JPH08130712A - Data editing method and editing device - Google Patents

Abstract

PURPOSE: To keep the degradation of picture quality and tone quality at the time of decoding irreversibly encoded moving pictures and music, performing an editing processing and then irreversibly encoding them within a certain limit. CONSTITUTION: At the time of taking out and decoding irreversibly encoded compression data or self-concluded partial data (example: GOP unit) in the compression data, the history of the number of times of the decoding/encoding processings of the data is referred to and the propriety of decoding is determined. In the case of being suitable, a desired editing processing (example: superimposed character insertion or the like) is performed to the decoded data and thereafter, irreversible encoding is performed again. At the time, history information is updated and added. The history information is written in the user area of a GOP layer in the case of being based on MPEG. Also, in the case of taking out partial data, they are returned to an original position where the partial data were present before being taken out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts compressed data encoded by an irreversible encoding system such as a bit stream conforming to MPEG of a moving image encoding standard into data of an original system before encoding. The present invention relates to a method and apparatus for decrypting and editing.

[0002]

2. Description of the Related Art As data compression processing by an irreversible coding method, orthogonal transformation processing and quantization processing used for compression of image data, and ATR used for compression of audio data.
There is AC processing (processing for minidiscs). In these encoding processes, images that are inconspicuous to the viewer and audio that is difficult to hear are discarded.

A user data area is provided in the bit stream conforming to the MPEG of the moving picture coding standard, and various kinds of information regarding the screen corresponding to the user data area can be arbitrarily set.

In Japanese Patent Laid-Open No. 4-87004, the number of times of dubbing is recorded on an audio tape as a dubbing destination, and various parameters at the time of playback are controlled according to the number of times to reduce deterioration of reproduced voice. Techniques for doing so are disclosed. Japanese Patent Laid-Open No. 4-212756 discloses a technique of prohibiting copying of DAT (digital audio tape) of a certain generation or more by adding the number of copy generations as attribute information when copying data.

[0005]

There is a case where it is desired to perform edit processing on the compressed data (or a part thereof) which is encoded by the lossy encoding method and recorded. For example, MP
You can insert subtitles in a moving image that has been encoded into a bitstream that conforms to EG, change the inserted subtitles to another language, and add special effects such as mosaic or blur to a part of a screen. This is when you want to have it. Or ATR of mini disc
This is a case where it is desired to perform mixing in (or part of) music that has been compressed by the AC method.

In such a case, the encoded data must be decoded once, subjected to a desired editing process, and then encoded and recorded again. However, if the decoding and coding processes are repeated in the lossy coding system, the image quality and the sound quality deteriorate. SUMMARY OF THE INVENTION It is an object of the present invention to suppress deterioration of image quality and sound quality within a certain limit when performing an edit process on a moving image or music that is lossy-encoded and recorded.

[0007]

According to the present invention, compressed data encoded by a predetermined lossy encoding system is decoded into data of an original system, and after the decoded data is subjected to a desired editing process. A data editing method in which the history information indicating that the decoding and the coding processing have been performed while performing the coding by the predetermined irreversible coding method is updated to join the coded data.
Further, in the above, before the decoding of the compressed data, the suitability of the editing process is determined based on the history information related to the number of decoding and encoding processes of the compressed data, and the data for performing the above respective processes only when it is suitable This is the editing method.

Further, according to the present invention, desired partial data which is self-completed is taken out from the compressed data encoded by a predetermined lossy encoding method, and the partial data is the data of the original method before the encoding. , And after performing the desired edit processing on the decoded data, the history information indicating that the data has been decoded and coded by the predetermined lossy coding method is updated and the code is updated. It is a data editing method in which the data after conversion is added and the partial data is returned to the original position before the extraction. Further, in the above, before the partial data is decoded, the suitability of the editing process is determined based on the history information related to the number of times the partial data is decoded and coded, and the data for performing the above processes only when it is suitable. This is the editing method. Further, when it is determined that the partial data is not suitable for the editing process, after taking out the partial source data corresponding to the partial data from the source data of the compressed data and performing each process such as the above editing process, A data editing method for replacing the partial data in the compressed data with data based on the partial source data.

In the present invention, the predetermined irreversible coding method in each of the above inventions is a moving picture coding standard MPEG.
It is a data editing method which is an encoding method for generating a bit stream conforming to the. Further, in the above, the self-contained partial data is GOP (Group
This is a data editing method for data in units of pictures. Further, in the above, it is a data editing method in which the history information is added to the user data area in the bit stream.

The present invention further comprises an extracting means for extracting history information relating to the number of decoding and encoding processes from the compressed data encoded by a predetermined lossy encoding method, and an editing process based on the history information. Determination means for determining the suitability of
When it is determined by the determination means that the compressed data is suitable for the editing process, the compressed data is decoded into the original data before the lossy encoding, and the original data decoded by the decoding means is used. Editing means for performing desired editing processing, coding means for coding the original method data after the editing processing by the editing means by the predetermined irreversible coding method, and corresponding to the decoding and the coding Then, the data editing apparatus has an updating means for updating the history information and a joining means for joining the history information updated by the updating means into the data encoded by the encoding means.

Further, the present invention is an extracting means for extracting history information relating to the number of times of decoding and encoding of desired partial data which is self-completed from the compressed data encoded by a predetermined lossy encoding method. A discriminating means for discriminating whether or not the partial data corresponding to the historical information is suitable for the editing process based on the historical information; Separation means for extracting the partial data corresponding to the information, decoding means for decoding the partial data extracted by the separation means into data of the original system before the predetermined lossy encoding, and decoding by the decoding means Editing means for performing desired editing processing on the original method data, and the original method data after the editing processing by the editing means is converted into the predetermined lossy encoding method. Encoding means for re-encoding, updating means for updating the history information corresponding to the decoding and the encoding, and data for encoding the history information updated by the updating means by the encoding means. In the compressed data existing before the partial data is taken out by the adding means, the data encoded by the encoding means and the history information added by the adding means And a returning means for returning to the original position. Further, when it is determined that the partial data is not suitable for the editing process, after taking out the partial source data corresponding to the partial data from the source data of the compressed data and performing each process such as the above editing process, The data editing device replaces the partial data in the compressed data with data based on the partial source data.

In the present invention, the predetermined irreversible coding method in each of the above inventions is a moving picture coding standard MPEG.
It is a data editing apparatus which is an encoding method for generating a bit stream conforming to the. Further, in the above, the self-contained partial data is data in units of GOPs. Further, in the above, it is a data editing device in which the history information is added to a user data area in the bit stream.

[0013]

Operation: Compressed data coded by a predetermined lossy coding method (eg, a bit stream compliant with MPEG of moving picture coding standard), or self-completed partial data in the compressed data (eg. : GOP unit data)
Decoded to original format data. At that time, if necessary,
The history information related to the number of times of decoding and encoding of the data is referred to, and the suitability of decoding is determined. Next, a desired editing process (eg, subtitle insertion, subtitle change, commercial insertion, commercial change, mosaic, blur, mixing, etc.) is performed on the decoded data in the original format data, and then a predetermined process is performed. It is encoded by a lossy encoding method.
In addition, history information (cumulative number of processing times, SNR value, etc.) regarding the number of times of decoding and encoding processing is added to the encoded data. For example, in the case of conforming to MPEG, it is written in the user data area. Also,
If the partial data has been processed, the partial data is returned to the original position before the extraction. Also,
If it is determined to be unsuitable for the determination, the portion of the source data of the compressed data is subjected to the above-described processing, if necessary, and then replaced with the partial data for which the determination is inappropriate.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing the circuit configuration of the embodiment apparatus, and FIG. 2 is an explanatory diagram showing the processing of the embodiment apparatus.

As shown in the drawing, a bit stream (compressed data) conforming to the MPEG of the moving picture coding standard is input to this apparatus. History information is extracted from the user data area (user data area of the GOP layer in this embodiment; see FIG. 2) in this bit stream by the demultiplexer and sent to the edit history judging section. The compressed data from which the history information has been extracted is sent to the MPEG video decoder, decoded, and stored in the temporary storage device. Also,
Displayed on the monitor screen.

The edit history determination section determines whether or not the edit processing of the screen (GOP) instructed by the history information is appropriate.
In other words, it is determined whether or not the degree of deterioration of the image quality is within a tolerable limit when the screen is subjected to the decoding and encoding processes for the editing process. The result is sent to the control unit. In the present embodiment, the history information is the number of decoding and coding processes for the editing process.

The control unit controls the switching of the switch SW according to the result of the suitability. That is, if it is determined that the screen is suitable for the editing process, the switch SW is set to M
It is set on the temporary storage device side of the PEG video decoder side,
As a result, the moving image data of the screen (moving image data decoded by the MPEG video decoder) is sent to the editing processing unit, and desired editing processing is performed.

On the other hand, when the editing history judging unit judges that the editing process is not suitable, the switch SW is set to the temporary storage device side on the source image input side. The moving image data (moving image data that has not been encoded or decoded) is sent to the editing processing unit and subjected to desired editing processing.

The moving image data which has been subjected to desired editing processing (processing for changing the telop (subtitle) on the commercial screen in this embodiment; see FIG. 2) in the editing processing section is then sent to the MPEG video encoder. It is sent, subjected to irreversible coding (adaptive suitable predictive coding, DCT conversion and quantization, variable length coding (this processing itself is reversible coding)) by a predetermined method and compressed. .

History information updated by the edit history updating unit is added to the compressed data, and the GO information of MPEG of the moving image coding standard is used.
The data of the user data area of the P layer is multiplexed by the multiplexer. That is, the control unit sends the determination result by the edit history determination unit to the edit history update unit,
In the edit history updating section, the history information is updated based on this discrimination result. For example, if it is suitable for editing,
“1” is added to the number of times the history information has been processed.
Further, if it is not suitable for the editing process, it is replaced with the source image, so the previous history information is initialized to "1". The history information updated in this way is multiplexed as described above.

The output of the multiplexer (the MPEG-compliant bit stream in which the history information is added to the user data area of the GOP layer) is then sent to the adder, and the compressed data (the bit stream input to this device is input. Is returned to the corresponding position (the position where the GOP existed before the extraction) in the remaining compressed data from which the GOP used for each of the above-mentioned processes has been taken out.

In this way, the processing shown in FIG. 2 is realized. That is, the (N-1) th GOP (drama screen) and (N + 1) conforming to the moving picture coding standard MPEG.
Nth GO sandwiched between the second GOP (drama screen)
A process of extracting P (commercial screen) and extracting history information from the user data area, and decoding compressed data into moving image data to insert a commercial telop (caption) and re-encoding A process of adding "1" to the number of times of processing which is information (the number of times of decoding and coding for editing processing) and multiplexing the user data area of the N-th GOP re-encoded, and history information multiplexing A process of inserting a subsequent code between the (N-1) th GOP (drama screen) and the (N + 1) th GOP (drama screen) is realized.

Although the above embodiment describes a bit stream conforming to MPEG, the present invention is not limited to the above embodiment, and the data compressed by the lossy encoding is decoded to perform the editing process. After that, it can be applied to the case of lossy encoding again. Further, in the above embodiment, the number of times of processing (the number of times of decoding and coding for the editing process is performed) is adopted as the history information, but any information relating to deterioration of image quality and sound quality can be adopted. For example, the SNR value obtained based on the image quality and the average SNR value may be adopted by decoding the re-encoded data.

[0024]

As described above, according to the present invention, the compressed data encoded by the predetermined lossy encoding method is decoded into the data of the original method and the editing process is performed, and then the predetermined lossy encoding method is used. When encoding, history information regarding the number of decoding and encoding processes is added. Therefore, if it is estimated that the deterioration of the image quality and sound quality will be significant by referring to the history information, for example, the compression Since the source data of the data can be edited and replaced with the data, the deterioration of image quality and sound quality can be kept within a certain limit.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an apparatus according to an embodiment.

FIG. 2 is an explanatory view showing a processing process by the apparatus of the embodiment.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H04N 7/30 H04N 7/133 Z

Claims (14)

[Claims] 1. The predetermined irreversible encoding after decoding the compressed data encoded by the predetermined irreversible encoding method into the data of the original method and applying a desired editing process to the decoded data. A data editing method of encoding by a method, updating history information indicating that decoding and encoding processing has been performed, and adding to the encoded data. 2. Appropriateness of edit processing of the compressed data is determined based on history information related to the number of times of decoding and encoding the compressed data encoded by a predetermined lossy encoding method,
If suitable, the compressed data is decoded into the original data before the encoding, the data after the decoding is subjected to a desired editing process, and then the data is encoded by the predetermined irreversible encoding method and the history. A data editing method for updating information and joining the encoded data. 3. A desired self-sufficient partial data is taken out from compressed data encoded by a predetermined lossy encoding method, and the partial data is decoded into data of the original method before encoding, After the desired editing processing is performed on the decoded data, the data after the coding is updated by performing the coding by the predetermined lossy coding method and updating the history information indicating that the decoding and the coding processing has been performed. A data editing method in which the partial data is returned to the original position where the partial data existed before being taken out. 4. Editing of partial data based on history information relating to the number of times of decoding and encoding of desired self-completed partial data in compressed data encoded by a predetermined lossy encoding method. Whether or not the processing is appropriate is determined, and when it is appropriate, the partial data is taken out, the original data before encoding is decoded, and the decoded data is subjected to desired editing processing, and then the predetermined irreversible code. Encoding by the encoding method and updating the history information to join the encoded data,
A data editing method in which the partial data is returned to the original position before the extraction. 5. The predetermined lossy encoding method according to claim 1, wherein the predetermined lossy encoding method is M of a moving image encoding standard.
A data editing method, which is an encoding method for generating a PEG-compliant bitstream. 6. The method according to claim 4, wherein the partial data is not suitable for edit processing,
Partial source data corresponding to the partial data is extracted from the source data of the compressed data, the desired editing process is performed on the partial source data, and then the partial source data is encoded by the predetermined lossy encoding method and decoded and A data editing method in which history information indicating that encoding processing has been performed is updated, the encoded data is added, and this is replaced with the partial data. 7. The method according to claim 3, claim 4, or claim 6, wherein the predetermined lossy coding method is a moving picture coding standard M.
A data editing method, which is an encoding method for generating a PEG-compliant bit stream, wherein the self-completed partial data is data in units of GOP. 8. The data editing method according to claim 5, wherein the history information is added to a user data area in the bitstream. 9. Extraction means for extracting history information related to the number of times of decoding and encoding processing from compressed data encoded by a predetermined lossy encoding method, and determining suitability of editing processing based on the history information. And a decoding unit that decodes the compressed data into the original data before the lossy encoding when the determination unit determines that the compressed data is suitable for the editing process. Editing means for performing a desired editing process on the original format data; encoding means for encoding the original format data after the editing processing by the editing means by the predetermined lossy encoding method; Updating means for updating the history information corresponding to the encoding, and a subscriber for adding the history information updated by the updating means to the data encoded by the encoding means. A data editing device having: 10. Extraction means for extracting history information related to the number of times of decoding and encoding of desired partial data which is self-completed from the compressed data encoded by a predetermined lossy encoding method, and the history. Discrimination means for discriminating whether or not the edit processing of the partial data corresponding to the history information is appropriate based on information, and corresponding to the history information from the compressed data when the determination means determines that the edit processing is appropriate. Separation means for extracting the partial data, decoding means for decoding the partial data extracted by the separation means into data of the predetermined original method before lossy encoding, and of the original method decoded by the decoding means Editing means for performing desired editing processing on the data, and encoding the original method data after the editing processing by the editing means by the predetermined irreversible encoding method Encoding means, updating means for updating the history information corresponding to the decoding and encoding, and adding the history information updated by the updating means to the data encoded by the encoding means. And the original position in the compressed data that existed before the partial data was taken out by the separating means, the data encoded by the encoding means and having the history information added by the adding means. A data editing device having a restoring means for returning to the. 11. The predetermined lossy encoding method according to claim 9 or 10, wherein the predetermined lossy encoding method is M of a moving image encoding standard.
A data editing apparatus that is an encoding method for generating a PEG-compliant bitstream. 12. The partial source data corresponding to the partial data in the source data of the compressed data according to claim 10, when the determination unit determines that the partial data is not suitable for editing processing. A source separation means for extracting the partial source data extracted by the source separation means, instead of the data after decoding the partial data,
Switching means for sending to the editing means, and history management means for instructing the updating means to initialize history information when the determination means determines that the partial data is not suitable for editing processing. A data editing device having. 13. The predetermined lossy encoding method according to claim 10 or 12, wherein the predetermined lossy encoding method is M of a moving image encoding standard.
A data editing apparatus, which is an encoding method for generating a PEG-compliant bit stream, wherein the self-contained partial data is data in units of GOP. 14. The data editing device according to claim 11, wherein the joining unit joins the history information to a user data area in the bitstream.