JPH0447878A - Digital signal recording and reproducing system - Google Patents

Abstract

PURPOSE:To record/reproduce both video and audio signals simultaneously by forming picture, audio and control areas with parts of bits in N bits, arranging a video signal to the picture area for each compression reference period and arranging an audio signal for an audio area and arranging a next or succeeding data or a data relating to the audio area to the control area. CONSTITUTION:Bits [b15-b4], bits [b3-b1] and a bit [b0] are used for picture, audio and control areas respectively. A video signal of the NTSC system is used, a picture data by 30 frames is arranged to the picture area for each compression reference period and the data is compressed within 1152000 bits. Reference picture data VB1, VB2,... corresponding to a picture data of a lst frame and differential compressed picture data DELTAc1, DELTAc2 to DELTAc29 corresponding to the picture data are arranged sequentially to the picture area. An audio data by the compressed reference period is arranged to the audio area, the ADPCM system is adopted for the coding system and the data is compressed within 288000 bits. The control area is provided with the synchronization, mode and control code section, a discrimination circuit discrimiantes the code and next and succeeding data are controlled under the control of a CPU.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording and reproducing method for simultaneously recording and reproducing a digital video signal and a digital audio signal for moving images.

[Prior art] Current digital audio recorder (hereinafter referred to as rD)
ATJ) 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 this way, when recording a digital video signal for a moving image, considering the transmission rate of DAT, etc., it is conceivable to compress the digital video signal and record it.

In this case, by simultaneously recording information indicating the method used for compression processing, decompression processing can be performed based on this information during playback. In other words, it becomes possible to deal with any type of compression processing during recording.

In addition, by simultaneously recording mode information such as the digital video signal to be recorded, the sampling clock of the digital audio signal, the number of bits per sample, and the number of frames of the video signal, the playback signal can be adjusted based on this information during playback. System processing can be changed. In other words, it becomes possible to cope with any signal mode during recording.

Therefore, in the present invention, a digital video signal for a moving image and a digital audio signal are simultaneously recorded and reproduced using compression processing, and data related to these digital signals is also simultaneously recorded and reproduced.

Means for Solving cfIn] This invention records and reproduces a digital signal of N bits (N is an integer), and a part of these N bits:
An image area, an audio area, and a control area are respectively formed.

The image area in each compression reference period contains compressed digital video signals for multiple screens constituting a moving image, and the audio area in each compression reference period contains digital audio for the compression reference period. A signal is placed there.

Further, the control area in each compression reference period is arranged with data related to digital signals allocated to the image area or audio area of the next and subsequent compression reference periods.

For example, regarding data regarding a digital signal, a plurality of pieces of the same data are distributed at predetermined intervals within one compression reference period.

[Operation] The amount of information in digital video signals for moving images is extremely large;
It is difficult to record and reproduce data simultaneously with digital audio signals using DAT as is.

However, in this example, since the moving digital video signal is compressed and recorded, it is easy to record and reproduce the digital audio signal simultaneously.

In addition, since data related to digital signals placed in the image area or audio area is recorded in the control area in each compression reference period, by changing the operation of the signal processing system based on this data during playback, Good reproduction processing is possible regardless of what kind of compression processing was performed during recording or what mode of signal was recorded.

In addition, the control area in each compression reference period contains data related to the digital signal in the image area or audio area in the next compression reference period, so when playing back the digital signal in the image area or audio area in each compression reference period. It becomes possible to control the operation of the reproduced signal processing system before processing.

In addition, since multiple pieces of the same data are distributed at predetermined intervals during one compression reference period, the data related to the digital signal can be efficiently captured no matter where the data is played back. The operation of the signal processing system can be controlled smoothly.

[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
Of the 0 bits, bits [, b15 to b4], bits [b3 to bl], and bits [b0] 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 , 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 Y1, the red difference signal U, and the blue difference signal V 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, 256H x 240V (7) pixel data is reduced to 1/2 by subsampling processing.

Furthermore, a total of 24 bits of the luminance signal Y, 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, reference image data corresponding to the image data of the first frame, VBI, VB2, φ
・ is arranged, followed by differentially compressed image data Δcl, Δc2, corresponding to the image data of the 2nd to 29th frames.
... Δc29 is sequentially arranged.

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

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 32kHz, 4 bits per sample, and 2 channels (stereo or 2 monaural channels), the amount of information is 32kHz 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
A voice region is formed by three bits b3 to bl of bO, and the transmission rate of the voice region is 96 kHz×3 bits=288 kbps (see FIGS. 2 and 3).

This can also be considered as 32 kHz x 9 bits = 288 kMS. Therefore, for example, as shown in FIG. 5, audio data is allocated to 8 bits out of each 9 bits,
Bit rate adjustment is performed. That is, 32kHz
zX8 bits = 256 kbps.

Furthermore, the controlled WIN 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 in the four synchronization code sections, respectively.

As shown in FIG. 4, synchronization code 1 is assigned to the synchronization code section immediately before the next compression reference period, and synchronization code 4 to 2 is assigned to the three previous synchronization code sections, 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 that follows the synchronization code 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 reference period. This mode code section contains data related to image data, audio data, etc. to be arranged in the next compression reference period.

The following data can be considered as data related to image data.

■Resolution data 256H x 240V 512HX 480V 768H , blue difference signal V red signal R1
Green signal G1 Blue signal B Other bit data 24 bits (8 [Y, R + 8 [Ll, G + 8 [
V, B]) 16 bits (6[Yco +5 [u] +5 [V])
9-bit (Y, U, Vt or R, G, 8 (7) compressed data) and other data related to audio data include the following.

■Encoding method data DPCM PCM (linear) PCM (nonlinear) Other ■Bit data 4 bits, 6 bits, 8 bits, IO bits 12 bits, 16 bits, etc. ■Sampling frequency data 16 kHz, 32 kHz, 44.1 kHz .

48 kHz, Others ■ Data on the number of channels 1 channel, 2 channels, etc. In addition to the data related to the image data and audio data mentioned above, the mode code section includes a scene change in the next compression reference period as described later. Sometimes, data indicating the presence or absence of a scene change is also arranged.

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

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

The same data is allocated to the four control code sections in each compression reference period. This control code section contains a microcode for decompressing image data to be placed in the next compression standard period, and is made to be compatible with any compression method 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 distributing the same data to 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 is started. 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 t in FIG. 6). That is, from time point tc, the reference image data VBN+2 after the scene change, differentially compressed image data ΔC1, Δc2, . . . are sequentially arranged and recorded in the image area.

In addition, along with this, the recording state of data in the control area is also reset, and a synchronization code 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 . The decoder 13 outputs a luminance signal Y, a red difference signal U, and a blue difference signal ■, and supplies them to the A/D converter 14, respectively.

Further, the video signal S■ outputted from the amplifier 12 is supplied to a synchronization separation and clock generation circuit 15. circuit 1
5 to 8, the frequency is synchronized with the synchronization signal of the video signal SV.
fsc/3 (fsc is color subcarrier frequency, 3.58M)
(z) clock CKRI is output, and this clock C
KRI is supplied to the A/D converter 14 as a sampling clock.

The A/D converter 14 samples each of the signals Y, U, and V so that the number of samples in one effective horizontal period is 256, and converts them into digital signals 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 110 including a CPU.
For each frame period, side a, side b, side a, side a, etc.
are connected sequentially.

The fixed terminal on the a-a side of the changeover switch 16 is connected to RAM1.
It is connected to the input side of 7a-17c. RAM 17a
~17c write/read is performed by RAM controller 1
20. In addition, RAM controller 1
The operation of 20 is controlled by 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 bit 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.

The RAMs 17a to 17c receive signals Y, Y, and Y, respectively, during one frame period connected to the changeover switch C side.
256 pieces in the horizontal direction between each of U and V,
240 sample data are written in the vertical direction.

Signals Y written in these RAMs 17a to 17c,
The 256H x 240V data regarding each of U and ■ is repeatedly read out twice in the next two frame periods.

The signal read out from the RAM 17a is transferred to the selector switch 1.
It is supplied to fixed terminals 8a, 18b, and 18c on the a side, the a side, and the a side, respectively. The signals read from the RAM 17b are supplied to fixed terminals on the bs, b side, and a side of the changeover switches 18a, 18b, and 18c, respectively. RAM
The signal read out from 17c is the changeover switch 18a,
It is supplied to fixed terminals on the a side, a side, and b side of 18b and 18c, 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 configured such that the changeover switch 16 is set to the a side, the b side, clpl, al+J,
. . , the a side, the a side, the b side, the a side, . . .

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 one frame for each of v is 1
It is said to be 72. 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 l-frame samples for 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 are supplied to the video RAMs 22a to 22c via the connection switch 20 and the changeover switch 21, and are 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 at the time of recording. The changeover switch 21 is sequentially connected to the a side, the b side, the a side, the a side, . . . for each compression reference period.

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-a side during the compression reference period.
The reference image data VBN and differentially compressed image data ΔC1 to Δc29 formed by the image compression unit 19 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 next one compression reference period.

Reference image data VBN and differentially compressed image data Δc1 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
are connected to sides a to c@, respectively, during a period when image data is read from the video RAMs 22a to 22b.

The operation of mixing circuit 24 is controlled by controller 110.

The left and right channel audio signals SAL and SAR supplied to the audio in terminal 31 are amplified by an amplifier 32 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 further encoded using the RAM 34 using the ADPCM method so that each 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 mode code, and a control code. The operation of the generation circuit 25 is controlled by the controller 110. Control data outputted from the generation circuit 25 is supplied to the mixing circuit 24 and arranged in the control area of recording data.

In this way, the mixing circuit 24 forms recording data as shown in FIG.
0 and recorded in DAT format.

Further, 26 is a scene change detection circuit.

The second 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 reference image data VBN using 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, record data as shown in FIG. 6 is formed, and this record data is supplied to the DAT 130 and
It is recorded in T format.

FIG. 8 shows a timing chart of the recording system regarding video signals and audio signals.

A and B in the figure are a video signal SV and audio signals SAL and SAR supplied to terminals 11 and 31, respectively. VGI, VG2, ... ・AGL AC3
, . . . are the video signal and audio signal of each compression reference period, respectively.

As shown in FIG.
L CVG2, . . . are sequentially written.

In addition, although not mentioned above, the RAM 34 also contains the above-mentioned video R.
Similar to AM22a to 22c, RAM a to C areas are provided, and as shown in the figure, audio DSP
33 ADPCM compressed audio data CA Gl,
CA 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,... 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, and image data, audio data, and control data are separated from the reproduced data.

The control data separated by the separation circuit 41 is supplied to a control data discrimination circuit 42, where a 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 section 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.

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 Δc1 to Δc1 for 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 46 are controlled by the controller 110. The connection switch 44 is turned on during playback. The changeover switch 45 selects all, bm for each compression reference period.
, c side, a side, . . .

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 separated by the separation circuit 41 and the differentially compressed image data Δcl to ΔC29 are written in the l 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 next one compression reference period.

Reference image data VBN and differentially compressed image data Δc1 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 switches 23 are connected to the all to C sides, respectively, during a period when image data is read from the video RAMs 22a to 22c.

As described above, the operation of the image decompression section 46 is controlled by the controller 110 based on the control code, 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 VBH. 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 for 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
are supplied to a matrix circuit 47, and primary color signals R, G, and B output from this matrix circuit 47 are supplied to a D/A converter 48. The D/A conversion 648 is supplied with a clock CKPI from the generation circuit 43. And D
/Analog primary color signal R% output from A converter 48
G and B are video out terminals 49R and 49R, respectively.
49G and 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.

Further, the audio data separated by the separation circuit 841 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 led to an audio out terminal 36 via an amplifier 35.

Note that when there is a scene change, the signal processing state is reset even if it is in the middle of the 1 second compression reference period. In other words, the changeover switch 45 is switched and writing to the next video RAM is started. Even during the processing of the image decompression unit 46 that is performed after one compression reference period, the formation of the first frame of image data is started from the reference 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 regarding video signals and audio signals.

From the DAT 130, compressed image data 9 of each compression reference period is
CV Gl, CV G2, meeting, compressed audio data C
AGI, CAG2, and φ are played in correspondence (
(See Figure 9A).

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

In addition, as shown in C in the figure, reproduced compressed audio data CAGI is stored in areas RAM a to RAM C of the RAM 34.
, CA G2, . . . 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,...
is output accordingly (see E in the same 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 input.

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 expansion section 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 1 has been input. When the synchronization code l is input, in step 54, any video RAM (video RA
(M22a to M22c are used sequentially), input of compressed image data for one compression reference frame is started.

Next, in step 56, it is determined whether synchronization code 1 has been input. When the synchronization code 1 b1 is manually input, in step 56, manual input of compressed image data corresponding to one compression standard interval is started in the next video RAM.

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.

Then, the monitor (v!) connected to terminals 49R to 49B.
J (not shown).

Next, in step 58, it is determined whether synchronization code l has been input. When the synchronization code I is input, it is determined in step 59 whether or not the stop key on the keyboard 14° 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 is performed after the decompression processing of the compressed image data written to any of the video RAMs 22a to 22c in the previous compression reference period is completed, and then the processing of the subsequent compression reference period needle is performed. When there is a scene change, the compressed image data of 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. (See the scene change section in Figure 9C9D). In other words, one of the two video RAMs contains the compressed image data before the scene change < c v
c Ni1) is written, and the compressed image data after the scene change (CV G N+2) is written to the other. In this sense, three video RAMs 22 a to 22
c is 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 playback is designated by operating the keyboard 140, it is determined in step 61 whether synchronization code 2, 3, or 4 has been input.

When any of these sync codes are human-powered,
At step 62, 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 63, it is determined whether synchronization code 1 was entered manually. 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, the reference image data is read from the video RAM, and the image decompression section 46 performs decompression processing to form image data for one frame, and stores the image data for one frame 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 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 period is displayed.

If the playback key is not on in step 67, it is determined in step 69 whether the stop key on the keyboard 140 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 the 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 manually.

When any of these synchronous coats are man-powered,
In step 72, the mode code placed next to the synchronization coat is loaded into the control area, and in step 73, based on the data indicating the presence or absence of a scene change in the mode coat,
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 synchronization code 1 has been input. When synchronization code 1 is input, in step 76, one of the video RAMs (Video RAM
22a to 22c are used sequentially) to write the reference image data immediately after the scene change.

Next, in step 77, reference image data is read from the video RAM, and the image decompression section 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 monitor connected to the terminals 49R-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 the keyboard 140 is on. If the playback key is on, the playback pause state of the DAT 130 is released in step 80, and the process returns to step 71. 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 keyboard 140 is on. If the stop key is not on, the process returns to step 79.

In step 81, 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 the time t has elapsed, it is determined in step 92 whether the stop key on the keyboard 140 is on. If the stop key is not on, step 68
The playback pause state of AT 130 is released and step 6
Return to 1.

In 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, at step 80, the DAT
The reproduction pause state of 130 is released, and the process returns to step 71.

In 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 pause key of the keyboard 140 is turned on to enter the playback pause state during the normal playback operation shown in the flowchart of FIG. It is also possible to configure a still image to be displayed on a monitor so that a still image of an arbitrary frame 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 input.

When any of these sync codes are human-powered,
In step 152, the mode code and control code placed following the synchronization code 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 153, it is determined whether synchronization code 1 has been input. When sync code 1 is manually generated,
In step 154, one of the video RAMs (Video R
(A M 22 a to 22 c are used sequentially), input of compressed image data for one compression standard interval is started.

Next, in step 155, it is determined whether synchronization code l has been input. When sync code 1 is input,
In step 156, N=0 is set, and in step 15
In step 7, L=1 is set, and in step 158, input of compressed image data for one compression standard interval to the next video RAM is started.

Next, in step 159, 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 (1!1 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.

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

Next, in step 163, it is determined whether synchronization code 1 has been input. If synchronization code 1 is not input, step 164 sets L=L+1, returns to step 160, and performs the same operation as described above.

When synchronization code 1 is input in step 163, it is determined in step 165 whether or not the stop key of 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, whereas when the stop key is on, the strobe playback operation is stopped.

In such a strobe playback operation, 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 for one second 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.

By the above-described playback operation, as shown in FIG.
2, V B 11, . . . are played back.

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

The reference image data VBI, VH2, reproduced in this way,
As shown in the figure, V B 11, . . . , are sequentially written into the video RAMs 22a to 22c.

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 VB1 and VH2) are changed to 3.
Displayed at intervals of 15 seconds. Therefore, 5/3
．． Fast-forward playback is performed at a rate of about 1541.6 times.

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

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

Next, in step 172, it is determined whether synchronization code 2, 3, or 4 has been input.

When any of these sync codes are entered,
At step 173, the mode 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 174, it is determined whether synchronization code 1 has been input. When sync code 1 is input,
In step 175, reference image data is written to any of the video RAMs (video RAMs 22a to 22c are used sequentially).

Next, in step 176, 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 stores the image data for one frame 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 178, it is determined whether two seconds have elapsed. When two seconds have elapsed, it is determined in step 179 whether the stop key on the 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 was shown in which fast-forward playback at a speed of about 1.6 times is performed, 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 CVGL CVG2, 11116 is compressed image data (reference image data VBN and differential compressed image data Δc1 to Δc29) of each compression reference period, and normally During playback, the files are played back in sequence every second.

In this example, the DAT 130 is placed in a normal speed playback state for three compression reference periods, then placed in a playback pause state for the same period of time, 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 (CVG4
~CVG6) are played continuously. Hereinafter, the same process will be repeated.

The compressed image data CVGI, CV G2, . . . of each compression reference period reproduced in this manner are sequentially written into the video RAMs 22a to 22c, as shown in FIG.

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 VGI, VG2, .
・is formed.

Then, a moving image based on the image data vG1, VG2, . . . is displayed on the monitor, but the same screen is displayed continuously two frames at a time. In other words, image data VGL
The time axis of the moving image based on VG2, . . . is 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 code 2, 3, or 4 was entered manually.

When any of these sync codes are entered,
At step 183, 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 184, N=0 is set, and then in step 185, it is determined whether synchronization code 1 has been entered manually.

When synchronization code 1 is input, N=N+1 is set in step 186, and then N=2 is set in step 187.
It is determined whether or not. If N=2, step 1
Go directly to step 88 and when N=2, step 18
9 to step 188.

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

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

In step 188, one compression group is stored in any video RAM (video RAMs 22a to 22c are used sequentially).
! Start inputting compressed image data for friends.

Next, in step 190, it is determined whether synchronization code 1 was entered manually. When synchronous court 1 is manually operated,
At step 191, it is determined whether N=3. N
If not equal to 3, the process returns to step 186 and the same operations as described above are repeated.

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 frames is written in 2c.

Next, in step 193, it is determined whether the same time T3 as the above-mentioned three compression reference intervals 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 N=0 in step 195, step 19
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 repeats the above-described operation, while when the stop key is on, the slow playback operation is stopped.

Note that the above example describes 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, but the 3 compression reference periods are It has been decided accordingly 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 173.

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 one shown in FIG. 20, the synchronization code IA
~4A, synchronous code IB~4B in a symmetrical position with mote code IA~4A (control code area in the example in Fig. 4),
Mode codes IB to 4B are arranged.

The synchronization code IA-4A and mode codes IA-4A can be detected during normal playback, while the synchronization code IB
~4B and mode code IB~4B can be detected during reverse playback.

Similar to the mode code in the example of FIG. 4, data corresponding to the next compression reference period in the normal reproduction direction is arranged in the mode code IA-4A.

Mode codes IB to 4B contain data corresponding to the next compression reference period in the reverse playback direction.

In addition to data similar to mode codes IA to 4A, this includes differential compressed image data Δc in the next compression period.
Variation data of the data amount from 1 to Δc29, data as to 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 Δc1 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 image condition, the differentially compressed image data Δcl~
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, in order to control the addresses of the video RAMs 22a to 22c during reverse playback and write playback data from the reverse direction to exactly the same address as during normal playback, each differentially compressed image data Δc
It is necessary to consider the data amount of l 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 synchronization code IA-4A and the remote code are
A reproducing operation is performed using F'IA to 4A.

Also, during reverse playback, synchronization codes IB to 4B are used.

A reproduction operation is performed using mode codes IB to 4B. In this case, based on the data amount fluctuation data of the differentially compressed image data arranged in mode codes IB to 4B,
The addresses of the video RAMs 22a to 22c are controlled, and playback data is omitted from the opposite direction to exactly the same address as during normal playback.

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

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

27200X31=843200 bitsThe image area of 1 compression standard wJrrJ is 11520 bits as mentioned above.
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 areas @BI to B29, 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, 2a or more is placed. area is used.

In this way, when 211 or more areas are used for one piece of differentially compressed image data, the information is placed and recorded at the beginning 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'' as the next block number part data, and ``0'' as the number part data.

As a result, image data Δc1 to Δc4 are arranged in regions B1 to 84, respectively, image data ΔC5 is arranged in regions B5 and B6, image data Δc6 to Δc19 are arranged in regions 87 to B20, respectively, and image data Δc20
is arranged in areas B21 and B22, and image data Δc2
It is shown that 1 to Δc29 are arranged in regions 823 to B31, respectively.

At the time of playback, this information is taken into the controller 110, and the addresses of the video RAMs 22a to 22c are controlled, so that the playback signal processing is performed correctly as in the case where the amount of data of each differentially compressed image data is fixed. Ru.

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 Δc1 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
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.

At the time of playback, this address information is taken into the controller 110 to control the addresses of the video RAMs 22a to 22C, so that the playback signal processing is performed correctly as in the case where the data amount of each differentially compressed image data is fixed. be made into

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 place a time code in the control 1Ill area of the recording data.

In the above example, the synchronization code section is 64 bits, but as shown in FIG. establish.

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

The 16-bit data of the time code 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 (2+6-1) 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 code mentioned above, 1
Searches can be performed with an accuracy of seconds, but by using different types of synchronization codes 1 to 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 precision, which is useful for screen adjustment during editing, for example.

Note that the configuration, arrangement position, and number of bits of the time code F 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 same figure, 201 is the DAT on the master side, and 201 is the DAT on the master side.
02 is a DAT on the slave side. These DAT201
and 202 are connected by a so-called digital audio interface DAI, and DAT2
From 01 to DAT 202, a synchronization signal such as a pit clock BCK is supplied to the DAT 202 in order to synchronize both. Further, the DAT 201 supplies the DAT 202 with various control flags for controlling the operation of the DAT.

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, it is necessary to arrange and record synchronization codes IB to 4B for reverse playback, as in the example in FIG.

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, 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 212, the frame image data at the time when the dubbing start key 201a was turned on is sequentially read out from the image expansion section 46, and a still image is displayed on the monitor 203.

Next, in step 213, the DAT 201 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 has been input. When the synchronous coat IB is manually operated, it is determined in step 215 whether the synchronous coat F' 4 B has been manually operated. When the synchronization code 4B is manually input, it is determined in step 216 whether or not the synchronization code 3B is manually input.

When the synchronization code 3B is input 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 is started.

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 IA
It is determined whether or not has been input. When the synchronization code IA is input, it is determined in step 223 whether or not the synchronization code 2A was input manually.

When synchronization code 2A is manually entered, step 224
Then, a recording stop flag is supplied from the DAT 201 to the DAT 202, the DAT 202 is placed in 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, synchronization codes 1 to 4 correspond to the synchronization code IA-4A in the example shown in FIG.

When the dubbing start key 201a is turned on and dubbing is pressed 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 synchronization code 3 was entered manually. When Synchronous Court 3 is manually operated,
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 1 has been input. When synchronization code 1 is input manually, it is determined in step 236 whether synchronization code 2 has been input.

When synchronization code 2 is input, in step 237, a recording stop flag is supplied from DAT 201 to 202, 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 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 interval opening setting key 201 is pressed.
The dubbing start time and dubbing end time are set using c. For example, the time is entered manually using "hours, minutes, and seconds."

Next, in step 242, the dubbing start key 201a is turned on, and in step 243, a recording pause flag is supplied from the DAT 201 to the DAT 202.
is considered to be in a recording pause state.

Next, in step 244, reproduction of the DAT 201 is started, and in step 245, it is determined whether the time code detected from the control area of the reproduced data is "dubbing start time - 1 second". When the time code is "dubbing start time - 1 second", it is determined in step 246 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 248, 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 code is "dubbing end time + 1 second", in step 249, the DA
A recording stop flag is supplied from T201 to 202, and DA
T 202 is placed in 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, it is possible to automatically dub a set visit. Further, by controlling based on the synchronization code, the data is recorded starting from the part immediately before synchronization code 4, and is also recorded up to the part immediately after synchronization code 2, so that the necessary part can be efficiently recorded.

In addition, in the example in FIG. 24, the DAT20 on the master side
Although the DAT 202 of the slave device is shown to be operated by keys, the slave DAT 202 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 some moving image compressed image data is arranged, still image image data SL
S2, . . . are recorded.

In this way, recording of still image image data SL S2, . . . can be easily realized by the signal processing device shown in FIG. 1.

In other words, the image data of each frame that is manually entered into the RAMs 17a to 17c in sequence 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 still image image data Sl, S2, . . . the same as the moving image reference image data VBN, 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 it has M 17 a - 17 c, even if the image data for still images is of high image quality, it is possible to record at least one continuous frame of three frames, so-called quick shooting of three images.

In addition, as shown in FIG. 28, image data S for still images
L S2, . . . A synchronization coat section and a mode code section are provided in the control area corresponding to immediately before the start of each fist. 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 bits and the arrangement position 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 be handled in the same way; in that case, changes will be required depending on the number of frames, etc. For example, if the number of frames is 25 frames/second. Sometimes, there are 24 pieces of differentially compressed image data, 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, not only audio signals but also video signals for moving images can be digitally recorded simultaneously through compression processing. Therefore, a very convenient recording and reproducing device, such as a DAT, can be obtained.

In addition, since data related to digital signals arranged in the image area or audio area, that is, compression information and signal mode information, are recorded in the control area, the operation of the signal processing system can be changed based on this data during playback. Therefore, regardless of what kind of compression processing was performed during recording or what mode of signal was recorded, it is possible to perform good reproduction processing.

In addition, the control area in each compression reference period contains data related to the digital signal in the image area or audio area in the next compression reference period, so when playing back the digital signal in the image area or audio area in each compression reference period. The operation of the reproduced signal processing system can be controlled before processing. Furthermore, data related to the digital signal is distributed in multiple pieces at predetermined intervals during the compression reference period, so data related to the digital signal can be efficiently captured no matter where it is played back from during playback. The operation of the signal processing system can be controlled smoothly.

[Brief explanation of drawings]

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-17c. 19 ・ 22 a - 22 C ・ 24 ・ ・ RAM ・・Image compression unit/Video RAM ・・Mixing circuit 130° 25 ・・Control data generation circuit 26 ・・Scene change detection circuit 33 ・・Audio DSP 41 ・・- Separation circuit 42...Control data discrimination circuit 46...Image decompression unit 110...Controller 120...RAM controller 201.202...DAT 140...Keyboard 203.1 Monitor still playback (1st Still playback) Figure 11 Still playback (Second still playback) Figure 12 Still playback (Third still playback) Figure 3 Figure 7 Film Hood No. 2310 figure

Claims (2)

[Claims] (1) A digital signal of N bits (N is an integer) is recorded and reproduced, and a portion of the N bits forms an image area, an audio area, and a control area, respectively, and the image area in each compression reference period is In the above, compressed digital video signals for multiple screens constituting a moving image are arranged, and digital audio signals for the above compression standard interval are arranged in the audio area for each compression standard period. A digital signal recording and reproducing method in which data related to a digital signal to be placed in the image area or audio area of the next and subsequent compression reference periods is placed in the control area in the period. (2) The digital signal recording and reproducing method according to claim 1, wherein the data regarding the digital signal is such that a plurality of pieces of the same data are distributed at predetermined intervals within one compression reference period.