JP2987246B2 - How to edit multimedia data - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for editing multimedia data used for editing multimedia information for games, education, and the like.

[0002]

2. Description of the Related Art At present, video data having a frame structure for games, education, and the like are encoded on a CD-ROM while being encoded for compressing the data amount and edited for combining with audio data. A recording / playback system for multimedia data to be played is under development.

[0003]

In recording the multimedia data, it is assumed that the video data and the audio data to be compressed / edited are in a synchronized state. Compression and editing. For this reason, when only audio data is changed to another data after compression / editing, such as in after recording, there is a problem that video data must be re-compressed, which lacks flexibility. Also, after filing the application of the present invention, the application is published
Japanese Patent Laid-Open No. 4-179998, "Multimedia software"
Software and temporary editing device ''
Record as a video signal with time code and
Recorded with the imcode, and recorded images and sounds
Multimedia data laid out on the time axis of the
A data editing method is disclosed. This editing method is
It says that data is edited by compressing images and sounds.
Data follows the layout pitch determined by the compression method
On the disk, for example, every 4 sectors divided by 1 sector
While the image data is distributed to empty sectors.
Attach audio data to certain image data for recording
When performing editing work such as changing, 2.5 sectors
Process the corresponding one frame image in frame units
Audio attachments cannot be made,
From a specific frame at the beginning to several frames
Is attached when changing the attached voice data in
Audio data is strictly synchronized from the beginning of the image data.
Audio and video data in units of frames.
Issues such as lack of flexibility in editing work compared to the method of reducing
It was something to have.

[0004]

SUMMARY OF THE INVENTION A multimedia data editing method according to the present invention encodes video data and audio data to be edited for data compression and associates them with each other with respect to reproduction timing. An intermediate stage of creating a possible video compressed data file and an audio compressed data file, wherein the video compressed data file assigns a time code to each frame with respect to the reproduction timing, The compressed data file is created by adding a recording start time code for enabling the mutual correspondence with respect to the reproduction timing, and creating the compressed data file in one step from the bit rate of audio data and the frame rate of video data determined by the data compression mode. For video data of frame Calculating the bit amount of audio data to be added, dividing the audio data with the calculated bit amount starting from the recording start time code, and dividing the video data and audio data based on the time code included in the video data of each frame. Final step of creating a multimedia data file containing video data and audio data by combining the frames.

[0005]

The method for editing multimedia data according to the present invention is an intermediate stage for creating a video compressed data file and an audio compressed data file including information for enabling mutual association with respect to reproduction timing, The video compressed data file is provided with a time code for enabling each frame to be associated with each other with respect to a reproduction timing, and the audio compressed data file is provided with a recording start time code for allowing each other with respect to a reproduction timing. , And each of the compressed data files created in this intermediate stage does not necessarily have to be created simultaneously. For this reason, when compressing and editing video data and audio data and changing only audio data to another data, such as after recording,
After re-creating the compressed data file for only this other audio data, only the final stage of combining with the already-compressed video compressed data file needs to be repeated, which has the advantage of being highly versatile. Hereinafter, the operation of the present invention will be described in more detail with reference to examples. In the description of the embodiment, the video compressed data file is a video capture file, the audio compressed data file is an audio capture file, and an attribute data file that records information for enabling mutual association with respect to playback timing is an attribute. Call it a file.

[0006]

FIG. 1 is a block diagram showing the configuration of a multimedia editing apparatus according to an embodiment of the present invention.
Is an A / D converter, 2, 5 are time code (TC) writing circuits, 3 is a video encoder, 6 is an audio encoder, 7 is a time code reading circuit, 8 is a host computer, 9 is a bus, and 10 is a memory. . Further, 11 is a buffer memory, 12 is a video decoder, and 13 and 15 are D /
An A converter, 14 is an audio decoder, and 16 is a monitor.

The A / D converters 1 and 4 and the time code reading circuit 7 are provided with analog video data, analog audio data, and time code (TC) of a frame configuration from a commercial video tape recorder (VTR). Are supplied. Analog video data supplied from the tape recorder is converted into digital video data by the A / D converter 1, written with a time code by a time code writing circuit 2, and encoded by a video encoder 3 for data compression. , Ie, hybrid coding that combines discrete cosine transform, quantization, and variable length coding.
The compressed video data is transferred to the host computer 8 via the bus 9, where it is subjected to various kinds of editing, and then temporarily written to the memory 10 via the bus 9 as a video capture file.

[0008] The analog data supplied from the tape recorder
The audio data is converted into digital audio data by the A / D converter 4, the time code is written by the time code writing circuit 5, and the audio encoder 3 performs encoding by ADPCM for data compression. The compressed audio data is transferred to the host computer 8 via the bus 9, where it is subjected to various kinds of editing, and then temporarily written to the memory 10 as an audio capture file via the bus 9.

The creation of the video capture file and the audio capture file and the writing to the memory 10 are performed by first creating the video capture file and writing to the memory 10, and then the audio capture file.
This is performed in two steps, such as the creation of a capture file and the writing to the memory 10. As shown in FIG. 2, the video capture file includes a video data file and a video attribute file. The audio capture file is composed of an audio data file and an audio attribute file as shown in FIG.

[0010] Video data files constituting the video capture file shown in FIG. 2, as shown in FIG. 4, frame # 1, the variable length organized in frames as frame # 2 ··· Including block data,
A fixed length header is added to the head of each. Here, a block is a unit area in a frame that is equally divided prior to the discrete cosine transform. The fixed-length header has a time code (TC), a video type (T) indicating whether the video data is a moving image or a still image, and a frame size indicating the number of horizontal and vertical pixels of the frame (Y signal). (DX, DY) and a quantization table (QY, QC) for recording a quantization table applied to each of the Y signal and the C signal in the order of block scanning. For quantization in hybrid coding, a quantization table that can be changed in frame units is applied. At the time of decoding, an inverse quantization table is generated for each frame from the quantization table, and inverse quantization corresponding to the quantization applied at the time of encoding is performed.

The video attribute file constituting the video capture file shown in FIG. 2 is shown in FIG.
As shown in the figure, the part added only to the first frame,
It is composed of a part created for each frame. The portion added to only the first frame is composed of a designated frame rate (FR) designated by the user at the time of compression, a designated bit rate (BR), and a spare area. The portion created for each frame is a time code (TC) including time information indicating the elapsed time from the reference time in hours, minutes, and seconds and a serial number of the frame, and is a moving image or a still image. Video type (T), frame holding time (F),
The frame size (DX, DY), the capture position (X, Y) indicating the start position of the compression area specified by the user during compression, and the data length (DL) indicating the total amount of compressed data for one frame in bytes. It is composed of The frame maintenance time (F) indicates how many frames are held during reproduction and display based on 30 frames per second. For example, when compressing the original moving image at a frame rate of 30 frames per second while thinning it out to 15 frames per second, “2” is designated as the frame holding time (F) during reproduction.

The audio data file constituting the audio capture file shown in FIG. 3 is composed of only compressed audio data, and has no header. As shown in FIG. 6, the audio attribute file includes a compression mode (M), a recording time (RT) indicated by hours, minutes, and seconds, a time code (STC) at the start of recording, and a data length (DL). It is composed of According to the present embodiment, the compression mode (M) of the audio data is the subband ADPCM, 16 KHz.
ADPCM, 8 kHz ADPCM, 4 kHz AD
There are four types of PCM.

The host computer 8 includes, in addition to the above-described video capture file and audio capture file, various parameters necessary for combining them to create a combination file which is multimedia information. A parameter file as shown in FIG.
Record at 0. The above video capture file,
FIG. 8 shows the relationship between the audio capture file, the parameter file, and the combination file.

In the parameter file shown in FIG.
“H” is information for specifying a recording destination channel. For video data, only “V0” of one channel can be specified, and for audio data, “A0” to “A1”
16 channels up to "5" can be designated. "VFIL
"E" is the file name of the video capture file, A
"FILE" is the file name of the audio capture file. “STIME” is information that specifies the recording start time of the audio capture file, and is specified by the hour, minute, second, and frame number with reference to the beginning of the combination file. “SBYTE” is a start byte that designates from which byte the recording of audio data in the combination file is to be started with the beginning (0th byte) of the audio capture file as a reference. "RBYTE" is information that points to the total number of recorded bytes of audio data. “FIN” and “FOUT” are information for specifying the fade-in speed and the fade-out speed of the audio, respectively.

A combination file created by the host computer 8 in accordance with the relationship shown in FIG. 8 and recorded in the memory 10 is constructed in units of video data files as shown in FIG. Is a two-byte start code added to the head of.
“DT” is 1-byte information that specifies the data type. As shown in FIG. 10, the data type (moving image / still image / audio), the channel number, and whether or not the subsequent data exists in the frame. Includes the indicated link bit. “DL” in FIG. 9 indicates the data length and indicates the total number of bytes of the data. “DATA” is compressed variable-length video data or audio data. "BL" is a variable-length blank area, and dummy data of all zeros is recorded at the end of the combination file such that the size of the combination file is an integral multiple of the number of bytes of one sector of the CD-ROM.

The host computer 8 synchronizes video data and audio data on a frame basis when creating the combination file. That is,
The host computer 8 adds one frame of video data to the audio data bit rate determined by the compression mode (M) included in the audio attribute file and the frame rate (FR) included at the beginning of the video attribute file. The bit amount of audio data to be calculated is calculated, and the recording start time code (ST
C), the video data and the audio data are combined in frame units based on the time code (TC) included in the header of the video data of each frame while dividing the audio data by the calculated bit amount from the starting point. Synchronize video data and audio data.

As shown in FIG. 11, the combination file created as described above is hierarchized by clips, scenes, and chapters, and an index is added to the beginning. A clip is a minimum recording unit including variable-length data corresponding to an integral multiple (for example, 225) of recording capacity of the minimum access unit (sector) of a CD-ROM serving as a recording medium. A scene is formed, and a plurality of scenes are collected to form a chapter.

As the data is hierarchized, the index added to the top of the data is also hierarchized as shown in FIGS. The root index arranged at the head of the index indicates the recording address of the chapter index of each chapter and the number of exclusive sectors. As shown in FIG. 13, the chapter indexes arranged after the root index are arranged in order from the first chapter # 1 to the last chapter #N, and the chapter index of an arbitrary chapter (for example, chapter #i) is shown in FIG. As shown in FIG. 5, the number of scenes (M), the number of clips included in each scene (C1, C2... CM), and the clip index of each scene. As shown in FIG. 15, the clip index of an arbitrary scene (for example, scene # 1) includes a recording address, the number of occupied sectors, and an attribute (moving image / audio channel) for all clips included in this scene.

[0019]

As described above in detail, the multimedia data editing method according to the present invention includes an intermediate step of creating a video capture file and an audio capture file that can be associated with each other with respect to playback timing. , and since this each capture file that you create in an intermediate stage is not necessarily required to be created simultaneously, in the case to try to change only to another one audio data after compression and editing, such as after-recording, After re-creating the capture file for this other audio data only, it is only necessary to repeat the final step of combining with the already-created video capture file, and the editing work is extremely flexible.
And data compression.
Video and audio data encoded for
Data, the audio compression determined by the data compression mode.
Bit rate of video data and frame rate of video data
Audio to be added to one frame of video data from the
Calculate the bit amount of the audio data
Audio data with the calculated bit amount starting from
Data included in the video data of each frame
Video and audio data based on timecode
Are combined in frame units, so the data
One frame of video even if the compression mode is changed
Audio data added to the data in frame units
Can be managed accurately, and the burden of cumbersome editing work
Has excellent effects such as being able to significantly reduce
You.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a configuration of an editing apparatus to which a multimedia data editing method according to an embodiment of the present invention is applied.

FIG. 2 is a conceptual diagram showing a configuration of a video capture file.

FIG. 3 is a conceptual diagram showing a configuration of an audio capture file.

FIG. 4 is a conceptual diagram showing a configuration of a video data file.

FIG. 5 is a conceptual diagram showing a configuration of a video attribute file.

FIG. 6 is a conceptual diagram showing a configuration of an audio attribute file.

FIG. 7 is a conceptual diagram showing a configuration of a parameter file.

FIG. 8: video capture file, audio
FIG. 3 is a conceptual diagram for explaining a relationship among a capture file, a parameter file , and an audio combination file.

FIG. 9 is a conceptual diagram showing a configuration of a combination file.

FIG. 10 is a conceptual diagram showing a configuration of a data type.

FIG. 11 is a conceptual diagram showing a relationship between compressed data and an index.

FIG. 12 is a conceptual diagram showing a configuration of the index in FIG. 11;

FIG. 13 is a conceptual diagram showing a configuration of a chapter index in FIG.

14 is a conceptual diagram showing a configuration of a chapter index in FIG.

FIG. 15 is a conceptual diagram showing a clip index of an arbitrary chapter in FIG. 14;

[Explanation of symbols]

 2, 5 time code writing circuit 3 video encoder 6 audio encoder 7 time code reading circuit 8 host computer 10 memory 11 buffer memory 12 video decoder 14 audio decoder 16 monitor

Claims (4)

(57) [Claims] 1. A method for editing multimedia data including video data and audio data, wherein the video data and the audio data to be edited are encoded for data compression, and the reproduction timings are associated with each other. at an intermediate stage of creating the video compression data files and audio compressed data file that can be
And the video compression data file is a playback timing file.
Time code to enable mutual association
Code to each frame, and
Files can be associated with each other for playback timing.
Recording time code for recording
The intermediate stage, to calculate the bit amount of audio data to be added to one frame of video data from the bit rate and frame rate of the video data of the audio data determined by the data compression mode, as a starting point the recording start time code while separated audio data with the calculated bit amount, the video data and audio data linked in frame units based on the time code included in video data of each frame, the video data and Oh
And a final step of creating a multimedia data file containing the audio data. 2. A combination of an attribute data file recording information for enabling mutual correspondence with respect to reproduction timing and a compressed data file recording compressed data, wherein the video compressed data file and the audio compressed data file are combined. 2. The method according to claim 1, wherein
How to edit the described multimedia data. 3. The multi-function device according to claim 1, wherein the video compression data file includes a frame rate, a frame number, or a time code at the time of video compression, as the information that can be associated with each other with respect to the reproduction timing. How to edit media data. 4. The multimedia according to claim 1, wherein the audio compression data file includes an encoded data rate or a time code at the time of audio compression, as the information enabling the mutual correspondence with respect to the reproduction timing. How to edit the data.