KR20200061559A - Method and system for additional data insertion between chunk - Google Patents

Abstract

The present invention relates to a method for inserting additional data to a video file. According to the present invention, the method for inserting additional data to a video file comprises: a step of analyzing a structure of a video file; a step of inserting at least a part of additional data between chunks; a step of modifying size information of media data of the video file; and a step of modifying chunk position information of the video file. The step of inserting additional data comprises the steps of reading a chunk based on the position and size information of the chunk, and inserting additional data after the read chunk, wherein other additional data is inserted after the next chunk of the chunk when there is other additional data and repeatedly perform the process until there is no additional data to be inserted or there is no free space between chunks.

Description

{Method and system for additional data insertion between chunk} in MPEG-4 standard video

The present invention relates to a method of inserting additional data desired by a user into a video file (eg, MPEG-4 standard video file) without affecting the video playback, and more specifically, if it does not affect video playback It also relates to a method and system for inserting a larger amount of additional data into a video file.

Recently, with respect to a video file, methods for generating and storing various types of additional data such as frame-based forgery prevention data, frame-based feature data, and company user data have been studied.

In the related art, after generating these additional data as metadata separate from a video, methods for storing and managing the video and metadata as separate files have been mainly used. However, this method has a disadvantage of being vulnerable to data omission or truncation when transferring video or metadata while causing a cost increase due to difficulty in file management.

In addition, in the prior art, among the file formats defined in the MPEG-4 video standard, a method of inserting additional data in a space to which user data can be added or inserting additional data in a space behind the file header was partially used, but these methods are Not only is it not suitable for inserting large sized additional data, but also has the disadvantage that the entire additional data can be lost when a truncation of video data occurs.

The present invention is to provide a method and system for inserting additional data into a video file that does not affect video playback.

Another object is to provide a method and system for inserting additional data that is easy to manage files while inserting various and/or large amounts of additional data.

To achieve the above object, a method of inserting additional data into a video file according to the present invention includes analyzing a structure of a video file, inserting at least a portion of the additional data between the chunks, and the video file And modifying the size information of the media data and modifying the chunk location information of the video file.

Insertion of additional data includes reading a chunk based on the location and size information of the chunk, and inserting additional data after the read chunk, but if there is another additional data to be inserted, the next chunk of the chunk is inserted. The other additional data is inserted later, and the above-described process is repeatedly performed until there is no additional data to be inserted or there is no free space between chunks.

The system for adding additional data to a video file according to the present invention includes a video storage unit for storing one or more video files, an analysis unit for analyzing a structure of a video file to insert additional data among the video files, and the analysis unit And an additional data inserting unit for inserting additional data based on the analysis result and a metadata correcting unit for correcting metadata of the video file.

According to the present invention, various and even large amounts of additional data can be inserted without affecting the reproduction of the MPEG-4 video.

In addition, since it has the advantage of managing video and additional data as a single file, the efficiency of file management increases compared to a method of managing video and additional data as separate files.

In addition, through the insertion of additional data between chunks, even when a phenomenon such as truncation of an image occurs, at least some additional data can be used.

1 is a configuration diagram of an additional data insertion system according to an embodiment of the present invention.
2 is a flowchart illustrating a method for inserting additional data according to an embodiment of the present invention.
3 is a flowchart illustrating a method for inserting additional data according to another embodiment of the present invention.
4 is a flowchart illustrating a method for inserting additional data according to another embodiment of the present invention.

The objects and effects of the present invention are not limited to those mentioned above, and the objects and effects of the present invention and technical configurations for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings.

In the description of the present invention, when it is determined that a detailed description of known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. Each of the following embodiments is provided to make the disclosure of the present invention complete, and to provide a complete knowledge of the scope of the invention to those skilled in the art to which the invention pertains, and to limit the scope of the invention. no.

Throughout the specification, when a part is said to "include" or "equipment" a component, this means that other components may be further included instead of excluding other components, unless specifically stated to the contrary. . In addition, terms such as "...unit", "...device", "...device", "...unit" or "...module" described in the specification may have at least one function or operation. Means a unit of processing, which may be implemented in hardware or software or a combination of hardware and software.

On the other hand, in each embodiment of the present invention, each component, functional blocks or means may be composed of one or more sub-components, the electrical, electronic, and mechanical functions performed by each component are electronic circuits , It may be implemented with various known devices such as an integrated circuit, an ASIC (Application Specific Integrated Circuit), or mechanical elements, or may be implemented separately, or two or more may be integrated into one.

In the present invention, a method of inserting additional data between chunks, which are consecutive units of payload data (media data played to a user) such as video or audio, is used. That is, since the video file is a large file, the media data played back to the user is managed by dividing and managing multiple pieces, so inserting additional data between these pieces is a technical core of the present invention.

By using such a method, more and more additional data can be inserted without affecting the video playback as compared with the existing methods, and the video and additional data can be managed as a single file.

To this end, after analyzing the file structure of the input video, a process of inserting additional data between chunks and a process of changing meta information and header information of the file by reflecting information of the changed file through inserting additional data is performed. .

Hereinafter, the configuration of the present invention will be described in detail through a preferred embodiment of the present invention (an example of inserting additional data in an MPEG-4 video) with reference to the accompanying drawings. It goes without saying that the technical idea of the present invention is not limited to MPEG-4, and can be applied to inserting additional data into video files of different formats within the same or similar categories.

In the MPEG-4 standard, all content is requested and downloaded in chunks. Chunk means a segment of content. It is not limited in size, but is usually divided into segments of 2 to 5 seconds. Before the service is started, the size of the chunk of the size is notified to the client (eg, the user terminal), and the client requests and downloads the chunk. Since there are several chunks of different quality for one content, adaptation is possible by selecting and requesting according to the situation. For example, if the mesh is good, a high quality chunk is requested, and if it is bad, a low quality chunk is requested.

MPEG-4 video has a hierarchical structure as follows.

● ftyp: File type box to check file compatibility

● moov: A movie box that stores all metadata on the media (movie box)

⊙ mvhd: movie header box

⊙ trak: A track box that defines a single track in a movie

tkhd : 트랙의 특성을 기술 (track header box)

tkhd: Describe the characteristics of the track (track header box)

edts : (edit box)

edts: (edit box)

elst: (edit list box)

mdia : 트랙의 미디어 타입과 샘플 데이타 (media box)

mdia: Media type of track and sample data (media box)

mdhd: describes the characteristics of the media (media header box)

hdlr: (handler reference box)

minf: (media information box)

hdlr: (handler reference box)

stbl: (sample table box)

stsd: Codec information required for decoding the track (sample description box)

stts: time of sample (time-to-sample box)

stsz: the size of the sample in the chunk (sample size box)

stsc: number of samples in chunk (sample to chunk box)

stco: the position of the chunk (chunk offset box)

...

⊙ trak...

⊙ trak...

...

● mdat: media data box that stores actual media

That is, ftyp (file type box, file type box to check file compatibility), moov (movie box, movie box to store all metadata of the media), mdat (media data box), media data box to store actual media ), and moov consists of mvhd (movie header box) and multiple trak (track box, box defining a single track in the movie), where trak is stbl (describing information of media sample data). sample table box). stbl includes table box information such as stsd (sample description box), stts (time-to-sample box), stsz (sample size box), stsc (sample to chunk box), and stco (chunk offset box).

1 is a schematic configuration diagram of a system for analyzing the above information and grasping the structure of a video file and inserting additional data according to the present invention.

A system for inserting additional data into a video file according to an embodiment of the present invention includes a video storage unit 110, an analysis unit 120, an additional data insertion unit 130, and a MOOV correction (metadata correction) 140 It includes.

The video storage unit 110 stores a video to be serviced and additional data is inserted, and the analysis unit 120 analyzes the structure of a video according to each standard such as MPEG-4.

The additional data inserting unit 130 reads a chunk based on the position and size information of the chunk identified by the analysis unit, inserts additional data after the chunk, and if there is another additional data to be inserted, the additional chunk The other additional data is inserted after the next chunk, and the above-described process is repeated until there is no additional data to be inserted or until the last chunk is reached (this will be described later in detail with reference to FIG. 2).

The MOOV correction unit 140 corrects metadata of a corresponding video file after inserting additional data so that no problem occurs in video playback. That is, the MOOV correction unit 140 at least corrects the size information of the media data and the location information of each chunk.

A method of inserting additional data according to an exemplary embodiment of the present invention is illustrated in FIG. 2, and a detailed description is as follows.

① First, open an MPEG-4 video file to insert additional data between chunks (S210);

② The structure of the MPEG-4 video file input through the above step (S210) is analyzed. Specifically, for the above-described ftyp, mdat, and moov, location information based on the start of a file and size information of each data are analyzed. In addition, among the information included in the moov, stco (chunk offset box) information including location information of each chunk is analyzed (S220).

③ After that, one chunk data to insert additional data is read (S230). In order to read the chunk data, the position information and the size information of the current chunk are required, and the position information of the current chunk uses the index value of the current chunk described in stco, and the size information is the index of the current chunk from the index value of the next chunk. You can use the value minus the value.

④ Insert the additional data after the chunk data read through the step (S230) (S240).

⑤ After completing the process of inserting additional data between chunks, modify/change mdat size information and moov (S250).

The mdat of the MPEG-4 standard consists of 4 bytes of size information, 4 bytes of type information, and a large number of chunk data. The size information of mda is added by adding the size of additional data and chunk data inserted between chunks. Correct it.

After finishing the process of changing the data of mdat, change the moov. After inserting additional data, moov information must be changed to enable normal playback of video. Specifically, among the moov information, stco information including the location information of the chunk is modified. Since the stco has the location information (offset) of each chunk, the size of additional data inserted between the chunks is added from the existing offset information. Update the offset information of stco.

As described above, a method of inserting additional data according to a preferred embodiment of the present invention has been described. However, after inserting additional data, additional data to be additionally inserted may still remain. Therefore, it is preferable to include a process of confirming whether additional data to be additionally inserted after insertion of additional data as shown in FIG. 3.

⑥ That is, after inserting additional data in step S240, check whether there is additional data remaining (S310), and if there is no more additional data to insert, proceed to the next step (S250) to correct the size information and moov of mdat. /Change and exit.

⑦ If there is additional data to be inserted, check whether there is space between the chunks to be inserted (S320), and if there is space, return to step (S230) to read the chunks and insert additional data thereafter. As a result of checking in step S320, if there is no empty space between chunks into which additional data can be inserted, the process proceeds to step S250, where mdat size information and moov are corrected/changed and ended.

FIG. 4 shows an embodiment different from FIG. 3 described above.

FIG. 4 takes a method of inserting additional data between the first chunk and the second chunk, and then inserting the additional data between the second chunk and the third chunk from the beginning or the middle in series. If it is, it is an efficient way.

As soon as the chunk is read in step S230, it is checked whether the read chunk is the last chunk (S410), and if the result of the check is the last chunk, it enters step S250, corrects/changes mdat size information and moov, exits, Otherwise, the process proceeds to step 240 to insert additional data.

In this way, the check of whether the additional data to be added remains and whether there is an empty space between chunks to be added, and a subsequent process according to the result of the check are various cases as in the embodiments of FIGS. 3 and 4. There may be, there may be a variety of other modifications, it is obvious that they all fall within the scope of the technical idea of the present invention.

Meanwhile, according to another embodiment of the present invention, a step (not shown) of selecting a location of a chunk to insert additional data may be further included.

Since a video file, such as an MPEG-4 video file, divides and includes media data into chunks of a certain length, there are usually a plurality of chunks (segments). There may be a method of inserting, and a method of dividing and inserting additional data to be inserted into a space between a plurality of chunks.

In addition, the method of inserting additional data by dividing it into a space between a plurality of chunks inserts additional data between the first chunk and the second chunk, and then inserts the additional data between the second chunk and the third chunk. As described above, a method of serially inserting from the beginning or the middle may be used. Alternatively, additional data is inserted between the 5th and 6th chunks, and then the additional data is inserted between the 10th and 11th chunks. You can also take a method of inserting additional data at intervals.

In addition, when inserting one additional data, the entire one additional data may be inserted as it is, or it may be divided and distributed and inserted between three or more chunks.

In such various insertion methods, it is preferable to determine whether to select a location to insert additional data and whether to insert additional data in a divided manner to have no or minimal effect on the playback of a video file even after inserting the additional data. Of course, the selection of the space between chunks where additional data will be inserted is determined based on the analysis result of the video file (eg, the number of chunks, the size of media data, the size of each chunk, etc.) and the properties and sizes of additional data This is preferred.

The preferred embodiments of the present invention have been described above, which are merely used in a general sense to easily describe the technical contents of the present invention and to help understand the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein. For example, although the name of the invention and the above-described embodiment are mainly described as embedding additional data in an MPEG-4 video file, the description is not excluded from being applied to video files of other formats. Therefore, it should be determined by the following claims in the scope of the present invention.

Claims (8)

Analyzing the structure of the video file,
Inserting at least a portion of additional data between the chunks;
Modifying the size information of the media data of the video file;
Modifying the chunk location information of the video file
Method of inserting additional data of a video file containing a.
The method of claim 1, wherein the analyzing step,
And reading a chunk offset value that is part of the metadata of the video file to determine the position of each chunk.
How to insert additional data in a video file.
According to claim 1, The step of inserting,
Reading the chunk based on the position and size information of the chunk,
And inserting additional data after the read chunk,
If there is another additional data to be inserted, the other additional data is inserted after the next chunk of the chunk, and the above-described process is repeatedly performed until there is no additional data to be inserted or there is no free space between chunks.
How to insert additional data in a video file.
According to claim 3, The step of checking the size information of each chunk,
Calculate by subtracting the index value of the chunk to check the size from the index value of the next chunk to check the size
How to insert additional data in a video file.
The method of claim 1, wherein modifying the size information of the media data,
Modifying the sum of the size of inserted additional data and the size of chunks to the new size of the media data
How to insert additional data in a video file.
A video storage unit that stores one or more video files,
Analysis unit for analyzing the structure of the video file to insert additional data among the video files,
An additional data insertion unit for inserting additional data based on the analysis result of the analysis unit;
Metadata correction to modify the metadata of the video file
Additional data insertion system of a video file containing a.
The method of claim 6, wherein the additional data insertion unit,
Based on the position and size information of the chunk identified by the analysis unit, the chunk is read and additional data is inserted after the chunk. If there is another additional data to be inserted, the additional chunk data is added after the next chunk of the chunk. Inserting and repeating the above process until there is no additional data to insert or the last chunk is reached.
System for inserting additional data of video files.
The method of claim 6, wherein the metadata correction unit,
After the additional data is inserted, the size information of the media data and the position information of each chunk are corrected.
Phosphorus data insertion system.

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