JPH04239280A - Editing method for digital vtr - Google Patents

Abstract

PURPOSE:To edit a picture signal by a field unit, even as for a digital VTR which records and reproduces a picture signal by compression-encoding it by an (n) frame unit. CONSTITUTION:The digital picture signal of the joint of the picture signal joining the picture signal to be newly recorded, is stored in memories 14 and 43 by the field unit, at the time of a preview preceding a real editing operation. At the time point of the joint on the real edition, the (n) frame of the unit of the compression-encoding is constituted of both the picture signal read from these memories and the picture signal to be recorded in order to record the picture signal.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an editing method in a digital VTR that performs compression encoding that completes in n frames (n is an integer, n≧1) and records it on a recording medium. Regarding something that allows editing on a field by field basis.

0002

[Prior Art] Conventionally, digital VTRs perform error correction processing that is completed on a field-by-field basis without using compression encoding.
With this method, it is possible to easily associate each field of a digital image signal recorded on a tape with a recording track on the tape. Therefore, this kind of digital V
With TR, digital image signals from a plurality of digital VTRs can be easily edited field by field by simply managing time codes.

0003

[Problems to be Solved by the Invention] However, in digital VTRs, such as consumer digital VTRs, which require data compression due to recording rate limitations, generally,
A compression encoding process that is completed in one to multiple frames is performed,
It is divided into multiple tracks and recorded. In this case,
Since compression encoding of image data is not completed field by field, it is not possible to easily associate each field with a recording track position on the tape.

[0004] For this reason, in digital VTRs that perform this type of compression encoding processing, it has been difficult to edit on a field-by-field basis.

[0005] In view of the above points, the present invention has made it possible to easily perform field-by-field editing even in digital VTRs that use compression encoding processing that is completed in units of one or more frames during recording processing. The present invention provides a method.

[0006]

[Means for Solving the Problems] In order to achieve the above object, in the present invention, when performing splice editing, the digital VTR is capable of storing digital image signals for n frames of compression encoding units. A memory means is provided, and prior to editing and recording of connecting the reproduced digital image signal of the digital VTR with another digital image signal, the joint position of the images is stored, and the reproduced digital image is stored in the memory means. Of the n frames including the joint of the unit of compression encoding of the signal, the digital image signal in field units before the joint is stored, and at the time of editing and recording, the digital VTR is connected to the other digital image signal. At the same time, the digital VTR is put into a recording state at the joint, and writing of the other digital image signal into the memory means is started, and the data is synthesized with the stored data, and the compressed code is n frames are formed in units of
After that, the other digital image signals are sequentially written into the memory means in units of n frames of compression encoding, and then compressed and encoded by the digital VTR. and record it.

[0007] Furthermore, when performing insert editing, a first memory means and a second memory means capable of storing digital image signals for n frames of the compression encoding unit are prepared, and the digital Prior to insert editing recording for inserting another digital image signal into the reproduced digital image signal of the VTR, the insertion start and end positions are stored, and the reproduction data is stored in the first memory means. Of the n frames including the start point of the unit of compression encoding of the digital image signal, the digital image signal in field units before the start point is stored in the second memory means, and the compressed image signal of the reproduced digital image signal is Of the n frames including the end point of the encoding unit, field unit digital image signals after the end point are stored, and the digital VTR is synchronized with the other digital image signals at the time of insert editing recording. At the starting point, the digital VTR is put into a recording state, and writing of the other digital image signal into the first memory means is started, and the data is combined with the stored data, and the compressed code is form a unit of n frames and convert it into the digital V
The other digital image signals are compressed and encoded by the TR and then recorded. After that, the other digital image signals are sequentially written into the memory means in units of n frames of compression and encoding, and then compressed and encoded by the digital VTR. At the end point, the other digital image signal immediately before the end point and the digital image signal read from the second memory means are combined to form n frames of the unit of compression encoding. , record this and end the insert editing.

[0008]

[Operation] The reproduced digital image signal of the digital VTR is a digital image signal that has been converted back into a time-series signal in a raster scanning format. In this invention, when performing joint editing or insert editing on this reproduced digital image signal and, for example, a reproduced digital image signal of another digital VTR, the joint ( (including the start and end points of insert editing) is stored in advance in field units smaller than n frames, which are units of compression encoding.

[0009] During the actual editing operation, the image data stored in the first and second memory means is used at the joint, and is combined with other digital image signals to be newly recorded and compressed. A unit of encoding of n frames is formed and recorded.

[0010] Therefore, editing operations such as joining image signals can be performed on a field-by-field basis.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the editing method for a digital VTR according to the present invention will be described below with reference to the drawings. The following example shows ADRC, which was proposed by the applicant of the present application, as a compression encoding method used in a digital VTR.
(Adaptive Dynamic RangeCo
ding; JP-A-61-144989, JP-A-6
1-144990, JP-A-62-92620).

[0012] The ADRC system is an encoding system that utilizes the strong spatio-temporal correlation of television image signals. That is, when an image for one screen is divided into blocks, each block often has only a small dynamic range due to local correlation. Therefore, in this ADRC method, the image is divided into blocks, the dynamic range of each block is determined, and the pixel data is adaptively re-encoded to reduce each pixel data to a smaller number of bits than the original number of bits. Can be compressed.

[0013] Methods for dividing an image into blocks include division only in the horizontal line direction (one-dimensional ADRC), and division into rectangular areas in both horizontal and vertical directions (two-dimensional ADRC).
), and further division (three-dimensional ADRC) considering a spatial region spanning a plurality of frames has been proposed (see the above-mentioned publications).

[0014] In three-dimensional ADRC, motion detection between two frames is performed for each block, and even more efficient encoding can be achieved by performing so-called frame dropping in static blocks, for example, without transmitting data of subsequent frames. In the case of this three-dimensional ADRC, each block requires a 1-bit motion information code, but in a still area, data can be compressed to 1/2, resulting in high compression efficiency.

[0015] The digital VTR of the example described below performs three-dimensional ADRC, and therefore the unit of compression encoding of the image signal is two frames, and the image signal of the two frames is divided into four tracks. recorded on tape.

FIG. 1 shows an embodiment of a digital VTR for implementing the editing method according to the present invention.

The digital VTR of this example includes a recording system 10, a reproduction system 20, an editing control section 41, an editing point input key 42, and an out point memory 43.

The recording system 10 is constructed as follows. That is, a raster scanning format image signal inputted through the input terminal 11 is converted into a digital image signal by the A/D converter 12 . This digital image signal is supplied to the first input terminal a of the editing input switching circuit 13.

The digital image signal obtained from this editing input switching circuit 13 is supplied to a blocking memory 14. This blocking memory 14 has a capacity to record two frames worth of digital image signals, and the image data is divided into blocks consisting of, for example, (4 pixels in the horizontal direction) x (4 pixels (4 lines) in the vertical direction). be done. The data of each divided block is then processed by a shuffling circuit 15.
After each block is distributed in two frames according to a predetermined rule, it is supplied to a compression encoding circuit 16 and subjected to three-dimensional ADRC compression encoding processing.

The compressed and encoded data from this compression encoding circuit 16 is supplied to a parity addition circuit 17, and
Parity data for error correction is generated and added. Then, the compressed image data to which this parity data has been added is supplied to the recording head HR via the recording modulation circuit 18 and the recording amplifier 19, and two frames of image data are recorded on the tape, for example, four times. recorded as a recording track.

The digital image signal compressed and encoded by three-dimensional ADRC and recorded as described above is reproduced by the reproduction system 20 and restored to the original raster scanning format image signal.

That is, the tape (
(not shown) is supplied to a reproduction equalizer and data restoration circuit 22 via a reproduction amplifier 21, and is restored to digital data. This restored digital data undergoes error correction in the error correction circuit 23 using the error correction code in the reproduced digital data.

The output data of this error correction circuit 23 is
The data is supplied to the compression/decoding circuit 24, and three-dimensional ADRC decoding processing is performed on each two frames of image data in units of blocks, which are the minimum processing units for encoding. The decoded block data is then sent to the deshuffling circuit 25.
is applied to restore the two frame blocks to their original order. The signal is then supplied to the block decomposition circuit 26 and converted into the original time-series digital image signal in raster scanning format.

The output data of the block decomposition circuit 26 is supplied to an error correction circuit 27, and the image data whose errors could not be corrected by the error correction circuit 23 is corrected by interpolation processing using surrounding image data.

The reproduced digital image signal VA from the error correction circuit 27 is supplied to one input terminal A of the editing monitor switching circuit 28, and is also supplied to the out point memory 43 and the third input terminal of the input switching circuit 13. c. The digital image signal from the monitor switching circuit 28 is supplied to the D/A converter 29 and converted back to an analog image signal, and this analog image signal is supplied to the monitor television receiver via the output terminal 31.

As mentioned above, the digital image data immediately after being played back from the tape is a signal in units of two frames, but the two frames of image data are divided into blocks and divided into a plurality of blocks. It is made up of blocks. Each block is compressed by ADRC block encoding, and each block data is distributed within the two frames according to a predetermined rule. Therefore, when performing editing processing on the image signal at this stage, editing can only be performed in units of two frames.

However, the output signal of the de-shuffling circuit 27 is a raster scanning format signal that is a time series of the original image signal. If this raster scanning format time-series signal is used, field-by-field editing can be easily performed, as will be described later.

In this example, editing work such as so-called assembly editing (joint editing) or insert editing is performed in this digital VTR, and other digital image signals, such as those of other digital VTRs, are input through the input terminal 44.
A reproduced digital image signal VB (in raster scan format) is inputted from the computer. This digital image signal VB
is supplied to the second input terminal b of the switching circuit 13 and also supplied to the other input terminal B of the switching circuit 28.

The editing control unit 41 controls the editing work, and switches between the preview mode, the recording mode, and the playback mode in the actual editing mode of this digital VTR as described later using a mode control signal M.
D, and furthermore, the switching control signals SE1 and SE2
The switching circuits 13 and 28 are controlled in this way. Further, in response to an input operation from the edit point input key 42, the designated edit point, that is, the joint position between the digital image signal VA and the digital image signal VB is stored.

The editing control unit 41 receives a time code TA corresponding to the positional information on the tape obtained from the signal reproduced by the reproduction system 20 of this digital VTR, and a digital image signal VB from the input terminal 44. A time code TB from another digital VTR is supplied. The joint position between the digital image signal VA and the digital image signal VB, which is the edit point input using the edit point input key 42, is stored as this time code.

Although not shown, the editing control section 41 also controls the synchronized operation of the digital VTR shown in FIG. 1 and another digital VTR that inputs the digital image signal VB from the input terminal 44. As a method of synchronous operation,
There is a method in which the digital VTR shown in Fig. 1 is servo-controlled based on the synchronizing signal to operate the digital VTR in synchronization with the editing point, that is, a synchronizing signal when another digital VTR is placed in the playback state. A synchronizing signal when in the playback state of the digital VTR is supplied to other digital VTRs.
There is a method of servo-controlling the TR based on the synchronization signal to perform synchronous operation.

The out-point memory 43 is used during insert editing as will be described later, and in this example, the out-point memory 43 has a maximum capacity of n
It is sufficient to have a capacity of (frame) - (1 field), and in this example, it has a capacity of 1.5 frames (3 fields). Writing and reading from this memory 43 is controlled by a memory control signal WR from the editing control section 41. The image data read from this memory 43 is supplied to the fourth input terminal d of the input switching circuit 13.

Next, operations during editing will be explained using insert editing as an example, with reference to FIGS. 2 to 4.

[Setting the editing point] Now, let us assume that the digital VTR configured as shown in FIG. , a case will be considered in which a reproduced image of VTR-B is inserted into a part of the reproduced image of VTR-A.

First, by monitoring the reproduced image signals from the recorded tapes loaded in the VTR-A and VTR-B,
Determine the in point IN and out point OUT of the insert,
An input operation is performed using the edit point input key 42, and the data of the input point IN and out point OUT is stored in the edit control section 41.

At this time, the track patterns on the tapes loaded in VTR-A and VTR-B are as shown in FIG. FIG. 2A shows the track pattern on the tape loaded in VTR-A before editing, and FIG. 2B shows the track pattern on the tape before editing.
It shows a track pattern on a tape loaded in a VTR-B. Further, FIG. 2C shows a track pattern on the tape loaded in the VTR-A after insert editing. In FIG. 2, the vertical dotted line indicates the digital image signal VA, and the horizontal dotted line indicates the digital image signal VB.

In this case, as shown in FIGS. 2A and 2B, if the in point and out point are in the middle of two frames of the unit of compression encoding, the in point and out point are The two frames of data in the unit of compression encoding include:
It is composed of a reproduced digital image signal VA of VTR-A and a reproduced digital image signal VB of VTR-B. For example, two frames of data, which is the unit of compression encoding at the in point, consists of two fields of the reproduced digital image signal VA and two fields of the reproduced digital image signal VB, and the unit of compression encoding at the out point. The two frames of data are composed of three fields of the reproduced digital image signal VB and one field of the reproduced digital image signal VA.

[Preview] Next, prior to the actual editing operation, a preview is performed based on the set in point and out point data.

[0039] That is, VTR-A and VTR-B are
After being rewound by a predetermined length from the in point, they are synchronized and enter a playback state. At this time, the monitor switching circuit 28 is switched to one input terminal A up to the in point, and as shown in FIG. 3C, the monitor image of the reproduced digital image signal VA (see FIG. 3A) of the VTR-A is displayed on the machine.

Further, up to the in point, the input switching circuit 13 is switched to the third input terminal c, and the reproduced digital image signal VA is supplied to the blocking memory 14. The block memory 14 includes an editing control section 4.
1, at the in point IN, the reproduced digital image signal V including this in point IN is generated as shown in FIG.
Among the two frames of compression encoding unit of A, the in point IN
The previous two fields of digital image signals VA are written and stored.

[0041] Then, at the in point IN, the monitor switching circuit 2
8 is switched to the other input end B side, and the out point OU
The reproduced digital image signal VB of the VTR-B up to T (Fig. 3B
(see) is displayed on the monitor receiver.

Next, when the out point OUT is reached, the monitor switching circuit 28 is switched again to the input terminal A side, and thereafter the monitor output image is the reproduced digital image signal VA of the VTR-A. Then, as shown in FIG. 3E, among the two frames of the unit of compression encoding of the reproduced digital image signal VA including this out point OUT, one field of the reproduced digital image signal VA after the out point OUT is stored in the out point memory. 43 and stored.

[Actual Editing] Next, the actual editing operation will be explained with reference to the time chart of FIG. This editing operation is performed as follows under the control of the editing control section 41.

[0044] First, the VTR-A is rewound from the in point IN to a preset number of seconds before, and then placed in a playback state. Similarly, VTR-B is also set to playback in synchronization with VTR-A.

In this case, there is generally a mechanical delay, so-called system delay, which is determined for each VTR for recording processing, so simply rewinding the same tape length and running in synchronization will result in a difference from the reproduced signal. Recording cannot be performed at the target track position on the tape indicated by the obtained time code. Therefore, the two-frame signal of the unit of compression encoding at the in point IN and the VTR to be recorded are
In consideration of the system delay of -A, VTR-B is rewound and played back in synchronization with VTR-A.

At this time, the input switching circuit 13
It is switched to the second input terminal b. However, VTR
-A is not in the recording mode, and the block memory 14 is not in either the writing or reading state due to the control signal from the editing control unit 41.

Then, at the in point IN, that is, the first image data of the inserted image of the reproduced image signal of the VTR-B, the VTR-A is put into the recording mode, and writing to the block memory 14 is started, and the It is combined with the written image signal VA of VTR-A to form two frames of data, which is the unit of compression encoding at this in point IN. This image data is then divided into blocks, compressed and encoded as described above, and sent to the recording system 10.
is recorded on the tape of VTR-A. After this IN point IN, the reproduced digital image signal VB of the VTR-B is sequentially divided into blocks in the blocking memory 14 two frames at a time, similarly compressed and encoded, and recorded on the tape of the VTR-A.

Next, at a point before the out point taking into account the data position of the two-frame compression coding unit at the out point OUT and the system delay of the VTR-A, the data is stored from the out point memory 43 at the time of preview. The reproduced digital image signal VA of one field of the VTR-A that has been written in advance is read out, and the input switching circuit 13
is switched to the input terminal d of. Then, it is synthesized with the reproduced digital image signal VB of VTR-B (3 fields of 2 compression-encoded frames) of VTR-B up until that point in the blocking memory 14, and this is recorded on the tape of VTR-A. -A becomes a stop state and editing ends.

As described above, according to the present invention, 2
Even in digital VTRs that perform compression encoding that completes frames, editing can be performed in units of fields.

The above example is an example of insert editing, but for example, in the case of so-called assembly editing in which the reproduced image signal VB of VTR-B is connected after the reproduced image signal VA of VTR-A, It is only necessary to pay attention to the in point IN in the above example, and editing can be performed in units of fields in exactly the same way.

[0051] In the above example, compression encoding is performed in units of two frames, but the processing unit of compression encoding may be one frame, or even three or more frames. good.

Further, the editing control unit 41 is provided separately as an editing device, and this editing device controls the VTR-
It is also possible to control A and VTR-B to perform editing operations as described above. In that case,
Synchronous operation of VTR-A and VTR-B can be performed using a reference synchronization signal from this editing device as a reference.

Furthermore, the memory for storing the image signal at the joint at the in point IN may of course be provided separately, instead of being shared by the blocking memory as in the example of FIG.

Further, the other digital image signal inputted from the terminal 44 is not limited to a digital image signal reproduced from another digital VTR, but may be an image signal obtained by digitizing a signal from a video camera, for example.

[0055] Furthermore, as a method of compression encoding processing, A
It is not limited to DRC, and various other compression encoding methods such as orthogonal transform encoding methods such as DCT, vector quantization methods, etc. can be used.

[0056]

As explained above, according to the present invention, in a digital VTR that compresses and encodes an image signal in units of one or a plurality of frames and records the image signal, an image at the joint between an image signal to be recorded and a newly recorded image signal can be recorded. By providing a memory for storing signals in units of fields, editing can be easily performed in units of one field as the minimum unit.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of a digital VTR with an editing function that implements an editing method according to the present invention.

FIG. 2 is a diagram for explaining a track pattern when insert editing is performed.

FIG. 3 is a time chart for explaining the operation during preview.

FIG. 4 is a time chart for explaining operations during actual editing.

[Explanation of symbols]

10 Recording system 13 Editing input switching circuit 14 Blocked memory 16 Compression encoding circuit 20 Reproduction system 28 Monitor switching circuit 41 Edit control section 43 Out point memory

Claims (2)

[Claims] Claim 1: A digital image signal is divided into n frames (n
is an integer and n≧1) is an editing method for a digital VTR in which compression encoding is performed and recorded on a recording medium. A memory means capable of storing image signals is prepared, and prior to editing and recording of connecting another digital image signal to the reproduced digital image signal of the digital VTR, a joint position of the images is stored, and the memory means Of the n frames including the joint in the unit of compression encoding of the reproduced digital image signal, the field-by-field digital image signal before the joint is stored, and when editing and recording, the digital image signal is stored in the digital VT.
R in synchronization with the other digital image signal, put the digital VTR into a recording state at the joint, and start writing the other digital image signal into the memory means, and The data is combined with the compressed data to form n frames of the unit of compression encoding, which is compressed and encoded and recorded by the digital VTR. After that, the other digital image signal is stored in the memory means. An editing method for a digital VTR, in which n frames of the unit of compression encoding are sequentially written, and then compressed and encoded by the digital VTR and recorded. Claim 2: The digital image signal is divided into n frames (n
is an integer, and is an editing method in a digital VTR that performs compression encoding that is completed when n≧1) and records it on a recording medium, and the digital image signal for n frames of the unit of compression encoding is a first memorizable memory means;
A second memory means is prepared, and prior to insert editing recording for inserting another digital image signal into the reproduced digital image signal of the digital VTR, the starting point position and ending point position of the insertion are stored. In addition, the first memory means stores digital image signals in field units before the starting point among n frames including the starting point of the unit of compression encoding of the reproduced digital image signal, and The memory means stores digital image signals in field units after the end point among n frames including the end point of the unit of compression encoding of the reproduced digital image signal, and when insert editing and recording, The digital VTR is played back in synchronization with the other digital image signal, the digital VTR is put into a recording state at the starting point, and writing of the other digital image signal into the first memory means is started. Then, it is combined with the stored data to form n frames of the unit of compression encoding, which is then compressed and encoded and recorded by the digital VTR, after which the other data is stored in the memory means. A digital image signal is sequentially written in n frames of the unit of compression encoding, and is compressed and encoded and recorded by the digital VTR, and at the end point, it is combined with the other digital image signal up to just before the end point. An editing method for a digital VTR, wherein n frames are composed of the unit of compression encoding by combining with the digital image signal read from the second memory means, and the insert editing is completed by recording the n frames.