JP2000324070A - Data conversion method, data converter and data transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently convert a data file with a format into a data file with another format. SOLUTION: In the case of converting a data file Dfa with a 1st format formed by multiplexing video and audio compressed data of a resource transmitter 10 into a data file Dfb with a 2nd format, a table file TBA is generated which can extract compressed data which are common between the 1st and 2nd formats from the data file Dfa. The data file Dfb can be generated by using the compressed data extracted from the data file Dfa on the basis of the table file TBA. The compressed data are extracted from the data file Dfb to generate the data file Dfa by generating a table file TBB. By storing the table files TBA, TBB and either of the data files, a data file with any format can be generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a data conversion method, a data conversion device, and a data transmission system.
More specifically, in order to convert a data file having a first format by multiplexing video data and audio data into a data file having a second format which is different from the first format and uses video data and audio data. In addition, a table file is generated that enables video and audio data to be extracted from the data file in the first format, and the video file and the audio data extracted from the data file in the first format are generated using the table file. To generate a data file of the second format.

[0002]

2. Description of the Related Art In recent years, with the improvement of techniques for compressing data such as images and sounds, various media, communication and broadcasting services have been provided using these techniques. For example, in the case of video data, MPEG (Moving Picture Experts Group) is used as the compression format.
Two video formats have been widely adopted. However, in an actual video / audio compression / reproduction system, video data, audio data, control data, and the like are used in a multiplexed format according to a multiplexing format corresponding to the system.

[0003] When a storage medium such as a DVD (Digital Video Disk) is targeted, a program stream PS of an MPEG2 system is adopted as a multiplexing format, and a digital satellite broadcast using CS (Communication Satellite) is used. A certain DVB (Digital V
For communication such as video broadcasting, the transport stream TS of the MPEG2 system is adopted as a multiplexing format.

As described above, even in systems having different multiplexing formats, there is a case where the constituent units of each format can be made common, and data can be mutually converted using the common constituent units. For example, in the program stream PS and the transport stream TS, PES (Packetized Elem
entary System) is known to be common.

Here, the program stream PS and the transport stream TS will be described with reference to FIG.

FIG. 7A shows a video (audio) compressed data stream (data sequence) ES. The compressed data stream is packetized and a PES header is added to generate a PES stream as shown in FIG. 7B. Is done.

[0007] The program stream PS is composed of a plurality of packs as shown in FIG. 7C. The packs are obtained by combining a plurality of PES streams into arbitrary numbers as shown in FIG. 7D. A pack header having a system time reference value SCR or the like is added to the head.

[0008] The transport stream TS is
As shown in FIG. 7G, the TS packet is composed of a plurality of TS packets.
S is divided into packets as shown in FIG. 7F, and a TS header having a program time reference value PCR or the like is added at the beginning.

For this reason, when converting the program stream PS into the transport stream TS, it is necessary to decompose the program stream PS into PES as a common unit, and to further convert the PES into TS packets to generate the transport stream TS. is there. When converting the transport stream TS to the program stream PS, it is necessary to extract data from the TS packets, reconstruct the PES, and further form a pack from a plurality of PESs to generate the program stream PS. .

FIG. 8 illustrates the mutual conversion between the program stream PS and the transport stream TS. The program stream PS recorded on a storage medium such as a DVD is read to generate a PS file. Is decomposed into PES to generate a PES file. Alternatively, the TS of the transport stream TS obtained by communication such as DVB
A file is generated, and data of this TS file is extracted to construct a PES to generate a PES file.

By generating a PES file in this way, it is possible to easily generate either the program stream PS or the transport stream TS from the PES file.

FIG. 9 is a flowchart showing a data conversion process from the program stream PS to the transport stream TS. First, in step ST21, PS
The file is read, and the process proceeds to step ST22. In step ST22, the pack is extracted from the read PS file, and the process proceeds to step ST23.

In step ST23, the PES is taken out of the pack, and the process proceeds to step ST24, where the process proceeds to step ST24.
Then, the extracted PES is written in the PES file.

Next, in step ST25, it is determined whether or not the processing for one pack has been completed. If the processing for one pack has not been completed, the flow returns to step ST23 to return to step ST23.
When the processing for the pack is completed, the process proceeds to step ST26.

In step ST26, it is determined whether or not the processing for all the packs has been completed. If the processing for all the packs has not been completed, the flow returns to step ST22. When the processing for all the packs is completed, the process proceeds to step ST27, where the generation of the PES file is completed.

In step ST28, the PES file is read out, and the process proceeds to step ST29, where step ST29 is executed.
Then, data of the TS packet size is read from the PES file.

Next, in step ST30, a TS packet is generated by adding a TS header to the read data, and in step ST31, a TS packet is written, and the process proceeds to step ST32.

In step ST32, it is determined whether or not the processing for one PES has been completed. If the processing for one PES has not been completed, the process returns to step ST29. Also 1P
When the processing for the ES is completed, the process proceeds to step ST33.

In step ST33, it is determined whether or not processing for all PES has been completed. If processing for all PES has not been completed, the process returns to step ST28. When the processing for all PESs ends, the conversion processing ends.

Thus, the program stream PS
Can be easily converted to a transport stream TS. Similarly, a PES file is generated from the transport stream TS, and the generated PES file is generated.
It is also easy to generate the program stream PS using the S file.

[0021]

When data conversion is performed between the program stream PS and the transport stream TS as described above, the data conversion device has three files, a PS file, a PES file, and a TS file. It will be. Therefore, a large-capacity recording medium (such as a hard disk) must be used to perform the conversion process. Further, since three files using PES as a common unit are stored, the utilization efficiency of the recording medium is not good.

Therefore, the present invention provides a data conversion method, a data conversion device, and a data transmission system capable of efficiently converting a data file of one format into a data file of another format.

[0023]

According to the data conversion method of the present invention, a data file having a first format obtained by multiplexing video data and audio data is different from the first format, and the video file and the audio data are multiplexed. When converting to a data file in the second format by using a file format, a table file that allows video data and audio data to be extracted from the data file in the first format is generated, and the first format is used by using the table file. In addition to extracting video data and audio data from the data file, a second format data file is generated using the extracted data.

Further, the data conversion device comprises a first data reproducing means for reproducing a data file in a first format by multiplexing video data and audio data, and a data file reproduced by the first data reproducing means. A first table file that allows video data and audio data to be extracted from the data file, extracts video data and audio data from the first format data file using the table file, and uses the extracted data to generate First
And a data processing means for generating a data file of a second format different from the format of.

Further, the data transmission system multiplexes the compressed video and audio data and records the multiplexed data as a first format data file, and reproduces and decodes the recorded first format data file in a non-linear manner. And a first data transmission device for transmitting video data and audio data, and multiplexing the compressed video and audio data and recording the multiplexed data as a data file in a second format different from the first format. A second data transmission device for transmitting video data and audio data by reproducing and decoding the data file of the second format in a non-linear manner;
A data file is read from the data transmission device of the first embodiment, a table file is generated from which compressed data can be extracted, and one of the data files in the first or second format is converted into the other data file using the table file. When a table file is generated based on the first format data file, the data processing device extracts compressed data from the first format data file using the table file, When a data file in the second format is generated using the compressed data and supplied to the second data transmission device, and a table file is generated based on the data file in the second format, the second file is generated using the table file. Format data files The compressed data is taken out, a data file in a first format is generated using the compressed data, supplied to a first data transmitting device, and recorded in one of the first and second data transmitting devices. Video data and audio data based on the compressed data obtained can be transmitted from the other data transmission device.

According to the present invention, compressed data of, for example, video and audio data to be transmitted is multiplexed into a data file of the first format, and the position of the compressed data is determined from the data file of the first format. And a table file indicating the data amount and the like are generated. Here, when transmitting the material of the data file of the first format from the device for transmitting the material based on the data file of the second format, the data file of the first format is used by using the table file. , Compressed video and audio data is extracted from the data, and a data file in the second format is generated from the extracted data.

[0027]

Next, an embodiment of the present invention will be described in detail. Here, one format is such that a video compressed data stream (data string) VES shown in FIG. 1C and an audio compressed data stream AES shown in FIG. 1D are obtained by adding a PES header to a packetized PES. As shown in FIG. 1B, a pack is formed by using a plurality of packs and adding a pack header. As shown in FIG.
2 system program stream PS). Note that 1 PES is, for example, 1 AAU (Aud) of compressed data for one frame of video data and audio data.
io Access Unit). A file of data in this format is referred to as a data file Dfa.

On the other hand, the format is 1 GOP (Group O) from a stream VES which is compressed data of video shown in FIG. 1C and a stream AES of compressed audio data shown in FIG. 1D.
f Pictures) Data is used in minutes and AUX
Data is also used, a header is added to each data, the data is put together, and then a system header is added. A file of data in this format is referred to as a data file Dfb.

In such two formats, FIG.
The data of the video stream VES shown in FIG. 1 and the data of the audio stream AES shown in FIG.

FIG. 2 shows the configuration of the data conversion system. The material sending device 10 accumulates material data as the above data file Dfa, and the material sending device 20 accumulates material data as the above data file Dfb.

The material sending devices 10 and 20 encode and compress video data and audio data, and record the compressed data in a plurality of hard disk devices capable of parallel processing in the above-described format. In addition, compressed data is read out from a hard disk device or the like in a non-linear manner and decoded at the same time to transmit multi-channel video data and audio data simultaneously, or the same material data is reproduced in multiple channels with a different playback time. And so on. The material sending devices 10 and 20 are connected via a communication network 50.

The data converter 30 is connected to the communication network 50 by using a computer. Also,
The file server 40 that stores data necessary for performing data conversion is connected to the communication network 50.

When the data conversion is performed by the data conversion device 30, the data file to be converted is converted into a data file of a new format by using a data file to be converted and a table file in which information on the data file is recorded. Can be.

FIG. 3 shows a list in which the data of the table file is dumped. The file name, the file size, and the video and audio PES of the data file to be converted are shown.
The number, bit rate, number of GOPs, etc. are recorded in the table file. Note that these data are used as Config data. Also, each PE is stored in the table file.
File pointer indicating the position of S, each PE of video and audio
The identification information ID of S and the data size of the compressed data in each PES are also recorded.

By using the information of the table file, it is possible to extract the data of the streams VES and AES as a common unit from the data file to be converted. Therefore, a data file of another format can be easily generated using the data of the common unit. Also,
Just keep a table file of both data files and a data file of either format,
Both formats can be supported.

Next, a data conversion operation, for example, an operation of converting a data file Dfa into a data file Dfb will be described.

FIG. 4 is a flowchart showing a process of generating a table file TBA of the data file Dfa to be converted.

In step ST1, the data file Dfa
And proceeds to step ST2, extracts a pack from the data file Dfa read in step ST2, and further extracts P from the extracted pack in step ST3.
The ES is taken out and the process proceeds to step ST4.

At step ST4, a file pointer indicating the start position of the PES and the stream V in the PES
ES, AES data size in table file TB
A and the process proceeds to step ST5.

In step ST5, it is determined whether or not the processing for one pack has been completed. If the processing for one pack has not been completed, the process returns to step ST3, and if the processing for one pack has been completed, Proceed to step ST6.

In step ST6, it is determined whether or not the processing for all the packs has been completed. If the processing for all of the packs has not been completed, the flow returns to step ST2 to perform the processing for the next pack. When the processing for all the packs is completed, the generation of the table file TBA is completed.

FIG. 5 is a flowchart showing a data conversion process for generating a data file Dfb using the data file Dfa and the table file TBA. Step S
In T11, the table file TBA is opened, and the process proceeds to step ST12. In step ST12, header information is generated based on the Config data of the table file TBA, recorded in the data file Dfb, and the process proceeds to step ST13.

In step ST13, the file pointer and data size of the PES are read from the table file TBA, and the process proceeds to step ST14.
Then, based on the read PES file pointer and data size, the stream VES and AES data are extracted and written into the data file Dfb.

In step ST15, it is determined whether or not writing of data for one GOP has been completed.
If the minute processing has not been completed, the process returns to step ST13. When the processing for one GOP is completed, the process proceeds to step ST16.

In step ST16, it is determined whether or not the processing has been completed for all PESs. Where all P
If the processing for the ES has not been completed, that is, if the processing for writing the data of the streams VES and AES in all the PESs to the data file Dfb has not been completed, the process returns to step ST12, and the processing of the next GOP is performed. Do. When the processing has been completed for all the PESs, the generation of the data file Dfb ends.

Thus, the table file TBA
Data file Dfa
Can be converted into a data file Dfb having a different format. When converting the data file Dfb into the data file Dfa, a table file having information capable of extracting data of the streams VES and AES, which are common units, from the data file Dfb and generating a header for the data file Dfa. Generate TBB. If the data of the table file TBB is used, the data file Dfb can be easily converted to a data file Dfa of a different format.

For example, when video and audio data stored in the material sending device 10 shown in FIG. 2 is used by the material sending device 20, the material data file used from the material sending device 10 is transmitted to the communication network 50. Data conversion device 3 via
The data conversion device 30 generates a table file for the read material data file.

Here, when the material data read from the material transmitting device 10 is used immediately by the material transmitting device 20, the data converter 30 uses the data of the table file to execute the format corresponding to the material transmitting device 20. Is generated and transferred to the material sending device 20 via the communication network 50.

When not immediately used, the material data file read from the material sending device 10 is
The table file corresponding to the material data file is recorded in the file server 40 via the communication network 50. Here, when a request to read the recorded material data file is made from the material sending device 20, data conversion of the material data file is performed using the data of the table file recorded in the file server 40, and the material sending device A material data file in a format corresponding to the format 20 can be supplied to the material sending device 20. When a request to read the material data file recorded in the file server 40 is made from the material sending device 10, the material data file is directly transferred from the file server 40 via the communication network 50 without performing data conversion.
The external storage device 60 such as a streamer connected to the data conversion device 30 as well as the material sending devices 10 and 20.
May be converted, or the converted data may be stored in the external storage device 60.

As described above, according to the above-described embodiment, as shown in FIG. 6, the table files TBA and TBB are prepared, and only one of the data file Dfa and the data file Dfb is held. It is possible to respond quickly to formats. Further, since the table files TBA and TBB have a smaller amount of data than the data files, the amount of data to be held can be reduced as compared with the conventional case where the data files of the two formats and the data file of the common unit are held. Thus, the use efficiency of a recording medium or the like can be greatly improved.

The format in the above embodiment is illustrative and not restrictive. Also,
Of course, the data file is not limited to a video or audio data file.

[0052]

According to the present invention, a table file indicating a data position, a data amount, and the like of a material is generated from a data file of the first format. Here, when transmitting the material of the data file of the first format from the device that transmits the material based on the data file of the second format, the data file of the first format is transmitted using the table file. Material data is extracted, and a data file in the second format is generated from the extracted data. Therefore, by storing the data file in the first format and the table file, the data file in the second format can be generated quickly.

Further, a table file based on the data file of the first format and a table file based on the data file of the second format are stored, and the data file of either the first or the second format is stored. Is stored, data files in the first and second formats can be easily generated.

[Brief description of the drawings]

FIG. 1 is a diagram showing a format of a data file.

FIG. 2 is a diagram showing a configuration of a data conversion system.

FIG. 3 is a diagram showing a table file.

FIG. 4 is a flowchart illustrating a process of generating a table file.

FIG. 5 is a flowchart showing a data conversion process.

FIG. 6 is a diagram for explaining mutual data conversion.

FIG. 7 is a diagram showing a relationship between a program stream and a transport stream.

FIG. 8 is a diagram for explaining mutual conversion between a program stream and a transport stream.

FIG. 9 is a flowchart showing a data conversion process from a program stream to a transport stream.

[Explanation of symbols]

10, 20 ... material sending device, 30 ... data conversion device, 40 ... file server, 50 ... communication network,
60 external storage device

Claims (4)

[Claims] 1. A data file having a first format by multiplexing video data and audio data, the data file being different from the first format and having a second format using the video data and audio data. When converting to the first format, a table file is generated from which the video data and audio data can be extracted from the first format data file, and the video data is converted from the first format data file using the table file. A data file in the second format using the extracted data and the extracted data. 2. A first apparatus for multiplexing video data and audio data to reproduce a data file in a first format.
And a first table file capable of extracting the video data and the audio data from the data file reproduced by the first data reproducing means, and using the table file to generate the first table file. And a data processing unit for extracting the video data and the audio data from the data file of the first format and generating a data file of a second format different from the first format using the extracted data. Data converter. 3. A data processing device comprising: a second data reproducing means for reproducing the data file of the second format; and a file storing means for storing a file, wherein the data processing means reproduces the data by the first data reproducing means. A first table file enabling the video data and the audio data to be extracted from the data file obtained, and extracting the video data and the audio data from the data file reproduced by the second data reproducing means. The file storage means stores the first and second table files generated by the data processing means and reproduced by the first or second data reproduction means. Stored in the file storage means by the data processing means. By using the first or the second table files and data files, claim 2, characterized in that for performing mutual conversion of the first format data file and the second format data files of
Data conversion device as described. 4. A method for multiplexing compressed video and audio data and recording the multiplexed data as a first format data file, and reproducing and decoding the recorded first format data file in a non-linear manner. And a first data transmission device for transmitting audio and audio data, and multiplexing the compressed video and audio data and recording the multiplexed data as a data file of a second format different from the first format. A second data transmission device for transmitting video data and audio data by reproducing and decoding a data file of the format in a non-linear manner; and reading a data file from the first or second data transmission device and compressing the data file. Generates a table file from which data can be extracted, and uses the table file to A data processing device for converting one of the data files of the first or second format into the other data file, wherein the data processing device converts the table file based on the data file of the first format; When generated, the compressed data is extracted from the data file in the first format using the table file, and a data file in the second format is generated using the compressed data to transmit the second data. When the table file is generated based on the data file of the second format, the compressed data is extracted from the data file of the second format using the table file, and the compressed data is supplied to the device. Using the first format A data file is generated and supplied to the first data transmission device, and video data and audio data based on compressed data recorded in one of the first and second data transmission devices are converted into the other data. A data transmission system capable of transmitting data from a transmission device.