JPH0447882A - Digital signal reproducing device - Google Patents

Abstract

PURPOSE:To attain strobo reproduction when a recorded signal is reproduced by outputting repetitively a picture data by one pattern subject to expansion processing at an interval of a prescribed pattern number till a picture data of a succeeding one-pattern of the picture data is obtained. CONSTITUTION:When the strobo reproduction is designated and a synchronization code are entered by the operation of a keyboard 140, the input of a compression picture data by one compression reference period is started into any video RAM (video RAMs 22a-22c are used sequentially). When the synchronization code is entered, the input of a compression picture data by one compression reference period is started into a succeeding video RAM. Then the reference picture data written in the video RAM at the preceding compression reference period is read, subject to expansion processing at a picture expansion section 46 and a still picture comprising a reference picture data is displayed on a monitor connecting to terminals 49R-49B. Thus, a still picture comprising a picture data at a frame at an interval of M frames is sequentially displayed on the monitor for each compression reference period and so-called strobo display is implemented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for reproducing a moving picture digital video signal and a digital audio signal recorded simultaneously.

[Prior art] The current digital audio recorder (hereinafter referred to as “D
(referred to as "AT") is designed to record and reproduce only digital audio signals.

[Problems to be Solved by the Invention] However, it would be very convenient if not only digital audio signals but also other signals such as digital video signals for moving images could be simultaneously recorded and reproduced.

In the case of recording a digital video signal for a moving image in this way, it would be even more convenient to use if not only the moving image display through normal playback but also special playback, such as strobe playback, could be performed.

Therefore, in the present invention, strobe playback is enabled when playing back a digital video signal for a moving image and a digital audio signal recorded at the same time.

[Means for Solving Problem 1] The present invention records a digital signal of N bits (N is an integer), and a portion of the N bits forms an image area, an audio area, and a control area, respectively. In the image area of each compression reference period, compressed digital video signals for multiple screens constituting a moving image are arranged, and in the audio area of each compression reference period, digital audio signals for the compression reference period are arranged. In an apparatus for reproducing a digital video signal that has been compressed for a plurality of screens separated from an image area of each compression reference period of a reproduced signal, and a means for decompressing a digital video signal for a plurality of screens separated from an image area of each compression reference period of a playback signal, and for a predetermined screen that has been expanded. and means for repeatedly outputting image data for every other screen until the next decompressed image data for one screen is obtained.

[Operation] In the above-described configuration, still images are sequentially displayed based on one screen's worth of decompressed image data at predetermined intervals. In other words, strobe playback becomes possible.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In this example, a DAT is used as the recording/reproducing device.

FIG. 2 shows the format of the digital signal recorded and reproduced in this example. 16 bits) [b15~b
O], bits [b15 to b4, bits [b3 to bll], and bit [bO] are an image area, an audio area, and a control area, respectively.

Here, the conventional audio sampling clock is 48k
If the DAT transmission rate is 48kHzX2X16bit = 1536kbps, as in the case of recording left and right two-channel digital audio signals at Hz, the transmission rate in the image area is 48kHzX2X12bit = 1152kbps, and the transmission rate in the audio area is: 48kHzX2X3bit = 288kbps, and the transmission rate in the control area is 48kHzX2X1bit = 96kbps (see Figure 3).

The recorded data is configured for a predetermined period, in this example, one second as a unit period (hereinafter referred to as "compression reference period").

That is, in each compression reference period, the image area is 115
The audio area is 288,000 bits, and the control area is 96,000 bits.

In this example, an NTSC video signal is used, and image data for 30 frames is arranged in the image area in each compression reference period. In this case, the image data for 30 frames has too much information as it is. For example, one frame of pixel data is 256H x 240V,
And when the luminance signal Y, red difference signal U, and blue difference signal ■ are each 8 bits, the amount of information for 30 frames is 2.
56X240X8X30X3 = 44236800 bits.

Therefore, the image data for 30 frames is 115,200
It is compressed to within 0 bits.

For example, pixel data of 256H x 240V is halved by subsampling processing.

Further, a total of 24 bits of the luminance signal Y1, red difference signal U, and blue difference signal V are compressed into 9 bits.

As a result, the amount of information for one frame is 256X24
0X1/2X9 = 276480 bits.

Further, the image data of the second to 29th frames are each differentially compressed image data using the image data of the first frame as reference image data, and the information amount of this differentially compressed image data is, for example, 27,200 bits. .

Therefore, the amount of information for 30 frames is 276,480
X1+27200X29=1065280 bits, which is within 1152000 bits.

Note that the remaining 86,720 bits are used for fixed length adjustment.

FIG. 4 shows an example of the structure of recorded data. At the beginning of the image area of each compression reference period are reference image data corresponding to the image data of the first frame, VBI, VB2, etc.
After that, differentially compressed image data Δcl, ΔC2, . . . corresponding to the image data of the 2nd to 29th frames are arranged.
. . , Δc29 are sequentially arranged.

Furthermore, audio data for this compression reference period is arranged in the audio area for each compression reference period.

This audio data is data within 288,000 bits.

For example, the ADPCM method is adopted as the audio data encoding method, and the data is compressed.

As a result, when the sampling frequency is 32 kHz, 4 bits per sample, and 2 channels (stereo or 2 monaural channels), the amount of information is 32 kHz x 4 bits x 2.
The channel is 256,000 bits, and the data is within 288,000 bits.

Note that the remaining 32,000 bits are used for frequency adjustment.

As mentioned above, the 16 bits b15 to b15 of the digital signal
An audio region is formed by 3 bits (3 bits) b3 to bl of bO, and the transmission rate of the audio region is 96 kHz x 3 bits = 288 kbps (2nd t!l, 3rd diagram M).

This can also be considered as 32kHz2X9 bits=288kbpS. Therefore, for example, as shown in FIG. 5, audio data is allocated to 8 bits out of each 9 bits, and the bit rate is adjusted. That is, 32k
Hz x 8 bits = 256 kbps.

Furthermore, the control area in each compression reference period is provided with a synchronization code section, a mode code section, and a control code section.

A plurality of synchronization code sections are provided in each compression reference period, and in this example, four synchronization code sections are provided at intervals of 0.25 seconds. For example, a 64×1 bit area is secured in each synchronization code section. A framing code is used as a synchronization code,
Different types of synchronization codes 1 to 4 are arranged among the four synchronization codes.

As shown in FIG. 4, the synchronization code l is assigned to the synchronization code section immediately before the next compression reference period, and the three synchronization code sections before that are assigned synchronization codes 4 to 2, respectively.
will be arranged.

A mode code section is provided following each synchronization code section. That is, in each compression reference period, 4
Each is provided. For example, each mode code section contains 64×1
The bit area is secured.

In this case, the end of the mode code section following the synchronization coat section having synchronization code 1 is arranged so as to be located at the beginning of the next compression reference period.

The same data is allocated to the four mode code sections in each compression base period. In this mode code section, data between image data, audio data, etc. to be arranged in the next compression reference period is arranged.

The following data can be considered as data between image data.

■Resolution data 256H x 240V 512HX 480V 768H Difference signal V Red signal R1
Green signal G, blue signal B Other bit data 24 bits (8 [V, R] + 8 [tJ, G] + 8 [V, 81
) 16 bits (6 [Y Co + 5 [U Co + 5 [V] ) 9 bits (Y, U, V or R, G, B compressed data) Other data intervening with audio data include the following: is possible.

■Encoding method data DPCM PCM (linear) PCM (nonlinear) Other ■Bit data 4 bits, 6 bits, 8 bits, 10 bits 12 bits, 16 bits, etc. ■Sampling frequency data 16kHz, 32kHz, 44.1kHz ,48kHz
, Other ■ Channel number data 1 channel, 2 channels, and other mode code section includes data between the image data and audio data mentioned above, as well as data when there is a scene change in the next compression reference period as described later. , data indicating the presence or absence of a scene change is also provided.

A control code section is provided following each mode code section. That is, there are four for each compression visit.

For example, an area of 23136×1 bits is secured in each control code section.

The same data is allocated to the four control code sections ξ in each compression reference period. This control code section includes a microcode for decompressing image data to be placed in the next compression reference period, and is made to be compatible with compression methods such as ζ during playback.

Although not shown in FIG. 4, a 736-bit guard area in which each bit is set to "0" is provided between the control code section and the synchronization code section.

As mentioned above, by placing the same data in the four mode code sections and the control code section, during playback, the mode code and control code can be efficiently obtained no matter where the playback starts. The operation of the playback signal processing system can be smoothly controlled.

FIG. 6 shows the structure of recorded data when there is a scene change.

When there is a scene change, the recording state of the image data is reset at a point in the middle of the compression reference period (see time point tc in FIG. 6). That is, from time point tc, the reference image data VBN+2 after the scene change, differentially compressed image data Δcl, ΔC2, . . . are sequentially arranged and recorded in the image area.

In addition, along with this, the recording state of the data in the control area is also reset, and a synchronization coat section having synchronization code 1 is provided immediately before the reference image data V B N+2. Data indicating that there is a scene change is placed in the mode code section of the compression reference period before the scene change.

FIG. 1 shows an example of a signal processing device used when recording and reproducing recorded data as shown in FIGS. 4 and 6 using DAT.

First, the recording system will be explained.

The NTSC color video signal SV supplied to the video in terminal 11 is amplified by an amplifier 12 and then supplied to a decoder 13 . A luminance signal Y, a red difference signal U, and a blue difference signal V are output from the decoder 13 and supplied to the A/D converter 14, respectively.

Further, the video signal SV output from the amplifier 12 is supplied to a synchronous separation and clock generation circuit 15. circuit 1
From 5 onwards, frequency 8 is synchronized with the video signal SVO simultaneous signal.
fsc/3 (fsc is the color subcarrier frequency of 3.58MH
z) clock CKRI is output, and this clock CK
RI is supplied to the A/D converter l4 as a sampling clock.

In the A/D converter 14, each of the signals Y, U, and V is sampled so that the number of samples in one effective horizontal frame is 256, and converted into a digital signal with 8 bits per sample.

Signals Y, U, and ■ output from the A/D converter 14 are supplied to a movable terminal of a changeover switch 16.

Although the control line is not shown, the changeover switch 16 is controlled by a controller 1i0 having a CPU,
For each frame period, a side, bm, a side, a side, ...
are connected sequentially.

Changeover switch 16 a~cl! The fixed terminal of l is the RAM
It is connected to the input side of 17a to 17c. RAM 17
Writing/reading of a to 17c is controlled by the RAM controller 120. Note that the operation of the RAM controller 120 is controlled by the controller 110.

The RAM controller 120 is supplied with the clock CKRI output from the circuit 15, and also supplied with the vertical synchronization signal VDR1 and the horizontal synchronization signal HDR as reference synchronization signals. Further, the controller 110 is supplied with a clock CKR2 having a frequency of 8 fsc output from the circuit 15 as a master clock, and a vertical synchronization signal VD.
R1 horizontal synchronization signal HDR is supplied as a reference synchronization signal.

Furthermore, the controller 110 receives the pit clock BCK (shown in FIG. 7B) from the DAT 130 and the clock LRCK (shown in FIG. 7A) for switching between left and right channels as a reference for timing with the DAT 130. Supplied as a clock.

Note that the operation of the DAT 130 is controlled by the controller 110.

RAM17a to 17c each have a selector switch a=
For the l frame visit connected to clll, the signal Y,
256 in the horizontal direction between each of U and V
240 sample data are written in the vertical direction. Signal Y written in these RAMs 17a to 17c
, U, and ■ are repeatedly read out twice during the next two frame periods.

The signal read out from the RAM 17a is transferred to the selector switch 1.
8a, 18b, 18c, all, a side, a, respectively
Supplied to the fixed terminal on the side. The signals read from the RAM 17b are of the changeover switches 18a, 18b, 18c.
These are supplied to fixed terminals on the b side, b side, and a side, respectively. R
The signal read from AM17c is transferred to selector switch 18.
It is supplied to the fixed terminals a, 18b, and 18c on the a side, the a side, and the b side, respectively.

Although the control lines are not shown, there are changeover switches 18a to 18c.
are switched and controlled by the controller 110. These changeover switches 18a to 18c are connected to the a side, the a side, the b side when the changeover switch 16 is sequentially connected to the a side, the b side, the a side, the a side, . . . for each frame. , side a,...
・Sequentially connected to.

The output signals of the changeover switches 18a-18c are each supplied to an image compression section 19. The operation of this image compression section 19 is controlled by a controller 110.

The image compression unit 19 performs the following processing on the first frame of image data among the 30 frames of image data constituting each compression reference period (1 second). First, subsampling processing is performed, and the signals Y, U,
The number of samples in l frame for each of V is 1
/2. Next, the 24-bit data is compressed to 9 bits. Thereby, reference image data VBN is formed.

Moreover, for the image data of the 2nd to 30th frames,
The following processing is performed respectively. First, subsampling processing is performed to obtain signals Y and U.

The number of samples in one frame between each of ■ is 172
It is said that Next, the 24-bit data is compressed to 9 bits. Furthermore, a difference from the reference image data is taken.

As a result, differentially compressed image data Δcl to Δc29 are formed.

Reference image data VBN and differentially compressed image data Δc1 to Δc2 formed by the image compression unit 19 in each compression reference period
9 is supplied to the video RAMs 22a to 22c via the connection switch 20 and changeover switch 21, and sequentially written to predetermined addresses.

Although the control lines are not shown, the connection switch 20 and the changeover switch 21 are switched and controlled by the controller 110. The connection switch 20 is turned on during recording. The changeover switch 21 is set to the a@ side, b side,
It is connected to the C side, a@, . . . in sequence.

Writing/reading of the video RAMs 22a to 22c is performed by R.
Controlled by AM controller 120.

The video RAMs 22a to 22c each have a changeover switch 21 connected to the a-C side during the compression reference period.
The reference image data VBN formed by the image compression section 19 and the differentially compressed image data ΔC1 to Δc29 are written.

Reference image data VBN and differentially compressed image data Δc1 to Δ written in these video RAMs 22a to 22c
c29 is read out during the following one compression reference period.

Reference image data VBN and differentially compressed image data Δcl to Δc2 read from video RAMs 22a to 22c
9 is supplied to the mixing circuit 24 via the changeover switch 23 and arranged in the image area of the recording data.

Although the control line is not shown, the changeover switch 23 is controlled by the controller 110. Changeover switch 23
The periods during which image data is read from the video RAMs 22a to 22b are from side a to C!, respectively. Connected to 1. The operation of mixing circuit 24 is controlled by controller 110.

In addition, the left and right channel audio signals SAL and SAR supplied to the audio in terminal 31 are connected to the amplifier 3.
2 and then supplied to an audio digital signal processor (audio DSP) 33.

The operation of the audio DSP 33 is controlled by the controller 110. In this audio DSP 33, the left and right channel audio signals SAL and SAR are each sampled with a 32 kHz clock, and are further encoded using the ADPCM method using the RAM 34 so that one sample has 4 bits. As a result, 256,000 bits of audio data are formed corresponding to each compression reference period.

The audio data formed by the audio DSP 33 is supplied to the mixing circuit 24, and is added to the audio area of the recorded data by the fifth
Arranged as shown in the figure.

In this case, the audio data output from the audio DSP is controlled so as to correspond to the image data supplied to the mixing circuit 24.

Further, 25 is a circuit for generating control data such as a synchronization code, a mote code, and a control code. The operation of this generating circuit 25 is controlled by a controller 110. The control data output from the generation circuit 25 is supplied to the mixing circuit 24 and arranged in the control area of recording data.

In this way, recording data as shown in FIG. 4 is formed in the mixing circuit 24, and this recording data is transferred to DAT 1.
30 and recorded in DAT format.

Further, 26 is a scene change detection circuit.

The detection circuit 26 is supplied with two consecutive frames of signals supplied to the image compression section 19 from the changeover switches 18a to 18c. Then, data at a plurality of sample points are compared based on the comparison position signal from the RAM controller 120, and it is determined whether the difference exceeds a specified value. When the number exceeds the specified value,
It is determined that it is a scene change, and the determination signal is supplied to the controller 110 and the RAM controller 120.

When a scene change occurs, the signal processing state is reset even during the 1 second compression reference period. In other words,
The image compression unit 19 starts forming the standard image data VBN based on the image after the scene change, and the changeover switch 21 is also switched to the next video RAM.

Note that the signal processing state of the audio system is also reset in the same way as the video system. The operation of the control data generation circuit 25 is also controlled, the generation timing of the synchronization code is controlled, and data indicating that a scene change has occurred is allocated to the mode code of the compression reference period before the scene change.

In this way, when there is a scene change, the mixing circuit 2
4, recorded data as shown in FIG. 6 is formed, and this recorded data is supplied to the DAT 130 and the DA
It is recorded in T format.

FIG. 8 shows a timing chart of a recording system between a video signal and an audio signal.

In the same figure, 'A' and 'B' are the video signal S and the audio signals SAL and SAR supplied to the terminals 11 and 31, respectively. vGl, VO2, ---AGI, AC3
, . . . are the video signal and audio signal of each compression reference period, respectively.

As shown in FIG.
Gl, CV G2, . . . are sequentially written.

In addition, although not mentioned above, the RAM 34 also contains the above-mentioned video R.
Similar to AM22a to 22c, areas RAMa to C are provided, and as shown in the figure, the audio DSP 33
Compressed audio data CAGI, CA converted into ADPCM with
G2, . . . are sequentially written.

In this way, the video signal and the audio signal are processed at the same timing, and even if there is a scene change, the DAT 130 stores the compressed image data C of each compression reference period.
VGI, CVG2,...Φ and compressed audio data CAG
L CAG2, . . . are recorded in correspondence (see E in the same figure).

Next, the reproduction system will be explained.

Data as shown in FIGS. 4 and 6 reproduced from the DAT 130 is supplied to the separation circuit 41. The operation of the separation circuit 41 is controlled by the controller 110,
Image data, audio data and 1liI from playback data
JIll data is separated.

The control data separated by the separation circuit 41 is also supplied to a control data discrimination circuit 42, where the synchronization code, mode code, and control code are discriminated, and the discrimination results are supplied to the controller 110.

Under the control of this controller 110, a reproduction signal processing system such as an image decompression unit and an audio DSP 33, which will be described later, performs processing corresponding to the format and compression method of the reproduced image data and audio data. Ru.

This makes it possible to deal with any situation regarding the image data and audio data to be reproduced. In the following, a case will be described in which data as shown in FIG. 4 or 6 is reproduced.

Further, 43 is a synchronization signal and clock generation circuit. The operation of this generating circuit 43 is controlled by a controller 110. Then, from the generation circuit 43, the frequency 4
f sc/3 clock CKPI, vertical synchronization signal V
DP, a horizontal synchronizing signal HDP, and a clock CKP2 with a frequency of 8 fsc are output.

The RAM controller 120 is supplied with the clock CKPI output from the generation circuit 43, and also supplied with the vertical synchronization signal VDP and the horizontal synchronization signal HDP as reference synchronization signals. The controller 110 also receives a clock CK with a frequency of 8 fsc output from the generation circuit 43.
P2 is supplied as a master clock, and a vertical synchronization signal VDP and horizontal synchronization signal HDP are supplied as reference synchronization signals.

Further, reference image data VBN and differential compressed image data Δcl~ of each compression reference period are separated by the separation circuit 41.
Δc29 is the connection switch 44 and the changeover switch 45
The data is supplied to the video RAMs 22a to 22C via the video RAMs 22a to 22C, and sequentially written to predetermined addresses.

Although the control lines are not shown, the connection switch 44 and the changeover switch 45 are controlled by the controller 110. The connection switch 44 is turned on during playback. The changeover switch 45 is set to the a side, bil
It is sequentially connected to l, c%, allJ, .

Writing/reading of the video RAMs 22a to 22c is performed by R.
Controlled by AM controller 120. RAM2
2a to 22c, the changeover switches 45 are set to a to C, respectively.
The reference image data VBN and differential compressed image data Δc1 to ΔC29 separated by the separation circuit 41 are written in one compression reference period connected to the side.

Reference image data VBN and differentially compressed image data Δc1 to Δ written in these video RAMs 22a to 22c
c29 is read out during the following one compression reference period.

Reference image data VBN and differentially compressed image data Δcl to Δc2 read from video RAMs 22a to 22c
9 is supplied to the image expansion section 46 via the changeover switch 23. Although the control line is not shown, the changeover switch 23 is controlled by the controller 110. The changeover switch 23 is connected to the a side to the C side, respectively, during a period when image data is read from the video RAMs 22a to 22c.

The operation of the image decompression section 46 is controlled by the controller 110 based on the control code as described above, and performs the opposite process to that of the image compression section 19.

In the image decompression unit 46, the following processing is performed on the reference image data VBN. First, 9 bits of data are expanded to 8 bits each for signals Y, U, and V. Next, interpolation processing is performed, and the signals Y, U,
The number of samples in one frame for each of V is doubled. This forms the first frame of image data.

Further, the following processing is performed on each of the differentially compressed image data Δcl to Δc29. First, the difference data is converted back to 9-bit data using the reference image data. Next, the 9-bit data is sent to the signals Y, U, V
are expanded to 8 bits each.

Furthermore, interpolation processing is performed, and the signals Y, U, V
The number of samples in one frame between each is doubled. As a result, image data of the second frame to the 30th frame is formed.

Signals y, u, v output from the image decompression unit 46
is supplied to the matrix circuit 47, and the primary color signals R, G, B output from this matrix circuit 47 are D/
A converter 48 is supplied. The D/A converter 48 is supplied with a clock CKPI from the generation circuit 43. Analog primary color signals R, G, and B output from the D/A converter 48 are respectively connected to the video out terminal 49R.
149G, 49B.

The terminal 50 is a synchronization signal output terminal, and this terminal 50 receives the decoded synchronization signal 5YNC output from the generation circuit 43.
is derived.

Furthermore, the audio data separated by the separation circuit 41 is supplied to the audio DSP 33, where the ADPCM signal is demodulated. The left and right audio signals SAL and SAR output from the audio DSP 33 are output from the amplifier 3.
5 to the audio out terminal 36.

Note that when there is a scene change, the signal processing state is reset even if it occurs during a 1-second compression reference visit.

In other words, the changeover switch 45 is switched and writing to the next video RAM is started. Even during the processing performed by the image decompression unit 46 after visiting the compression standard, the formation of the first frame of image data is started from the standard image data VBN after the scene change.

Note that the signal processing state of the audio system is also reset in the same way as the video system.

FIG. 9 shows a timing chart of a reproduction system between a video signal and an audio signal.

From the DAT130, compressed image data CVGI, CV G2, . . . for each compression standard, and compressed audio data CA
G1. CAG2, and are played in correspondence (9th
(See Figure A).

The video RAMs 22a to 22c contain reproduced compressed image data CVGI, CV G2, and
... are written sequentially.

In addition, in the RAM a - c area of the RAM 34, as shown in FIG.
CAG2, ·φ are sequentially written.

In this way, compressed image data and compressed audio data are processed at the same timing, and terminals 49R to 49B and 36
are the video signals VGI and V of each compression reference period, respectively.
G2, . . . and audio signals AGI, AC3, . . . are output in correspondence (see E in the figure).

FIG. 10 is a flowchart showing the operation of the video system during normal playback.

In the figure, when the playback key of the keyboard 140 is turned on, it is determined in step 51 whether synchronization code 2, 3, or 4 has been entered manually.

When any of these sync codes are entered,
At step 52, the mode code and control code placed following the synchronization code are loaded into the control area, and the image decompression unit 46 and the like are set to operate in accordance with the compressed image data to be reproduced.

Next, in step 53, it is determined whether synchronization code l has been input. When synchronization code 1 is input, step 54 is performed to input one of the video RAMs (Video RAM
22a to 22c are sequentially used), manual processing of compressed image data for one compression reference period is started.

Next, in step 55, it is determined whether synchronization code 1 has been input. When synchronization code 1 is input manually, input of compressed image data for one compression reference period to the next video RAM is started in step 56.

Next, in step 57, the video RA
The compressed image data written in M is sequentially read out and the image decompression section 46 starts decompression processing.

The image is then displayed on a monitor (not shown) connected to the terminals 49R to 49B.

Next, in step 5, it is determined whether synchronization code 1 has been input. When the synchronization code I is input, it is determined in step 59 whether or not the stop key of the keyboard 140 is on.

When the stop key is not on, the process returns to step 56 and repeats the above-described operation, while when the stop key is on, the playback operation is stopped.

Note that the decompression processing in step 57 begins after the decompression processing of the compressed image data written in any of the video RAMs 22a to 22c in the previous compression reference period is completed, and then begins processing for the subsequent compression reference period.

Therefore, when there is a scene change in the middle, the compressed image data for a certain compression reference period is read from the - video RAM and decompressed, while the compressed image data is written to the other two video RAMs. Processing is performed (see the scene change section in FIG. 9C9D). In other words, the compressed image data before the scene change (CV G N+1) is written to one of the two video RAMs, and the compressed image data after the scene change (CV G N+1) is written to the other.
G N+2) is written. In this sense, three video RAMs 22a-22c are used.

Although not mentioned above, as an IC for performing compression processing in the image compression section 19 and decompression processing in the image decompression section 46, there is, for example, Intel Corporation's compression/decompression IC [82750PB].

Next, special playback such as still playback and strobe playback will be explained.

First, still playback will be explained. The playback tape running speed in still playback is the same as in normal playback.

FIG. 11 is a flowchart showing the operation of still playback (first still playback) in which still images based on reference image data are sequentially displayed by manual operation.

In the figure, when the first still reproduction is designated by operating the keyboard F' 140, it is determined in step 61 whether synchronization code 2, 3, or 4 has been manually operated.

When any of these synchronous coats are man-powered,
In step 62, the moat code and control code placed following the synchronization code are loaded into the control area, and the image decompression unit 46 and the like are set to operate in accordance with the compressed image data to be reproduced.

Next, in step 63, it is determined whether the synchronization court 1 has been manually operated. When synchronization code 1 is input, in step 64, one of the video RAMs (Video RAM
22a to 22c are used sequentially) to write reference image data.

Next, in step 65, reference image data is read from the video RAM, and the image decompression unit 46 performs decompression processing to form image data for one frame, and this image data for one frame is stored in the memory. Store in.

Then, image data for one frame is repeatedly read out from this memory, and a still image based on the reference image data is displayed on the monitor connected to the terminals 49R to 49B.

Next, in step 66, the DAT 130 is placed in a reproduction pause state.

Next, in step 67, it is determined whether the playback key on keyboard 140 is on. If the playback key is on, the playback pause state of the DAT 130 is released in step 68, and the process returns to step 61. Then, by the same operation as described above, a still image based on the reference image data of the next compression reference visit is displayed.

If the play key is not on at step 67, it is determined at step 69 whether the stop key of keyboard F'I 40 is on. If the stop key is not on, the process returns to step 67.

In step 69, when the stop key is on, the first
Stops the still playback operation.

FIG. 12 is a flowchart showing the operation of still playback (second still playback) in which still images based on reference image data immediately after a scene change are sequentially displayed by manual operation.

In the figure, when second still playback is designated by operating the keyboard 140, it is determined in step 71 whether synchronization code 2, 3, or 4 has been input.

When any of these sync codes are human-powered,
In step 72, the mode code placed next to the synchronization code is loaded into the control area, and in step 73, based on data indicating the presence or absence of a scene change in the mode code,
It is determined whether there is a scene change or not. If there is no scene change, the process returns to step 71.

When there is a scene change, the control code placed following the mode code is fetched in step 74.

Then, based on the mode code and the control code, the image expansion section 46 and the like are set to operate in accordance with the compressed image data to be reproduced.

Next, in step 75, it is determined whether the synchronization code] has been input. When synchronization code 1 is entered manually, in step 76 any video RAM (Video RAM
M22 a ~ 22 c! , tJll primary use), the reference image data immediately after the scene change is written.

Next, in step 77, the reference image data is read from the video RAM, and the image decompression unit 46 performs decompression processing to form image data for one frame, and this image data for one frame is stored in the memory. Store.

Then, image data for one frame is repeatedly read out from this memory, and a still image based on the reference image data immediately after the scene change is displayed on the monitors connected to the terminals 49R to 49B.

Next, in step 78, the DAT 130 is placed in a reproduction pause state.

Next, in step 79, it is determined whether the playback key on keyboard 140 is on. If the playback key is on, the playback pause state of the DAT 130 is released at step 80, and the process returns to step 7]. Then, by the same operation as described above, a still image based on the reference image data immediately after the next scene change is displayed.

If the playback key is not on in step 79, it is determined in step 81 whether the stop key on the keyboard 140 is on. If the stop key is not on, the process returns to step 79.

Step 8] When the stop key is on, the second
Stops the still playback operation.

Figure 13 shows still playback (3rd stage) in which still images based on reference image data are automatically displayed sequentially at predetermined time intervals.
12 is a flowchart showing the operation of still playback. Steps corresponding to those in FIG. 11 are indicated with the same reference numerals.

In the figure, after the DAT 130 is placed in a playback pause state in step 66, it is determined in step 91 whether or not time t has elapsed.

When time t has elapsed, it is determined in step 92 whether the stop key of keyboard 140 is on. If the stop key is not on, step 68
The playback pause state of 130 is released and the process returns to step 61.

Step 92, when the stop key is on, the third
Stops the still playback operation.

The rest is the same as the example in FIG. 11.

In this third still playback, still images based on reference image data of each compression reference period are automatically displayed on the monitor one after another at time intervals determined by time t.

Figure 14 shows still playback (fourth stage) in which still images based on standard image data immediately after a scene change are automatically displayed one after another.
12 is a flowchart showing the operation of still playback. Steps corresponding to those in FIG. 12 are indicated with the same reference numerals.

In the figure, after placing the DAT 130 in a playback pause state at step 78, it is determined at step 94 whether time t has elapsed.

When time t has elapsed, it is determined in step 95 whether the stop key of keyboard 140 is on. If the stop key is not on, step 80
The reproduction paused sushi of 130 is canceled and the process returns to step 71.

Step 95, when the stop key is on, the fourth
Stops the still playback operation.

The rest is the same as the example in FIG. 12.

In this fourth still playback, the next scene change is detected after time t has elapsed, and still images based on the reference image data immediately after the scene change are automatically displayed on the monitor one after another.

Note that when the normal playback operation shown in the flowchart of FIG. 10 is being performed, for example, when turning on the Bose key of the keyboard 140 to enter the playback pause state, the image of the l frame formed by the image decompression unit 46 immediately before is used. It is also possible to configure the monitor to display still images, so that any frame of still images can be monitored.

Next, strobe playback will be explained. The playback tape running speed in strobe playback is the same as in normal playback.

FIG. 15 is a flowchart showing the operation of strobe playback.

In the figure, when strobe playback is designated by operating the keyboard 140, it is determined in step 151 whether synchronization code 2, 3, or 4 has been entered manually.

When any of these sync codes are human-powered,
At step 152, the mode code and control code placed following the synchronization code are taken into the control area, and the image decompression section 46 and the like are set to operate in accordance with the compressed image data to be reproduced.

Next, in step 153, it is determined whether synchronization code 1 was entered manually. When sync code 1 is input,
In step 154, one of the video RAMs (Video R
AM 22a to 22c 4i (sequential use), manual processing of compressed image data for one compression reference period is started.

Next, in step 155, it is determined whether synchronization code 1 was entered manually. When sync code 1 is input,
In step 156, N=O is set, and in step 15
7, L=1 is set, and in step 158, input of compressed image data for one compression reference amount to the next video RAM is started.

Next, in step 159, the video R is
The reference image data written in the AM is read out and expanded by the image expansion section 46. And terminals 49R to 49
A still image based on the reference image data is displayed on a monitor (not shown) connected to B.

Next, in step 160, N=N+1 is set, and the differentially compressed image data ΔCN is read out from the video RAM and decompressed.

Next, in step 161, it is determined whether N is equal to LXM+1. Here, M is the number of frame skips in strobe display, and is set in advance using the keyboard 140.

In step 161, if they are not equal, in step 16
Returns to 0 and performs the same processing as described above. On the other hand, when they are equal, in step 162, a still image based on the differentially compressed image data ΔcN is displayed on the monitor.

Next, in step 163, it is determined whether synchronization code 1 was entered manually. If synchronization code 1 is not input, step 164 sets L=L+.1, and the process returns to step 160 to perform the same operation as described above.

When the synchronization court 1 is manually operated in step 163, it is determined in step 165 whether or not the stop key of the keyboard 140 is on.

When the stop key is not on, the process returns to step 156 and the same operation as described above is repeated, while when the stop key is on, the strobe playback operation is stopped.

In the strobe playback operation as shown in 2, in each compression reference period, still images based on image data of every M frame are sequentially displayed on the monitor, so-called strobe display.

Next, fast-forward playback will be explained.

FIG. 16A shows reproduced image data during normal reproduction, and VBI, VB2, . . . are reference image data of each compression reference period, and are reproduced at 1 second intervals during normal reproduction.

In this example, when certain reference image data, for example VBI, is played back, the playback tape running speed of the DAT 130 is doubled from the normal speed and run for 2 seconds, and then the playback tape running speed is returned to the normal speed and the next The reference image data of (shown in FIG. 3B) is reproduced.

Thereafter, similar operations are repeated.

The reason why the reproduction tape running speed is returned to normal before reproducing the reference image data is to allow the rotary head to scan correctly without crossing the recording track.

As shown in FIG.
6, V B 11 . . . is played back.

Note that in the portion shown by the broken line, the rotating head scans across the recording track, and correct image data cannot be obtained.

The reference image data VBI, VB6, reproduced in this way
V B II, . . . are sequentially written to the video RAMs 22 a to 22 c, as shown in the figure.

Then, the reference image data written in the video RAMs 22a to 22c is read out, supplied to the image expansion section 46, and expanded, thereby forming image data for one frame. Then, the still image based on the image data for one frame continues to be displayed until the image data for one frame is formed using the next reproduced reference image data (E in the same figure).
(illustrated).

In this way, during normal playback, the contents displayed at intervals of 5 seconds (for example, images based on the reference image data VBl and VB6) are changed to 3.
Displayed at intervals of 15 seconds. Therefore, 5/3
．． 1!5ζ Fast-forward playback of approximately 1.6 times is performed.

FIG. 17 is a flowchart showing the operation of this fast-forward playback.

In the figure, when fast-forward playback is specified by operating the keyboard 140, the controller 110 moves to step 171.
The DAT 130 is controlled to be in a normal speed playback state.

Next, in step 172, it is determined whether synchronization court 2, 3, or 4 was manually operated.

When any of these synchronization coats are manually operated,
In step 173, the moat coat and control coat placed following the synchronization coat are loaded into the control area, and the image expansion section 46 and the like are set to operate in accordance with the compressed image data to be reproduced.

Next, in step 174, it is determined whether the synchronization court 1 has been manually operated. When synchronous code 1 is input,
In step 175, one of the video RAMs (Video R
A M 22 a to 22 c are used sequentially) to write reference image data.

Next, in step 176, the reference image data is read from the video RAM, and is expanded by the image decompression unit 46 to form image data for one frame, and this image data for one frame is stored in the memory. Store. Then, image data for one frame is repeatedly read out from this memory, and a still image based on the reference image data is displayed on the monitor connected to the terminals 49R to 49B.

Next, in step 177, the controller 110 controls the DAT 130 to double the tape running speed.

Next, in step 17B, it is determined whether two seconds have elapsed. When two seconds have elapsed, it is determined in step 179 whether the stop key on keyboard 140 is on.

When the stop key is not on, the process returns to step 171 and the same operation as described above is performed, and when the stop key is on, fast-forward playback is stopped.

In the above description, an example is shown in which fast-forward playback is performed at a rate of approximately 1.6 times, but fast-forward playback at any speed is possible by adjusting the playback tape running speed and running time.

Next, slow playback will be explained.

FIG. 18A shows reproduced image data during normal reproduction, and CVGI, CV G2, . . . are compressed image data of each compression reference period (reference image data VBN and differential compressed image data ΔC1 to ΔC29). And, during normal playback, it is played sequentially every second.

In this example, the DAT 130 is put into a normal speed playback state for three compression reference periods, then put into a playback pause state for the same period as that period, and this is repeated thereafter.

By the operation of the AT 130 as described above, as shown in FIG.
I to CVG3) are played back consecutively, and then after the same period, the compressed image data (CVG
4 to CVG6) are played continuously. Hereinafter, the same process is repeated. The compressed image data CVGI, CVG2, etc. of each compression reference period reproduced in this way is stored in the video RAM 22 a to 2 as shown in C in the same figure.
2 (are sequentially written to.

The compressed image data written in the video RAMs 22a to 22c is then read out and supplied to the image decompression section 46 for decompression processing. In this case, as in normal playback, 30 frames worth of image data VGL VO2, .
・is formed.

Then, a moving image based on this image data VGL VO2 is displayed on the monitor, but the same screen is displayed continuously two frames at a time. In other words, image data VGI
, VO2, . . . are expanded twice and displayed (as shown in the figure).

In this way, the time axis of the moving image displayed on the monitor is expanded by twice, so that a 1/2 slow-motion image is displayed on the monitor.

FIG. 19 is a flowchart showing the operation of this slow playback.

In the figure, when slow playback is specified by operating the keyboard 140, in step 181, the controller 110
The DAT 130 is controlled to be in a normal speed playback state.

Next, in step 182, it is determined whether synchronization coat 2, 3, or 4 has been manually operated.

When any of these sync codes are human-powered,
At step 183, the mote code and control code placed following the synchronization code are taken into the control area, and the image expansion section 46 and the like are set to operate in accordance with the compressed image data to be reproduced.

Next, in step 184, N=0 is set, and then in step 185, it is determined whether synchronization code 1 has been input.

When synchronization code 1 is input, N=N+1 is set in step 186, and then N=N+ is set in step 187.
2 or not is determined. If N=2, go directly to step 18; if N=2, go directly to step 1.
The process advances to step 188 via step 89.

In step 189, reading of compressed image data for three compression reference periods that are continuously written to the video RAMs 22a to 22c is started, and the image decompression section 46 starts decompression processing, and the monitor connected to the terminals 49R to 49B (see FIG. (not shown)
Display video images.

In this case, the same screen is displayed continuously two frames at a time.

In step 188, input of compressed image data for one compression reference period to one of the video RAMs (the video RAMs 22a to 22c are sequentially used) is started.

Next, in step 190, it is determined whether the same amount of core F1 has been manually applied. When sync code 1 is manually generated,
At step 191, it is determined whether N=3. N
If not equal to 3, the process returns to step 18 and repeats the same operations as described above.

When N=3, in step 192, the DAT 130 is controlled by the controller 110 to enter a playback pause state. At this point, the video RAM 22a-2
Compressed image data for three consecutive compression reference periods is written in 2c.

Next, in step 193, it is determined whether the same time T3 as the three compression reference periods described above has elapsed.

Here, the reason why it is not set to 3 seconds is because the 3 compression reference periods may become shorter than 3 seconds when there is a scene change as described above.

Next, in step 194, the DAT 130 is controlled by the controller 110, and the playback pause state is released.
After step 195, N=O, step 19
At step 6, it is determined whether the stop key of the keyboard 140 is on.

When the stop key is not on, the process returns to step 186 and the above-described operation is repeated, while when the stop key is on, the slow playback operation is stopped.

In addition, although the above description is based on an example in which the normal speed playback state for 3 compression reference periods and the playback pause state for the same period are repeated, the 3 compression reference periods contain 3 video RAMs 22 a to 3. 22C, and is not limited to this. For example, it may be one compression reference period or two compression reference periods.

Furthermore, although the above example shows an example in which 1/2 slow playback is performed, slow playback at any speed is possible by adjusting the pause period. For example, if the pause period is twice the compression reference period played back at normal speed,
If the same screen is displayed for three frames, the time axis of the moving image displayed on the monitor will be expanded three times, resulting in slow playback of 1/3.

Next, reverse playback will be explained.

In order to realize reverse playback, the recorded data is structured as shown in FIG. The data structure of the control area is changed with respect to the example in FIG. 4.

That is, four synchronization codes IA~4 are used in each compression reference period.
A and mode codes IA to 4A are arranged. These are similar to the synchronization code and mode code in the example of FIG.

In the case shown in FIG. 20, the synchronous code F'
The synchronization code IB is located symmetrically with the mode codes IA to 4A (the area of the control coat in the example in Figure 4).
~4B, mode code IB ~4B are arranged.

Same month code IA~4A, mode code IA~4A
can be detected during normal playback, while synchronization codes IB to 4B and mode codes IB to 4B can be detected during reverse playback.

Mode codes IA to 4A contain data corresponding to the next compression reference period in the normal playback direction, similar to the mote code in the example shown in FIG.

Mode code IB-4B contains data corresponding to the next compression reference period in the reverse playback direction.

In addition to data similar to mote code IA-4A, this includes differential compressed image data Δc in the next compression period.
Variation data on the amount of data l to Δc29, data on whether or not the period is immediately before the occurrence of a scene change, data on the period in that case, etc. are arranged.

In the above description, the amount of data of the differentially compressed image data Δcl to Δc29 is fixed, and therefore the arrangement position of each differentially compressed image data is fixed. However, as will be described later, depending on the state of the image, the differentially compressed image data ΔC1 to
The data amount of Δc29 may be varied to improve the performance of image data. In this case, the arrangement position of each differentially compressed image data changes. Therefore, as will be described later, during reverse playback, the addresses of the video RAMs 22a to 22c are controlled, and from the reverse direction the address ζ is exactly the same as during normal playback.
To write this playback data, each differential compressed image data Δ
It is necessary to consider the amount of data from cl to Δc29.

This is the mode code, differentially compressed image data ΔC1~
This is the reason why the fluctuation data of the data amount of Δc29 is arranged.

This variation in data amount will be described later.

By configuring the recorded data as shown in FIG. 20, during normal playback, the playback operation is performed using the synchronization code IA-4A and the mode codes IA-4A.

Further, during reverse playback, the playback operation is performed using the synchronization codes IB-4B and the remote code '1B-4B. In this case, the addresses of the video RAMs 22a to 22c are controlled based on the fluctuation data of the data amount of the differentially compressed image data arranged in the remote controllers F' IB to 4B, and the addresses of the video RAMs 22a to 22c are controlled from the opposite direction to the normal playback. Playback data is written to the same address.

As a result, the subsequent decompression processing in the image decompression section 46 is performed in the same manner as during normal playback, and a reverse playback screen is displayed on the monitor.

It should be noted that with the structure of the recorded data as shown in FIG. 20, still playback in the reverse direction, fast forward playback, and slow playback can be performed in the same way.

Next, fluctuations in the amount of data of the differentially compressed image data ΔC1 to Δc29 will be explained.

FIG. 21 shows an example of realizing variation in data amount.

As the area of reference image data, 276,480 pits are provided as in the case where the amount of data is fixed as described above.

In addition, as the areas of the differentially compressed image data Δcl to Δc29, there are 31 areas B1-27200 bits each.
B51 is provided. The total area is 843,200 bits.

27200 x 31 = 843200 bits The image area between the 1 compression reference strings is 1152000 bits as described above, and the remaining 32320 bits are used for fixed length adjustment.

Reference image data is arranged in the reference image data area. This is similar to the case where the amount of data is fixed as described above.

Also, basically, the differentially compressed image data Δcl to Δc2
9 are placed in area B1-829, respectively, but if the image changes rapidly from an image with little movement to an image with large movement and the differentially compressed image data cannot be accommodated in the 27200-bit area, two or more area is used.

When two or more areas are used for one piece of differentially compressed image data in this way, the information is placed and recorded at the end of the control code, for example, as shown in the figure.

Data 1 to 29 indicating differentially compressed image data using two or more areas are arranged in the block number section. Also,
In the number part, data indicating the number of areas to be used (for example, 2 is "0" and 3 is "1") is arranged.

For example, when two areas are used for each of the differentially compressed image data ΔC5 and Δc20, the first block number part data is "5" and the number part data is "5".
"0", "20" is assigned as the data for the next block number section, and "0" is assigned as the data for the number section.

As a result, image data ΔC1 to ΔC4 are arranged in areas Bl-B4, respectively, image data ΔC5 is arranged in areas B5 and B6, image data ΔC6 to Δc19 are arranged in areas 87 to B20, respectively, and image data ΔC5 is arranged in areas B5 and B6, respectively. Δc20
is arranged in areas B21 and B22, and image data Δc2
1 to Δc29 are shown to be arranged in regions B23 to B31, respectively.

At the time of playback, this information is taken into the controller 10, and the addresses of the video RAMs 22a to 22c are controlled so that the playback signal processing is performed correctly in the same way as in the case where the data amount of each differentially compressed image data is fixed. be done.

FIG. 22 shows another example of realizing variation in data amount.

As in the case where the amount of data is fixed, 276,480 bits are provided as the area for the reference image data.

Moreover, the area of differentially compressed image data Δcl to Δc29 is
Only the bits corresponding to the amount of data are provided.

Then, differentially compressed image data Δc provided in the image area
Corresponding to each of the areas 1 to Δc29, the control area includes video RAMs 22a to 22 which are written during playback.
The address information of 2c is arranged as, for example, 18-bit data.

During playback, this address information is taken into the controller 110, and the addresses of the video RAMs 22a to 22C are controlled to ensure that the playback signal is processed correctly, as in the case where the data amount of each differentially compressed image data is fixed. It is made to be done.

By varying the amount of data as shown in FIGS. 21 and 22, it is possible to record and reproduce differentially compressed image data with an amount of data that corresponds to the image condition, and the performance of the image data can be improved. .

In addition, from the perspective of being able to use the image area effectively, the second
Although the example in FIG. 2 is better, the example in FIG. 21 is better from the viewpoint of effective use of the control area.

Next, time code will be explained.

Although not mentioned above, it is conceivable to arrange a time code in the control area of recording data.

In the above example, the synchronization code section is 64 bits, but as shown in FIG. 23, for example, the synchronization code section is 48 bits, and a 16-bit time code section is provided between the synchronization code section and the mote code section. .

Similarly to the synchronization code section and the mode code section, this time code section is provided, for example, four times in one compression reference period (1 second), and the same data is allocated to the four time code sections. .

The 16-bit data in the time coat section represents, for example, absolute time (seconds). In this case, if each digit of the decimal number is represented by a 4-bit binary number, so-called BCD (binary coded decimal) data, time from 0 to 9999 seconds can be represented. Also, if it is 16-bit binary data, 0 to
It can represent a time of (216-1) seconds.

During playback, by importing the time code recorded in this way, it can be used to control searches, display of remaining tape capacity, position adjustment during editing, etc.

In addition, by using the time coat mentioned above, 1
Searches can be performed with an accuracy of seconds, but by using different types of synchronization codes 1-4, searches can be performed with an accuracy of 174 seconds.

Furthermore, as described above, by using the variation data of each differentially compressed image data arranged in the control area, it becomes possible to search with frame accuracy, which is effective for screen adjustment during editing, for example.

Incidentally, the configuration, arrangement position, and number of hits of the time court are not limited to the example shown in FIG. 23. For example, the time code structure may be expressed in hours, minutes, and seconds.

Next, by using the signal processing device shown in FIG.
The signal with the data structure of the example in Figure 4 or the example in Figure 20 is DA
An example will be described in which a tape recorded with T is digitally dubbed using two DATs.

FIG. 24 shows a configuration for digital dubbing using two DATs.

In the figure, 201 is a DAT on the master side, and 202 is a DAT on the slave side. These DAT2
01 and 202 are connected by a so-called digital audio interface DAI, and DA
A synchronization signal such as a pit clock BCK is supplied from T201 to DAT 202 in order to synchronize both. Roughly speaking, DAT 202 has more DA than DAT 201.
Various control flags are provided to control the operation of T.

Further, the DAT 201 is equipped with at least a video reproduction circuit of the signal processing device shown in the example of FIG. 1, and a monitor 203 is connected to the video out terminal.

Further, the DAT 201 is provided with a dubbing start key 201a, a dubbing stop key 201b, and a dubbing period setting key 201C in addition to normal recording/reproducing keys (not shown).

First, an example will be described in which dubbing is performed for an arbitrary period while monitoring the playback screen along the flowchart of FIG. 25. In this dubbing example, in addition to the synchronization codes IA to 4A, synchronization codes IB to 4B for reverse playback must be arranged and recorded as in the example in FIG. 20.

When the dubbing start key 201a is turned on and dubbing is instructed while the DAT 201 is in the normal playback state and a moving image is displayed on the monitor 203, step 211
Then, a recording pause flag is supplied from the DAT 201 to the recording pause flag 202, and the DAT 202 is placed in a recording pause state.

Next, in step 212, the frame image data at the time when the dubbing start key 201a was turned on is sequentially read out from the image decompression unit 46, and a still image is displayed on the monitor 203.Next, in step 213 , DAT20
1 starts reverse playback. Even during this reverse playback, still images continue to be displayed on the monitor 203.

Next, in step 214, it is determined whether the synchronization code IB was entered manually. When the synchronization code IB is entered manually, it is determined in step 215 whether or not the synchronization code 4B has been input. When synchronization code 4B is input, it is determined in step 216 whether synchronization code 3B is input.

When the synchronization code 3B is input manually in step 216, the reverse playback of the DAT 201 is stopped in step 217.

Next, in step 218, a pause release flag is supplied from the DAT 201 to the DAT 202, and the DAT 202 is placed in a recording state.

Next, in step 219, normal playback of the DAT 201 is started, and the digital audio interface DAI
Playback data is supplied to the DAT 202 via the DAT 202, and recording begins.

Then, in step 220, display of a moving image is started on the monitor 203.

Next, in step 221, it is determined whether the dubbing stop key 201b is on. When the dubbing stop key 201b is on, in step 222, the synchronization code F'
It is determined whether IA has been input. Synchronous court IA
is input, it is determined in step 223 whether synchronization code 2A has been input.

When the synchronous code F 2 A is input, step 2
At 24, a recording stop flag is supplied from the DAT 201 to the DAT 202, the DAT 202 is brought into a stopped state, and recording is stopped.

Then, in step 225, reproduction of the DAT 201 is stopped, and the dubbing operation is ended.

According to the dubbing example shown in FIG. 25, a still image based on the frame image data at the time when the dubbing start key 201a is turned on is displayed, so that it is possible to confirm the image at which dubbing is to be started. Furthermore, the synchronization code 4A is controlled based on the synchronization code.

It is recorded from the part immediately before 4B, and the synchronization code 2A
, 2B, the necessary parts can be recorded efficiently.

Next, an example will be described in which dubbing for an arbitrary period is executed while monitoring the playback screen along the flowchart of FIG. 26. It should be noted that this dubbing example can be applied to recording in either the configuration shown in the example shown in FIG. 4 or the example shown in FIG. 20. In the figure, synchronous courts 1 to 4 correspond to synchronous courts IA to 4A in the example of FIG. 20.

When the dubbing start key 201a is turned on and dubbing is instructed while the DAT 201 is in the normal playback state and a moving image is displayed on the monitor 203, step 231
Then, the recording pause flag is supplied from the DAT 201 to the recording pause flag 202, and the DAT 202 is placed in a recording pause state.

Next, in step 232, it is determined whether the synchronization court 3 has been manually operated. When sync code 3 is manually generated,
At step 233, a pause release flag is supplied from the DAT 201 to the DAT 202, and the DAT 202 is placed in a recording state. As a result, recording of playback data supplied from the DAT 201 via the digital audio interface DAI is started.

Next, in step 234, it is determined whether the dubbing stop key 201b is on. When the dubbing stop key 201b is on, it is determined in step 235 whether synchronization code l has been input. When synchronization code 1 is input, it is determined in step 236 whether synchronization code 2 is input.

When synchronization code 2 is input, a recording stop flag is supplied from DAT 201 to 202 in step 237, DAT 202 is placed in a stopped state, and recording is stopped.

Then, in step 238, reproduction of the DAT 201 is stopped, and the dubbing operation is ended.

In the dubbing example shown in FIG. 26 as well, the control based on the synchronization code records from the part immediately before the synchronization code 4 and also records up to the part immediately after the synchronization code 2, so that necessary parts can be efficiently recorded.

Next, an example in which dubbing is performed during a set dubbing period will be described along the flowchart of FIG. 27. Note that this dubbing example can be applied to a dubbing in which a time code is recorded, as shown in FIG.

First, in step 241, the dubbing period setting key 201
The dubbing start time and dubbing end time are set using c. The time is entered manually using, for example, 1 hour, minute, and second.

Next, in step 242, when the dubbing start key 201a is turned on, in step 243, a recording pause flag is supplied from the DAT 201 to the DAT 202, and the DAT 202 is supplied with a recording pause flag.
is placed in a recording pause state, and then, in step 244, D
Playback of the AT 201 is started, and in step 245 it is determined whether the time code detected from the control area of the playback data is "dubbing start time - 1 second". When the time code is "dubbing start time - 1 second",
At step 246, it is determined whether synchronization code 3 has been input.

When synchronization code 3 is input in step 246, a pause release flag is supplied from DAT 201 to 202 in step 247, and DAT 202 is placed in a recording state. As a result, recording of playback data supplied from the DAT 201 via the digital audio interface DAI is started.

Next, in step 24, it is determined whether the time code detected from the control area of the reproduced data is "dubbing end time + 1 second". When the time coat is "dubbing end time + 1 second", in step 249, the DA
A recording stop flag is supplied from T201 to 202, and DA
T202 is set to a stopped state, and recording is stopped.

Then, in step 250, reproduction of the DAT 201 is stopped, and the dubbing operation is ended.

According to the dubbing example shown in FIG. 27, H) dubbing for a predetermined period can be automatically performed. Also,
By controlling based on the synchronization code, recording starts from the part immediately before the synchronization code 4, and also records up to the part immediately after the synchronization code 2, so that necessary parts can be efficiently recorded.

In addition, in the example in Fig. 24, the DAT20 of the master
1, the DAT 202 on the slave side may be provided with operation keys and configured to be operated by keys.

By the way, in the above example, only image data for a moving image is recorded, but it is also possible to record image data for a still image by switching.

In this case, as shown in FIG. 28, after certain moving image compressed image data is arranged, still image image data S1, S
2,... are recorded.

In this way, recording of image data S1, S2, etc. for still images can be easily realized using the signal processing apparatus shown in FIG. 1.

That is, RAM 17a to 17c! :III
Next, the image data of each input frame is read out and recorded as still image data in the data area.

In this case, the image compression unit 19 performs compression processing to make the image data S1, S2, etc. for still images the same as the reference image data VBN for moving images, and also reduces the compression rate. Alternatively, image data for still images of higher image quality can be recorded by expanding the area and recording without compression.

According to the signal processing device shown in FIG. 1, the RA for three frames is
Since M17a to M17c are included, even if the image data for still images is of high image quality, it is possible to record at least three consecutive frames, so-called continuous shooting of three images.

In addition, as shown in FIG. 28, image data S for still images
1, S2, etc. immediately before the start of each.
A synchronization code section and a mode code section are provided in the mW region. In the mode code section, data indicating the still image mode is arranged.

During playback, control is performed to shift from moving image playback processing to still image playback processing based on data indicating that the still image mode is detected from the control area of the playback data.

In the example shown in FIG. 28, image data S for still images
1. S2. ... are arranged consecutively, but they may be arranged at predetermined intervals.

In the above embodiment, for the total number of bits of the digital signal recorded and reproduced in the DAT, which is 16 bits,
Although 12 bits are used as an image area, 3 bits are used as an audio area, and 1 bit is used as a control area, it goes without saying that the number of pits and the positions of the pits are not limited to these.

In the above embodiment, the video signal is NTSC.
This is an example of handling C method, but PA
Video signals of other formats such as L format or SECAM format can also be handled in the same way. In that case, changes will be required depending on the number of frames, etc. For example, when the number of frames is 25 frames/second, there are 24 pieces of differentially compressed image data from Δcl to Δc24.

Further, in the above-described embodiments, the recording/reproducing apparatus is a DAT, but the present invention can be similarly applied to a disc or an optically recorded recording medium.

[Effects of the Invention] As described above, according to the present invention, still images based on the decompressed image data of one screen at predetermined intervals are sequentially displayed, and so-called strobe playback can be performed. In this way, strobe playback is possible, so
Devices that are more user-friendly, such as DA
You can get T.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a signal processing device according to the present invention, FIGS. 2 to 6 are diagrams for explaining recorded data, and FIGS. 7 to 9
The figure is a diagram for explaining the example in Figure 1, Figure 10 is a flowchart showing the operation during normal playback, Figures 11 to 15 are flowcharts showing the operation in still playback, and Figure 16 is the operation in fast forward playback. 17 is a flowchart showing the operation of fast-forward playback, FIG. 18 is an explanatory diagram of the operation of slow playback, FIG. 19 is a flowchart showing the operation of slow playback, and FIG. 20 is a flowchart showing the operation of reverse playback. Figures 21 and 22 are diagrams showing the configuration of recorded data when varying the amount of data, Figure 23 is a diagram for explaining time codes, and Figure 24 is a diagram for explaining digital dubbing. FIGS. 25 to 27 are flowcharts showing the dubbing operation, and FIG. 28 is a diagram showing the structure of recording data when switching between moving images and still images. 17a to 17c, No. 34 4φRAM 19... Image compression section 22a to 22c -◆-Video RAM M24... Mixing circuit 25... Control data generation circuit 26... Scene change detection circuit 33... Audio DSP 41...Separation circuit 42...Control data discrimination circuit 46...Image expansion unit 110...Controller 120 Fist/pot RAM controller 130.201.202 Eyes/DAT 140...Keyboard 203...◆Monitor 1/(413 to Hz x 2) Digital signal format system Will I area (L pit) Still playback (1st still playback) Figure 11 Still playback (3rd still playback) Funeral 3 Figure 7 Figure 5 Code No. 23 Fig. 24

Claims (1)

[Claims] (1) It is recorded in the state of a digital signal of N bits (N is an integer), and a part of the above N bits forms an image area, an audio area, and a control area, respectively, and the above image area in each compression reference period is , a device for reproducing a digital video signal in which compressed digital video signals for multiple screens constituting a moving image are arranged, and digital audio signals for the compression reference period are arranged in the audio area in each compression reference period; means for decompressing the compressed digital video signal for the plurality of screens separated from the image area of each of the compression reference periods of the playback signal; A digital signal reproducing device comprising: means for repeatedly outputting image data until the next expanded image data for one screen is obtained.