the upper right of the image, the image of slice # 2 is displayed. At the lower left of the image, the image of slice # 3 is displayed. At the lower right of the image, the image of slice # 4 is displayed.

  FIG. 17 shows an example in which the image is divided into four in the vertical direction (eye shape). At the top of the image, the image of slice # 1 is displayed. The second image from the top of the image displays the image of slice # 2. At the third position from the top of the image, the image of slice # 3 is displayed. At the fourth position from the top of the image, the image of slice # 4 is displayed.

  In the case of an undivided video stream, only one slice segment exists in one picture data.

  A special reproduction in a video stream having such a divided slice segment structure will be considered.

  As described above, in order to improve the operability, it is necessary to shorten the update interval of the display image. Conventionally, data of the entire I picture has been read and the entire I picture has been displayed. However, it is assumed that only the data of the first slice segment (slice segment # 1) of the I picture is read and only the first slice segment (slice segment # 1) of the I picture is displayed.

  FIG. 18 is an example of a time table (TMS) corresponding to reading in units of divided slice segments. FIG. 19 shows the correspondence between each item of the time table (TMS) and the data. When recording a video stream, the video stream is analyzed. Then, a time table (TMS) is created by extracting the time information or information on the data separation position.

  Note that two types of time tables, code TM and code TMS, are used. The time table corresponding to the divided slice segment is distinguished from the code TM by the code TMS. The time table is recorded on the recording medium together with the video stream. The recording medium is, for example, an optical disk.

  Each item of the time table (TMS) will be described.

  “Time” is the display time of the GOP indicated by the row at each time. The time is recorded in the form of time information in the system clock format, time information in the ntp format, or the time difference from the head of the stream. When the reproduction is started by designating the time, the time column is searched, and the reproduction is started from the data near the specified time.

  Here, “time” is the display time of the GOP. One GOP usually includes a plurality of images. Since there is a display time for each image, the GOP has a plurality of display times. When recording in the time table as the display time of the GOP, the display time of the first image in the order of display in the GOP can be used. Alternatively, the display time of the first image in the decoding order can be used. In this case, the leading image is an IRAP picture.

  The “time” stored in the time table does not necessarily need to match the display time of the image. For example, instead of the image display time itself, time information with reduced accuracy or time information for other data can be used. These factors take into account, for example, the accuracy of the system clock of the playback device, the relationship with the data access, or the data length that can be stored in the time table.

  “IRAP start position” is a storage position of an IRAP picture. The storage position of the IRAP picture is a random access point of the GOP. The storage position of the IRAP picture is usually the same as the start position of the GOP. “IRAP end position” indicates the end of data of the entire IRAP picture. By reading the data from the IRAP start position to the IRAP end position, there is data that can decode the IRAP picture.

  “# 2 start position” indicates the start position of the second slice segment (slice # 2). “# 2 start position” indicates the end position of the first slice segment (slice # 1). “# 3 start position” indicates the start position of the third slice segment (slice # 3). Further, “# 3 start position” indicates the end position of the second slice segment (slice # 2). “# 4 start position” indicates the start position of the fourth slice segment (slice # 4). Further, “# 4 start position” indicates the end position of the third slice segment (slice # 3). “# 4 end position” indicates the end position of the fourth slice segment (slice # 4). Usually, this position is the same as the end position of the IRAP picture.

  The “parameter set” stores a parameter set of data of the IRAP picture. The parameter set includes, for example, an AUD (Access Unit Delimiter), a VPS (Video Parameter Set), an SPS (Sequence Parameter Set), a PPS (Picture Parameter Set Entrance Entrance Entrance), and a SEI (Supplemental Entrance Entrance Enhancement). include.

  In the time table (TMS) shown in FIG. 19, the end position of the slice segment is stored. For example, the end position of the IRAP picture and the end position of slice # 4. However, a method of storing and using the data size in the table instead of the end position can be adopted.

  The start position and the end position are recorded in the form of a byte position or a block position from the beginning of the data. Further, when the TS is used as the multiplexing method, the start position and the end position are recorded in the form of the position of the TS packet. The start position and the end position are recorded as positions necessary for reading data.

  The information indicating the data position of the segment can be a relative position from the head of the GOP. As a result, the data size of the position information can be reduced.

  In the optical disk, data is read in a unit of data to some extent. For this reason, the position does not necessarily have to be strict. It is also possible to reduce the data amount of the position information by increasing the unit indicating the position.

  In this example, information on slice segments is also recorded in a single time table. However, it is also possible to store the slice segment information in another table. In this case, information about the same GOP and IRAP picture can be extracted from the time stamp information or the entry position in the table.

  A method of storing the parameter set in another table is also conceivable. This is because the parameter set has a larger size than the position information. Also, the data length of the parameter set changes depending on the image.

  When fast-forward playback is performed using only the slice segment # 1 of the I-picture, the information required in the time table is the time, the IRAP start position, and the # 2 start position. In this case, the start position of # 2 is used as the end position of slice segment # 1.

  The fast forward reproduction using only the slice segment # 1 will be described with reference to FIG. GOP (01) to GOP (06) are stream data. Originally, stream data is a continuous data file. However, for ease of explanation, the lines are changed in GOP units. TMS (time table) is the above-mentioned time table. The TMS (time table) associates the time information with the position of the image data.

  It should be noted that the IRAP start position and the # 1 start position have the same value and are also used on the time table. The required values are the start position and end position of slice # 1. The IRAP start position is regarded as the # 1 start position, and the # 2 start position is regarded as the # 1 end position.

  In the case of fast forward reproduction, the entries of the time table are sequentially read. From the IRAP start position and # 2 start position of each GOP, data of the first slice segment of the I picture of this GOP is read. Then, this data is decoded and displayed on the screen. The IRAP start position is the start position of slice segment # 1. The # 2 start position is the end position of the slice segment # 1.

  By repeating this, fast forward reproduction can be performed. In this case, the read data amount is one fourth that of the case where all the I pictures are displayed. For this reason, the update interval of the image at the time of fast forward reproduction can be shortened.

  In this example, the display is updated only for a part of the screen. That is, only the image at the position of the first slice segment is displayed. In the case of vertical / horizontal division into four (cross-shaped), for example, it is an upper left quarter area of the image. In the case of vertical division into four (eye-shaped), it is the upper quarter area of the image. Other parts remain unchanged. Alternatively, other parts are not displayed.

  When the user performs a fast-forward operation, it is only necessary that the target scene can be determined. For this reason, it is often better to consider operability when the update interval is shorter than when the entire screen is visible.

  In addition, the first slice segment and the second slice segment are displayed in the same manner. In this way, fast-forwarding can be performed by displaying half of the screen.

  Furthermore, when fast-forward playback is performed at high speed, the GOP to be displayed can be thinned out and played back. In other words, one GOP is skipped or two GOPs are displayed.

  In the fast-forward playback operation, the fast-forward speed can be adjusted by pressing the fast-forward button on the remote control a plurality of times. When used in combination with the conventional fast-forward for displaying the entire I picture, the display method can be selected by the number of times the remote control button is pressed.

  For example, when the button is pressed once, the entire I picture of all GOPs is displayed and fast-forward playback is performed. When the button is pressed twice, only some of the slice segments of the I pictures of all GOPs are displayed, and fast-forward playback is performed. When the button is pressed three times, one GOP is skipped, and only a partial slice segment of the I picture is displayed to perform fast-forward playback. When the button is pressed four times, two GOPs are skipped, only a partial slice segment of the I picture is displayed, and fast forward reproduction is performed.

  If the broadcast stream does not have multiple slice segments, this method cannot be used. However, when recording a broadcast, re-compression or format conversion is often performed. At this time, it is also possible to reconstruct an HEVC video stream having a plurality of slice segments. Even when recording an externally input video other than a broadcast, special reproduction can be performed by this method by similarly creating compressed data as an HEVC video stream having a plurality of slice segments.

<Modification 1>
In the description so far, only a part of the image may be updated at the time of special reproduction such as fast forward. However, it may be easier to find the target scene when the entire image is updated. Therefore, a method of updating the entire image while setting the data to be read to be a part of a slice segment is considered.

  FIG. 21 is an explanatory diagram of fast-forward playback. In this example, the position information of all slices in the time table (TMS) is used.

  In the case of fast forward reproduction, the entries of the time table are sequentially read. From the IRAP start position and # 2 start position of the first GOP, data of the first slice segment of the I picture of this GOP is read. The IRAP start position is the start position of slice segment # 1. The # 2 start position is the end position of the slice segment # 1. This data is decoded and displayed at the position of slice segment # 1 on the screen. In FIG. 21, the position of slice segment # 1 on the screen is at the upper left of the screen.

  From the # 2 start position and # 3 start position of the next GOP, data of the second slice segment of the I picture of this GOP is read. The # 2 start position is a start position of the slice segment # 2. The start position of # 3 is the end position of slice segment # 2. This data is decoded and displayed at the position of slice segment # 2 on the screen.

  At this time, decoding of the slice segment # 2 requires data of the parameter set (PS) of this picture. The parameter set (PS) is located at the head of the picture. That is, the parameter set (PS) is arranged before the slice segment # 1. Therefore, when the parameter set (PS) is read simultaneously with the slice segment # 1, it can be read at once. However, when reading the parameter set (PS) and the slice segment # 2, two readings occur.

  In the read operation of the optical disk, it takes time to change the read position. Therefore, the following three methods can be considered as the reading operation at this time.

  In the first method, two reading operations of the parameter set (PS) and the slice segment # 2 are performed. The second method reads the parameter set (PS), slice segment # 1 and slice segment # 2 at a time. The third method uses a parameter set (PS) and data of slice segment # 2. Then, when creating the time table, a copy of the data of the parameter set (PS) necessary for decoding the I picture is stored in the time table.

  In this description, the third method is described. That is, the description is based on the assumption that a copy of the data of the parameter set (PS) is stored in the time table. In this case, the data of the parameter set (PS) and the data of the slice segment # 2 stored in the time table are input to the decoder, and decoding is performed.

  In the next GOP, data of slice segment # 3 is similarly extracted, and the image at the position of slice segment # 3 on the screen is updated. In FIG. 21, the position of slice segment # 3 on the screen is at the lower left of the screen.

  By shifting the slice segment to be displayed every time the image is updated in this way, the entire screen can be updated by updating the image several times, even if one update is a part of the image Can be. Images at different times are displayed depending on the position of the screen. Images at different times are displayed for each slice segment. However, it is easier to grasp the scene than when displaying a part of the image. That is, it is possible to realize special reproduction with better operability.

  In this description, the image is updated in one slice segment. However, one GOP can update the images of a plurality of slice segments. For example, half of the image can be updated alternately.

  In the above description, the images were updated in the order of slice # 1, slice # 2, slice # 3, and slice # 4 in the order of the slice numbers. The update of the image does not necessarily need to be performed in the order of the slice numbers. Any order can be set during reproduction.

  FIG. 22 shows an example of an image update order. FIG. 22A shows an example in which an image is updated in the order of slice # 1, slice # 2, slice # 3, and slice # 4. FIG. 22 (2) is an example in which an image is updated in the order of slice # 1, slice # 2, slice # 4, and slice # 3. FIG. 22 (2) updates the image clockwise. FIG. 22 (3) is an example in which an image is updated in the order of slice # 1, slice # 4, slice # 3, and slice # 2. FIG. 22D is an example in which the image is updated in the order of slice # 1, slice # 3, slice # 4, and slice # 2. FIG. 22D updates the image in a counterclockwise direction.

  If a slice segment to be displayed at the time of reproduction can be selected, the order of updating images can be reversed between fast forward reproduction and rewind reproduction. For example, in the case of fast-forward, the clockwise rotation is as shown in FIG. 22 (2), and in the case of rewinding, it is counterclockwise as shown in FIG. 22 (4). In this way, by reversing the order of updating the image between fast-forward and rewind, even if the fast-forward operation and the rewind operation are repeated, it is easy to grasp the current state, and the operability is improved. improves.

  FIG. 23 is an example of a case where the image is divided into four in the vertical direction (eye shape). Also in this case, by reversing the order of updating the images, it is easy to grasp fast-forward and rewind. For example, the fast forward is updated from slice # 1 to slice 4 (FIG. 23 (1)). Then, rewinding is updated from slice # 4 to slice 1 (FIG. 23 (2)).

<Modification 2>
In the above description, the readout position information for all slice segments is stored in the time table. In order to reduce the size of the time table, a method of recording only read position information of some slice segments is also conceivable.

  FIG. 24 shows a time table (TMS) storing read position information of one slice segment.

  In this example, information on the read position of the slice segment corresponding to each time in the time table is stored. For example, in the rows corresponding to GOP (01) and GOP (05), read position information of slice segment # 1 is stored. In FIG. 23, for example, the information of GOP (01) is described in the first row of the time table. The information of GOP (05) is described in the fifth row of the time table.

  When recording a stream, GOPs to be recorded are counted sequentially. Then, the remainder (remainder) of dividing the count value of the GOP by the number of slice segments in one image is obtained. In FIG. 24, the number of slice segments in one image is four. The value obtained by adding 1 to this value (remainder) is defined as the value of the slice segment. Then, the position of the slice segment is recorded in the time table.

  In this example, information is described at the slice start position and the slice end position at each time. The order of the slices is the order of slice # 1, slice # 2, slice # 3, and slice # 4. Although not shown in FIG. 24, an IRAP start position and an IRAP end position are also recorded. This is for compatibility with other trick play or display of the entire IRAP image.

  When performing special reproduction such as fast forward using this time table, performing fast forward without skipping a GOP updates the entire screen. Also, for example, when the GOPs are skipped one by one and reproduced, slice # 1 and slice # 3 are updated. Also, for example, when a GOP is reproduced skipping every three, slice # 1 is updated.

  Regardless of the double speed of fast-forward, in order to update the entire image, a slice segment can be selected by using a random number or a pseudo-random number when reading position information is stored in the time table. In this case, the slice segments updated on the screen are irregular. However, the entire image can be updated irrespective of the multiple of the fast forward.

  As a pseudo random number generating means, for example, a linear feedback shift register using an M-sequence can be used.

  In the pseudo-random number generation using the M-sequence, it is possible to specify the number of values and the number of times, and to generate a data string in which the appearance probabilities of each value are uniform and have no periodicity during the specified times. The number of values is, for example, four values from 1 to 4. The number of times is, for example, 1000 times.

  For example, if a time table is created using these pseudo-random number generating means, a slice segment can be selected so that the same pattern is not repeated in the time table. As a result, even when the double speed of the fast forward is changed, it is possible to prevent only a specific slice segment from being updated. It is not always necessary to eliminate the repetition of the same pattern throughout the time table. If the same pattern is repeated at a sufficiently long period, there is no practical problem. A sufficiently long cycle is, for example, about 1000 rows.

  The number of pseudo-random numbers is selected so that periodicity does not occur in the entire time table. However, if the periodicity of the pseudo-random numbers is set long, the amount of calculation increases. And even if it is given in advance as a data string of random numbers, the data amount increases.

  In the fast forward operation or the rewind operation, fast forward or rewind with a small skip amount is mainly used. For example, no GOP is skipped, or one to several tens of GOPs are skipped. Therefore, the period of the pseudo random number can be set short.

  As an example, a time table having a periodicity of about 1000 lines has been described. When the GOP of 999 is skipped, there occurs a problem that only some of the images are updated. However, fast-forward playback and rewind playback when a 999 GOP is skipped are not often used. Further, even if skipping the GOP of 999 instead of skipping the GOP of 999 is adopted, the double speed of the fast forward seen from the user hardly changes. Therefore, it can be easily avoided.

  Assuming that the average length of a GOP is 0.5 second, a 2-hour video is composed of 14,400 GOPs. Then, the periodicity of 1000 rows occurs about 15 times in a 2-hour video. The periodicity becomes a problem when fast-forwarding a 2-hour video at 15 frames. Normally, such a high-speed fast-forward operation is not performed.

  In this case, the size of the random number table when the pseudo random number sequence is given to the control program as a calculated random number table is estimated in advance. A random number sequence having four values and the number of times of 1000 is represented by 2 bits. In this case, the total size is 250 bytes. The length of the periodicity of the pseudo-random number can be set in relation to operability and device implementation.

<Modification 3>
In the examples so far, when changing the display position of the slice segment, the readout position and the end position of the slice segment are stored in the time table. When necessary, a parameter set (PS) is stored in a time table. Therefore, the data of the time table becomes large. Also, two readings of the parameter set (PS) and the slice segment occur.

  By replacing the order of the slice segments when recording the video stream, these extra operations can be avoided, and efficient special reproduction can be performed.

  FIG. 25 is an explanatory diagram of fast-forward playback. As in FIG. 24, GOP (01) to GOP (06) are stream data. Originally, it is a continuous data file, but for ease of explanation, the lines are changed in GOP units.

  In the stream of FIG. 25, the storage order of the slice segments is changed for each IRAP picture at the head of each GOP. Here, the number of the slice segment indicates the display position on the screen. The number of the slice segment displayed at this display position is shown as a number on the stream data.

  In FIG. 25, as an example, data is arranged as follows. In GOP (01), slice segment # 1 is arranged at the head of an IRAP picture. In GOP (02), slice segment # 2 is arranged at the head of the IRAP picture. In GOP (03), slice segment # 3 is arranged at the head of the IRAP picture. In GOP (04), slice segment # 4 is arranged at the head of the IRAP picture. In GOP (05), slice segment # 1 is arranged at the head of the IRAP picture. In GOP (06), slice segment # 2 is arranged at the head of the IRAP picture.

  In the above description, the slice segment has been simply described from the viewpoint of data division. However, the management including the display position is realized using tiles in addition to the slice segment of the HEVC standard. Therefore, when replacing the storage position of the slice segment in the time table, it is necessary to correct the slice header information and the tile information of each slice segment as necessary to obtain consistency. The tile information is included in the parameter set.

  The procedure at the time of fast-forward playback is the same as that described with reference to FIG. The description using FIG. 20 is for the case of reproducing only the slice segment # 1. However, in the example of FIG. 25, the slice segment placed at the head is replaced. Therefore, the slice segment for which the image is updated changes, and the entire screen is updated.

  When selecting the slice segment arranged at the top in a simple order, only the images of some of the slice segments are updated at double speed of fast forward. Therefore, a slice segment to be arranged at the head can be determined by a method using the above-described random number or pseudo random number.

  As described above, by changing the order of the slice segments at the time of recording, it is possible to improve the operability of scene search by special reproduction such as fast forward and rewind.

  Up to now, the slice segment has been described as being divided into four segments. This is because it is adopted in 4K / 8K broadcasting in Japan.

  In practice, re-compression or format conversion may be performed when recording a broadcast or recording on an optical disc. In this case, the form of the slice segment division can be freely changed in addition to the division into four.

  For example, one image can be divided into 3 × 3 nine divisions. In this case, it is conceivable to update only the center segment by trick play. This is because the central segment is likely to contain important information. Further, the slice segment can be simply divided into two. Special reproduction can also be performed by updating two segments alternately.

  Further, although the description has been given of the example of the optical disk, the same effect can be obtained with other storage devices such as a hard disk drive (HDD) or an SSD (solid state drive).

  Even when the transmission band is limited by a network or the like and the delay of data transfer is large, it is possible to suppress the data transfer amount at the time of trick play and improve the operability.

Embodiment 4 FIG.
The problem of the fourth embodiment is similar to the problem of the third embodiment. That is, the fourth embodiment addresses the problem that it takes time to display one frame of image when performing special playback such as fast forward on a disc on which 8K broadcast is recorded.

  For example, Japanese Patent Application Laid-Open Publication No. 2006-245744 (0016 to 0020, FIG. 2) discloses an access time including an address of an I picture stored in an information recording medium and a calculated scheduled playback time of the I picture. Creating a table is described. Then, at the time of special reproduction, reproduction of the I picture is performed with reference to the planned reproduction time of the access time table. If it takes a long time to decode the I picture, the reproduction cannot be performed at the scheduled reproduction time.

  In the third embodiment, an image is divided into a plurality of slice segments. At the time of special reproduction, the screen display is partially updated in slice segment units. Thereby, the update interval of the image (I picture) is shortened, and the responsiveness at the time of special reproduction is improved.

  However, when the display of a part of the screen is updated, the visibility of the video scene may be reduced. For example, there is a case where images of different scenes are mixed on the screen.

  In the fourth embodiment, a configuration is adopted in which the displayed video scene is easily grasped while utilizing the method of the third embodiment. The video playback device according to Embodiment 4 can suppress a decrease in visibility of a video scene even when updating the screen display in slice segment units during special playback.

  Therefore, in the fourth embodiment, information of “continuity of video scene” is added to the time table (TMS). The information of “continuity of video scene” is “scene continuity number” in FIG. Further, information of “priority slice segment to be updated in screen display” is added to the time table (TMS). The information of “priority slice segment to be updated in screen display” is “priority slice information” in FIG.

  In the fourth embodiment, the case where the slice segment is divided into four in the vertical direction (eye shape) is described. However, other division methods can be used. For example, it is possible to cope with the case where the slice segment is configured in the vertical and horizontal four divisions (the cross-shaped). Further, it is possible to cope with a case where the slice segment is configured more finely as in the case of eight divisions in the vertical direction. Here, when the dividing method is described as a “matrix”, the vertical division into four (eye-shaped) indicates that the image is divided into four rows. Similarly, the vertical / horizontal division into four (cross-shaped) indicates division into two rows and two columns.

  FIG. 26 is a new time table (TMSN) obtained by adding “scene continuity number 2601” and “priority slice information 2602” to the time table (TMS) of FIG. The other components are the same as in FIG. 18 and will not be described. One line of the time table (TMSN) is information of one entry. Each entry points to a randomly accessible I picture.

  The scene continuity number 2601 is information serving as an index indicating “continuity of video scenes”. Therefore, the scene continuity number 2601 may be numerical information or information such as a flag. In the fourth embodiment, a description will be given assuming that a numerical value from 0 to 255 can be set in the scene continuity number 2601. When creating this index information, first, a histogram is created for each I-picture image of each entry. The histogram is color distribution information obtained by measuring the number of pixels of each color in the image. By comparing the histograms of the images, it can be easily determined whether or not the images are similar.

  Using such a comparison, it is determined whether the previous entry and the current entry are similar images. If the images are similar, the scene continuity number 2601 is set to the same value. If the image is not a similar image, the value of the scene continuity number 2601 of the previous entry is incremented to set the value. That is, an operation of increasing the value of the scene continuity number 2601 by 1 is performed.

  In the fourth embodiment, the value of the scene continuity number 2601 is set in the range of 0 to 255. Therefore, when incrementing the maximum value of 255, it is assumed that a value of 0 is set in a round. In this embodiment, the value of the scene continuity number 2601 is set in a range from 0 to 255. However, the range of the value of the scene continuity number 2601 may be narrower. Also, the range of the value of the scene continuity number 2601 may be wider.

  In the fourth embodiment, similar image comparison using a histogram that is relatively simple and has a small processing load is performed. However, whether or not the image is similar may be determined using the object shape, texture, or feature amount in the image.

  The priority slice information 2602 indicates in which part of the screen important information for grasping the screen is concentrated in the video scene. Therefore, the priority slice information 2602 is used when determining which slice segment is updated at the time of trick play. That is, this is information indicating “priority slice segment to be updated in screen display”.

  The priority slice information may be 1-bit flag information indicating that the center of the screen is important. Alternatively, the priority slice information may be numerical information indicating the importance of each divided screen by dividing the screen into a plurality.

  In the fourth embodiment, a 1-bit flag indicating that the center of the screen is important will be described as priority slice information 2602. An example in which one image is divided into four in the vertical direction (eye shape). For example, in the case of a content such as a movie having black bands at the top and bottom, the slice segment # 1 at the top of the screen and the slice segment # 4 at the bottom of the screen include a black band. Therefore, the slice segment # 1 and the slice segment # 4 have less useful video information for the user to recognize the screen. In general programs, information to be presented to the user is often arranged at the center of the screen.

  In the case of such a program, limiting the update of the display image to the center of the screen makes it easier for the user to recognize the video scene.

  The fourth embodiment will exemplify a case of a slice segment divided into four in the vertical direction (eye shape) shown in FIG. Also, the description will be made assuming that each entry of the time table (TMSN) has 1-bit priority slice information 2602.

  For example, when the value of the priority slice information 2602 is “1b”, the display screen is updated in order only for the slice segments # 2 and # 3, which are the slice segments at the center of the screen. On the other hand, when the value of the priority slice information 2602 is “0b”, the update of the display screen is not restricted. That is, all the slice segments # 1 to # 4 are sequentially updated. Note that “1b” indicates that the bit value is “1”. “0b” indicates that the bit value is “0”.

  When generating the priority slice information 2602, a histogram is created for each slice segment. For example, when many black pixels are included in the slice segment # 1 and the slice segment # 4, it can be determined that the movie has black bands above and below. In that case, “1b” is set in the priority slice information 2602.

  In the fourth embodiment, it has been described that the priority slice information 2602 has 1-bit information. However, 4-bit information (at the time of dividing into four) for setting whether or not the display is updated for each slice segment may be used. Alternatively, the priority slice information 2602 may be 2-bit information. In this case, for example, “00” indicates no priority slice. “01” is the priority slice at the center in the vertical direction. “10” is the priority slice at the center in the horizontal direction. “11” is the priority slice at the center in the vertical and horizontal directions.

  In addition, this time, an example has been described in which the importance of the slice segment at the center portion with respect to the slice segment divided into four in the vertical direction is recorded as flag information. As another example, it may be recorded as flag information that the center slice segment is important with respect to the four horizontal slice segments. Further, when the slice segment is divided into nine portions of 3 × 3 (3 rows × 3 columns), the flag information may indicate that only the central portion of the screen is important. Further, an example is shown in which priority slice information 2602 is provided for each entry constituting the time table (TMSN). However, one piece of priority slice information 2602 may hold information for all entries of the time table (TMSN).

  FIG. 27 is an explanatory diagram showing a video scene during special reproduction. The video scene (original image) 2700 at the time of special reproduction is switched in order from video scene # 01 to video scene # 05. Note that video scene # 01 to video scene # 03 are similar video scenes. In the video scene # 01 to the video scene # 03, for example, the number “1” has moved to the right. Similarly, video scene # 04 to video scene # 05 are similar video scenes. As an example, from the video scene # 04 to the video scene # 05, the numeral “2” has moved to the right. Further, the position of the slice segment to be displayed and updated is indicated by an arrow as an update slice location 2710.

  A video scene 2701 shows a display example of a video scene when scene continuity control is not performed. Video scene # 11 is the same as video scene # 01. In video scene # 12, only slice segment # 2 is switched to slice segment # 2 of video scene # 02 with respect to video scene # 11. In the video scene # 13, only the slice segment # 3 is switched to the slice segment # 3 of the video scene # 03 with respect to the video scene # 12. In video scene # 14, with respect to video scene # 13, only slice segment # 4 is switched to slice segment # 4 of video scene # 04. In video scene # 15, with respect to video scene # 14, only slice segment # 1 is switched to slice segment # 1 of video scene # 05.

  The video scene # 14 which is no longer a similar video scene becomes a video considerably different from the original video scene # 04. That the scenes are not similar is that the scenes are not continuous. Similarly, the video scene # 15 is a video considerably different from the original video scene # 05.

  Further, in the video scenes # 14 and # 15, images of video scenes # 01 to # 03, which are similar images of the original image, and slice segments of completely different video scenes # 04 to # 05 are mixed. Is displayed. Therefore, it becomes difficult for the user to grasp the video scene itself.

  A video scene 2702 shows a display example of a video scene when the continuity control of the scene is performed. Video scene # 21 is the same as video scene # 01. In video scene # 22, only slice segment # 2 is switched to slice segment # 2 of video scene # 02 with respect to video scene # 21. That is, video scene # 22 is the same as video scene # 12. In video scene # 23, only slice segment # 3 is switched to slice segment # 3 of video scene # 03 with respect to video scene # 22. That is, video scene # 23 is the same as video scene # 13. In video scene # 24, all of slice segments # 1 to # 4 have been switched to video scene # 04. That is, video scene # 24 is the same as video scene # 04. In video scene # 25, only slice segment # 2 is switched to slice segment # 2 of video scene # 05 with respect to video scene # 24.

  When performing the continuity control of the scene, the display screen is updated for all slice segments # 1 to # 4 in the video scene # 24 after the switching of the similar video scene. With this configuration, the user can easily grasp the screen even when a similar video scene is switched.

  FIG. 28 is a flowchart showing a sequence for updating the display screen using the scene continuity number 2601.

  When the special reproduction is instructed, first, the scene continuity number 2601 of the entry on the display screen is read. Thereafter, the display screen is updated for all slice segments of the I picture (S2801).

  It is confirmed whether or not there is an instruction to stop the trick play (S2802). If there is an instruction to stop the trick play, the trick play process is stopped (S2809). In this case, "yes" in FIG. 28 is selected. If there is no instruction to stop the special reproduction, the process moves to step S2803. In this case, "no" in FIG. 28 is selected.

  In step S2803, entry information of the reproduction position is read from the time table (TMSN) (S2803). At this time, a method of reading entry information is determined according to the reproduction speed of the special reproduction. For example, it is determined whether to read all entry information or to read some entry information. Part of the entry information indicates entry information that is thinned out by reading every other entry or every other entry according to the reproduction speed.

  Then, the scene continuity number 2601 of the entry information is read. Then, the read scene continuity number 2601 is compared with the scene continuity number 2601 at the immediately preceding display position (S2804). Then, it is determined whether the video scenes are the same (S2805).

  If it is determined in step S2805 that the video scene is the same, only the slice segment at the next position is read. Then, the display of the read slice segment position is updated (S2806).

  If it is determined in step S2805 that the video scene is different, it is determined whether the reproduction speed of the special reproduction is low (S2807). For example, a low speed is set to a special reproduction speed of 10 times or less. Similarly, a case where the special reproduction speed exceeds 10 times speed is defined as high speed. The boundary between the high speed and the low speed is not limited to 10 times speed.

  If the reproduction speed of the special reproduction is high in step S2807, the width of skipping the video scene is increased. In this case, there is a high possibility that the value of the video scene continuity number 2601 is different. In such a case, the process shifts to step S2806 with an emphasis on the response of the display update. Then, the display update of the next slice location is performed. After the process in step S2806, the process returns to step S2802.

  If the reproduction speed of the special reproduction is low in step S2807, the display is updated for all slice segments (S2808). When the trick play speed is low, the user is likely to be searching for a desired video scene. For this reason, importance is placed on grasping the screen rather than responsiveness. Note that the process may move to step S2808 without performing the process based on the reproduction speed of the special reproduction in step S2807. After the processing in step S2808, the process returns to step S2802.

  FIG. 29 is an explanatory diagram showing a display example of a video sequence using the priority slice information 2602. The video scene (original image) 2900 at the time of special reproduction is switched in order from video scene # A1 to video scene # A5. The video scenes # A1 to # A3 are similar video scenes. In the video scene # A1 to the video scene # A3, for example, the letter “A” moves to the right. Similarly, video scenes # A4 to # A5 are similar video scenes. As an example, in the video scene # A4 to the video scene # A5, the alphabet “B” moves to the right. In the example shown in FIG. 29, the video scenes # A1 to # A5 are provided with black bands at the top and bottom. The position of the slice segment whose display is to be updated is indicated by an arrow as an update slice location 2710.

  A display example of a screen when priority slice control is not performed is shown in a video scene 2901. Video scene # B1 is the same as video scene # A1. In the video scene # B2, only the slice segment # 2 is switched to the slice segment # 2 of the video scene # A2 with respect to the video scene # B1. In the video scene # B3, only the slice segment # 3 is switched to the slice segment # 3 of the video scene # A3 with respect to the video scene # B2. In video scene # B4, only slice segment # 4 is switched to slice segment # 4 of video scene # A4 with respect to video scene # B3. In video scene # B5, only slice segment # 1 is switched to slice segment # 1 of video scene # A5 with respect to video scene # B4.

  The video scene # B4 that is no longer a similar video scene becomes a video that is significantly different from the original video scene # A4. That the scenes are not similar is that the scenes are not continuous. Similarly, the video scene # B5 is a video that is considerably different from the original video scene # A5.

  The reason why the images are different is that the display areas of the black bands existing at the top and bottom of the screen are updated in the video scene # B4 and the video scene # B5. The user grasps the screen in the display area other than the black band. Therefore, the user cannot recognize the update of the screen only by updating the black belt portion. As a result, in the video scene # B4 and the video scene # B5, almost no screen information of the video scene # A4 and the video scene # A5, which are original images, is displayed. For this reason, it is difficult for the user to recognize the original image.

  An example of a screen display when priority slice control is performed is shown in a video scene 2902. Video scene # C1 is the same as video scene # A1. In video scene # C2, only slice segment # 3 is switched to slice segment # 3 of video scene # A2 with respect to video scene # C1. In the video scene # C3, only the slice segment # 2 is switched to the slice segment # 2 of the video scene # A3 with respect to the video scene # C2. In video scene # C4, only slice segment # 3 is switched to slice segment # 3 of video scene # A4 with respect to video scene # C3. In the video scene # C5, only the slice segment # 2 is switched to the slice segment # 2 of the video scene # A5 with respect to the video scene # C4.

  In this example, the display of the slice segment unnecessary for grasping the screen is not updated. As a result, a special reproduction display method can be achieved in which both the screen update frequency and the screen recognizability are compatible. In the video scene # C5 portion of this example, an image close to the video scene # A5 that is the original image is displayed.

  FIG. 30 is a flowchart showing a sequence for updating the display screen using the priority slice information 2602.

  When trick play is instructed, priority slice information 2602 of the entry on the display screen is read.

  When the priority slice information 2602 is “0b”, the display screen is updated for all slice segments. On the other hand, if the priority slice information 2602 is “1b”, the display screen is updated only for slice segment # 2 and slice segment # 3 in the center of the screen (S3001).

  If there is an instruction to stop the trick play, the trick play process ends (S3008). In this case, “yes” in FIG. 30 is selected. If there is no instruction to stop the special reproduction, the process moves to step S3003. In this case, “no” in FIG. 30 is selected.

  In step S3003, the entry information of the reproduction position is read from the time table (TMSN) (S3003). At this time, a method of reading entry information is determined according to the reproduction speed of the special reproduction. For example, it is determined whether to read all entry information or to read some entry information. Part of the entry information indicates entry information that is thinned out by reading every other entry or every other entry according to the reproduction speed.

  Then, based on the presence or absence of the set value of the priority slice information 2602 of the read entry information, it is determined whether or not the display area is restricted by the priority slice (S3004).

  If the value of the priority slice information 2602 is “1b” in step S3004, the display area of the screen of the slice segments # 1 and # 4 is painted black (S3005).

  As described above, for example, when the value of the priority slice information 2602 is “1b”, the display screen is sequentially limited to slice segments # 2 and # 3, which are the slice segments at the center of the screen. Update. On the other hand, when the value of the priority slice information 2602 is “0b”, all slice segments # 1 to # 4 are sequentially updated.

  In the fourth embodiment, if the priority slice information is set, the display is updated only at the center of the screen. Therefore, the display areas of the top and bottom slice segments of the screen are painted black. Note that the blackening processing of the screen in step S3005 may not be performed. In this case, for example, the image of the previous slice segment is displayed as it is.

  Then, the display screen of the slice segment is sequentially updated only for the slice segment # 2 and the slice segment # 3 which are the center part of the screen (S3006).

  On the other hand, if the value of the priority slice information is “0b” in step S3004, the display screen of the slice segment is sequentially updated in all slice segments (S3007). That is, in this case, there is no particular display restriction on the screen.

  By configuring as in Embodiment 4, even when updating the screen display in slice segments at the time of special playback, excellent responsiveness of updating the display screen is achieved, and video recording that makes it easy to grasp the video scene of the display screen is achieved. A playback device can be provided.

  Also, display control during special reproduction can be performed using both the scene continuity number 2601 and the priority slice information 2602. That is, if the sequence is not continuous at the time of the processing in step S3006, all priority slices may be updated. Similarly, if the sequence is not continuous at the time of processing in step S3007, all slices may be updated.

  The time table (TM) and the time table (TMSN) may be recorded as the same table information. Alternatively, the time table (TM) and the time table (TMSN) may be managed as separate tables and recorded as separate files.

  When recorded as another file, the entries constituting the time table (TM) and the time table (TMSN) are recorded in association with each other as the same entry information. When the time table (TM) is edited, the information cannot be matched with the time table (TMSN). For this reason, hash information of the time table (TM) is recorded in the time table (TMSN), and it is confirmed whether or not the association between the time table (TMSN) and the time table (TM) is normal before reproduction. It may be configured as follows.

  Although the example in which the priority slice information 2602 exists in the time table (TMSN) has been described, the priority slice information 2602 may be stored outside the time table (TMSN). In this case, since the priority slice cannot be set for each entry, the setting is the same for all related entries.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments.

  The contents of the invention will be described below as supplementary notes based on the above embodiments.

<Appendix>
<Appendix 1>
A tuner / demodulation unit for receiving broadcast waves,
A demultiplexing unit that demultiplexes the multiplexed stream of the broadcast wave,
A decoding unit for expanding the demultiplexed compressed data of the multiplexed stream;
A recording / playback control unit that collects video data or control information for recording from the data expanded by the decoding unit,
A video recording / reproducing apparatus characterized in that, when recording video data included in the broadcast wave using the MMT format, packet data is recorded as video data combined.

<Appendix 2>
3. The video recording / reproducing apparatus according to claim 1, wherein a time table including a time at which the collected video data is reproduced and a position at which the video data at the time is recorded is created and recorded together with the collected video data. .

<Appendix 3>
A tuner / demodulation unit for receiving broadcast waves,
A demultiplexing unit that demultiplexes the multiplexed stream of the broadcast wave,
A decoding unit for expanding the demultiplexed compressed data of the multiplexed stream;
A recording / playback control unit that collects video data or control information for recording from the data expanded by the decoding unit,
A video recording / reproducing apparatus, wherein when recording video data included in the broadcast wave using the MMT format, the video data is recorded as a file in a BMFF format.

<Appendix 4>
4. The video recording / reproducing apparatus according to claim 3, wherein when the video data is recorded on an optical disc, a management data portion and a stream data portion of the BMFF format file are recorded at different positions on the optical disc. .

<Appendix 5>
3. The video recording / reproducing apparatus according to claim 2, wherein the asset information is recorded in the time table.

<Appendix 6>
3. The video recording / reproducing apparatus according to claim 2, wherein HDR metadata is recorded in the time table.

<Appendix 7>
3. The video recording / reproducing apparatus according to claim 2, wherein the time table records a data size or an end position of an IRAP picture decoded first in a GOP.

<Appendix 8>
3. The video recording / reproducing apparatus according to claim 2, wherein positions of a plurality of images in a GOP are recorded in the time table.

<Appendix 9>
The video data has a structure of a slice segment constituting an image,
3. The video recording / reproducing apparatus according to claim 2, wherein a position of the slice segment is recorded in the time table.

<Appendix 10>
When combining or recording the packet data, delimit the video data,
2. The video recording / reproducing apparatus according to claim 1, wherein a head of the separated video data is placed at a break position of a block used when accessing the video data.

<Supplementary Note 11>
11. The video recording / reproducing apparatus according to supplementary note 10, wherein a unit that divides the video data is a GOP unit.

<Appendix 12>
11. The video recording / reproducing apparatus according to supplementary note 10, wherein a unit that divides the video data is a picture unit.

<Appendix 13>
11. The video recording / reproducing apparatus according to Supplementary Note 10, wherein a position at which the video data is divided is an IRAP picture head, an I picture head, or a P picture head.

<Appendix 14>
11. The video recording / reproducing apparatus according to supplementary note 10, wherein a unit for dividing the video data is a unit of a slice segment.

<Appendix 15>
15. The video recording / reproducing apparatus according to Appendix 14, wherein, when recording the video data, information on a read position of the video data is recorded in units of I-picture slice segments as management data.

<Appendix 16>
16. The video recording / reproducing apparatus according to supplementary note 15, wherein the information on the read position is information on a read position of the slice segment.

<Appendix 17>
17. The video recording / reproducing apparatus according to appendix 15 or 16, wherein the order of recording the slice segments is changed for each GOP when recording the video data.

<Appendix 18>
18. The video recording / reproducing apparatus according to any one of Supplementary Notes 15 to 17, wherein when reproducing the video data, a part of the slice segment is displayed for each image.

<Appendix 19>
19. The video recording / reproducing device according to supplementary note 18, wherein a position where the some slice segments are displayed is changed for each of the images.

  Reference Signs List 100 video recording / reproducing device, 11 tuner / demodulation unit, 12 external input unit, 13 network unit, 21 demultiplexing unit, 31 audio decoding unit, 32 video decoding unit, 33 subtitle decoding / rendering unit, 34 data broadcasting / EPG processing Unit, 41 recording / playback control unit, 51 built-in recording device, 52 optical disk drive, 53 optical disk, Af management file, Hm head data, Ba broadcast wave, Sm multiplexed stream, Se elementary stream, Ds audio data, Di0, Di1 video data, Dc subtitle data, Db data broadcast data, Dd display device, Es audio device, Ei external device, Ne network, Ha horizontal axis, Va1, Va2 vertical axis, P1, P2, P3 position, Pad pa , SI (MPT) control packet, TP TLV packet, TM, TMS time table, V video packet, V (RAP) video packet, 2601 scene continuity number, 2602 priority slice information 2700 video scene (original), 2701 screen table Illustrative example (without scene continuity control), 2702 screen display example (with scene continuity control), 2710 updated slice location, 2900 video scene (original), 2901 screen display example (without priority slice control), 2902 screen display example (with priority) With slice control).

Claims (3)

A video playback device that plays back recorded data that records a broadcast stream,
The recording data includes video information including an I picture, a first time table indicating a start position of the I picture, and a second time table indicating a start position of a plurality of slice segments constituting the I picture. Time table, including continuity information indicating the continuity of the video scene included in the video information,
When fast-forwarding playback of the recording data, if the continuity information indicates that the continuity information is continuous, one of the plurality of slice segments constituting the I picture is played back, and When the continuity information indicates discontinuity, all of the slice segments constituting the I picture are reproduced. A video recording device that records a broadcast stream on a recording medium,
Recording the broadcast stream including video information including an I picture;
Generating a first time table indicating the start position of the I picture and recording it on a recording medium;
Generating and recording on a recording medium a second time table indicating start positions of a plurality of slice segments constituting the I picture;
Generate and record continuity information indicating the continuity of the video scene included in the video information on a recording medium,
When fast-forwarding the broadcast stream, if the continuity information indicates that the continuity information is continuous, one of the plurality of slice segments constituting the I picture is played back, If the continuity information indicates discontinuity, all the slice segments constituting the I picture are reproduced. A video recording medium for recording a broadcast stream reproduced by a video reproduction device,
The broadcast stream including video information including an I picture;
A first time table indicating a start position of the I picture;
A second time table indicating start positions of a plurality of slice segments constituting the I picture;
Continuity information indicating the continuity of the video scene included in the video information, is recorded,
The video playback device,
When fast-forwarding the broadcast stream, determine whether the continuity information indicates continuity or discontinuity, indicating that the continuity information is continuous In the case, one of the plurality of slice segments constituting the I picture is reproduced, and if the continuity information indicates discontinuity, the I picture is composed. A video recording medium, which is used for a process of reproducing all the slice segments to be reproduced.

Images