JP4818373B2 - SVC file data sharing method and file - Google Patents

Description

  The present invention relates to a SVC (Scalable Video Coding) file data sharing method and a file thereof, and more particularly, to a SVC file data sharing method and a file sharing method using a base track reference. About.

  FIG. 1 is a diagram illustrating the concept of scalable video coding (SVC).

As shown in FIG. 1, SVC encodes a plurality of video layers into one bit string.
The SVC hierarchy is composed of one basic hierarchy and one or more extended hierarchies that are continuously stacked on the basic hierarchy.

  Each extension layer can represent the maximum bit rate, screen rate, and resolution given to each extension layer based on the lower layer information. SVC can support various bit rates, screen rates, and resolutions as the number of extended layers is continuously increased.

  As described above, the SVC is an encoding technology that can solve problems related to bandwidth diversity, receiver terminal performance and resolution diversity, content consumers' various preferences, and the like that occur in different network environments. It is.

  FIG. 2 is a diagram showing the file format of the multimedia file.

  In general, when trying to save video content to a file, in order to ensure free access to any location of the content and to facilitate reprocessing of the content, in addition to the content encoding information, Separate metadata about the conversion method, length, content, optional access information, etc.

  A unit called a track is defined as one media unit that can be continuously played back.

  As shown in FIG. 2, a multimedia file is generally stored in a structure having an audio track and a video track.

  When coding video content in SVC form, the multimedia file has more than one video track, which is due to the characteristics of SVC.

  FIG. 3 is a diagram illustrating a scalable hierarchy of content coded by SVC.

  SVC is characterized in that a plurality of video layers are encoded into one bit string.

  As shown in FIG. 3, the scalable base bitstream is one bitstream p 1 to pm having the highest image quality, and includes the entire encoded data 310.

  A sub-bitstream (0 to a or 0 to b transmission target encoded data a or transmission target encoded data b) can be freely generated from a scalable base bitstream according to the supported bandwidth of the network and user terminal specifications.

  The sub bitstream a 320 includes transmission target encoded data a, and the sub bitstream b 330 includes transmission target encoded data b.

  Each of the scalable base bit stream, the sub bit stream a, and the sub bit stream b is composed of one or more scalable layers p1, p2,.

  The scalable base bitstream is a bitstream having any scalable hierarchy p1 to pm.

  The remaining sub bitstreams have only a scalable layer (p1 to pi for subbitstream a or p1 to p3 for subbitstream b) up to a specific step among scalable layers p1 to pm.

  FIG. 4 is a diagram illustrating a file format of an SVC file for storing content coded in SVC.

  As shown in FIG. 4, the scalable base bit stream and the sub bit stream are configured by being divided into separate tracks (generally referred to as a scalable base track and a sub track, respectively).

  In this case, when two or more video tracks are included in one file and two or more video tracks are included in one file, metadata representing a scalable hierarchy can be separately placed for each track. .

  Conventionally, when SVC coded content is stored in a file, (1) the data is repeated and duplicated in the common part of the track metadata, and (2) the relationship of the track correlated with another track cannot be displayed. It was.

  The SVC file data sharing method and the file according to the present invention can reduce the storage capacity by avoiding the repetition of data common to each scalable hierarchy in the case where SVC coded content is stored in a file, so that another track can be reduced. It is an object of the present invention to provide convenience when reprocessing the content stored in the SVC file by displaying the relationship of the tracks correlated with each other.

  According to the present invention, there is provided a data sharing method for an SVC file including media data having at least one scalable layer in each frame, wherein at least one metadata for at least one scalable layer included in the media data is stored. Storing a scalable hierarchy entry in a scalable base track, and subtracks generated based on a part of at least one of the scalable hierarchies included in the media data that is a base of the scalable base track, Storing the scalable hierarchy identification information and the scalable base track identification information; and based on the scalable hierarchy identification information and the scalable base track identification information, And a step of sharing the scalable layer entry stored in the table base track.

  According to the present invention, there is provided a data sharing method for an SVC file including a plurality of media data including a scalable base track including at least one scalable layer, and at least generated based on any one of the plurality of scalable base tracks. One sub-track has a step of storing identification information of the scalable base track that is a generation base among the plurality of scalable base tracks.

  An SVC file having media data having at least one scalable layer in each frame according to the present invention for solving the above-described problem is provided with at least one scalable layer entry storing metadata for at least one of the scalable layers, respectively. And a scalable base track that is generated on the basis of the scalable base track, and instead of the scalable layer entry, the identification information of the scalable layer and the identification information of the scalable base track that is the generation base of the scalable layer And at least one sub-track.

  The SVC file including a plurality of media data including a scalable base track including at least one scalable layer according to the present invention includes identification information of the scalable base track that is a generation base among the plurality of scalable base tracks. At least one sub-track generated based on any one of the plurality of stored scalable base tracks.

  According to the present invention, in the case of storing SVC coded content in a file, (1) by sharing metadata for each track, avoiding repetition of common data for each scalable hierarchy, and (2) base track By placing a reference, you can display the relationship of tracks that are semantically correlated to another track.

  According to the present invention, when storing SVC coded content in a file, by displaying a track correlated with another track by reducing the storage capacity by avoiding repetition of data common to each layer, Provide convenience when reprocessing stored content.

1. Sharing Metadata by Track FIG. 5 is a diagram showing a ScalableLayerEntry stored in each track of the metadata of the SVC file.

  As shown in FIG. 5, the ScalableLayerEntry of Layer 1 can overlap the scalable base track and the subtrack generated based on the scalable base track.

  When storing SVC coded content in a file, metadata including additional information in each scalable layer (Layer) is referred to as ScalableLayerEntry.

  In the SVC file, a ScalableLayerEntry is included in the sgpd (Sample Group Description Box) of the track.

  When other sub-tracks are generated based on the scalable base track, the scalable hierarchy between the two tracks has a common scalable hierarchy.

  The common scalable hierarchy has the same metadata ScalableLayerEntry, and data overlaps a common part of the metadata.

  FIG. 6A is a diagram illustrating an SVC file sharing a ScalableLayerEntry according to an exemplary embodiment of the present invention.

  According to the present invention, the same metadata ScalableLayerEntry for a common scalable layer is not recorded for each track, but scalable base track identification information ref_track ID for specifying a scalable base track and scalable layer identification information ref_layer ID for specifying a scalable layer are set. use.

  FIG. 6A is a diagram illustrating an SVC file that shares a ScalableLayerEntry between tracks according to an exemplary embodiment of the present invention.

  The scalable base track includes a scalable hierarchy entry that has metadata for the scalable hierarchy.

  The sub-track generated based on the scalable base track has the identification information of the scalable layer and the identification information of the scalable base track that is the generation base of the scalable layer, instead of the scalable layer entry.

  In FIG. 6A, the sub-track uses the scalable base track identification information ref_track ID = 1 specifying the scalable base track and the scalable hierarchy identification information ref_layer ID = 1 specifying the scalable hierarchy, and does not store the scalable layer entry in an overlapping manner. .

Among the scalable hierarchies, the identification information of the scalable hierarchies used as the generation base and the identification information of the scalable base track are represented by sgpd tracks of the sub-tracks.
The syntax for sharing the ScalableLayerEntry value of the scalable base track using the scalable base track identification information ref_track ID and the scalable hierarchy identification information ref_layer ID of the present invention is as follows.

  As described above, according to the present invention, the scalable base track identification information ref_track ID and the scalable hierarchy identification information ref_layer ID are placed, and any metadata designating the same hierarchy can be obtained by referring to the original metadata. The same contents need not be stored repeatedly.

  FIG. 6B is a flowchart of a method for sharing a ScalableLayerEntry between tracks of metadata of an SVC file according to an exemplary embodiment of the present invention.

  First, the scalable layer entry ScalableLayerEntry storing metadata for the scalable layer included in the media data of the SVC file is stored in the scalable base track (S601).

  In the sub-track generated based on the scalable base track, the identification information of the scalable layer and the identification information of the scalable base track that are the generation base are stored (S602).

  The scalable base track and the scalable layer entry are shared based on the identification information of the scalable layer and the base information of the scalable base track that are the generation bases stored in the subtrack (S603).

  The identification information of the scalable layer and the identification information of the scalable base track that are the bases of generation are represented by the sgpd track of the scalable subtrack.

  As described above, according to the present invention, (1) by sharing metadata for each track, it is possible to avoid repetition of data common to each scalable hierarchy. Hereinafter, (2) the base track reference for displaying the relationship between tracks that are semantically correlated with each other according to the present invention will be described.

2. Base Track Reference FIG. 7A is a diagram illustrating an SVC file having scalable base track identification information according to an exemplary embodiment of the present invention.

  According to the present invention, it is possible to display which scalable base track is derived from each subtrack.

  In this way, it is possible to display the relationship between the tracks that are related to each other, and to provide convenience when re-processing the stored content.

  As shown in FIG. 7A, there is subordinate metadata called track reference tref 710 in metadata trak 700 representing a track.

  The syntax of the track reference tref 710 is as follows.

  The track reference tref 710 may have a plurality of track ID trak-IDs with different types.

The track ID of the scalable base track is stored in the track reference tref 710 as a type called sbas 711, and it is possible to display which track is the scalable base track from which the sub track is derived.
Hint, cdsc, and scal also display the role that the track plays like the sbas 711 according to the present invention, and also refer to the track in which the track is used.

  As described above, according to the present invention, when a track having the same content is composed of one scalable base track and a plurality of subtracks derived therefrom, the scalable base track can be searched for each subtrack. A possible reference sbas 711 can be used to display the relationship between the sub-tracks.

FIG. 7B is a diagram illustrating a method for managing by combining sub-tracks having the same scalable base track according to an exemplary embodiment of the present invention.
When storing content in a file, two or more contents can be stored in one file.

  In this case, if the content to be stored is SVC coded content, each content has a scalable base track and at least one sub-track derived from each scalable base track separately from the scalable base track. Can do.

  In this case, each sub-track needs to define what the scalable base track derived from itself is.

  The track ID of the scalable base track is stored in the sbas 711 type, the track indicating which scalable base track is derived from each sub track is displayed, and sub tracks having the same scalable base track are combined. Can be managed.

  As shown in FIG. 7B, the subtrack A and the subtrack B were generated based on the scalable base track X.

  The sbas track of the track reference tref of the subtrack A and the subtrack B stores the track ID of the scalable base track X and displays which track the scalable base track derived from itself is. S701).

  The sub track C and the sub track D were generated based on the scalable base track Y.

  The sbas track of the track reference tref of the subtrack C and the subtrack D stores the track ID of the scalable base track Y and displays which track the scalable base track derived from itself is ( S702).

  According to the present invention, management can be performed by combining subtracks generated based on the same scalable base track based on the identification information of the scalable base track.

  For example, there may occur a case where any track generated based on the scalable base track Y is to be deleted.

  In such a case, according to the present invention, the sbas track of the track reference tref is referred to and generated from the scalable base track Y by deleting any track having the track ID of the scalable base track Y in the sbas track. You can easily manage every subtrack.

  As described above, according to the present invention, the ScalableLayerEntry that is metadata representing the scalable hierarchy of the subtrack is stored for the overlapping ScalableLayerEntry by sharing only the scalable base track identification information ref_trackID and the scalable hierarchy identification information ref_layerID. Avoid wasting space.

  Also, by placing a base track reference called sbas in the sub-track, it is possible to display the relationship between the tracks that are semantically related to each other, thereby providing convenience when reprocessing the stored content.

  The present invention can also be embodied as computer-readable code on a computer-readable recording medium. Computer readable recording media include all types of recording devices that can store data that can be read by a computer system.

  Examples of computer-readable recording media include ROM (Read Only Memory), RAM (Random Access Memory), CD-ROM, magnetic tape, floppy (registered trademark) disk, optical data storage device, etc. Also included are those embodied in the form of a carrier (for example, transmission over the Internet). The computer-readable recording medium is distributed in a computer system connected to a network, and a computer-readable code is stored and executed in a distributed manner.

  So far, the present invention has been described with a focus on preferred embodiments thereof. Those skilled in the art will appreciate that the invention can be varied in form and detail without departing from the spirit and scope of the invention as defined in the claims. Accordingly, the disclosed embodiments should be considered in an illustrative, not a limiting sense. The scope of the present invention is shown not in the above description but in the claims, and all differences within the equivalent scope should be construed as being included in the present invention.

It is a figure which shows the concept of SVC. It is a figure which shows the file format of a multimedia file. It is a figure which shows the scalable hierarchy of the content coded by SVC. It is a figure which shows the file format of the SVC file which preserve | saves the content coded by SVC. It is a figure which shows ScalableLayerEntry preserve | saved at each track | truck of the metadata of an SVC file. FIG. 6 is a diagram illustrating an SVC file sharing a ScalableLayerEntry between tracks according to an exemplary embodiment of the present invention. 4 is a flowchart of a method for sharing a ScalableLayerEntry between tracks of metadata of an SVC file according to an exemplary embodiment of the present invention. FIG. 6 is a diagram illustrating an SVC file having scalable base track identification information according to an exemplary embodiment of the present invention. FIG. 6 is a diagram illustrating a method for managing by combining sub-tracks having the same scalable base track according to an exemplary embodiment of the present invention.

Claims (4)

A data sharing method for an SVC file having media data including at least one scalable layer in each frame ,
The method
Storing at least one scalable layer entry storing metadata for at least one of the scalable layers included in the media data in a scalable base track;
Identification information of the at least one scalable layer and identification information of the scalable base track are included in a subtrack generated based on a part of the scalable layer included in the media data serving as a base of the scalable base track. A step of saving
Including
Based on the identification information of the scalable layer and the identification information of the scalable base track, the scalable layer entry stored in the scalable base track is shared,
The identification information of the scalable layer and the identification information of the scalable base track are represented by a sgpd track of a scalable subtrack.
A method characterized by that. A method for sharing data of an SVC file having a plurality of media data including a scalable base track having at least one scalable hierarchy ,
The method
Storing at least one sub-track generated based on the at least one scalable base track with identification information of the scalable base track that is a base for generating the sub-track among the scalable base tracks ;
Managing by combining sub-tracks generated based on the same scalable base track based on the identification information of the scalable base track ; and
The SVC file data sharing method , wherein the identification information of the scalable base track is represented by an sbas track of a track reference type box including track reference information of the at least one sub-track . When loaded into and executed by a computer, the computer read-usable medium storing a computer program for executing the method according to the computer to claim 1. A computer-readable recording medium storing a computer program for causing a computer to execute the method according to claim 2 when the computer reads and executes the computer program.

Images