JPH0918830A - Video editing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video editing device which is capable of performing the edition processing by a frame unit for the video data encoded for every GOP by using an inter-frame correlation. SOLUTION: In a video editing device 1, the video data recorded in an MO disk drive 16 is decoded in an MPEG decoding part 19 and the prescribed frame of the decoded video data is replaced by the other video data selected by a switch 11. The new video data including the images of the frames before and after the video data is reencoded in an MPEG encoding part 12 in a state that the original GOP frame constitution before an edition is maintained based on the signal showing the delimitation of the GOP which is inputted from the MPEG decoding part 19 and the video data is recorded in the MO disk drive 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes use of inter-frame correlation to arbitrarily select video data recorded by compression coding for each group off picture (GOP) for each predetermined number of frames. The present invention relates to a video editing device capable of appropriately performing editing processing on frames.

[0002]

2. Description of the Related Art Generally, front and rear images are similar in a continuous moving image. Therefore, when compression coding is performed for transmitting or recording a moving image, this property is used to
A method of reducing the redundancy in the time axis direction and reducing the amount of information by taking the difference between the images before and after and encoding the difference value is used.

[0003] MPEG (Moving Picture Experts Grou
Such a moving picture coding algorithm standardized by p) (hereinafter, this coding method is referred to as MPEG).
Will be described. In MPEG, an I picture (Intra-coded picture) and a P picture (Forward predictive coded picture: Predictive-coded pic) are used.
ture), B picture (bidirectional predictive coded image: Bidirect
ionally predictive-coded picture) is encoded as three types of pictures.

An I picture is a picture coded using only closed information in one image without using prediction. Therefore, the I-picture can be reconstructed with only the information of the I-picture itself when decoding.
A P picture is a frame that uses unidirectional prediction.
That is, the I picture or P picture that is a frame that was input earlier in time and has already been decoded is used as a prediction image that serves as a reference for taking the difference.

A B picture is a frame that uses bidirectional prediction, and is an I picture or P picture that is positioned earlier in time and has already been decoded as a prediction image, and a B picture that is positioned later in time and has already been decoded. Three types of images are used: I-pictures or P-pictures, and complementary images made from both. A GOP is composed of a series of pictures including one or a plurality of I pictures.
The subsequent processing such as transmission or recording is performed in units of.

This MPEG encoding will be specifically described with reference to FIG. 5A and 5B are diagrams for explaining the MPEG encoding method, FIG. 5A is a diagram showing a picture for a frame of an input image, and FIG. 5B is a diagram showing an order of transmitted code data. Note that, in FIG. 5, numbers indicate frame numbers, I, B, P indicate types of pictures, and arrows in FIG. 5A indicate prediction relationships. In the example shown in FIG. 5, one frame is composed of nine frames, frame 0 to frame 8.

In this GOP, frame 2 is an I picture, and this image is coded by this I picture only. Then, based on this I picture, P of frame 5
The picture and the P picture of frame 8 are predictively coded. Then, the B picture between them is predictively coded based on the I picture and the P picture. That is, the P picture of frame-1 and the frame 2
B picture of frame 0 and frame 1 based on the I picture of frame 3, frame 3 and frame 4 based on the I picture of frame 2 and P picture of frame 5
B pictures are predictively coded. Further, the B pictures of the frame 6 and the frame 7 are predictively coded based on the P picture of the frame 5 and the P picture of the frame 8.

In consideration of the processing order of these predictive coding and the required image at the time of decoding, the processing is performed in the frame order as shown in FIG. 5B at the time of transmission or recording.

[0009]

However, with respect to the video data coded by utilizing the inter-frame correlation as described above, some video data is edited by replacing it with another video data. There is a problem that processing cannot be performed properly. That is, in the above-described encoding method, if an editing process such as video replacement is performed on a GOP basis, the editing can be performed without relatively degrading the image quality. However, in the GOP or in a plurality of GOPs. When video is exchanged from a frame in the middle of GOP, the continuity of the GOP sequence cannot be maintained,
There is a problem that normal image decoding cannot be performed.

Therefore, an object of the present invention is to perform edit processing in arbitrary frame units on video data which is coded for each GOP using inter-frame correlation without causing deterioration of image quality. An object is to provide such a video editing device.

[0011]

Therefore, the video editing apparatus of the present invention compresses a video signal to record it on a recording medium, reproduces and decodes the recorded video signal, and compresses the recorded video signal. A video editing apparatus for compressing and recording another video signal on the above, wherein a video signal compression-encoded in GOP units consisting of a plurality of continuous frames is input by using correlation between frames, Decoding means for decoding a video signal, switching means for selectively outputting a video signal supplied from the decoding means, and a video signal input from the outside, and a video signal supplied from the switching means Based on the GOP frame structure at the time of the compression coding of the video signal before the switching process, so as to have the same frame structure as the GOP frame structure. And a Goka means.

[0012] Preferably, the decoding means outputs a GOP head pulse indicating a head frame of a GOP from an input compression-coded video signal, and the coding means supplies the supplied GOP head pulse. And the video signal supplied from the switching means is compression-encoded. Specifically, the encoding means compresses the video signal according to the MPEG method, and the decoding means decodes the compressed video signal according to the MPEG method.

Further, the video editing apparatus of the present invention compresses a video signal to record it on a recording medium, reproduces and decodes the recorded video signal, and adds another video signal on the compressed and recorded video signal. A video editing apparatus for compressing and recording a video signal, in which a video signal compressed in GOP units composed of a plurality of continuous frames is input by using the correlation between frames, and the video signal is decoded. Means, a control section for outputting a selection control signal, a video signal supplied from the decoding means, and a video signal input from the outside selectively based on the selection control signal supplied from the control section. Based on a GOP frame structure for outputting the switching means for outputting and the video signal supplied from the switching means for the compression coding of the video signal before the switching processing,
Encoding means for performing compression encoding again so as to have the same frame configuration as the OP frame configuration.

Preferably, the control section is connected to an external interface and outputs the selection control signal based on an edit signal supplied via the interface.
Also preferably, the control unit is connected to an external interface and outputs a recording control signal based on an edit signal supplied via the interface, and a video signal compression-coded based on the recording control signal. Is recorded on the recording medium. More preferably, the decoding means detects a GOP head pulse indicating the head frame of the GOP from the input compression-coded video signal, and the coding means synchronizes with the supplied GOP head pulse. Then, the video signal supplied from the switching means is compression-encoded. Specifically, the encoding means compresses the input video signal by an MPEG method, and the decoding means decodes the compression-encoded video signal by an MPEG method.

According to such a video editing apparatus of the present invention, the video data recorded on the recording medium is decoded by the decoding means, and the decoded video data is in an uncompressed state, that is, Edit processing is performed with no correlation between frames. Then, based on the signal indicating the GOP delimiter obtained at the time of decoding by the decoding means, re-encoding is performed by the encoding means while maintaining the original GOP frame structure before editing, and recorded again on the recording medium. To do.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a video editing apparatus of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing the configuration of the video editing apparatus according to this embodiment.
The video editing device 1 includes a switch 11 and an MPEG encoding unit 1.
2, the first buffer memory 13, the correction code adding unit 14,
The recording amplifier 15, the MO disk drive 16, the error correction unit 17, the second buffer memory 18, the MPEG decoding unit 19, the system controller 20, and the servo system control unit 21 are included. The video editing apparatus 1 of the present embodiment is a digital video disk recorder that uses a magneto-optical disk (MO disk) apparatus as a recording medium and compresses the same image by MPEG to record it.

First, the structure of each part will be described. The switch 11 is a selector that selects a video signal to be output to the recording system. When the video signal is normally recorded on the MO disk, the switch 11 selects the terminal a and outputs the digital video signal input from the outside to the recording system. Further, when editing or the like, the switch 11 is appropriately switched to select recording data. For example, in insert editing, when a new video signal to be inserted is selected, the switch 11 is connected to the terminal a.
When the original reproduction video signal to be inserted is selected, the switch 11 is switched to the terminal b. The select signal for controlling the switching of the switch 11 is input from the system controller 20.

The MPEG encoding unit 12 compresses and encodes the input uncompressed video signal in the MPEG format. The MPEG encoding unit 12 is based on the GOP head frame pulse of the reproduced video signal input from the MPEG decoding unit 19 when re-encoding the video signal that has been reproduced in the case of performing edit processing or the like. , So as to maintain continuity with the GOP sequence in the original video signal. The first buffer memory 13 performs rate conversion for recording the compressed video signal on the disc. The correction code adding unit 14 adds a code word for error correction.

The recording amplifier 15 is usually a means for amplifying the recording data to which the error correction code is added so as to finally record it on the MO disk. However, at the time of editing, the recording amplifier 15 selects recording data based on the recording control signal input from the system controller 20. That is, of the recording data to which the error correction code is added, only the desired data is actually M
Its output is controlled so that it is recorded on the O disk.
The selection of the data is performed on a GOP basis.

The MO disk drive 16 is a recording device for actually recording the input recording data on the MO disk. The servo system control unit 21 uses the MO disk drive 1
Controls the servo system of the disk drive of No. 6.

The error correction unit 17 performs error correction processing on the signal reproduced by the MO disk drive 16. The second buffer memory 18 performs rate conversion of the reproduced compressed video signal. Second buffer memory 18
Adjusts the rate of the compressed video signal input to the MPEG decoding unit 19 so that the reproduced image is appropriately output from the MPEG decoding unit 19.

The MPEG decoding section 19 decodes the reproduced compressed video signal and converts it into an uncompressed digital video signal. The converted digital video signal is output from the output terminal and also input to the terminal b of the switch 11 so that the editing process can be performed. Further, the MPEG decoding unit 19 generates a signal indicating the GOP head frame of the decoded uncompressed digital video signal, and MPEG
It outputs to the encoding unit 12 and the system controller 20. The processing system including the error correction unit 17 for reproducing the compressed video signal recorded on these MO discs, the second buffer memory 18, and the MPEG decoding unit 19 is called a reproduction system.

The system controller 20 is a control unit for controlling each part of the video editing apparatus 1 and the entire operation of the video editing apparatus 1, and is composed of a normal processor or the like. For example, the system controller 20 controls the servo system control unit 21 to control the operation of the MO disk drive 16. Further, the system controller 20 has an external interface unit. In the present embodiment, this interface means is RS-422. The video editing apparatus 1 is operated by an operating device such as a remote control device connected by this interface. That is, an operation signal from the outside is input to the system controller 20 via this interface section.

Further, the system controller 20 particularly generates the following control signals when, for example, performing a video editing process. First, the system controller 20 controls the timing of frame synchronization between the reproduced video signal and the input video signal, and then sends the select signal of the switch 11 from the edit signal input via an external interface such as RS-422. Generate and switch 1
Apply to 1. Further, like the select signal, the system controller 20 generates a recording control signal for selecting data to be recorded in the recording amplifier 15 based on an edit signal input from the outside through an external interface such as RS-422. . The select signal of the switch 11 and the recording control signal may be generated by one edit signal. At this time, the recording control signal delayed with respect to the select signal by the delay of the signals supplied to the MPEG encoding unit 12, the first buffer memory 13 and the correction code adding unit 14 may be generated.

Next, the operation of the video editing apparatus 1 will be described with reference to FIG.
This will be described with reference to FIGS. First, a process when insert editing is performed on a video signal having a GOP length of 2 frames will be described with reference to FIG. FIG. 2 is a timing chart showing the flow of insert edit signals when GOP length = 2 frames.

First, the MO disc on which the video signal to be edited is recorded is reproduced by the MO disc drive 16 and a reproduction output as shown in FIG. 2A is obtained. The video signal is reproduced and output in GOP units. This output data is subjected to error correction in the error correction unit 17, and then subjected to buffering and rate conversion in the second buffer memory 18, and I picture and B in frame units as shown in FIG. The compressed data consisting of pictures is arranged. This compressed data is MPEG
The data is decoded by the decoding unit 19 and becomes an uncompressed data stream as shown in FIG. At this time, a pulse indicating the first frame of the GOP as shown in FIG. 2D is generated and input to the MPEG encoding unit 12 and the system controller 20. This pulse
When the compressed data input by the MPEG decoding unit 19 is decoded, the pulse is generated when the first frame of the GOP, that is, the I picture is detected. For example, this pulse is generated at the timing of outputting non-compressed data.
Output from Incidentally, the MPEG encoding unit 12 and the system controller 20 operate in synchronization with this pulse.

Insertion editing is performed on the reproduced video signal as shown in FIG. 2C to replace the IN point and the OUT point with another video signal. That is, FIG. 2 (E)
Frames V2, V of the insert video signal as shown in
2 frames of No. 3 are inserted into the second frame of GOP1 and the first frame of GOP2 of the reproduced video signal.
In this case, the system controller 20 first manages the timing of frame synchronization, and then, based on the edit signal input through the external interface, FIG.
A recording data select signal as shown in (1) is generated and the switch 11 is applied. In the switch 11, the recording data is selected based on this select signal. That is, the switch 11 has the terminal a only between the IN point and the OUT point.
The signals of frames V2 and V3 of the insert video signal input from the outside are output to the recording system. During the other period, the switch 11 is switched to be connected to the terminal b, and the reproduced uncompressed data stream is output to the recording system. As a result, an uncompressed data stream as shown in FIG. 2G is input to the recording system.

This uncompressed data stream is again MP
The EG encoding unit 12 compresses the compressed data stream as shown in FIG. In addition, this MPE
When the non-compressed data stream is re-encoded by the G encoding unit 12, it is necessary to perform encoding so as to maintain the GOP sequence in the original reproduction stream, which is input from the MPEG decoding unit 19. Using the GOP head frame pulse shown in FIG. 2D, the MPEG encoding unit 12 performs encoding that maintains the GOP sequence. The compressed video data stream is rate-converted in the first buffer memory 13, and the correction code adding unit 14
Then, an error correction code is added to obtain compressed data for each GOP recordable on the MO disc as shown in FIG. 2 (I).

Then, in the recording amplifier 15, FIG.
Based on the recording control signal supplied from the system controller 20 as shown in (J), only the desired GOP data is recorded on the MO disc by the MO disc drive 16. The recording control signal is generated by the system controller 20 based on an edit signal input via an external interface such as RS-422. FIG.
In the above example, the video of GOP1 and GOP2 is re-recorded by the newly encoded video signal.

Next, insert editing when the GOP length is 4 frames will be described with reference to FIGS. 3 and 4. FIG. 3 and FIG. 4 are timing charts showing the signal flow of insert editing when GOP length = 4 frames. Even when the GOP length is 4 frames, the basic operation is the same as when the GOP length is 2 frames described above.

First, when the video signal to be edited is reproduced in the MO disc drive 16, a reproduction output as shown in FIG. 3A is obtained. This output data is error-corrected in the error correction unit 17, buffered and rate-converted in the second buffer memory 18, and the compressed data in units of frames as shown in FIG. 3B is converted. . Furthermore, this compressed data is MP
The data is decoded by the EG decoding unit 19 and becomes an uncompressed data stream as shown in FIG. At this time M
The GOP head frame pulse generated by the PEG decoding unit 19 is as shown in FIG.
2 and the system controller 20 and operates in synchronization with this pulse. This pulse is used when decoding the compressed data input to the MPEG decoding unit 19.
This pulse is generated when the first frame of the GOP, that is, an I picture is detected, and this pulse is output from the MPEG decoding unit 19 at the timing of outputting uncompressed data, for example.

When such a reproduced video signal is replaced with another video signal as shown in FIG. 3 (E) between the IN point and the OUT point shown in FIG. 3 (C), the system controller 20 first , And generates a recording data select signal as shown in FIG. 3 (F) based on the edit signal input via the external interface. Based on this select signal, the switch 11 appropriately selects the input data,
As shown in (G) and FIG. 4 (G), an uncompressed data stream with a new video signal inserted is obtained. This uncompressed data stream is again compressed by the MPEG encoding unit 12 to generate a compressed data stream as shown in FIG. An error correction code is added at 14 to obtain compressed data for each GOP recordable on the MO disk as shown in FIG. 4 (I).

Then, in the recording amplifier 15, FIG.
Based on the recording control signal as shown in (J), the desired G
Only OP data is recorded on the MO disc by the MO disc drive 16. The recording control signal is generated by the system controller 20 based on the edit signal input via the external interface. In the example of FIG. 3, the video of GOP3 is not actually newly inserted, but since the B picture of GOP3 is affected by the insert, this GOP3 is also affected by the newly encoded video signal. It has been recorded again.

When such insert editing as illustrated in FIGS. 2 to 4 is performed, the IN point and the OUT point are located in the middle of the GOP of the reproduced video signal, and the MO
Since recording on the disc is performed in GOP units, this I
When only the image between the N point and the OUT point is compressed and recorded,
The GOP sequence cannot be continuous. However, in the video editing apparatus 1 of the present embodiment, input data is appropriately selected at the stage of the uncompressed data stream, inserted into the reproduction data, and re-encoded, so that the GOP sequence is maintained and the GOP sequence is maintained. Insert editing can be performed so that switching of images occurs.

The video editing apparatus of the present invention is not limited to this embodiment, and various modifications can be made.
For example, the configuration of the video editing device is not limited to the configuration shown in FIG. 1 and may be any configuration. Specifically, the rate conversion by the first buffer memory and the second buffer memory, the error correction in the correction code adding unit and the error correction unit, and the like may be performed using arbitrary methods, and the input / output data may be predetermined. It may not be necessary when the condition of is satisfied. Further, the specific circuit configuration of the recording amplifier and the system controller may be any configuration.
Further, the specific circuit configuration of the servo system control unit that controls the MO disk drive may be any configuration.

In this embodiment, the MO disk is used as the recording medium for recording the video data, but the recording medium is not limited to this. For example, any recording medium such as a hard magnetic disc, a compact disc (CD), a digital video disc (DVD), etc. may be used as the recording medium of the video data. Further, the editing processing in the video editing apparatus according to the present embodiment has been described as the insert editing in which a predetermined frame of the original video data is replaced with another video data, but the present invention is not limited to this and any editing processing is possible. You may go. For example, an editing process may be performed such that a special effect is applied to a predetermined frame of original video data, a predetermined section is cut, or completely new video data is inserted.

[0037]

According to the video editing apparatus of the present invention, by using the correlation between frames, it is possible to perform the editing process on a frame-by-frame basis even for video data which is compression-encoded on a GOP basis. . When the editing is performed, the image quality of the edited image and the images before and after it are hardly deteriorated. Therefore, it is possible to provide a video editing apparatus capable of appropriately performing desired editing processing on video data recorded by the above method.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a video editing apparatus according to an embodiment of the present invention.

FIG. 2 is a timing chart showing a signal flow when insert editing is performed on a video signal having a GOP length of 2 frames in the video editing apparatus shown in FIG.
(A) shows a disc playback signal, (B) shows compressed playback data after rate conversion, (C) shows non-compressed playback data, (D) shows a GOP head frame pulse, (E) is a diagram showing an insert video signal, (F)
Shows a data select signal, (G) shows a video signal after editing, (H) shows compressed recording data before rate conversion, (I) shows a disc recording signal, and (J).
FIG. 6 is a diagram showing a recording control signal.

3 is a timing chart showing a signal flow when insert editing is performed on a video signal having a GOP length of 4 frames in the video editing apparatus shown in FIG.
(A) shows a disc playback signal, (B) shows compressed playback data after rate conversion, (C) shows non-compressed playback data, (D) shows a GOP head frame pulse, (E) is a diagram showing an insert video signal, (F)
Is a diagram showing a data select signal, and (G) is a diagram showing a video signal after editing.

FIG. 4 is a timing chart showing a signal flow when insert editing is performed on a video signal having a GOP length of 4 frames in the video editing apparatus shown in FIG.
(G) is a diagram showing a video signal after editing, (H) is a diagram showing compressed recording data before rate conversion, (I) is a diagram showing a disc recording signal, and (J) is a diagram showing a recording control signal. .

[Fig. 5] Fig. 5 is a diagram illustrating a basic method of a moving image encoding method according to MPEG, (A) showing a picture for a frame of an input image, and (B) showing the order of transmitted encoded data. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Video editing device, 11 ... Switch, 12 ... MPEG encoding part, 13 ... 1st buffer memory, 14 ... Correction code addition part, 15 ... Recording amplifier, 16 ... MO disk drive, 17 ... Error correction part, 18 ... second buffer memory, 19 ... MPEG decoding section, 20 ... system controller, 21 ... servo system control section

Claims (8)

[Claims] 1. A video signal is compressed and recorded on a recording medium,
In a video editing device that reproduces and decodes a recorded video signal and compresses and records another video signal on top of the compressed and recorded video signal, the correlation between the frames is used to A video signal compressed and encoded in units of GOP (Group of Pictures) is input, and a decoding unit for decoding the video signal, a video signal supplied from the decoding unit, and an external input Switching means for selectively outputting the video signal to be generated, and G for compressing and encoding the video signal supplied from the switching means before the switching processing.
A video editing apparatus having a coding means for compressing and coding again based on an OP frame structure so as to have the same frame structure as the GOP frame structure. 2. The decoding means is a GOP indicating a head frame of a GOP from an input compression-coded video signal.
The video editing apparatus according to claim 1, wherein a head pulse is output, and the encoding means compression-encodes the supplied GOP head pulse and the video signal supplied from the switching means. 3. The encoding means MPE the video signal.
The video editing apparatus according to claim 1, wherein the video data is compressed by a G system, and the decoding means decodes the compressed video signal by an MPEG system. 4. A video signal is compressed and recorded on a recording medium,
In a video editing device that reproduces and decodes a recorded video signal and compresses and records another video signal on top of the compressed and recorded video signal, the correlation between the frames is used to A video signal compressed in units of GOP (Group of Pictures) is input, a decoding means for decoding the video signal, a control section for outputting a selection control signal, and the decoding means are supplied. A video signal supplied from the control unit, and a video signal supplied from the switching unit for selectively outputting the video signal supplied from the control unit based on a selection control signal supplied from the control unit. G when the compression encoding of the video signal of
A video editing apparatus having a coding means for compressing and coding again based on an OP frame structure so as to have the same frame structure as the GOP frame structure. 5. The video editing apparatus according to claim 4, wherein the control section is connected to an external interface and outputs the selection control signal based on an edit signal supplied via the interface. 6. The control unit is connected to an external interface and outputs a recording control signal based on an edit signal supplied through the interface, and a video signal compression-encoded based on the recording control signal. The video editing apparatus according to claim 4, wherein is recorded on the recording medium. 7. The GOP indicating the head frame of the GOP from the input compression-coded video signal.
5. The video editing apparatus according to claim 4, wherein a head pulse is detected, and the encoding means compressively encodes the video signal supplied from the switching means in synchronization with the supplied GOP head pulse. 8. The encoding means compresses the inputted video signal by an MPEG system, and the decoding means compresses the compression-encoded video signal by M.
The video editing apparatus according to claim 4, wherein the video editing apparatus performs decoding by the PEG method.