JP3239408B2 - Audio signal processing device for digital VTR - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an SD (Standard Resolution)
Digital VTR for selectively recording digital and HD (high resolution) digital video signals on magnetic tape
Related to an audio signal processing device.

[0002]

2. Description of the Related Art In recent years, a digital VT for digitizing a color video signal and recording it on a recording medium such as a magnetic tape.
As R, a D1 format component digital VTR and a D2 format composite digital VTR for broadcasting stations have been put to practical use.

The former digital VT of D1 format
R represents the luminance signal and the first and second color difference signals, respectively.
After performing A / D conversion at sampling frequencies of 5 MHz and 6.75 MHz, the signal is subjected to predetermined signal processing and recorded on a tape. Since the sampling frequency ratio of these component components is 4: 2: 2, the ratio is changed to 4: 1. : 2: 2 system.

The latter digital VT of D2 format
R performs sampling and A / D conversion of the composite color video signal with a signal having a frequency four times the frequency fsc of the color subcarrier signal, performs predetermined signal processing, and records the signal on a magnetic tape. I have.

[0005] Since these digital VTRs are designed on the assumption that they are used for broadcasting stations, the image quality is given top priority, and one sample has an A / D conversion of, for example, 8 bits.
The converted digital color video signal is recorded without substantial compression. In the digital VTR of the D1 format, a segment system using 10 tracks in one field in the NTSC system and 12 tracks in the PAL system is adopted as a track pattern. The segment method is adopted
It is based on the fact that it is difficult to record a large amount of recording data on one track, and that shortening the track length can reduce the effects of track linearity defects even when the track pitch is narrow.

In a digital VTR, it is necessary to record a digital audio signal, a tracking pilot signal, and the like in addition to a digital image signal on a track. In the D1 format digital VTR described above, audio data is recorded at the center of a track, and a time code and a control signal for tracking are recorded in the longitudinal direction of the tape. In D2 format,
Audio data is recorded at both ends of the track, and a time code and a control signal for tracking are recorded in the longitudinal direction of the tape in the same manner as in the D1 format.

At the time of recording / reproducing, an error occurs, so that a digital image signal, a digital audio signal,
The subcode is encoded with an error correction code. As an error correction code, a product code in which encoding is performed with separate error correction codes in a row (horizontal) direction and a column (vertical) direction of a matrix data array is known. The product code has high error correction capability because each data symbol belongs to two error correction code sequences.

In a conventional digital VTR, a PCM audio signal of one field is recorded in a plurality of tracks in a distributed manner because of the segment system. P of each track
The CM audio signal is encoded with the above product code.
However, when there are many errors, the error cannot be completely corrected by the error correction code. At this time, the error data is modified so that the error does not become annoying. For example, mean value interpolation is performed to replace the error sample with the mean value of the correct samples before and after the error sample.

In order to effectively perform this error correction, P
Interleaving is performed to separate recording positions between consecutive samples in a sequence of CM audio signals. Conventional interleaving is performed in a PCM audio signal recorded on one track. As a result, when a large number of errors occur such that the PCM audio signal of the track is almost in error, it becomes impossible to correct errors as well as error correction, and the PCM audio signal of the track is lost. This error causes annoying abnormal sounds. To solve this problem, an effective interleaving process is required.

[0010]

It is necessary that not only SD video signals but also HD video signals can be recorded as digital video signals. HD video signal is S
Since the amount of information is larger than that of the D video signal, for example, one frame of the SD video signal is recorded on ten tracks, and
It is conceivable that the D video signal is recorded on 20 double tracks. Regarding audio information, the amount of information is the same between SD and HD. However, the area where audio information can be recorded is also doubled as a result of doubling the number of tracks.

Accordingly, an object of the present invention is to provide an audio signal processing device of a digital VTR capable of recording audio information effectively in a digital VTR capable of selectively recording SD video signals and HD video signals. .

[0012]

SUMMARY OF THE INVENTION The present invention compresses and encodes an input digital video signal for a predetermined period, and converts the encoded digital video signal into 2N (N) magnetic tapes by a magnetic head mounted on a rotating drum. A digital VTR audio signal processing apparatus for recording as an integer number of tracks, a circuit for recording a signal of a predetermined period as 2N (N is an integer) tracks when an input digital video signal has a standard resolution; When an input digital video signal has a high resolution, a circuit for recording a signal of a predetermined period as 4N tracks, and when recording a high resolution digital video signal, N sets of two adjacent tracks in the 4N tracks 2N consisting of
A digital VTR audio signal processing device comprising: a circuit for recording a digital audio signal for a predetermined period in the same interleave processing as when a standard resolution digital video signal is recorded for a plurality of tracks. .

[0013]

In recording an HD video signal, a digital video signal of a predetermined period (for example, one frame period) is recorded while being divided into 4N (for example, 20) tracks. A digital audio signal for one frame period is divided into N (= 5) sections. For each section of the audio data, two streams each including even-numbered and odd-numbered samples are formed. These two streams are recorded on 2N tracks composed of N sets of two adjacent tracks by the same interleave processing as when recording the SD video signal. Thereby, the processing of the audio signal can be made common, and the error correction capability can be enhanced.

[0014]

An embodiment of the present invention will be described below. This embodiment is a digital VTR capable of selectively recording an HD digital video signal and an SD digital video signal on the same magnetic tape. FIG.
2 shows the configuration of a signal processing unit on the recording side and reproducing side of the digital VTR.

In the configuration on the recording side shown in FIG. 1A, an HD digital video signal is
1 receives an SD digital video signal. These input signals are supplied to the HD signal processing circuit 2 and the SD signal processing circuit 22. These circuits perform processing such as extraction of valid data, compression coding such as DCT, and buffer rig for reducing the amount of information generated per frame to a predetermined value or less.
At the output of the HD signal processing circuit 2, data compressed at a rate of, for example, 50 MBPS appears, and the SD signal processing circuit 2
For example, data compressed to a rate of 25 MBPS appears in the output of No. 2. That is, after the compression processing, the data amount has a relationship of (HD: SD = 2: 1).

The outputs of the signal processing circuits 2 and 22 are supplied to framing circuits 3 and 23, respectively. The framing circuit 3 outputs two pieces of recording data each having a data amount of 25 MBPS.
The recording data of the data amount of MBPS is output. The framing circuits 3 and 23 arrange the compressed video data in a predetermined order. One output data of the framing circuit 3 is supplied to a parity generation circuit 5 and the other output data is supplied to an input terminal a of the switch circuit 4.
The output data of the framing circuit 23 is supplied to the other input terminal b of the switch circuit 4. This switch circuit 4
Is supplied to the parity generation circuit 25.

The switch circuit 4 is connected to the H
It is controlled by the D / SD mode signal. That is, in the case of the HD mode, the switch circuit 4 selects the input terminal a,
In the case of the SD mode, the input terminal b is selected. In the SD mode, the parity generation circuit 5 is inactive. This mode signal is supplied to a capstan motor control circuit (not shown), and the tape speed in the HD mode is set to S.
It is twice that of the D mode.

The outputs of the parity generation circuits 5 and 25 are supplied to multiplexers 6 and 26, respectively. PCM audio signals are supplied to the multiplexers 6 and 26 from the input terminals 7 and 27, and the PCM audio signals are supplied to the outputs of the parity generation circuits 5 and 25 in the time axis direction.
M audio signals are inserted. The audio signal processing circuit will be described later. Further, the subsequent multiplexers 8 and 28 add sub data from input terminals 9 and 29.

The outputs of the multiplexers 8 and 28 are supplied to channel coding encoders 10 and 30. Channel coding is for preventing waveform distortion of a reproduced signal and for correctly reproducing a signal, and includes randomization using an M sequence and processing of a partial response system.

The output signals of the encoders 10 and 30 are supplied to multiplexers 11 and 31. In these circuits 11 and 31, pilot signals and amble signals for ATF (automatic tracking follow-up) from input terminals 12 and 32 are added. The output signal of the multiplexer 11 is supplied to the head H1 via the delay circuit 13 and the recording amplifier 14, and is supplied to the head H2 via the recording amplifier 15. The output signal of the multiplexer 31 is supplied to the head H3 via the delay circuit 33 and the recording amplifier 34, and is supplied to the head H4 via the recording amplifier 35. The delay circuits 13 and 33 operate as demultiplexers for recording the data processed by one system with two heads.

Of the heads H1 to H4, the set of heads H1 and H3 and the set of heads H2 and H4 are mounted at 180 ° facing each other with respect to the rotating drum. Each set of heads has an integral structure. A magnetic tape is obliquely wound around the peripheral surface of the drum at a winding angle slightly larger than 180 ° or slightly smaller than 180 °.
A set of heads H1 and H3 and a set of heads H2 and H4 alternately contact the magnetic tape, and four tracks are formed by one rotation of the drum. Heads H1 (H2) and H3
(H4), the extending direction (referred to as azimuth angle) of each gap is different. For example ± 20
° azimuth angle is set.

H at which the switch circuit 4 selects the input terminal a
In the D mode, one frame of HD data is recorded on a magnetic tape as 20 tracks by all the heads H1 to H4. In the SD mode in which the switch circuit 4 selects the input terminal b, the tape speed is set to half of that in the HD mode, and no recording data is supplied to the heads H1 and H2. Data is recorded on the magnetic tape as ten tracks. In the same tape or cassette tape, a mixture of a pattern recorded in the SD mode and a pattern recorded in the HD mode is allowed. The head H
1 to H4 may be mounted on the drum in close proximity.

Next, the structure of the reproducing side will be described with reference to FIG. 1B. The reproduction data from the head H1 is supplied to one input terminal of the switch circuit 43 via the reproduction amplifier 41, and the reproduction data from the head H2 is supplied to the reproduction amplifier 42.
To the other input terminal of the switch circuit 43. Similarly, the reproduction data of the heads H3 and H4 are also supplied to the switch circuit 63 via the reproduction amplifiers 61 and 62, respectively. The switch circuits 43 and 63 alternately select the reproduction output of the two heads and output one-channel reproduction data.

The reproduced data from the switch circuits 43 and 63 are supplied to channel encoding decoders 45 and 65 via equalizers 44 and 64, respectively. The output of decoders 45 and 65 is TBC 46
And 66, and the time axis fluctuation is removed. T
Output terminals 47 and 67 from the outputs of BCs 46 and 66
The playback audio data is respectively extracted. This reproduced data is supplied to an audio signal processing circuit described later.

The output of TBCs 46 and 66 is EC
The signals are supplied to C (error correction circuits) 48 and 68, respectively, to decode the error correction code. The output of ECC 48 is supplied to frame decomposing circuits 49 and 69,
The output of C68 is supplied to the frame decomposition circuit 69. The frame decomposing circuits 49 and 69 decompose the frame so that the data having the frame structure is suitable for the decoding process, and the next SD image processing circuit 50 and HD image processing circuit 70
Supplied to In these processing circuits 50 and 70,
Decoding of compression coding such as DCT is performed. An SD digital video signal is obtained at an output terminal 51, and an output terminal 71
, An HD digital video signal is obtained.

The track pattern in the above embodiment will be described. FIG. 2 shows an array of data recorded on one track. In the figure, the left end of the track is the head entry side, and the right end is the head separation side. Further, no data is recorded in the margin and the IBG (inter-block gap), which are hatched areas.
In a preamble section (preamble or postamble) added to both ends of the data recording section, for example, a pulse signal having a frequency equal to the bit frequency of data is recorded, and a PLL provided on the reproduction side for extracting a bit clock is used. It is easy to lock.

Margins are provided at both ends of one track, and ATF pilot signals ATF1 and ATF2 are recorded adjacent to these margins. In the scanning direction of the head from the recording section of the pilot signal ATF1, the recording section of the audio signal (audio 1), the recording section of the video signal, the recording section of the audio signal (audio 2), the recording section of the subcode, the pilot signal AT
The recording section of F2 is provided in order. The effective area of one track is 16041 bytes long. At the end of the track, the contact between the head and the tape is unstable,
Pilot signals ATF1 and ATF2 are recorded. Also, at the time of high-speed reproduction in which the speed of the magnetic tape is higher than that at the time of recording, the contact at the end on the head separation side is more stable than that at the head entry side. Therefore,
The recording section of the subcode is on the side close to the end on the head separation side.

The recording data is composed of many sync blocks. A sync block has a sync block sync signal at the head thereof, an ID signal indicating the block identification and the position of the block in the screen, and a parity of data or an error correction code thereafter. It is. The length of the sync block differs between video data, audio data, and subcode, reflecting the difference in the amount of information in one track. In this example, AT
Each recording section and non-recording section of the effective area in one track other than the section (ATF1 and ATF2) of the F pilot signal is defined based on the length of the audio sync block. As shown, audio 1 and 2
Is selected as (14 × audio sync block), the video section is selected as (288 × audio sync block), and the subcode section is selected as (4 × audio sync block). Further, the lengths of the amble section and the IBG are defined as shown in the figure.

As described above, since the recording section and the non-recording section of each data are defined on the basis of the length of the audio sync block, the timing for controlling each section at the time of recording and reproduction is controlled. Can be simplified.

The audio signal processing circuit will be described with reference to FIGS. FIG. 3 shows a configuration for recording processing, in which analog audio signals AU1 and AU2 are supplied to input terminals 81A and 81B, respectively. These are connected to the PC by the A / D converters 82A and 82B.
After being converted into M audio signals, the RAM 83A, 83B
Is provided as its data input. Audio signal A
Both U1 and AU2 are two-channel (L / R) signals.

A write control circuit 84 and a read control circuit 85 for controlling the writing and reading operations of the RAMs 83A and 83B are provided. The mode signal MD and the frame ID are supplied.
The RAMs 83A and 83B have a configuration of, for example, two banks, and are provided for interleaving the PCM audio signal for one frame period according to the mode signal MD as described later.

The data output from the RAM 83A is supplied to an input terminal a of the switch circuit SW1 and an input terminal c of the switch circuit SW2. The data output from the RAM 83B is supplied to the input terminal b of the switch circuit SW1 and the input terminal d of the switch circuit SW2. Switch circuits SW1, SW2
Is switched by a control signal output from the read control circuit 85. The output signals of the switch circuits SW1 and SW2 are supplied to the parity generation circuits 86A and 86B, and a product code is encoded using, for example, a Reed-Solomon code. Audio data including parity is obtained from the output terminals 87A and 87B, respectively. These two audio data are respectively recorded in the audio recording sections (audio 1 and audio 2) in the above-described track format.

FIG. 4 shows the configuration of processing of reproduced audio data. Reproduction data from the sections of audio 1 and audio 2 are supplied to input terminals 91A and 91B, respectively. These are ECC92A, 92B
Undergoes error correction processing. The error-corrected data and error flags from the ECC 92A are stored in the RAM 93A,
93B, and the output of ECC 92B is similarly stored in RAM
93A and 93B.

A write control circuit 94 and a read control circuit 95 are provided in association with the RAMs 93A and 93B. These circuits 94 and 95 are supplied with an audio mode signal MD and a frame ID separated from the reproduction data. The RAMs 93A and 93B have a two-bank configuration, and perform deinterleaving complementary to interleaving during recording according to the mode signal MD. RAM9
The read output of 3A is supplied to a D / A converter 96A,
The read output of the RAM 93B is supplied to the D / A converter 96B. A reproduction audio signal corresponding to the data of the section of audio 1 is taken out to the output terminal 97A, and a reproduction audio signal corresponding to the data of the section of audio 2 is taken out to the output terminal 97B.

SD video signal, for example, 525 lines / 60
In a field system (for example, NTSC system), 1
As shown in FIG. 6, the recording data of the frame has 10 (N
= 5) is divided into tracks T0 to T9 and recorded. As described above, in this example, sections (audios 1 and 2) in which audio data can be recorded independently in one track are provided. As an example, it has a length of one frame period (the sampling frequency is 48 kHz, 16
PCM audio signals of bit linear quantization (2 channels) can be recorded in audio 1 and 2 sections.

An interleave process over 2N tracks is performed for each PCM audio signal in one frame period. FIG. 5 shows an L (left) channel PCM audio signal in one frame period in an analog manner. This PCM audio signal sequence for one frame period is expressed as (N =
Divide into sections of 5). A sequence including even-numbered samples in the PCM audio signal sequence included in the first section is represented by L0, and a sequence including the odd-numbered samples is represented by L1.
It expresses. Similarly, regarding the PCM audio signal sequences included in the second, third, fourth, and fifth sections, sequences L2, L4, L6,
L8 and sequences L3, L5, L including odd-numbered samples
7, L9 is formed. From the PCM audio signal of the R (right) channel in one frame period, PCM audio signal sequences R0 to
R9 is formed.

These PCM audio signal sequences are interleaved, error-correction-coded, and recorded in audio 1 and audio 2 sections. As a recording mode of the PCM audio signal, a soft tape mode used when a professional company such as a movie company produces a soft tape,
A user recording mode in which the user performs recording by himself is prepared. In the soft tape mode, one sample of the PCM audio signal is 16 bits, and in the user recording mode, one sample is 12 bits and the sampling frequency is 32 kHz. Therefore, the data amount of the PCM audio signal in the user recording mode is half that in the soft tape mode.

FIG. 7A shows the interleaving processing of the PCM audio signal in the soft tape mode. Track T
The first group (tracks T0 to T9) in the first half of
In the section of audio 2 in (4), (L1, L3, L5, L
7, L9) is recorded, and in the section of the audio 1,
(R0, R2, R4, R6, R8) are recorded. (R1, R3, R5, R7, R9) is recorded in the section of audio 2 of the second group of tracks T5 to T9 in the second half, and (L0, L2, L9) is recorded in the section of audio 1.
4, L6, L8) are recorded.

FIG. 7B shows the interleaving of the PCM signal in the user recording mode. In the user recording mode, as described above, since the data amount is half that of the soft tape mode, the PCM audio signal is recorded in each section of audio 1 and audio 2 in the same format as the soft tape mode. it can. Audio 1
As an example, the audio section 1 of the track T0
(L1, R0) are recorded in the tracks, and (L3, R2) (L5, R4) (L7, R6)
(L9, R8) (R1, L0) (R3, R2) (R5,
L4) (R7, L6) (R9, R8) are respectively recorded. In this case, the section of audio 1 is divided into the first half and the second half, and the upper half of the data (L
1, L3,..., R9) are recorded, and data (R0, R2,.

FIG. 8 shows another example of interleaving in the user recording mode. The example of FIG. 8 is obtained by exchanging the recording tracks of L2 and L3, R2 and R3, L6 and L7, R6 and R7 in FIG. 7B. The interleaving of FIG. 8 can be similarly applied to the soft tape mode. In the interleaving of FIG. 8 as well, one and the other of a pair of data sequences obtained by dividing one frame of a PCM audio signal into N are the first.
And the tracks included in the second group and the tracks included in the second group.

In a 625 line / 50 field system (for example, the PAL system), one frame of recording data is divided into (2N = 12) tracks T0 to T11 and recorded. Therefore, over these 12 tracks,
A PCM audio signal for one frame period is divided into (N = 6) sections, and an interleave process is performed for each PCM audio signal in each section. This interleaving process is the same as in the above-described 525 / 60-field system, and a description thereof will not be repeated.

When an error occurs in reproduced data due to scratches on the tape, dust or fingerprints attached to the tape,
If the error exceeds a level that can be corrected, error correction is performed on the error data to reduce the effect of the error. The above-described interleave processing is excellent in this error correction capability.

First, the error correction capability in the soft tape mode will be described with reference to FIG. As shown in FIG. 9A, it is assumed that an error (indicated by a hatched area) occurs in both the width and the length of the tape, and audio data can be reproduced only from the audio 2 section. In this case,
As is clear from FIG. 9A, the odd-numbered sequence of the L channel (L1, L3, L5, L7, L9) and the odd-numbered sequence of the R channel (R1, R3, R5, R7, R7).
9) is obtained as non-error data. Using these odd-numbered samples, even-numbered error samples can be corrected. As the retouching method, for example, a method of using an average value of samples before and after the error sample instead of the error sample can be adopted.

Next, as shown by the hatched area in FIG. 9B, when both audio 1 and audio 2 of the tracks T0 to T4 have errors, the tracks (T1, T2, T3, R5, R5, R7, R9) (L0, L2, L
4, L6, L8) can be obtained as data without errors. Therefore, for the R channel, (R0,
R2, R4, R6, R8) can be average-interpolated.
Regarding the channels, (L1, L3, L5, L7, L
The series of 9) can be averaged.

In the user recording mode, a high retouching ability is exhibited as in the soft tape mode. On the first record,
When the same data is recorded in audios 1 and 2, by selecting non-error data from both sections, error correction and error correction can be performed strongly. However, in this example, there is no guarantee that both data are the same, since after-recording is allowed. In such a case, error correction is performed for each of audio 1 and audio 2.

As shown by the hatched area in FIG. 10A, if a scratch in the longitudinal direction of the tape occurs due to a defect in the tape running system, the reproduced data in the first half of the audio 1 near the tape edge becomes an error. That is, the PC in the lower half of FIG. 10A
M audio signals (R0, R2,..., L6, L
8) is the error data, the upper half of which (L1,
L3,..., R7, R9) are correct data.
In this case, error data can be corrected by average value interpolation using correct data.

Next, as shown in FIG. 10B, in the user recording mode, audio PCs of tracks T0 to T4 are recorded.
When the M signal becomes error data, the error data can be corrected by the correct audio PCM signal from the audio 1 or 2 of the remaining tracks T5 to T9.

When data is recorded by two magnetic heads as in this embodiment, one of the magnetic heads may clog. When one of the magnetic heads logs, for example, tracks T0, T2, T4, T6, and T8
Cannot obtain correct playback data from At the time of the head clog, in both the soft tape mode and the user recording mode, the odd-numbered sequence of the L channel and the even-numbered sequence of the R channel become error data. These error data are stored in tracks T1, T3,
Correct reproduction data from T5, T7, and T9 can be interpolated.

Next, audio signal processing at the time of recording an HD video signal will be described. In the HD mode, the heads H1 to H4 are used, and the tape speed is twice as high as that in the SD mode. Therefore, as shown in FIG. 11A, one frame of data has 20 (4N, N = 5) tracks T0 to T0. T19
Is formed on the magnetic tape. In the HD mode, the same audio signal processing as in the SD mode is performed.
And SD, the amount of audio data is equal,
Also, the area in which audio can be recorded is twice as large as that of SD. It is preferable to utilize this point effectively.

As in the case of the above-mentioned SD mode, as shown in FIG. 11B, each channel (L, R) of a PCM audio signal of one frame is divided into five, and signals in each divided section are divided into an even-numbered sample sequence and an odd-numbered sample. Divide into series. Then, in the soft mode, as shown in FIG. 12A, interleaved recording is performed on 10 of the 20 tracks. This interleaving is performed by five sets T0, T1, T4, T5, and T of two adjacent tracks.
8, T9, T12, T13, T16, T17
This is performed in the same manner as in the above-mentioned SD mode (FIG. 7A).

The remaining ten tracks T2, T3, T
6, T7,..., T18 and T19, PCM audio signals L 'and R' of another system are interleaved and recorded. The PCM audio signal of another system may be a completely different signal or a 4-channel rear signal.

In the user recording mode, as shown in FIG. 12B, a PCM audio signal is recorded in audio 1 and audio 2 in the same interleaved manner by using two adjacent tracks out of 20 tracks. 10
Tracks T0, T1, T4, T5,..., T1
6 and T17, one stereo signal is interleaved and recorded as in the SD mode (FIG. 7B) described above. On the remaining ten tracks, PCM audio signals L 'and R' of other systems are recorded after the same interleaving processing. When recording different PCM signals for audio 1 and audio 2, respectively, four stereo signals can be recorded.

The above-described interleaving is an example in which one frame of a PCM audio signal is divided into five parts, similarly to the SD mode. However, one frame of a PCM audio signal is recorded in correspondence with one frame being recorded on 20 tracks. Signal 1
It may be divided into 0 sections, and each section may be divided into an even sample sequence and an odd sample sequence. That is, L-
For the channel, each of the 10 splits has (L1
0, L11) (L12, L13) (L14, L15)
(L16, L17) (L26, L27) (L
28, L29). The same applies to the R-channel.

FIG. 13A shows the interleaving of 20 sample sequences per channel obtained in 10 divisions in the case of the soft mode. FIG. 12 described above.
As in A, two stereo signals L, R and L ',
R ′ is recorded using audio 1 and audio 2 sections. The signals of each system are recorded on two adjacent tracks. If attention is paid only to the section of audio 1 or audio 2, it is the same as the interleaving of FIG. 12A.

FIG. 13B shows user mode interleaving. In the user mode, 32 kHz, 12 bits /
Although it has been described that the sample is converted to PCM,
In FIG. 13B, as in the soft mode, 48 kHz,
16 bit / sample PCM conversion and audio 1
And one audio PCM signal in each of the audio 2 sections.

FIG. 14 shows another example of soft mode interleaving. In the section of audio 2, 1
The PCM audio signal of the system is audio 2 in FIG. 13A.
Are recorded in the same interleave as that of the section. In the section of audio 1, the same PCM audio signal is recorded with the same interleave as that of audio 2. FIG. 14 shows double recording, which makes it possible to perform error countermeasures and error correction during reproduction more strongly.
In FIG. 14, since the same interleaving as in FIG. 13B is performed, an example of the user mode is omitted.

The above interleaving in the SD mode or the HD mode can be realized by controlling the read addresses of the RAMs 83A and 83B of the audio signal processing circuit and controlling the switch circuits SW1 and SW2 shown in FIG. For example, in the user mode in the SD mode for recording a video signal captured by a video camera integrated with a VTR, the analog video signal AU2 is supplied to the input terminal 81B. This signal is converted to PCM by the A / D converter 82B,
The data is sequentially written to M83B.

Reading from the RAM 83B implements the interleaving of FIG. 7B. RAM83
The read output of B is the input terminal a of the switch circuit SW1,
The parity signal is supplied to the parity generation circuits 86A and 86B via the input terminal c of the switch circuit SW2. Output terminal 8
The recording audio signal from 7A is recorded in the audio 1 section of the track, and the recording audio signal from the output terminal 87B is recorded in the audio 2 section of the track. Therefore, audios 1 and 2 have the same PCM
An audio signal is recorded.

Thereafter, when the after-recording is performed, the recording audio signal is supplied only from the input terminal 81B,
The switch circuit SW1 is set to select the input terminal b, and the switch circuit SW2 is set to select the input terminal c. Therefore, when dubbing, only the section of audio 1 is rewritten. At the time of reproduction, R in the configuration of FIG.
Deinterleaving is performed by controlling the writing of the AMs 93A and 93B.

[0060]

According to the present invention, in the HD mode in which the digital video signal is recorded on twice as many tracks as in the SD mode, the same interleaving process as in the SD mode is performed on 2N of the tracks. Can be shared with SD and HD.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a signal processing unit according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a data array of one track according to an embodiment of the present invention.

FIG. 3 is a block diagram illustrating an example of a configuration of an audio signal recording process;

FIG. 4 is a block diagram illustrating an example of a configuration of a reproduction process of an audio signal.

FIG. 5 is a schematic diagram illustrating division of one frame of audio data in the SD mode.

FIG. 6 is a schematic diagram showing a track pattern of segment recording of one frame of data in the SD mode.

FIG. 7 is a schematic diagram illustrating an example of audio data interleaving in the SD mode.

FIG. 8 is a schematic diagram of another example of interleaving of audio data in the SD mode.

FIG. 9 is a schematic diagram used to explain error correction of audio data recorded in a soft tape mode.

FIG. 10 is a schematic diagram used to explain error correction of audio data recorded in a user recording mode.

FIG. 11 is a schematic diagram showing a track pattern of segment recording of one frame of data in the HD mode, and FIG.
FIG. 7 is a schematic diagram illustrating division of one frame of audio data in a D mode.

FIG. 12 is a schematic diagram illustrating an example of interleaving of audio data in an HD mode.

FIG. 13 is a schematic diagram of another example of audio data interleaving in the HD mode.

FIG. 14 is a schematic diagram of still another example of audio data interleaving in the HD mode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 HD video signal input terminal 21 SD video signal input terminal H1-H4 Magnetic head

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Okada 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-2-49275 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G11B 20/12-20/12 103 H04N 5/91-5/92

Claims (1)

(57) [Claims] An input digital video signal for a predetermined period is compression-encoded, and the encoded digital video signal is recorded as 2N (N is an integer) tracks on a magnetic tape by a magnetic head mounted on a rotating drum. In a digital VTR audio signal processing apparatus, when the input digital video signal has a standard resolution,
Means for recording the signal for the predetermined period as 2N (N is an integer) tracks; means for recording the signal for the predetermined period as 4N tracks when the input digital video signal has a high resolution; At the time of recording a digital video signal of a resolution, the same interleaving processing as at the time of recording of the digital video signal of the standard resolution is performed on 2N tracks composed of N sets of two adjacent tracks in the 4N tracks. Means for recording the digital audio signal for the predetermined period.