JP2016072858A - Media data generation method, media data reproduction method, media data generation device, media data reproduction device, computer readable recording medium and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide data of streaming media capable of easily performing access to a specific time position on the basis of index information.SOLUTION: A media data generation method for generating data of streaming media capable of accessing a specific time position on the basis of index information in a computer includes the steps of: acquiring data of a reproducible unit as contents from among given content data and using the data to generate data of a single segment; and connecting the data of the single segment to generate a segment file that is data of a distributable unit as data of streaming media.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a technique for distributing media data such as video and audio.

  As a technique for streaming video data, there are an HLS (HTTP Live Streaming) system and an MPEG-DASH (dynamic adaptive streaming over HTTP) system internationally standardized by ISO / IEC. Both of these are used with a playlist that divides the original video data into files (media segments) of about 10 seconds and describes the playback order.

  A player who becomes a client obtains a fragmented file from the server in the playback order based on the playlist. At this time, if a plurality of bit rate files are prepared on the server side, the client player is in the NW state ( It is possible to reproduce the video without interruption as much as possible by acquiring and reproducing the video data of the optimum bit rate from the server while mainly monitoring the communication speed). Hereinafter, these techniques are referred to as ABR (Adaptive BitRate) techniques.

  Each video data file is read as progressive download. Therefore, when video data is shredded, one point is how long the video data is divided. However, if the video data is divided too short, client access to the server increases and the server side is increased. There is a problem that file management becomes complicated especially in the case of content for a long time due to the load or the increase in the number of files. On the other hand, if the file is divided for a long time, if the communication speed is reduced during the downloading of the one fragmented file, the video playback buffer in the player is depleted, and the video gets stuck and stops at worst. I can't see it. Therefore, it is generally recommended that the video data division length is about 10 seconds.

  Here, in the HLS system, when ABR is generally performed, it is determined whether or not the bit rate needs to be changed for each length of the segment file of video data. However, since the NW communication speed generally changes from moment to moment (particularly in the mobile environment), even if the segment length of the video data file is set to a length of several seconds to 10 seconds, even under various NW environments. Even if ABR is used, it is very difficult to distribute video with high quality without interruption.

JP 2013-214799 A JP2013-214800A

  In the MPEG-DASH system, a so-called index file that can refer to a specific point in a segment file is newly defined. By writing information for making this index file accessible in GOP (Group of Pictures) unit (usually about 0.5 seconds to 1 second), which is a group of several frames in the video, ABR can be controlled without being limited by the length of the segment file.

  The index file also contains frame information that is located in the first frame of the GOP and that can be accessed randomly (= decodes only with stream data of this frame without depending on other frames). When playing (operations such as fast forward, rewind, and jump), only frame data necessary for reproduction can be acquired from the server, and NW traffic can be greatly reduced.

  By the way, the file format of video data used for video data distribution is mostly used in the MPEG-2 TS format (ISO / IEC 13818) used in digital terrestrial broadcasting and the file format on a PC. MP4 format (ISO / IEC 14496-15) is available. The HLS format supports only the MPEG-2 TS format as the video data file format, and the MPEG-DASH format supports both the MPEG-2 TS format and the MP4 format. The MPEG-DASH format supports the MP4 format. Is the mainstream.

  The MPEG-2 TS format is a format for transmitting and receiving moving image / audio data by dividing it into fixed-length packets, and is originally a method that assumes that media is streamed. By applying the technology, the above-described ABR control and trick play can be realized.

  On the other hand, the MP4 format is mainly intended for file storage in a computer or the like, and there is a problem as described below when MPEG-DASH streaming is performed using an MP4 format file.

  As shown in FIG. 1, in the MP4 format, as a file structure, an audio track and a video track are completely separated in one file, and header information and actual data in each track are also included. It has a separated structure. The same applies to the case where MP4 is divided into segments and segmented. This file structure has the following problems:

  (1) Due to the structure in which video and audio are separated, it is necessary to access video and audio twice when accessing the contents of the file. It is necessary to describe two points, i.e., the point of the video data and the point of video data synchronized with the point. In the case of the MPEG-2 TS format, such a problem does not occur because video data and audio data are alternately arranged.

  (2) When an ABR is attempted on a GOP basis, the GOP is generally composed of about 0.5 seconds to 1 second. Therefore, access to both video data and audio data is synchronized within this short time. Therefore, high performance is required on the server side and client side, which is not suitable for operation in a wide range of terminals and server environments.

  These problems can be solved by dividing the file into GOP lengths and segmenting, but as mentioned at the beginning, the problem is that the server access is enormous, the number of files increases, and the management becomes complicated Will occur and is not realistic.

  (3) The information corresponding to the I frame used when performing trick play does not include information for identifying a normally used container, and the trick play operation is to extract and display only the I frame from the video data file. There are problems that are difficult to realize. In general, it is possible to access in GOP units, but it is difficult to access only I frames.

  The above problem is not limited to the case where streaming delivery is performed by MPEG-DASH using the MP4 file format.

  The present invention has been made in view of the above points, and an object of the present invention is to provide streaming media data that allows easy access to a specific time position based on index information.

According to an embodiment of the present invention, there is provided a media data generation method for generating streaming media data capable of accessing a specific time position based on index information in a computer,
Acquiring unit data that can be reproduced as content from given content data, and generating single segment data using the data; and
There is provided a method of generating media data, comprising the step of connecting the single segment data and generating a segment file that is a unit of data that can be distributed as streaming media data.

  According to the embodiment of the present invention, it is possible to provide streaming media data that allows easy access to a specific time position based on index information.

It is a figure which shows the general structure of MP4. It is a figure which shows the example of the system configuration | structure which concerns on embodiment of this invention. 1 is a configuration diagram of a media data generation device 100. FIG. 2 is a configuration diagram of a media data distribution apparatus 200. FIG. 2 is a configuration diagram of a user terminal 300. FIG. It is a figure which shows the structural example of the segment file in this Embodiment. It is a figure which shows the structural example of the segment file in this Embodiment. It is a flowchart which shows the example of a process sequence which produces | generates a segment file. It is a figure which shows the structural example of a delivery package. It is a figure which shows the structural example of an index file. It is a flowchart which shows process procedure example 1 in trick play. It is a flowchart which shows the process procedure example 2 in trick play.

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is only an example, and the embodiment to which the present invention is applied is not limited to the following embodiment. For example, in this embodiment, MPEG DASH is used as the media data distribution method, but the media data distribution method to which the present invention can be applied is not limited to MPEG DASH.

  In this specification, video, audio, characters, and the like that are played back and output by a user terminal (player) by streaming data distribution are collectively referred to as “media”, and data distributed by streaming is referred to as media data. “File” is a form of “data”.

(System configuration)
FIG. 2 shows a configuration diagram of a system according to the embodiment of the present invention. As shown in FIG. 2, the system according to the present embodiment includes a media data distribution device 200 and a user terminal 300. The media data distribution apparatus 200 and the user terminal 300 are each connected to a network 400 (for example, the Internet) and can communicate with each other.

  FIG. 2 shows the media data generation device 100. The media data generation device 100 is a device that generates media data from original content data and provides the media data to the media data distribution device 200, for example. The media data generation device 100 may be connected to the network 400 or may be an independent device that is not connected to the network 400. The media data distribution apparatus 200 may include the function of the media data generation apparatus 100.

  The media data distribution device 200 distributes media data to the user terminal 300 based on a request from the user terminal 300. The user terminal 300 requests media data from the media data distribution apparatus 200, receives the media data from the media data distribution apparatus 200, reproduces the media data, and outputs the media.

  Next, the functional configuration of each device will be described. In the following, an outline of the configuration and functions will be described, and detailed operation examples will be described later.

  As shown in FIG. 3, the media data generation apparatus 100 includes an original file input unit 101, an original file storage unit 102, an original file analysis unit 103, a segment file generation unit 104, a segment file storage unit 105, an index file generation unit 106, A package generation unit 107 is included.

  The original file input unit 101 inputs an original file of content that is a target for generating a segment file or the like, and stores the original file in the original file storage unit 102. The original file analysis unit 103 analyzes the data of the original file stored in the original file storage unit 102, and at least includes bit rate information, I frame information (byte position, time position, etc.), GOP unit information (bytes) Position, time position, etc.). The information obtained by the analysis is used for generating a segment file and also for generating a distribution package including index file generation.

  The segment file generation unit 104 generates a multi-segment format segment file and stores it in the segment file storage unit 105, as will be described later, using the analysis result of the original file analysis unit 103. The segment file storage unit 105 also stores the analysis result from the original file analysis unit 103. The index file generation unit 106 generates an index file using the analysis result.

  The package generation unit 107 generates a distribution package including an MPD file, an index file, a segment file, and the like. An MPD (Media Presentation Description) file is a file that stores metadata describing information such as media data necessary for streaming distribution / playback.

  Next, a configuration example of the media data distribution apparatus 200 will be described with reference to FIG. As shown in FIG. 4, the media data distribution apparatus 200 includes a data distribution control unit 201, a segment file storage unit 202, and an MPD file storage unit 203. The segment file storage unit 202 stores (a set of) segment files, and the MPD file storage unit 203 stores MPD files, index files, and the like. The data distribution control unit 201 distributes segment file data and MPD file data to the user terminal 300. Note that the media data distribution apparatus 200 is realized by a WWW server, for example.

  Next, a configuration example of the user terminal 300 will be described with reference to FIG. The user terminal 300 may be referred to as a “media data playback device”. In addition, although the user terminal 300 is not limited to a specific apparatus, the user terminal 300 is implement | achieved by PC, a smart phone, a tablet, etc., for example.

  As illustrated in FIG. 5, the user terminal 300 includes a user interface unit 301, a media playback processing unit 302, an MPD file storage unit 303, and a media data acquisition unit 304. The media data acquisition unit 304 is provided with a buffer 305 for temporarily storing media data.

  The user interface unit 301 includes a function of accepting an operation instruction from the user to the user terminal 300, notifying each function unit of the content of the instruction, and displaying reproduced media. The user interface unit 301 may be a functional unit integrated with a display (display unit), or the display (a part of the user interface unit 301) may be another device connected to the user terminal 300.

  The media playback processing unit 302 performs media playback by decoding the media data acquired by the media data acquisition unit 304 and outputs the media to the user interface unit 301. The MPD file storage unit 303 stores MPD files (including index files). The user terminal 300 may acquire the MPD file from the media data distribution apparatus 200 or may acquire it from another apparatus (for example, the media data generation apparatus 100).

  Based on the instruction from the user interface unit 301 and the MPD file data, the media data acquisition unit 304 requests the media data distribution device 200 for media data to be played back, and acquires the media data from the media data distribution device 200. It has a function.

  Each of media data generation apparatus 100, media data distribution apparatus 200, and user terminal 300 according to the present embodiment executes, for example, a program describing the processing contents described in the present embodiment on one or a plurality of computers. This can be realized. In other words, the functions of each device can be realized by executing a program corresponding to processing executed in the device using hardware resources such as a CPU, memory, and hard disk built in the computer. It is. The above-mentioned program can be recorded on a computer-readable recording medium (portable memory or the like), stored, or distributed. It is also possible to provide the program through a network such as the Internet or electronic mail.

  The segment file having a multi-segment structure described in this embodiment can be recorded on a computer-readable recording medium (portable memory or the like), stored, or distributed. In addition, data including the segment file and the index file (distribution package, etc.) can be recorded on a computer-readable recording medium (portable memory, etc.) and stored or distributed. .

(Example of segment file structure)
FIG. 6 shows an example of the structure of the segment file according to the present embodiment. The segment file is generated by the segment file generation unit 104 of the media data generation device 100.

  As shown in FIG. 6, a set of segment files is called a package (part of a distribution package described later), and the package is an initialization segment file (indicated by A in the figure) and a plurality of segment files (one Is indicated by B). This is the same as the structure defined in the existing MPEG DASH.

  In the present embodiment, as shown in FIG. 6C, each segment file has a multi-segment structure in which a plurality of single segments are connected. As shown in FIG. 6D, each single segment has a structure in which initialization data is attached to one GOP. The GOP includes data of each frame including an I frame and a PorB frame, and corresponding audio data (indicated by E). The initialization data is initialization data assumed to be added when it is assumed that a single segment is one file. The single segment in this embodiment is not an actual file but data stored in a segment file. The user terminal 300 can normally decode and display the encoded data in the single segment by interpreting the initialization data.

  That is, the multi-segment structure is a structured segment file (logical file) in which segments (single segment structure) configured in units of GOPs are connected in a number of stages. In the multi-segment structure, the file unit is the same as that of a general segment file, and the file is divided into several seconds to 10 seconds. By adopting a configuration in which the segment file is further logically segmented in GOP units as the internal structure of the segment file, data access in GOP units becomes possible. Also, by adding Box information that can identify an I frame to the initialization data portion in each single segment, it is possible to realize random access trick play that extracts only the I frame.

  The BOX information is, for example, TrackRunBox (run), and includes, for example, the compression method, the position (byte position) of the I frame in a single segment, the playback time of the I frame, and the like as I frame information. With this information, the user terminal 300 can appropriately decode only the I frame.

  The BOX structure is a structure that is internationally standardized as ISO Base Media File Format in ISO / IEC 14496-12. By adopting the internationally standardized structure in this way, video reproduction by a wide range of clients is guaranteed.

  The example shown in FIG. 6 is an example including video data and audio data, but may include only video data or only audio data. Further, it may include a caption telop (text data).

  In addition to a configuration in which video and audio are included in the same file as shown in FIG. 6, it is also possible to configure audio and video (or subtitles) as separate files. A configuration example in this case is shown in FIG. As shown in FIG. 7, in this configuration, the duration (reproduction time) and the number of each single segment are the same for video and audio. As a result, even when the index files are separate for video and audio, it is possible to synchronize the video and audio.

(Segment file generation procedure)
Next, a procedure for generating a segment file having a multi-segment structure as shown in FIG. 6 will be described with reference to FIG. The generation procedure is executed by the media data generation device 100 shown in FIG. 3. Hereinafter, the generation procedure will be described as an operation of the media data generation device 100.

  The media data generation device 100 acquires data in units that can be reproduced as content from given content data, generates single segment data using the data, and concatenates the single segment data. Then, a segment file which is a unit of data that can be distributed as streaming media data is generated. More specifically, it is as follows.

  An original file that is a target for generating a set of segment files is input from the original file input unit 101. The original file is a data file in which video is encoded. Data stored in the file may be called content data. The original file is stored in the original file storage unit 102 and is read into the original file analysis unit 103.

  The original file analysis unit 103 analyzes the input original file, for example, information on the bit rate of the content data, information in GOP units (byte position, time position, time length, etc.) in the file, Information (byte position, time position, time length, etc.) of frames (I frame, P frame, B frame), etc. are obtained (step 101).

  The analysis result in step 101 is passed to the segment file generation unit 104 and stored in the segment file storage unit 105.

  Next, the segment file generation unit 104 performs single segmentation for each GOP unit of data, for example, with the structure shown in FIG. 6 (step 102). That is, in the example of FIG. 6, for each GOP, a single segment composed of initialization data, data of each frame, and audio data is generated. If there is already a single segment, the segment file generation unit 104 connects the single segment generated this time to the end of the already generated single segment.

  In this example, the segment length is set to a predetermined time length, and in step 103, it is determined whether or not the connected single segment has reached the segment length. If the segment length has been reached, one segment file is output and stored in the segment file storage unit 105 (Yes in step 103, step 104). If the segment length has not been reached (No in step 103), the single segmentation / connection in step 102 is repeated. In other words, single segmentation / concatenation is repeated until the segment length is reached.

  If unprocessed data remains in the input file after step 104 (No in step 105), the processing from step 102 is repeated as the next segment file generation processing. When the end of the input file is reached, the process is terminated (Yes in step 105).

  In the above example, the GOP unit is given as an example of a unit that can be played back as content corresponding to one single segment, but this is only an example, and playback is possible as content corresponding to one single segment. The unit may be a multiple GOP unit or a frame unit.

(About distribution package)
When performing video distribution using MPEG DASH, the media file itself (segment file set) to be distributed, an index file in which index information is written, and an MPD (Media Presentation Description) in which presentation information about distribution is written. ) Prepare three types of files. When performing ABR, media files having different bit rates are prepared. Note that the index file is not essential, and media playback can be performed on the user terminal 300 even without the index file.

  These three types of files are collectively referred to as a distribution package. FIG. 9 shows an example of a distribution package. The distribution package structure itself shown in FIG. 9 is an existing one. This embodiment is different from the prior art in that each segment file has a multi-multi-segment structure.

  The MPD file is a unit of “Period” constituting a program or content, “AdaptationSet” describing information such as video / audio / subtitles, and “Representation” describing information such as bit rate and resolution of video / audio. And “SegmentInfo” that describes information related to the segment file.

  As shown in FIG. 9, “AdaptationSet” under “period” describes encoding information of audio, subtitles, and video. In “Representation”, the bit rate of audio, the resolution and bit rate of video are described. Each information can be defined so that ABR for switching the bit rate of audio, the bit rate / resolution of video, etc. depending on the NW state or the like can be performed. In FIG. 9, “100 Mbps” and “50 Mbps” are shown.

  The package generation unit 107 of the media data generation apparatus 100 can generate a distribution package having a structure as shown in FIG. 9 from information obtained by analyzing content data. For example, distribution package generation can be executed as processing following segment file generation and index file generation. That is, when generating single segment data, the content data is analyzed, the single segment information is obtained, index information is generated based on the single segment information, and the index information and the segment file are Including the streaming media distribution package. Further, by acquiring the bit rate information from the analysis result, a segment file for each bit rate and index information for each bit rate can be generated.

(About index files)
Next, an index file when the multi-segment structure is used will be described. FIG. 10 shows a configuration example of the index file. The index file is generated by the index file generation unit 106 using the analysis result of the original file stored in the segment file storage unit 105 in the media data generation apparatus 100 shown in FIG.

  As shown in FIG. 10, the index file is “Segment” (indicated by 1) that is a SegmentType Box representing the index file itself, in order from the beginning of the file, and a Segment that stores the file size and duration information of the entire plurality of segment files. Index Box “sidx” (indicated by 2), Segment Index Box “sidx” (indicated by 3) storing index information (information in GOP units) of a single segment in the segment file for each segment file, It is composed of a Sub-Segment Index Box “six” (indicated by 4) that stores index information of the I frame and other frames.

  When generating an index file based on the multi-segment structure in the present embodiment, the index file generating unit 106 stores the index information of each segment file (= multi-segment structure) in “sidx” indicated by 2, and the multi-segment structure A pointer (index information) to each single segment is stored in “sidx” indicated by 3. Further, as I frame information in the GOP, a pointer (index information) to the I frame information described in the “run box” in the initialization data in the single segment is stored in “six” indicated by 4.

  For example, single segment index information includes a time position and a data position in the segment file of the single segment. The “time position” includes, for example, a time (time) when a GOP medium in the single segment starts and a reproduction time length of the GOP. This may consist of a start time and an end time. The “data position” includes, for example, the first byte position of the single segment (and / or GOP) and the byte length (size) of the single segment (and / or GOP). It may also consist of a start byte position and an end byte position. The same applies to the index information of each frame.

  In particular, regarding I frames, as index information, for example, the byte position of the I frame in the segment file (relative position from the previous I frame), time information for displaying the I frame (time described in the container) Stamp), the size of the GOP including the I frame, and the GOP display time.

  By having the byte position information as described above as index information, the user terminal 300 designates the URL of the segment file and the data range thereof, and in response to an HTTP GET request, the GOP ( Alternatively, data of an arbitrary I frame) can be acquired and reproduced.

  For example, the user terminal 300 acquires the index information from the media data playback device 200, acquires the segment files corresponding to the desired content one by one, refers to at least the single segment information included in the index information, and Media data can be reproduced from an arbitrary time position in the obtained segment file.

  In addition, when segment files having different bit rates are included in the distribution package, the bit rate can be switched from an arbitrary time position in the acquired segment file.

(Trick play example)
Next, an example of a trick play procedure when the multi-segment structure as described above is employed will be described. This operation is executed by the media data distribution apparatus 200 and the user terminal 300 shown in FIGS.

  As a premise of each of the following processing procedure examples, the user terminal 300 acquires an MPD file and an index file from, for example, the media data distribution device 200, stores them in the MPD file storage unit 303, and sequentially stores segment files according to information such as MPD files. It is assumed that a desired medium is being reproduced by acquiring.

  First, processing procedure example 1 in trick play will be described with reference to FIG. In step 201, a fast forward or rewind operation is requested from the user via the user interface unit 301 of the user terminal 300. Here, N-times speed playback (fast forward or rewind) is assumed.

  The media acquisition unit 304 refers to the index file to specify the segment file at the playback position at the time when the operation is performed, and also specifies the I frame in the segment file, and from the target segment file, the I frame Are acquired from the media data distribution apparatus 200 for every N frames (I frame is skipped every N-1) (step 202). When only the I frame is acquired, the initialization data of the single segment to which the I frame belongs is also acquired. Since the initialization data exists, the media playback processing unit 302 can normally decode (play back) the I frame.

  The I frame acquired by the media data acquisition unit 304 is played back by the media playback processing unit 302, and the media playback processing unit 302 displays the image of the I frame for the GOP time via the user interface unit 301 (step 203). . The GOP time is included in the initialization data. Alternatively, the index file may include the GOP time, and only the GOP time may be displayed by referring to the index file.

  Depending on the stream, there may be a peculiar example in which the GOP length (time) is not constant due to scene change countermeasures, but in this case, the display time is adjusted to the standard GOP time during playback.

  Thereafter, I frame download and playback are repeated (step 204) until the end and top of the media content are reached or the normal playback state is switched by the user operation (in FIG. 11, these are called end triggers).

  Next, a processing procedure example 2 in trick play (jump) will be described with reference to FIG. In step 301, the user performs a jump operation using a seek bar or the like displayed on the user interface unit 301.

  The media data acquisition unit 304 determines the playback position (time information) to be the jump destination based on the operation content (the position of the seek bar as the jump destination), further refers to the index file, and corresponds to the segment corresponding to the corresponding playback position. The GOP position (byte position) in the file and segment file is specified (step 302).

  The media data acquisition unit 304 acquires the segment file data from the media data playback device 200 from the byte position specified in step 302 and plays it back (step 303).

  That is, when a jump is performed, the start position of the GOP of the video data included in the index information corresponding to the playback position that is the jump destination is referred to, and the GOP data in the segment file that includes the GOP is used. Play sequentially.

(Summary of embodiment)
As described above, according to the present embodiment, there is provided a media data generation method for generating streaming media data capable of accessing a specific time position based on index information in a computer. A unit of data that can be played back as content, and generating single segment data using the data, and linking the single segment data and distributing it as streaming media data Generating a segment file, which is a possible unit of data, is provided.

  The single segment data includes, for example, GOP data. The single segment data includes one or more of video data, audio data, and text data. The segment file has a segment length of, for example, MPEG-DASH (Dynamic Adaptive Streaming over HTTP).

  The media data generation method, when generating the data of the single segment, analyzing the content data, obtaining information of the single segment, and generating index information based on the information of the single segment; And generating a streaming media distribution package including the index information and the segment file.

  Further, the index information may be generated based on the information of the I frame of the video data acquired when the single segment data is generated. The index information may be generated based on the bit rate information of the video data acquired when the single segment data is generated.

  Further, according to the present embodiment, in a computer, a method of reproducing streaming media data including the segment file generated by the media data generation method, the step of obtaining the index information, and the segment file Each of which includes acquiring the media data from an arbitrary time position in the segment file with reference to at least single segment information included in the index information, and reproducing the media data. A media data playback method is provided.

  In the media data reproduction method, when the distribution package includes segment files having different bit rates, the bit rate may be switched from an arbitrary time position in the acquired segment file.

  In addition, when a fast forward or rewind instruction is received, the process of acquiring and reproducing only the I frame from the segment file is continuously executed with reference to the I frame information included in the index information. It is good as well. Further, when a jump instruction is received, the GOP in the segment file including the GOP is referred to by referring to the start position of the GOP of the video data included in the index information corresponding to the playback position as the jump destination. It is good also as reproducing | regenerating continuously in order from this data.

  In addition, according to the present embodiment, a media data generation apparatus that generates streaming media data that can be accessed at a specific time position based on index information, and plays back as content from given content data A unit that obtains data in a possible unit and generates single segment data using the data, and a segment file that is a unit data that can be distributed as streaming media data by linking the single segment data. And a means for generating. A media data generating apparatus is provided.

  The media data generation device, when generating the data of the single segment, analyzing the content data, obtaining the information of the single segment, and generating index information based on the information of the single segment; It is good also as a means to produce | generate the delivery package of streaming media containing the said index information and the said segment file.

  Further, according to the present embodiment, there is provided a media data playback apparatus for playing back streaming media data including the segment file generated by the media data generation method, the means for acquiring the index information, and the segment file Means for acquiring each one, and means for acquiring and reproducing media data from an arbitrary time position in the segment file with reference to at least single segment information included in the index information, A media data playback device is provided.

  According to an embodiment of the present invention, there is also provided a computer-readable recording medium for storing streaming media data that can be accessed at a specific time position based on index information. A computer storing a segment file, which is a unit of data that can be distributed as streaming media data, having a data structure in which data of a single segment including data of a unit that can be reproduced as content is connected. A readable recording medium is provided. The computer-readable recording medium may further store index information generated based on the single segment information acquired by analyzing the content data.

(Effect of embodiment)
As described in the present embodiment, by adopting a multi-segment structure as a file of distribution video data, a client player (eg, user terminal 300) takes into account the load on server access and the merit of switching ABR. Data access may be performed in units of GOPs, and data access may be performed in units of segment files or data units in the middle as usual. A player that supports high-speed ABR in GOP units using an index file can realize ABR in GOP units, and a player that does not support high-speed ABR in GOP units using an index file What is necessary is just to reproduce | regenerate video by data acquisition for every normal segment file.

  Also, if information in units of GOP is written in the index file, the video data file does not necessarily have to be segmented, and the video data is distributed only with one video data file, one index file, and a playlist. Is also possible.

  In addition, since the video data file is configured logically independently in GOP units, by using the time stamp information (PTS in the MPEG-2 TS format, CTS / DTS in the MP4 format) in the video data file, Digest video generation (cut editing) from video data can also be performed in GOP units. In addition, by describing the cut editing information in the index file, it is possible to easily create a digest video playlist without changing the original video data file (and distribution by MPEG-DASH). Can). Since this digest video playlist describes only the information of video cut points (in point-out point), video data files increase even in the case where many users generate digest video. Therefore, server resources can be saved.

  In addition, since video can be accessed in GOP units, for example, while a CM is being distributed, control that prohibits a user operation to skip the CM on the player side can be easily performed. Also, CM content replacement processing can be easily realized.

  The present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the scope of the claims.

100 Media Data Generation Device 200 Media Data Distribution Device 300 User Terminal 400 Network 101 Original File Input Unit 102 Original File Storage Unit 103 Original File Analysis Unit 104 Segment File Generation Unit 105 Segment File Storage Unit 106 Index File Generation Unit 107 Package Generation Unit 201 Data distribution control unit 202 Segment file storage unit 203 MPD file storage unit 301 User interface unit 302 Media playback processing unit 303 MPD file storage unit 304 Media data acquisition unit 305 Buffer

Claims (18)

In a computer, a media data generation method for generating streaming media data capable of accessing a specific time position based on index information,
Acquiring unit data that can be reproduced as content from given content data, and generating single segment data using the data; and
Concatenating the single segment data to generate a segment file that is a unit of data that can be distributed as streaming media data;
A media data generation method characterized by comprising:   The media data generation method according to claim 1, wherein the single segment data includes GOP data. The media data generation method according to claim 1 or 2, wherein the single segment data includes one or more of video data, audio data, and text data. The media data generation method according to any one of claims 1 to 3, wherein the segment file has a segment length of MPEG-DASH (Dynamic Adaptive Streaming over HTTP). When generating the data of the single segment, analyzing the content data, obtaining information of the single segment, and generating index information based on the information of the single segment;
Generating a streaming media distribution package including the index information and the segment file;
5. The media data generation method according to claim 1, further comprising: The media data generation method according to claim 5, wherein the index information is generated based on information of an I frame of video data acquired when generating the single segment data. The media data generation method according to claim 5 or 6, wherein the index information is generated based on bit rate information of the video data acquired when generating the single segment data. A method for reproducing streaming media data including the segment file generated by the media data generation method according to any one of claims 5 to 7 in a computer,
Obtaining the index information;
Obtaining the segment file step by step;
Obtaining media data from an arbitrary time position in the segment file with reference to at least single segment information included in the index information, and playing back the media data; and
A media data playback method comprising: The media data playback method according to claim 8, wherein when the distribution package includes segment files having different bit rates, the bit rate is switched from an arbitrary time position in the acquired segment file. When a fast forward or rewind instruction is received, the process of acquiring and reproducing only the I frame from the segment file is continuously executed with reference to the information of the I frame included in the index information. 10. The media data reproduction method according to claim 8 or 9, characterized in that: When a jump instruction is received, the GOP data in the segment file including the GOP is referenced with reference to the start position of the GOP of the video data included in the index information corresponding to the playback position as the jump destination. The media data playback method according to any one of claims 8 to 10, wherein the media data is played back continuously in order. A media data generation device that generates data of streaming media that can access a specific time position based on index information,
Means for acquiring unit data that can be reproduced as content from given content data, and generating single segment data using the data;
Means for concatenating the single segment data and generating a segment file which is a unit of data that can be distributed as streaming media data;
A media data generation apparatus comprising: Means for analyzing the content data, obtaining the information of the single segment, and generating index information based on the information of the single segment, when generating the data of the single segment;
Means for generating a distribution package of streaming media including the index information and the segment file;
The media data generation device according to claim 12, further comprising:   The program for functioning a computer as each means in the media data generation apparatus of Claim 12 or 13. A media data playback device for playing back streaming media data including the segment file generated by the media data generation method according to any one of claims 5 to 7,
Means for obtaining the index information;
Means for acquiring the segment files one by one;
Means for acquiring and reproducing media data from an arbitrary time position in the segment file with reference to at least information of a single segment included in the index information;
A media data reproducing apparatus comprising:   The program for functioning a computer as each means in the media data reproduction apparatus of Claim 15. A computer-readable recording medium for storing streaming media data capable of accessing a specific time position based on index information,
A segment file, which is a unit data that can be distributed as streaming media data, has a data structure obtained by concatenating single segment data including unit data that can be reproduced as content, obtained from given content data. A computer-readable recording medium characterized by being stored. The computer-readable recording medium according to claim 17, further comprising: index information generated based on the information of the single segment acquired by analyzing the content data.

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