JP2015153441A - Information processor, information recording device, information recording medium, information processing method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a configuration allowing to acquire random access point information from a TS packet when converting and recording BDMV(Blu-ray(R) Disc Movie) data in an MP4 file.SOLUTION: A data conversion part acquires random access point information necessary for the random access reproduction of reproduction data as conversion object data from a stream file as a storage file of reproduction object data S102, and sets the acquired random access point information as the configuration data of a data file after format conversion. The data conversion part acquires the random access point information from the header of the TS packet of the clip AV stream file of the BDMV format data S104, and records the acquired information in an MP4 file mfra box S105 to S108.

Description

  The present disclosure relates to an information processing device, an information recording device, an information recording medium, an information processing method, and a program. More specifically, the present invention relates to an information processing apparatus, an information recording apparatus, an information recording medium, an information processing method, and a program that execute data recording with format conversion, for example.

  DVD (Digital Versatile Disc) and BD (Blu-ray (registered trademark) Disc) are widely used as information recording media (media) for recording various contents such as movies and music.

Various data such as images, sounds, and reproduction control data are recorded on these discs in a data recording format defined in advance.
For example, a BDMV (Blu-ray (registered trademark) Disc Movie) format is used as a data recording format for a BD.
In order to reproduce the recorded data in the BDMV format, it is necessary to hold a program for reproducing the BDMV format data.

In recent years, an increasing number of users are viewing content such as movies on smartphones (smartphones) and mobile terminals such as tablet terminals.
Such a portable terminal does not always have a playback application compatible with the BDMV format. Therefore, when copying the recording data of the BD to the media of the mobile terminal, it is necessary to change the recording format to a format that can be played back by the playback application of the mobile terminal that is not in the BDMV format.
Note that data copy processing between media is described in, for example, Japanese Patent Application Laid-Open No. 2008-98765 and Japanese Patent Application Laid-Open No. 2011-2222078.

There is an MP4 file format (hereinafter referred to as MP4) as a data recording format standardized in consideration of use by a portable terminal or the like.
Many mobile terminals have a playback application that can play back MP4 data recorded in the MP4 file format, and when recording content on the media of the mobile terminal, it is required to record in MP4 format.

Therefore, for example, when copying data in the BDMV format to a medium such as an SD card used in the portable terminal, it is necessary to perform a copy process with format conversion from BDMV to MP4.
However, no specific proposal for this format conversion has been made at present. If format conversion is not performed reliably, content reproduction at the copy destination may not be possible.

JP 2008-98765 A JP 2011-2222078

  The present disclosure has been made in view of such problems. For example, an information processing apparatus and an information recording apparatus that enable normal data reproduction after format conversion in a configuration in which data recording processing involving format conversion is performed. It is an object to provide an information recording medium, an information processing method, and a program.

The first aspect of the present disclosure is:
A data conversion unit for performing data format conversion;
The data converter is
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information It exists in the information processing apparatus set as data.

  Furthermore, in an embodiment of the information processing apparatus according to the present disclosure, the data conversion unit acquires the reproduction control information from an information recording medium on which the conversion target data is recorded or from the outside via a communication unit.

  Furthermore, in an embodiment of the information processing apparatus according to the present disclosure, the data conversion unit executes a process of converting BDMV format data into MP4 format data, and a clip AV stream file that is a reproduction target data storage file of the BDMV format data The random access point information is acquired from, and the acquired random access point information is set as metadata in the MP4 file.

  Furthermore, in an embodiment of the information processing apparatus according to the present disclosure, the data conversion unit stores the random access point information in an mfra box or a tfra box set in an MP4 file.

  Furthermore, in an embodiment of the information processing apparatus according to the present disclosure, the data conversion unit has a transport priority recorded in a header of a transport packet (TS packet) that is a configuration packet of a clip AV stream file of BDMV format data. Based on the set value, it is determined whether or not the transport packet storage data includes data serving as a random access point.

  Furthermore, in an embodiment of the information processing apparatus according to the present disclosure, the data conversion unit sets an adaptation field recorded in a header of a transport packet (TS packet) that is a configuration packet of a clip AV stream file of BDMV format data. Based on the value, an unused area of the transport packet storage data is determined.

  Furthermore, in an embodiment of the information processing apparatus of the present disclosure, the data conversion unit includes a presentation time stamp (PTS) stored in a transport packet (TS packet) that is a configuration packet of a clip AV stream file of BDMV format data. And applying the acquired presentation time stamp (PTS) to generate time information to be recorded in the mfra box or tfra box set in the MP4 file.

  Furthermore, in an embodiment of the information processing apparatus according to the present disclosure, the data conversion unit converts the BDMV format data to generate a CFF file according to CFF (Common File Format).

  Furthermore, in an embodiment of the information processing apparatus according to the present disclosure, the information processing apparatus further includes a recording unit that records data after the data format conversion on the second information recording medium.

Furthermore, the second aspect of the present disclosure is:
A data conversion unit for performing data format conversion;
A recording unit that records the conversion data of the data conversion unit on an information recording medium;
The data converter is
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information Set as data,
The recording unit is
The information recording apparatus records format conversion data including the random access point information on an information recording medium.

  Furthermore, in an embodiment of the information recording apparatus of the present disclosure, the data conversion unit executes a process of converting BDMV format data into MP4 format data, and a clip AV stream file that is a reproduction target data storage file of the BDMV format data The random access point information is acquired from, and the acquired random access point information is set as metadata in the MP4 file.

Furthermore, the third aspect of the present disclosure is:
A data processing unit for generating recording data for an information recording medium;
The data processing unit
Random access point information necessary for random access playback of BDMV format data is recorded in a header of a transport packet (TS packet) that is a constituent packet of a clip AV stream file that is a storage file of playback target data, and information recording It is in an information recording device for recording on a medium.

  Furthermore, in an embodiment of the information recording apparatus according to the present disclosure, the data processing unit sets a transport priority setting value of a header of the transport packet (TS packet) to data stored in the transport packet (TS packet). A different value is recorded depending on whether or not is data corresponding to a random access point.

  Furthermore, in an embodiment of the information recording device of the present disclosure, the data processing unit may store data stored in each transport packet (TS packet) as either random access point compatible data or random access point non-compatible data. A transport packet (TS packet) is generated by setting one of the data.

  Furthermore, in an embodiment of the information recording apparatus of the present disclosure, the data processing unit records unused area information of transport packet storage data in an adaptation field of a header of the transport packet (TS packet).

Furthermore, the fourth aspect of the present disclosure is:
A stream file that is a storage file for data to be played, and
Storing the playback control information file storing the playback control information of the stream file as recording data;
An information recording medium in which random access point information having different values depending on whether or not the stored data of the packet is random access point compatible data is recorded in the header of the packet constituting the stream file,
An information processing device that performs format conversion of data stored in the information recording medium determines whether or not the packet storage data is random access point compatible data by analyzing the header of the packet, and performs format conversion based on the determination result The information recording medium enables later generation and recording of metadata.

Furthermore, the fifth aspect of the present disclosure is:
An information processing method executed in an information processing apparatus,
The data converter
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information The information processing method is set as data.

Furthermore, the sixth aspect of the present disclosure is:
A program for executing information processing in an information processing apparatus;
After the data conversion unit obtains the random access point information necessary for random access playback of the playback data that is the conversion target data from the stream file that is the storage file of the playback target data, after the format conversion of the acquired random access point information It is in the program to be set as the configuration data of the data file.

  Note that the program of the present disclosure is a program that can be provided by, for example, a storage medium or a communication medium provided in a computer-readable format to an information processing apparatus or a computer system that can execute various program codes. By providing such a program in a computer-readable format, processing corresponding to the program is realized on the information processing apparatus or the computer system.

  Other objects, features, and advantages of the present disclosure will become apparent from a more detailed description based on embodiments of the present disclosure described below and the accompanying drawings. In this specification, the system is a logical set configuration of a plurality of devices, and is not limited to one in which the devices of each configuration are in the same casing.

According to the configuration of an embodiment of the present disclosure, a configuration in which random access point information can be acquired from a TS packet when BDMV data is converted and recorded into an MP4 file is realized.
Specifically, the data conversion unit acquires random access point information necessary for random access playback of playback data that is conversion target data from a stream file that is a storage file of playback target data, and the acquired random access point information Is set as the configuration data of the data file after format conversion. The data conversion unit acquires random access point information from the header of the TS packet of the clip AV stream file of BDMV format data, and records the acquired information in the MP4 file mfra box.
With this configuration, when BDMV data is converted into an MP4 file and recorded, random access point information can be acquired from the TS packet.
Note that the effects described in the present specification are merely examples and are not limited, and may have additional effects.

FIG. 25 is a diagram for describing a configuration example of an information processing device. It is a figure explaining the structure of the data conversion part of information processing apparatus. It is a figure explaining the example of a directory structure of the data recorded on a medium according to a BDMV format. It is a figure explaining the response | compatibility with the play list prescribed | regulated in a BDMV format, and reproduction | regeneration data. It is a figure explaining the structural example of MPEG2TS (transport stream) as a data structure of a clip AV stream (Clip AV Stream) file. It is a figure explaining an MP4 file format. It is a figure explaining the structure of CFF (Common File Format). It is a figure explaining the example of a data structure of the mfra box of CFF (Common File Format). It is a figure explaining the format conversion process example of a playlist unit. It is a figure explaining the correspondence of the reproduction | regeneration data in the case of producing | generating a CFF file from BDMV format data. It is a figure explaining the random access point information set to the TS packet of the clip AV stream file of BDMV format data. It is a figure explaining the problem at the time of utilizing the random access point information set to the TS packet of the clip AV stream file of BDMV format data. It is a figure explaining the structure which solves the problem at the time of utilizing the random access point information set to the TS packet of the clip AV stream file of DMV format data. It is a figure explaining the example which recorded random access point information on TS packet of the clip AV stream file of BDMV format data. FIG. 10 is a diagram illustrating a flowchart for explaining a format conversion processing sequence executed by the information processing apparatus. It is a figure explaining the flow of data and a process in information processing apparatus at the time of format conversion process execution.

Hereinafter, details of the information processing apparatus, the information recording apparatus, the information recording medium, the information processing method, and the program of the present disclosure will be described with reference to the drawings. The description will be made according to the following items.
1. 1. Outline of configuration and processing of information processing apparatus 2. About the BDMV format About MP4 file format 4. An example of data format conversion processing 5. Problems with random access point information acquisition in format conversion 6. Configuration that makes it possible to identify random access points based on TS packets 7. Data storage configuration for TS packet 8. Configuration in which random access point information is recorded in the header of a TS packet of a clip AV stream file of BDMV format data 9. Format conversion processing sequence executed by information processing apparatus Summary of composition of this disclosure

[1. Overview of information processing device configuration and processing]
First, an outline of a configuration and processing of an information processing apparatus according to an embodiment of the present disclosure will be described.
FIG. 1 is a block diagram illustrating a configuration example of an information processing apparatus 100 according to an embodiment of the present disclosure. The information processing apparatus 100 reads out data recorded on a first medium 110 that is an information recording medium such as a BD (Blu-ray (registered trademark) Disc), for example, and a second medium 120 that is an information recording medium such as a flash memory. So-called copy processing is performed.
Alternatively, a process of recording data input via the communication unit 103 on the second medium 120 such as a rush memory is performed.

  Note that the data format of data input via the first medium 110 or the communication unit 103 is a first format, and the format of data recorded on the second medium 120 is a second format.

  The information processing apparatus converts the first format data into the second format data when recording the first format data input via the first medium 110 or the communication unit 103 in the second medium 120 such as a flash memory. The process to do is performed.

In the following embodiment, the format of data input from the first medium 110 or the communication unit 103 is described as a BDMV format, and the recording format of the second medium is described as an MP4 format.
The information processing apparatus 100 executes format conversion from the BDMV format to the MP4 format during data recording processing on the second medium 120.

  As shown in FIG. 1, the information processing apparatus 100 includes a control unit 101, an input unit 102, a communication unit 103, a storage unit 104, an output unit 105, a first media IF (interface) 106, a data buffer 107, and a data conversion unit 108. And a second media IF 109.

  The control unit 101 performs control of data processing executed in the information processing apparatus 100 such as data recording / playback using media and data copy processing between media. These controls are performed according to a program stored in the storage unit 104, for example. Done.

The input unit 102 is an input unit such as a switch, button, or touch panel that can be operated by the user, and is an input unit that inputs instructions for various processes such as reproduction, copying, and recording.
Further, the input unit 102 may have a configuration including an imaging unit that inputs an image or sound to be recorded on a medium, and a microphone.
The communication unit 103 communicates with, for example, an external server or an external device, and is used for various communication processes such as acquisition of recording data for media, control information related to the recording data, or permission information for copy processing.

The storage unit 104 is used as a storage area for a program executed by the control unit 101, a parameter area used for program execution, and a work area during program execution.
Specifically, it is also used as an area for temporarily storing data read from the first medium 110 when data is recorded on the second medium 120 or data input via the communication unit 103.
The storage unit 104 is configured by, for example, a RAM, a ROM, and the like.
The output unit 105 is used for output processing of reproduction data from the medium, and further used for displaying the progress of data recording processing on the second medium 120 and displaying messages to the user, and is configured by a display, a speaker, and the like.

  The first media interface (IF) 106 is a data recording / reproducing unit that accesses the first medium 110 such as a BD (Blu-ray (registered trademark) Disc) and performs data recording and data reading on the first medium 110. A functional interface.

The data buffer 107 is a buffer that temporarily stores read data from the first medium 110 and data input from the communication unit 103. For example, data to be recorded on the second medium 120 is temporarily stored.
The data conversion unit 108 records data recorded in the first medium 110 or data in the first format, which is the format of data input via the communication unit 103, on the second medium 120 that is the data recording destination. A format conversion process for converting to a second format which is a format is executed. The detailed configuration and processing of the data converter 108 will be described later.

  The second media interface (IF) 109 is an interface that functions as a data recording / reproducing unit that accesses the second medium 120 and performs data recording or reading processing on the second medium 120.

As described above, the information processing apparatus 100 performs processing for recording the first format data input via the first medium 110 or the communication unit 103 in the second medium 120 such as a flash memory. In this process, a process for converting the first format data into the second format data is performed.
The first format is BDMV format data, for example, and the second format is MP4 format data.

  Note that the information processing apparatus 100 acquires only data that cannot be acquired from the first medium 110 from an external server via the communication unit 103, and acquires data read from the first medium 110 and the communication unit 103. You may perform the process which records received data on the 2nd medium 120 collectively.

In the configuration shown in FIG. 1, the first medium 110 is, for example, a BD (Blu-ray (registered trademark) Disc). The second medium 120 is a flash memory such as an SD card, for example.
The first medium 110 and the second medium 120 are not limited to the above combinations, and various combinations are possible.

Next, the detailed configuration of the data conversion unit 108 will be described with reference to FIG.
As shown in FIG. 2, the data conversion unit 108 includes a data analysis unit 151, an image data conversion unit 152, an audio data conversion unit 153, a caption data conversion unit 154, and a multiplexing process execution unit 155.

The data analysis unit 151 is based on read data from the first medium 110 stored in the data buffer 107 or an identifier (PID: program ID) set in data (packet) input via the communication unit 103. Each data (packet)
image data,
Audio data,
Subtitle data,
Classify into these three types of data.

  The data analysis unit 151 outputs image data to the image data conversion unit 152, outputs audio data to the audio data conversion unit 153, and outputs caption data to the caption data conversion unit 154.

  The image data conversion unit 152, the audio data conversion unit 153, and the caption data conversion unit 154 are a first format that is a data format of input data, for example, a second format for recording BDMV format data on the second medium 120, specifically, For example, executes processing for conversion into format data in the MP4 format.

That is, the image data conversion unit 152 generates MP4 format image data, which is a data recording format for the second medium 120, and outputs the image data to the multiplexing processing execution unit 155.
The audio data conversion unit 153 generates MP4 format audio data and outputs the audio data to the multiplexing process execution unit 155.
The caption data conversion unit 154 generates MP4 format caption data and outputs it to the multiplexing process execution unit 155.

Note that each of the image data conversion unit 152, the audio data conversion unit 153, and the caption data conversion unit 154 performs necessary decryption processing, encoding processing, encryption processing, and the like in the format conversion processing of each data.
That is, each of the image data conversion unit 152, the audio data conversion unit 153, and the caption data conversion unit 154 performs a decoding process according to the encoding mode (for example, MPEG2) of the first format (for example, BDMV) that is the input data. The encoding process according to the encoding mode of the second format (for example, MP4) which is the recording format for the second medium 120 is executed.

When the input data is encrypted data, each of the image data conversion unit 152, the audio data conversion unit 153, and the caption data conversion unit 154 executes the decoding process and performs format conversion using the decoded data. .
Further, when it is necessary to use the recording data for the second medium 120 as encrypted data, each of the image data conversion unit 152, the audio data conversion unit 153, and the caption data conversion unit 154 follows a predetermined encryption algorithm. Perform encryption processing.

The multiplexing processing unit 155
(A) second format (MP4) format image format data generated by the image data generation unit 152;
(B) audio format data in the second format (MP4) generated by the audio data generator 153;
(C) Subtitle format data in the second format (MP4) generated by the subtitle data generation unit 154,
(D) data extracted from, for example, a reproduction control information file stored in the storage unit 104;
For example, multiplexing processing of each of these data is executed to generate recording data in the second format (MP4) format.

  The data generated by the multiplexing process execution unit 155 is recorded on the second medium 120 via the second media interface 109.

  As described above, the information processing apparatus 100 uses the second format, which is the recording format of the second medium 120, of the recording data of the first medium 110 or the data of the first format (BDMV format) input via the communication unit 103. A process of converting to the format (MP4) and recording on the second medium 120 is executed.

  Hereinafter, the BDMV format, which is the format of the content that is the copy source, and MP4, which is the recording format for the copy destination medium, will be sequentially described.

[2. About BDMV format]
The BDMV format will be described with reference to FIG.
FIG. 3 is a diagram showing a directory of recording data according to the BDMV format recorded on a ROM-type BD (Blu-ray (registered trademark) Disc) which is the first medium 110, for example.

As shown in FIG. 3, the directory is divided into a management information setting unit 171 (AACS directory) and a data unit 172 (BDMV directory).
The management information setting unit 171 (AACS directory) stores a CPS unit key file and a usage control information file that are data encryption keys.

On the other hand, under the BDMV directory of the data part 172,
Index files,
Playlist files,
Clip information file,
Clip AV stream file,
BDJO file,
For example, these files are recorded.

The index file stores title information as index information applied to the reproduction process.
The playlist file is a file that defines the playback order of contents in accordance with the program information of the playback program specified by the title, and has playback position information and designation information for clip information.
The clip information file is a file specified by the playlist file, and has reproduction position information of the clip AV stream file and the like.
The clip AV stream file is a file storing AV stream data to be reproduced.
The BDJO file is a file that stores execution control information of a file that stores JAVA (registered trademark) programs, commands, and the like.

The sequence in which the information processing apparatus reproduces the content recorded on the information recording medium is as follows.
(A) First, a specific title is designated from the index file by the reproduction application.
(B) A reproduction program associated with the designated title is selected.
(C) A playlist that defines the playback order of contents is selected according to the program information of the selected playback program.
(D) The AV stream or the command as the actual content data is read out by the clip information defined in the selected playlist, and the AV stream is reproduced and the command is executed.

FIG. 4 shows the following data recorded on the first medium 110:
Playlist files,
Clip information file,
Clip AV stream file,
It is a figure explaining the correspondence of these data.

  An AV stream composed of image and audio data as actual reproduction target data is recorded as a clip AV stream (Clip AV Stream) file, and a playlist (PlayList) is used as management information and reproduction control information file of these AV streams. A file and a clip information file are defined.

These multiple categories of files are shown in FIG.
A playlist layer including a playlist (PlayList) file,
A clip layer consisting of a clip AV stream (Clip AV Stream) file and a clip information (Clip Information) file,
It can be divided into these two layers.

Note that one clip AV stream (Clip AV Stream) file is associated with one clip information (Clip Information) file, these pairs are considered as one object, and these are collectively referred to as a clip (Clip). There is also.
Detailed information of data included in the clip AV stream file, for example, management information such as an EP map in which I picture position information of MPEG data is recorded is recorded in the clip information file.

  A clip AV stream (Clip AV Stream) file stores data in which MPEG2 TS (transport stream) is arranged in accordance with a BDMV format specified structure. Details of this configuration will be described later with reference to FIG.

  In addition, in the clip information (Clip Information) file, for example, the data position of the byte string data of the clip AV stream file and the playback time such as the playback start point when expanded on the time axis (entry point: EP), etc. The management information for acquiring the reproduction start position of the data stored in the clip AV stream file, such as the corresponding data such as the position, is stored.

  For example, when a time stamp indicating the playback time elapsed position from the start point of the content is given, the clip information file is referred to, and the data read position of the clip AV stream file, that is, the address as the playback start point is acquired. Is possible.

The playlist (PlayList) file has designation information of a playback section for playable data included in a clip (= clip information file + clip AV stream file) layer.
In the playlist (PlayList) file, one or more play items (PlayItem) are set, and each play item is a playback section for playable data included in a clip (= clip information file + clip AV stream file) layer. Specified information.

  A clip AV stream (Clip AV Stream) file storing actual image and audio data to be reproduced has a MPEG2 transport stream (TS) file structure as shown in FIG. 5, for example.

The MPEG2 transport stream file structure has the following settings.
1) An MPEG2 transport stream file is composed of an integer number of aligned units.
2) The size of the aligned unit is 6 kB (= 6144 bytes (2048 × 3 bytes)).
3) The aligned unit starts from the first byte of the source packet.
4) The source packet is 192 bytes long. One source packet includes a TP_extra_header and a transport packet (TS packet). The TP_extra_header is 4 bytes long, and the transport packet (TS packet) is 188 bytes long.
5) A transport packet (TS packet) has a header (TP header) and a payload portion. The payload of one TS packet stores encoded data of any one type of data such as an image and sound.
6) A PID (program ID) indicating the data type of the payload is recorded in the header (TP header) of the transport packet (TS packet).
7) The payload of a transport packet (TS packet) is composed of a packet (packeted elementary stream (PES)) that stores an elementary stream (ES) that is encoded data such as an image or sound, a PES header, and the like. The
8) In the PES header, a presentation time stamp (PTS) indicating playback time information of the elementary stream (ES) stored in the subsequent PES packet is recorded.

[3. About MP4 file format]
Next, an outline of the MP4 file format will be described with reference to FIG.
In FIG. 6, the following two examples are shown as examples of the MP4 file format defined by ISO / IECC 14496-14.
(A) Fragmented (split type) MP4 file (fragmented movie)
(B) Non-fragmented MP4 file (Non-fragmented movie)
These MP4 files shown in FIGS. 6A and 6B are files set as one processing unit in data recording or reproduction processing according to the MP4 format.

(A) A fragmented (divided type) MP4 file (fragmented movie) is a file format in which data such as images and sounds, which are reproduction target data, is divided and stored for each reproduction data within a predetermined time.
(B) A non-fragmented (non-segmented) MP4 file (Non-fragmented movie) is a file format in which data such as images and sounds that are reproduction target data is stored without being divided.

In the MP4 file, an area is set in units of boxes, and data defined in units of boxes is stored in each box.
Each box has areas of a box size (box-size), a box type (box-type), and box data (box-data).
The box data size (byte size) is recorded in the box size (box-size).
In the box type (box-type), the type of data stored in the box is recorded.
In the box data (box-data), data of the type indicated by the box type is recorded.

The following types of boxes are set in the fragmented (split type) MP4 file shown in FIG.
moov box,
trak box,
moof box,
traf box,
mdat box,
mfra box,
tfra box,
Each box above is set.

Actual data that is reproduction target data such as images, sounds, and captions is divided into mdat boxes and stored.
Further, each mdat box is associated with a moof box, and the moof box stores metadata such as attribute information and reproduction control information related to the divided actual data stored in the mdat box associated with the moof box. To do.

  The fragmented (divided type) MP4 file shown in FIG. 6 (a) has a large number of pieces of real data (mdat) that is divided data of reproduction target data and metadata corresponding to the divided real data (moof) as one set data. It has a configuration in which set data is stored, and metadata regarding all of the plurality of stored set data is stored in a moov box.

A traf box is set in the metadata (moof) corresponding to the divided actual data.
The traf box stores reproduction sequence information of associated real data (mdat) and the like.

The moov box is a box set as a storage area for metadata such as reproduction control information of data stored in the entire MP4 file.
One or more trak boxes are set in the moov box. The trak box can be set for each data type such as image, sound, subtitle, etc., and stores reproduction sequence information of each data.

If the playback data stored in the MP4 file includes a plurality of different image data, such as HD images, 4K images, etc., it is possible to set individual trak boxes according to these image types. .
Also, if the stored audio data of the MP4 file includes a plurality of different audio data, for example, Japanese audio, English audio, etc., individual trak boxes can be set according to these audio types.
Similarly, when the stored subtitle data of the MP4 file includes a plurality of different subtitle data, for example, Japanese subtitles, English subtitles, etc., individual trak boxes can be set according to these subtitle types.

  The official name of the mfra box is a Movie Fragment Random Access Box, which stores information on data locations that can be accessed randomly.

Each data such as an image, sound, and caption stored in MP4 is encoded according to a predetermined algorithm, and is not configured to start playback from all arbitrary playback points.
The data position at which reproduction can be started is defined in advance as a random access point, and information on the random access point is recorded in the mfra box.
A playback device that plays back MP4 format data can acquire a random access point by referring to the information recorded in the mfra box. The playback device can perform data playback from the random access point by acquiring data position and playback time information such as image data, audio data, and caption data corresponding to the random access point based on the recording information of the mfra box.

For example, in the case of MPEG image data, MPEG encoded image data includes each picture of IPB having a different encoding mode. Each picture of PB refers to one of the preceding and subsequent encoded data. Without it, it cannot be decrypted. On the other hand, an I picture can be decoded independently. In MPEG image data, the position of an I picture is a random access point.
The MP4 encoded data also has the same configuration, and a data position at which reproduction can be started is defined in advance as a random access point according to the encoding algorithm of each data such as image, audio, and caption. Information about the random access point is recorded in the mfra box. ,

In the mfra box, a tfra box that is a storage box of random access point information corresponding to a track (trak) set for each data type such as image, audio, and caption is set.
The official name of the tfra box is a Track Fragment Random Access Box, which stores random access point information in units of tracks according to the data type such as image, audio, and subtitle.

A non-fragmented (non-fragmented movie) MP4 file (Non-fragmented movie) shown in FIG. 6B is a file format in which data such as images and sounds that are reproduction target data is stored without being divided.
The following types of boxes are set in the non-fragmented (non-divided) MP4 file shown in FIG.
moov box,
trak box,
mdat box,
Each box above is set.

The mdat box stores actual data to be reproduced.
The moov box stores metadata set in correspondence with actual data (mdat) that is reproduction target data, for example, metadata including attributes of reproduction target data (mdat) and reproduction control information.
The trak box set in the moov box stores reproduction sequence information of actual data (mdat).

  Similar to the above-described (a) fragmented (divided) MP4 file, one or more trak boxes are set in the moov box set in (b) non-fragmented (non-divided) MP4 file. Each trak box is set for each data type, such as image, audio, and caption.

FIG. 6 shows a basic configuration example of the MP4 file format.
DECE (Digital Entertainment Content Ecosystem), a standardization organization for the MP4 format, has standardized CFF (Common File Format) as a new MP4-based file format. This CFF will be described with reference to FIG.

  The CFF (Common File Format) shown in FIG. 7 basically has the same data configuration as that of the fragmented movie MP4 described with reference to FIG.

That is, in the CFF (Common File Format) file shown in FIG. 7, the following boxes are set as in the fragmented (split type) MP4 file shown in FIG.
moov box,
trak box,
moof box,
traf box,
mdat box,
mfra box,
tfra box,
Each box above is set.

The data stored in each box is almost the same as the fragmented (split type) MP4 file in FIG.
However, in CFF, each mdat box has a restriction that only one type of data is stored.
That is, in each mdat box,
(A) Image (b) Audio (c) Subtitle One kind of data is stored. There is a restriction that the above data (a) to (c) should not be mixed and stored.

When a plurality of different image data such as HD images, 4K images, etc. are included in the CFF file, these different images are stored in different mdat boxes.
Similarly, different audio data such as Japanese audio and English audio are stored in individual mdat boxes, and Japanese subtitles and English subtitles are also stored in different mdat boxes.

In the general fragmented (divided) MP4 file shown in FIG. 6A, different types of data such as images, audio, and subtitles are stored in the mdat box set as a storage box for one divided data (fragment). It was allowed to store a mixture.
However, in the CFF (Common File Format) shown in FIG. 7, there is a restriction that only one type of data can be stored in one mdat box.

That is, only one kind of data of image, sound, or subtitle is individually stored in each mdat box.
Accordingly, the moof box, which is a metadata storage area corresponding to the mdat box, is also set to store metadata set corresponding to one type of data of image, audio, and caption.

The data stored in the mdat box, which is the data part of the MP4 file format, is divided into samples as basic data units.
In CFF (Common File Format), a set of only image samples, a set of only audio samples, a set of only subtitle samples, or a set of data samples of the same type is stored in one mdat box. .

Furthermore, the CFF defined by DECE also defines the coding mode (codec) and data format of images, audio, and subtitles that are allowed to be stored in the CFF file. Examples of data formats that are allowed to be stored in the CFF file include the following data formats.
Image (Video): AVC, HEVC
Audio (Audio): MPEG4-AAC, Dolby, AC-3
Subtitle: SMPTE Timed Text (SMPTE-TT)

The mfra box is a box for recording the random access point information described above with reference to FIG.
In the mfra box, a tfra box that is a storage box of random access point information corresponding to a track (trak) is set.
The tfra box stores random access point information in units of tracks (tracks) corresponding to data types such as images, sounds, and captions.
As described above, when a CFF file includes a plurality of different image data, for example, HD images, 4K images, etc., these different images are stored in different mdat boxes and set as different tracks (traks). Is done.
Similarly, different audio data such as Japanese audio and English audio are also stored in individual mdat boxes, and Japanese subtitles and English subtitles are also stored in different mdat boxes and set as different tracks (trak). .

  Accordingly, the tfra box, which is a storage box for track-compatible random access point information, also stores random access point information for track (trak) set according to the type of each image, the type of audio, and the type of subtitles. It is set individually as an area.

FIG. 8 shows a specific data example of the mfra box.
The mfra box illustrated in FIG. 8 includes a random access point information storage box corresponding to a plurality of tracks (trak), that is, a plurality of tfra boxes.
The following information is described in units of track ID (trak_ID) which is a track (trak) identifier.
(A) Random access point time information (time)
(B) Data location information of random access point (traf_number / run_number / sample_number)

(A) Random access point time information is information indicating a reproduction time position of randomly accessible data.
(B) The data location information of the random access point is information indicating the location of the randomly accessible data stored in the MP4 file.
This position information includes the following information.
(A) traf number (track fragment box number)
(B) trun number (track fragment runbox number)
(C) sample number (sample number)
These are all information indicating the data position of the random access point, and using this information, it is possible to acquire randomly accessible data from the MP4 (CFF) file.

[4. Example of data format conversion process]
Next, an example of data format conversion processing executed by the information processing apparatus 100 according to the present disclosure will be described.
The information processing apparatus according to the present disclosure executes a process of converting BDMV format data into MP4 format data, specifically, CFF (Common File Format) described with reference to FIG.

An example of the format conversion process will be described with reference to FIG.
When the MP4 format data is generated by converting the BDMV format data, various settings can be made as to which data unit of the BDMV data generates one MP4 file.

  The MP4 file includes two types of MP4 files: a fragmented MP4 file described above with reference to FIG. 6 and a non-fragmented movie, and a CFF with constraints. Although there is a file, here, an example of processing when a CFF file is generated will be described.

Hereinafter, an example of processing for generating one CFF file in units of playlists defined as playback units in the BDMV format will be described.
In FIG.
(A) BDMV format data before format conversion (B) CFF file generated after format conversion The figure explaining these two correspondences is shown.

The BDMV format data before format conversion shown in (A) includes the following data.
(A1) One playlist # 1, which is subject to format conversion,
(A2) Clip information file (CI # 1) specified by playlist # 1;
(A3) Clip AV stream (ST # 1) designated as reproduction data by the clip information file (CI # 1),

  In the present embodiment, one playlist set in the BDMV format, and playback control information and playback data used by the playlist are used as format conversion processing units, and one MP4 file for each processing unit, that is, Then, the CFF file shown in FIG. 9B is generated.

In this format conversion, the component data of the clip AV stream (ST # 1) as reproduction target data is divided and stored in a plurality of mdat boxes as reproduction target data storage units set in the MP4 file.
Note that when this data division storage process is performed, according to the CFF file specification, each mdat stores only one type of data of image audio and subtitles individually.

Each data of the playlist # 1 and the clip information file (CI # 1) is stored in the moov box and moof box which are metadata storage sections of the MP4 file (CFF).
Control information applied only to the data stored in each mdat box is stored in a moof box associated with each mdat box, and control information related to data stored in a plurality of mdat boxes is stored in a moov box.
By such processing, the BDMV format data is converted into MP4 format (CFF) data to generate one CFF file.

  With reference to FIG. 10, a description will be given of an example of storage processing of image data and audio data in a reproduction data storage box (mdat) of a CFF file when the BDMV format data is converted and a CFF file is generated.

In the CCF file, data such as images, sounds, and captions, which are reproduction target data, are divided into data types and stored in the mdat box.
Note that the CFF standard defines the maximum amount of data that can be stored in one mdat box.
Image data can be stored in a single mdat box with a playback time of up to 3 seconds.
Also, audio data can be stored in one mdat box with a reproduction time of up to 6 seconds.

In the CFF file, a large number of mdat boxes storing image data within a reproduction time of 3 seconds and mdat boxes storing audio data within a reproduction time = 6 seconds are set.
A moof box that stores attribute information, playback control information, and the like related to playback data stored in each mdat box is set corresponding to each of these many mdat boxes.

FIG. 10A shows an image data sequence and an audio data sequence obtained by decoding the encoded image data and audio data stored in the clip AV stream file (00000.m2ts) in the BDMV format.
The clip AV stream file has the transport stream configuration described above with reference to FIG. The transport stream is composed of a number of transport packets (TS packets).

A clip AV stream file (00000.m2ts) can store a mixture of encoded data of image data and audio data, but each transport packet that is a component of the clip AV stream file contains image data and audio data. Only one kind of data is stored.
That is, the clip AV stream file (00000.m2ts)
TS packet storing encoded image data,
TS packet storing encoded audio data,
These are mixed data.

The (a) image data and (b) audio data shown in (1) of FIG. 10 are obtained by separating the encoded image data and the encoded audio data included in the clip AV stream file (00000.m2ts) and further performing decoding processing. 3 shows a data string in which image data and audio data are arranged in the order of reproduction.
(A) One rectangular frame of image data is one video frame, and (b) one rectangular frame of audio data is one audio frame.
The data type such as whether the data stored in each TS packet is an image or sound can be identified by the PID of the header information set in the TS packet.

  When generating a CFF file by converting the format of the BDMV format data, the image data and audio data extracted from the clip AV stream file in the BDMV format shown in FIG. 10A are sequentially stored in the mdat box of the CFF file. Is done.

FIG. 10B shows a part of the CFF file, that is, a part of the box constituting the CFF file. The following boxes are sequentially set in the CFF file.
moov box,
moof box,
mdat box,
moof box,
mdat box,
:
Thereafter, the moof box and the mdat box are repeated.

Image data and audio data are stored separately and sequentially in the mdat box of the box set in these CFF files. Note that all MP4 format encoding processing is performed and stored.
The image data is sequentially stored in accordance with the rule that the reproduction time is within 3 seconds and the audio data is within the reproduction time of 6 seconds.

When a CFF file is generated by converting the format of BDMV format data, TS packets constituting the clip AV stream file included in the BDMV format data are sequentially acquired from the head and separated for each data type such as image data and audio data. In this case, the mdat storage data is generated by executing the encoding according to MP4.
Whether it is an image storage TS packet or an audio data storage TS packet is determined based on the header information (PID) of the TS packet.

[5. Problems of random access point information acquisition in format conversion]
As described above with reference to FIGS. 6, 7, and 8, in the MP4 (CFF) format, there are an mfra box and a tfra box as fields for recording random access point information related to reproduction data.

  When the MP4 (CFF) file is generated by converting the format of the BDMV format data, the random access point of the reproduction data included in the BDMV format data is determined, and the mfra box or tfra box of the MP4 (CFF) file is determined according to the determination information. It is necessary to generate information for recording.

In BDMV format data, random access point information for image data is recorded in an EP map that is data constituting a clip information file.
However, the amount of information in the EP map is relatively large. If this EP map is expanded on a memory and a random access point is analyzed, the amount of memory used becomes enormous, and there is a memory area available for other data processing. It becomes small and the possibility of causing a processing delay increases.

Further, the EP map of the clip information file of the BDMV format data records the random access point information of the image data, but there is a problem that the random access point information of the audio data is not recorded.
Therefore, there is a problem that even if the EP map is analyzed, information regarding random access points for audio data cannot be obtained, and information for recording random access point information for each track defined in the MP4 format cannot be obtained.

[6. Configuration that makes it possible to identify random access points based on TS packets]
Next, a configuration for solving the above problem will be described.
The configuration described below is a configuration in which a random access point can be determined based on TS packets that constitute a clip AV stream file included in BDMV format data.
This configuration will be described with reference to FIG.

FIG. 11 shows an example of a clip AV stream file included in the BDMV format data. As described above, the clip AV stream file is composed of a large number of TS packets (transport packets).
This is the TS packet described with reference to FIG.

Each TS packet individually stores encoded data of any one type of data such as image data, audio data, caption data, and the like.
One rectangle shown in FIG. 11 is one TS packet.
Each TS packet has a header part and a data part, and various information such as PID as packet identification information is recorded in the header part.
The data portion stores image encoded data, audio encoded data, and the like.

As one field of header information of TS packet,
Transport priority (transport_priority)
There is.
This field is a field that is allowed to be used in various modes.

In this example,
The “transport priority (transport_priority)” field is used as a recording field for information indicating whether the TS packet storage data is data serving as a random access point.

For example, when TS packet storage data is data that becomes a random access point,
The set value of the transport priority (transport_priority) is set to “1”.
On the other hand, if the TS packet storage data is not a random access point,
The set value of the transport priority (transport_priority) is set to “0”.

For example, the TS packet 301 in the clip AV stream file shown in FIG. 11 is a TS packet that stores image data serving as a random access point.
In this case, the header of this TS packet 301 is
The set value of the transport priority (transport_priority) is set to “1”.

Further, the TS packet 302 in the clip AV stream file shown in FIG. 11 is a TS packet storing audio data to be a random access point.
In this case, the header of this TS packet 302 is
The set value of the transport priority (transport_priority) is set to “1”.

Other TS packets are TS packets that store images or audio data that do not become random access points, and for these packets, the headers of these TS packets,
The set value of the transport priority (transport_priority) is set to “0”.

That is, the transport priority (transport_priority) value of the header of each TS packet is set to be recorded as follows.
When the TS packet storage data is data that becomes a random access point, “1” is recorded, and when it is not a random access point, “0” is recorded.

In this way, random access point information indicating whether or not the TS packet storage data is random access point configuration data is recorded in the header of the TS packet.
With this header information recording configuration, an information processing apparatus that converts BDMV format data into MP4 format only analyzes header information of TS packets of a BDMV clip AV stream file, and random access point correspondence data is stored in which packet. It is possible to determine whether or not there is.

  With this configuration, the information processing apparatus that converts the BDMV format data into the MP4 format does not need to develop and refer to the EP map of the clip information file of the BDMV format data. Also, random access point information such as audio data other than image data that cannot be acquired from the EP map can be acquired.

  The information processing apparatus that converts the BDMV format data into the MP4 format sequentially acquires TS packets of the BDMV clip AV stream file, analyzes the header information, and stores the MP4 (CFF) file described above with reference to FIG. Data for recording in the mfra box is generated.

In the mfra box, access point information is recorded in units of tracks. That is, it is necessary to record access point information for each data type such as images and captions in each tfra box.
These data types can be identified with reference to the PID (program ID) in the header information of the TS packet.

Note that the access point information recorded in the mfra box described with reference to FIG. 8 needs to record the data position and reproduction time information of the access point.
As for the data position (traf_number / run_number / sample_number shown in FIG. 5), information indicating the data position in the MP4 file generated by the data conversion can be acquired and recorded.
As for the playback time information (time), the presentation time stamp (PTS) recorded in the PES header stored in the payload of the TS packet including the random access point data is acquired, and this PTS value is used. It is possible to record.

As described above, when the MP4 file is generated by converting the BDMV format data, the type of the data stored in the packet is referred to by referring to the PID recorded in the header information of the TS packet of the BDMV clip AV stream file, that is, image, audio The subtitles are discriminated.
In conjunction with this type determination processing of the stored data of the TS packet, if the setting value of the transport priority (transport_priority) is acquired,
(A) TS packet storage data type determination processing;
(B) a process for determining whether or not the stored data of the TS packet is data serving as a random access point;
These two processes can be performed together, and the process can be made efficient.

[7. Data storage configuration for TS packets]
In the process of the present disclosure, as described with reference to FIG. 11, whether or not the TS packet storage data is the configuration data of the random access point is included in the header of the TS packet of the clip AV stream file that is the BDMV configuration data. Record the indicated random access point information. With this configuration, random access point information can be efficiently acquired during the format conversion process.

However, one image frame (video frame) serving as a random access point and encoded data of one sound frame serving as a processing unit of sound data are not necessarily stored in one TS packet.
A data storage configuration example for the TS packet will be described with reference to FIG.
FIG.
(A) Reproduced image data (b) Image data storage TS packet sequence FIG.

(A) The reproduced image data is a data sequence similar to the data sequence shown in (a) of FIG. 10A, and is obtained by decoding the encoded image data included in the clip AV stream file (00000.m2ts). The data string which arranged the image data to be displayed in the order of reproduction is shown.
One rectangular frame is one video frame corresponding to one reproduced image.
Assume that the random access point image 322 shown in the reproduced image shown in FIG.
The preceding frame image 321 preceding the random access point image 322 is an image that does not become a random access point.

  FIG. 12B shows an example of a TS packet sequence storing encoded image data of an image having such a setting. This TS packet sequence is a data sequence in which only TS packets storing image data are selected from TS packets constituting a clip AV stream file in BDMV format data.

Since each TS packet can store only encoded data with an upper limit of 184 bytes, for example, the encoded data of the preceding frame image 321 is distributed and stored in TS packets P1, P2, and P3 shown in the figure.
Also, the encoded data of the random access point image 322 is distributed and stored in TS packets P3, P4, and P5.
The TS packet P3 has a setting in which a part of the encoded data of the preceding frame image 321 that does not become a random access point and a part of the encoded data of the random access point image 322 are mixedly stored.

Thus, when TS packets in which encoded data corresponding to random access points and encoded data of data that does not become random access points are mixed are set, the header information described above with reference to FIG. 11 cannot be set.
That is, the value of “transport priority (transport_priority)” used as a field for recording random access point information cannot be set.

  In order to prevent the occurrence of such a problem, a configuration is adopted in which TS packets in which encoded data corresponding to random access points and encoded data of data that does not become random access points are mixed are not generated.

A TS packet setting example in which this countermeasure has been taken will be described with reference to FIG.
FIG. 13 is similar to FIG.
(A) Reproduced image data (b) Image data storage TS packet sequence Each of these data is shown.

(A) Reproduced image data is a data string in which image data obtained by decoding encoded image data included in a clip AV stream file (00000.m2ts) is arranged in the order of reproduction.
One rectangular frame is one video frame corresponding to one reproduced image.
Assume that the random access point image 322 shown in the reproduced image shown in FIG.
The preceding frame image 321 preceding the random access point image 322 is an image that does not become a random access point.

  FIG. 13B shows an example of a TS packet sequence storing the encoded image data of the image set as shown in FIG. This TS packet sequence is a data sequence in which only TS packets storing image data are selected from TS packets constituting a clip AV stream file in BDMV format data.

Each TS packet can store only encoded data having an upper limit of 184 bytes.
In this example, the encoded data of the preceding frame image 321 is distributed and stored in TS packets P1, P2, and P3 shown in the figure.
Also, the encoded data of the random access point image 322 is distributed and stored in TS packets P4, P5, and P6.

  The difference from the example shown in FIG. 12 is that a TS packet in which the encoded data of the preceding frame image 321 that does not become a random access point and the encoded data of the random access point image 322 are mixed is not set.

In this way, a configuration is adopted in which TS packets in which encoded data corresponding to random access points and encoded data of data that does not become random access points are mixed are not generated.
With this setting, the random access point information recorded in the header of each TS packet can be reliably classified into one of the following two settings.
(1) Transport priority (transport_priority) = 1: TS packet storage data is data serving as a random access point.
(2) Transport priority (transport_priority) = 0: TS packet storage data is data that does not become a random access point.

If such a TS packet is set, an empty area may occur in the data storage unit in the TS packet.
In the TS packet P3 shown in FIG. 13, the encoded data of the preceding frame image 321 is stored. This data amount is less than 184 bytes, which is the data capacity of the TS packet, and a free space is generated.
Information about this free area is recorded in an adaptation field (adaptation_field) in the header information of the TS packet.

In the adaptation field (adaptation_field) of the TS packet header, for example, the valid data storage area in the data storage area of the TS packet and byte position data indicating the boundary position of the unused area are recorded.
By recording such unused area information, an information processing apparatus that performs format conversion reads only the valid data storage area and does not read useless data in the empty area during the data reading process in format conversion. And efficient processing is realized.

    [8. Configuration in which random access point information is recorded in the header of a TS packet of a clip AV stream file of BDMV format data]

As described above, in the embodiment of the present disclosure, the following information is recorded in the header of the TS packet of the clip AV stream file of the BDMV format data.
(1) Transport priority (transport_priority) = value indicating access point information,
(2) Adaptation field (adaptation_field) = unused area information,
These pieces of information are recorded in the header of the TS packet.

  For example, when the information processing apparatus performs data recording processing of BDMV format data, it generates and records a clip AV stream file in which the additional information (1) and (2) is recorded in the TS packet header. If such a data recording process is performed, the information processing apparatus can generate the data stored in the mfra box of the MP4 format based on the acquired information from the header of the TS packet or the like when converting the recorded data into the MP4 format. Become.

  FIG. 14 is a diagram showing an example of a BDMV directory having a clip AV stream file in which the additional information (1) and (2) is recorded in the TS packet header.

The difference between the directory structure shown in FIG. 14 and the directory structure described above with reference to FIG. 3 is that the following information is recorded in the header of the TS packet of the clip AV stream file in the directory shown in FIG. It is.
(1) Transport priority (transport_priority) = value indicating access point information,
(2) Adaptation field (adaptation_field) = unused area information.

  As shown in FIG. 14, the BDMV format data having the clip AV stream file in which the additional information (1) and (2) described above is recorded in the header of the TS packet is obtained by the information processing apparatus 100 shown in FIG. The data can be recorded when data is recorded on the first medium 110.

  For example, the data recording application (program) executed by the control unit 101 includes a sequence for recording the additional information (1) and (2) in the TS packet header. By performing data recording processing according to this program, data recording having the directory structure shown in FIG. 14 is possible.

  Note that this data recording process is performed, for example, by recording video data recorded via an imaging unit or a microphone constituting the input unit 102 of the information processing apparatus 100 shown in FIG. 1 or video data input via the communication unit 103. It can be executed during processing.

[9. About format conversion processing sequence executed by information processing apparatus]
Next, a format conversion processing sequence executed by the information processing apparatus 100 will be described with reference to a flowchart shown in FIG.

The flowchart shown in FIG. 15 is executed according to a program stored in a storage unit, for example, under the control of the control unit of the information processing apparatus.
Processing of each step shown in the flow will be described sequentially.

(Step S101)
First, the information processing apparatus inputs BDMV format data to be converted from a medium or an external server, and acquires a playlist file to be converted from the input data.

(Step S102)
Next, the clip information file specified by the playlist file selected as the conversion target and the clip AV stream file associated with the clip information file are acquired.

(Step S103)
In step S103, the image, audio, and subtitle data stored in the clip AV stream file is separated for each data type. This process is a process executed by the data analysis unit 151 of the data conversion unit 108 shown in FIG.

(Step S104)
In step S104, the header information of the TS packet stored in the clip AV stream file is analyzed to determine a packet including random access point data.
That is, the following information recorded in the header of the TS packet of the clip AV stream file:
(1) Transport priority (transport_priority) = value indicating access point information,
(2) Adaptation field (adaptation_field) = unused area information,
This information is analyzed.

Further, when the transport priority (transport_priority) value indicates access point data, the presentation time stamp (PTS) is acquired from the PES header included in the payload of the TS packet.
This process is executed by the data analysis unit 151 or the control unit 101 of the data conversion unit 108 shown in FIG. The analysis result and the acquired information are held in the storage unit 104 as random access point information for mfra box recording.

  As described above, the packet classification process based on the PID in step S103 and the process in step S104 are processes for sequentially analyzing TS packets, and these processes may be executed together.

(Step S105)
Next, in step S105, the random access point information acquired based on the TS packet analysis in step S104 and stored in the storage unit 104 is applied and recorded in the mfra box or tfra box of the MP4 (CFF) file. Generate data.
That is, the data described above with reference to FIG. 8 is generated.

Specifically, the data conversion unit 108 or the control unit 101 of the information processing apparatus executes the following processes to generate data to be recorded in the mfra box or tfra box of the MP4 (CFF) file.
(1) The transport packet storage data becomes a random access point based on the transport priority setting value recorded in the header of a transport packet (TS packet) that is a constituent packet of a clip AV stream file of BDMV format data. (2) Based on the setting value of the adaptation field recorded in the header of a transport packet (TS packet) that is a constituent packet of a clip AV stream file of BDMV format data It is determined whether or not an unused area is included in the packet storage data.
(3) A presentation time stamp (PTS) stored in a transport packet (TS packet) that is a configuration packet of a clip AV stream file of BDMV format data is acquired, and the acquired presentation time stamp (PTS) is applied, Time information to be recorded in the mfra box or tfra box set in the MP4 file is generated.

(Step S106)
Next, in step S106, the format conversion of each data of image, sound, and caption is executed to generate data to be stored in each mdat box of the MP4 (CCF) file.
This process is a process executed by the image data converter 152, the audio data converter 153, and the caption data converter 154 of the data converter 108 shown in FIG.

(Step S107)
Next, in step S107, the contents of the playlist file and clip information file are analyzed to generate data to be stored in the metadata recording box (moov / trak / moof / traf) of the MP4 (CFF) file.
This process is executed by the control unit 101 shown in FIG. 1 and the multiplexing processing unit 155 of the data conversion unit 108 shown in FIG.

(Step S108)
In step S108, the MP4 (CFF) file is generated by storing data in the MP4 (CFF) file box (moov / trak / moof / traf / mdat / mfra / tfra).
This process is executed by the control unit 101 shown in FIG. 1 and the multiplexing processing unit 155 of the data conversion unit 108 shown in FIG.
The generated MP4 (CFF) file is recorded on the second medium, and the process is completed.

FIG. 16 is a diagram for explaining the flow of data generated in the format conversion process.
The example shown in FIG. 16 shows the data flow when reading the BDMV format data recorded on the first medium 110, converting it into MP4 format data, and recording it on the second medium 120.

The playlist file selected from the first medium 110 is
Playlist file [00001. mpls]
And
First, the control unit 101 uses the playlist file [00001. mpls] is read from the first medium 110 and stored in the storage unit 104.

Next, the control unit 101 selects the playlist file [00001. mpls] and the clip AV stream file associated with the clip information file are acquired.
The acquired file is the following file.
Clip information file [00011. clpi]
Clip AV stream file [00011. m2ts]

Acquired
Clip information file [00011. clpi]
These files are stored in the storage unit 104.
Also,
Clip AV stream file [00011. m2ts]
These files are input to the data conversion unit 108 via the data buffer 107.

  Note that the clip AV stream file [00011. The header analysis of the TS packet of m2ts] may be executed by either the data conversion unit 108 or the control unit 101. When executed by the control unit 101, the clip AV stream file [00011. m2ts] is output to both the data conversion unit 108 and the control unit 101 in parallel.

  In the data conversion unit 108, the data analysis unit 151 shown in FIG. 2 separates the image, audio, and subtitle data based on the PID (program ID) set in the header of each TS packet of the clip AV stream file. The separated data is output to the image data converter 152, the audio data converter 153, and the caption data converter 154.

Further, the data analysis unit 151 or the control unit 101 of the data conversion unit 108 analyzes the TS packet of the clip AV stream file, and acquires random access point information.
That is, data (see FIG. 8) to be recorded in the mfra box or tfra box of the MP4 (CFF) file is acquired. The acquired data is temporarily stored in the storage unit 104.

The image data conversion unit 152, the audio data conversion unit 153, and the caption data conversion unit 154 execute format conversion of input data. That is, a process of converting the BDMV format data into MP4 (CFF) format data to be recorded on the second medium 120 is executed.
Note that each of the image data conversion unit 152, the audio data conversion unit 153, and the caption data conversion unit 154 performs necessary decryption processing, encoding processing, encryption processing, and the like in the format conversion processing of each data.

  The image data conversion unit 152, the audio data conversion unit 153, and the caption data conversion unit 154 generate MP4 format data and output the data to the multiplexing process execution unit 155.

The multiplexing processing unit 155
(A) second format (MP4) format image format data generated by the image data generation unit 152;
(B) audio format data in the second format (MP4) generated by the audio data generator 153;
(C) Subtitle format data in the second format (MP4) generated by the subtitle data generation unit 154,
(D) reproduction control data acquired from a reproduction control information file such as a playlist file or clip information file and stored in the storage unit 104;
(E) Random access point information extracted from the TS packet of the clip AV stream file and stored in the storage unit 104;
Multiplex processing of each of these data is executed to generate recording data in the second format (MP4) format.

The reproduction control information file stored in the storage unit 104 is
Playlist file [00001. mpls],
Clip information file [00011. clpi]
These files.
Further, the storage unit 104 stores random access point information extracted from TS packets of the clip AV stream file.
These data may be deleted from the storage unit 104 when the MP4 (CFF) file is generated by the multiplexing process.

  The random access point information is data to be recorded in the mfra box tfra box of the MP4 (CFF) file described above with reference to FIGS.

  The multiplexing processing unit 155 of the data converting unit 108 executes the multiplexing processing of the MP4 format image, audio, and subtitle data, the data extracted from the reproduction control information file, and the random access point information, to obtain the second format. (MP4) format recording data is generated.

  The generated MP4 (CFF) file is recorded on the second medium 120 via the second media interface 109.

In the example shown in FIG. 16, BDMV format data is recorded on the first medium 110, and data read from the first medium 110 is converted to generate an MP4 (CFF) file to be stored on the second medium 120. It has been described as an example of processing to be recorded.
However, as described above, the data subjected to the format conversion process may be data input externally via the communication unit 103. In this case, all read data from the first medium 110 shown in FIG. The setting is input via the unit 103.

[10. Summary of composition of the present disclosure]
As described above, the embodiments of the present disclosure have been described in detail with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiments without departing from the gist of the present disclosure. In other words, the present invention has been disclosed in the form of exemplification, and should not be interpreted in a limited manner. In order to determine the gist of the present disclosure, the claims should be taken into consideration.

The technology disclosed in this specification can take the following configurations.
(1) having a data conversion unit for performing data format conversion;
The data converter is
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information An information processing device set as data.

  (2) The information processing apparatus according to (1), wherein the data conversion unit acquires the reproduction control information from an information recording medium on which the conversion target data is recorded or from the outside via a communication unit.

  (3) The data conversion unit executes processing for converting BDMV format data into MP4 format data, and acquires and acquires the random access point information from a clip AV stream file that is a reproduction target data storage file of the BDMV format data The information processing apparatus according to (1) or (2), wherein the random access point information is set as metadata in the MP4 file.

  (4) The information processing apparatus according to (3), wherein the data conversion unit stores the random access point information in an mfra box or a tfra box set in an MP4 file.

  (5) The data conversion unit generates transport packet storage data based on a transport priority setting value recorded in a header of a transport packet (TS packet) which is a constituent packet of a clip AV stream file of BDMV format data. The information processing apparatus according to any one of (1) to (4), wherein it is determined whether or not includes data serving as a random access point.

  (6) The data conversion unit is configured to store transport packet storage data based on a setting value of an adaptation field recorded in a header of a transport packet (TS packet) that is a configuration packet of a clip AV stream file of BDMV format data. The information processing apparatus according to any one of (1) to (5), wherein an unused area is determined.

  (7) The data conversion unit acquires a presentation time stamp (PTS) stored in a transport packet (TS packet) that is a constituent packet of a clip AV stream file of BDMV format data, and acquires the acquired presentation time stamp (PTS) ) To generate time information to be recorded in the mfra box or tfra box set in the MP4 file, the information processing apparatus according to any one of (1) to (6).

  (8) The information processing apparatus according to any one of (1) to (7), wherein the data conversion unit converts the BDMV format data to generate a CFF file in accordance with a CFF (Common File Format).

  (9) The information processing apparatus according to any one of (1) to (8), further including a recording unit that records data after data format conversion in a second information recording medium.

(10) a data conversion unit that performs data format conversion;
A recording unit that records the conversion data of the data conversion unit on an information recording medium;
The data converter is
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information Set as data,
The recording unit is
An information recording apparatus for recording format conversion data including the random access point information on an information recording medium.

  (11) The data conversion unit executes processing for converting BDMV format data into MP4 format data, and acquires and acquires the random access point information from a clip AV stream file that is a reproduction target data storage file of the BDMV format data The information recording apparatus according to (10), wherein the random access point information is set as metadata in the MP4 file.

(12) having a data processing unit for generating recording data for the information recording medium;
The data processing unit
Random access point information necessary for random access playback of BDMV format data is recorded in a header of a transport packet (TS packet) that is a constituent packet of a clip AV stream file that is a storage file of playback target data, and information recording An information recording device for recording on a medium.

(13) The data processing unit
The setting value of the transport priority of the header of the transport packet (TS packet) is recorded according to whether or not the stored data of the transport packet (TS packet) is random access point compatible data. (12) The information recording device according to (12).

(14) The data processing unit
The storage data of each of the transport packets (TS packets) is set to either random access point compatible data or random access point incompatible data to generate a transport packet (TS packet) (12 ) Or (13).

  (15) The data processing unit according to any one of (12) to (14), wherein unused area information of transport packet storage data is recorded in an adaptation field of a header of the transport packet (TS packet). Information processing device.

(16) a stream file that is a storage file of reproduction target data;
Storing the playback control information file storing the playback control information of the stream file as recording data;
An information recording medium in which random access point information having different values depending on whether or not the stored data of the packet is random access point compatible data is recorded in the header of the packet constituting the stream file,
An information processing device that performs format conversion of data stored in the information recording medium determines whether or not the packet storage data is random access point compatible data by analyzing the header of the packet, and performs format conversion based on the determination result An information recording medium that enables later generation and recording of metadata.

(17) An information processing method executed in the information processing apparatus,
The data converter
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information Information processing method set as data.

(18) A program for executing information processing in an information processing device,
After the data conversion unit obtains the random access point information necessary for random access playback of the playback data that is the conversion target data from the stream file that is the storage file of the playback target data, after the format conversion of the acquired random access point information Program to set as the configuration data of the data file.

  The series of processing described in the specification can be executed by hardware, software, or a combined configuration of both. When executing processing by software, the program recording the processing sequence is installed in a memory in a computer incorporated in dedicated hardware and executed, or the program is executed on a general-purpose computer capable of executing various processing. It can be installed and run. For example, the program can be recorded in advance on a recording medium. In addition to being installed on a computer from a recording medium, the program can be received via a network such as a LAN (Local Area Network) or the Internet and can be installed on a recording medium such as a built-in hard disk.

  Note that the various processes described in the specification are not only executed in time series according to the description, but may be executed in parallel or individually according to the processing capability of the apparatus that executes the processes or as necessary. Further, in this specification, the system is a logical set configuration of a plurality of devices, and the devices of each configuration are not limited to being in the same casing.

As described above, according to the configuration of an embodiment of the present disclosure, a configuration in which random access point information can be acquired from a TS packet when BDMV data is converted and recorded into an MP4 file is realized.
Specifically, the data conversion unit acquires random access point information necessary for random access playback of playback data that is conversion target data from a stream file that is a storage file of playback target data, and the acquired random access point information Is set as the configuration data of the data file after format conversion. The data conversion unit acquires random access point information from the header of the TS packet of the clip AV stream file of BDMV format data, and records the acquired information in the MP4 file mfra box.
With this configuration, when BDMV data is converted into an MP4 file and recorded, random access point information can be acquired from the TS packet.

DESCRIPTION OF SYMBOLS 100 Information processing apparatus 101 Control part 102 Input part 103 Communication part 104 Storage part 105 Output part 106 1st media interface 107 Data buffer 108 Data conversion part 109 2nd media interface 110 1st medium 120 2nd medium 151 Data analysis part 152 Image Data conversion unit 153 Audio data conversion unit 154 Subtitle data conversion unit 155 Multiplexing processing unit

Claims (18)

A data conversion unit for performing data format conversion;
The data converter is
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information An information processing device set as data. The data converter is
The information processing apparatus according to claim 1, wherein the reproduction control information is acquired from an information recording medium on which the conversion target data is recorded or from the outside via a communication unit. The data converter is
Execute processing to convert BDMV format data to MP4 format data,
The information processing apparatus according to claim 1, wherein the random access point information is acquired from a clip AV stream file that is a reproduction target data storage file of BDMV format data, and the acquired random access point information is set as metadata in an MP4 file. . The data converter is
The information processing apparatus according to claim 3, wherein the random access point information is stored in an mfra box or a tfra box set in an MP4 file. The data converter is
Based on the transport priority setting value recorded in the header of a transport packet (TS packet) that is a constituent packet of a clip AV stream file of BDMV format data, the transport packet storage data includes data that serves as a random access point. The information processing apparatus according to claim 1, which determines whether or not. The data converter is
2. An unused area of transport packet storage data is determined based on a setting value of an adaptation field recorded in a header of a transport packet (TS packet) that is a constituent packet of a clip AV stream file of BDMV format data. The information processing apparatus described in 1. The data converter is
A presentation time stamp (PTS) stored in a transport packet (TS packet) that is a constituent packet of a clip AV stream file of BDMV format data is acquired,
The information processing apparatus according to claim 1, wherein time information to be recorded in an mfra box or a tfra box set in the MP4 file is generated by applying the acquired presentation time stamp (PTS). The data converter is
The information processing apparatus according to claim 1, wherein the BDMV format data is converted to generate a CFF file in accordance with CFF (Common File Format). The information processing apparatus further includes:
The information processing apparatus according to claim 1, further comprising: a recording unit that records data after data format conversion on the second information recording medium. A data conversion unit for performing data format conversion;
A recording unit that records the conversion data of the data conversion unit on an information recording medium;
The data converter is
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information Set as data,
The recording unit is
An information recording apparatus for recording format conversion data including the random access point information on an information recording medium. The data converter is
Execute processing to convert BDMV format data to MP4 format data,
The information recording apparatus according to claim 10, wherein the random access point information is acquired from a clip AV stream file that is a reproduction target data storage file of BDMV format data, and the acquired random access point information is set as metadata in an MP4 file. . A data processing unit for generating recording data for an information recording medium;
The data processing unit
Random access point information necessary for random access playback of BDMV format data is recorded in a header of a transport packet (TS packet) that is a constituent packet of a clip AV stream file that is a storage file of playback target data, and information recording An information recording device for recording on a medium. The data processing unit
The transport priority setting value of the header of the transport packet (TS packet) is recorded differently depending on whether the stored data of the transport packet (TS packet) is data corresponding to a random access point. Item 13. The information recording device according to Item 12. The data processing unit
13. The transport packet (TS packet) is generated by setting storage data of each transport packet (TS packet) to either random access point compatible data or random access point incompatible data. The information recording device described in 1. The data processing unit
The information processing apparatus according to claim 12, wherein unused area information of transport packet storage data is recorded in an adaptation field of a header of the transport packet (TS packet). A stream file that is a storage file for data to be played, and
Storing the playback control information file storing the playback control information of the stream file as recording data;
An information recording medium in which random access point information having different values depending on whether or not the stored data of the packet is random access point compatible data is recorded in the header of the packet constituting the stream file,
An information processing device that performs format conversion of data stored in the information recording medium determines whether or not the packet storage data is random access point compatible data by analyzing the header of the packet, and performs format conversion based on the determination result An information recording medium that enables later generation and recording of metadata. An information processing method executed in an information processing apparatus,
The data converter
Random access point information required for random access playback of playback data that is the conversion target data is acquired from the stream file that is the storage file of the playback target data, and the format of the data file after format conversion of the acquired random access point information Information processing method set as data. A program for executing information processing in an information processing apparatus;
After the data conversion unit obtains the random access point information necessary for random access playback of the playback data that is the conversion target data from the stream file that is the storage file of the playback target data, after the format conversion of the acquired random access point information Program to set as the configuration data of the data file.

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