JPS62157372A - Trick play method in r-dat device - Google Patents

Abstract

PURPOSE:To attain the fine trick play of a three-fold speed reproduction, etc., by reading out a sound data symbol by symbol in a numerical order from the first address space of a RAM, and then, reading out the sound data similarly from the second address space. CONSTITUTION:At the time of a normal reproduction, an address generator 17 generates an address in the same order as a symbol recording order to the RAM at a recording time. In the three-fold speed reproduction, for example, the address generator 18 generates addresses in the same order as the symbol recording order to the first address space, then, generates addresses in the same order as to the second address space. Accordingly, at the time of the normal reproduction, sound data are read out symbol by symbol in a numerical order from the RAM. First, at the time of the three-fold speed reproduction, sound data are read out symbol by symbol in a numerical order from the first address space 11-1 of the RAM, and then, sound data are read out symbol by symbol in the numerical order from the second address space 11-2.

Description

Detailed Description of the Invention <Industrial Application Denominator> The present invention is a digital audio device (R
- A trick play method in a DAT device).

<Prior art> Digital audio in which a head is rotated while being inclined relative to the longitudinal direction of the magnetic tape, digital audio data is recorded on the magnetic tape by the head, and the audio data is read from the magnetic tape and reproduced. There is a tape device (referred to as an R-DAT device).

The rotating head configuration used in such an R-DAT device is
It has approximately the same configuration as a rotating head in a VTR. In other words, as shown in FIG.
The relative positional relationship between the magnetic tape and each head is determined so that the running loci of I and HO2 on the surface of the magnetic tape MT are inclined with respect to the longitudinal direction of the magnetic tape MT. Then, every time the rotating body RB rotates 1800 times, each head MDI
, HD2 alternately contact the magnetic tape MT for 90 degrees each time, so that audio data is recorded on the magnetic tape or audio data is read from the magnetic tape. FIG. 5 is an explanatory diagram of the recording pattern recorded on the magnetic tape MT.
I and T2 are patterns recorded by heads HDI and HD2, respectively, Vt is the tape speed, and vh is the head rotation speed. Note that the R-DAT device performs azimuth recording. In other words, the gap of the first head MDI is tilted by θ degrees with respect to the vertical direction of the track for recording (+azimuth recording), and the gap of the second head HD2 is tilted by θ degrees in the opposite direction with respect to the gap of the first head. (
- azimuth) record).

In addition, in the R-DAT device, the first drum signal DRR, which is turned on and off every rotation of the cylinder (rotary head) shown in FIG. The second drum signal CLC (T is the rotation period) which turns off /off, the segment signal HTC synchronized with the contact between the head and the tape, and the P parity /Q
A parity switching signal PQS is generated, and the following signal processing and recording/reproducing processing are performed in synchronization with these signals.

(At the time of IJDi recording, when the first drum signal DRR is at the 4-level in the recording time chart of FIG. 6, the L - channel and R-channel audio data are separated into upper n bits and lower n bits data (symbols), and are arranged in chronological order in the order of sampling.
It is stored in the address space and the second address space.

Note that two tracks of audio data are recorded in the first RAM 11a per cylinder rotation.

On the other hand, in parallel with the storage of audio data in the first RAM 11a, audio data is read from the second RAM 11b, subjected to predetermined processing, and output. That is, when the head and tape are not in contact, in other words, when the segment signal HTC is at a low level (period Tl, T3), error detection and correction codes (P, Q parity codes) are added to the data stored in the second RAM 11b. However, during the period T2 when the head and the tape are in contact (when the segment signal HTC is in the heel pulse), the second R
The audio data is sequentially read from the first address space of AM11b and recorded on the magnetic tape MT by the first head HDI,
During the period T4 when the head contacts the tape, the second R
The audio data read from the second address space of the AM 11b is sequentially recorded on the magnetic tape MT by the two-head HD2.

Then, when the drum rotates once and the first drum signal DRR becomes high level, the AD converter output is then transferred to the second RAM1.
The audio data stored in RAM 1b and in the previous cycle in the first RAM 11a is similarly added with an error detection and correction code, output, and recorded on the magnetic tape. From then on,
Similar processing is repeated.

! During playback, when the first drum signal is at a low level in the time chart for playback shown in FIG. 6, the audio data read by the first head is stored in the first address space of the first RAM 11a, and the second head reads The read audio data is stored in the second address space.

On the other hand, in parallel with the storage of audio data in the first RAM 11a, audio data is read from the second RAM 11b, subjected to predetermined processing, and output to the DA converter. That is,
When the head and tape are not in contact, in other words, when the segment signal HTC is at a low level (TI, T3 period), the second RA
The data stored in M11b is subjected to the error detection correction process.

Thereafter, when the segment signal HTC is at a high level, the second R is stored in the same order as the symbol is stored in the second RAM during recording.
When audio data is read symbol by symbol from AM and output to the DA converter, L-channel and R-channel audio data consisting of 2·n (=16) bits per sampling are divided into upper n bits and lower n bits. Separate into symbols, each as L IU p L I L 'R,U,
If they are arranged in time series in the order of sampling as R, L (i=1.2.3...), the result will be as shown in FIG. Incidentally, the inside of the above notation means the L-channel, R means the R-channel, the suffix U means the upper 8-bit data, and the suffix L means the lower 8-bit data.

In FIG. 7, when two symbols are numbered as pairs in chronological order, these data are stored in the first or second RAM 11.
a, 11 b's first and second address spaces 11-1.11
-2, and are stored in sequence as shown in FIG. Furthermore, 1
l-3 (shaded area upward to the right) is the P parity storage area, 1l
-4 (shaded area downward to the right) is the Q parity storage area.

One of the first and second RAMs, for example, the lR
The data stored in the first at L/S space 11-1 of the AM 11a is first stored on a magnetic tape by the first head,
The data stored in the second address space 11-2 is then stored on the magnetic tape by the second head. During this time, the next audio data is stored in the second RAM 11b. Thereafter, the data stored in the first address space 1'1-1 of the second RAM 11b is stored on the magnetic tape by the first head, and then the data stored in the second address space 11-2 is stored in the magnetic tape by the second head. stored on tape. Thereafter, the first RAM is used in the same manner.

Data is alternately written from the second RAM onto the magnetic tape.

As a result, the audio data group for one track to be stored in the first address space 11-1 of the RAM is stored as i or (i=1.2, 3
．． ), the audio data group for one track to be stored in the second address space 11-2 is 1-(i=1.2, 3.
), audio data is stored track by track on the magnetic tape MT as shown in FIG.

Now, during normal playback, the first and second heads accurately trace the tracks recorded on the magnetic tape and read audio data one track at a time in the recording order on the magnetic tape MT shown in FIG. Then, the audio data read by the first head is stored in the first address space of the first RAM 11a.
The audio data read by the head is stored in the second address space, and is then stored in the RAM in the same order (1-2→3→4→... ) Read the audio data and output it to the DA converter.

While the audio data is being output from the first RAM 11a to the DA converter, the audio data for two tracks read from the magnetic tape by the first and second heads are transferred to the second head.
Stored in the first and second address spaces of RAM,
After the output from 11a is completed, the audio data is output from the second RAM.

<Problems to be Solved by the Invention> By the way, in triple-speed playback, in which the magnetic tape is sent and played back at three times the speed of normal playback, audio data can only be read from the magnetic tape for every three drags. do not have. For this reason, as shown in FIG. 10, the first head reads a 1+ track audio data group, then the second head reads a temporally discontinuous 2-track audio data group, and thereafter the first head 4+ alternately with the second head.

The voice data groups of 5-27, 8-... are read continuously (
(lower margin) will be taken away.

Then, the signal processing unit combines the two consecutive audio data groups into the first address space 11 of the first or second RAM.
-1 and stored in the second address space 11-2. For example, 1+ and 2-, which are discontinuous in time, form a pair, and 1+ is the first
2- is stored in the second address space 11-2.

Thereafter, the symbols are read in the same order as the symbols were stored in the RAM during recording.

Therefore, the 1+ audio data and the 2- audio data must be output alternately to the DA converter, which does not result in music. FIG. 11 is an explanatory diagram showing this situation, in which SDa,
SDb is the audio signal waveform by 1+ and 2-, respectively, and SD
, is the audio signal waveform during triple speed playback.

In light of the above, an object of the present invention is to provide a trick method that allows trick plays such as triple speed playback to be performed satisfactorily.

Means to solve problems〉 FIG. 1 is a schematic explanatory diagram of the present invention.

MT is magnetic tape, l+ and j (i=1.2. . .)
are a group of audio data for one track recorded on a magnetic tape during recording, lla is a RAM, 11-1 is a first address space, and 11-2 is a second address space.

Effect> During 3x speed playback, audio data group 1+ for one track each read from the magnetic tape MT by the first and second heads,
2- is stored in the first address space 11-1 and second address space 11-2 of the RAM 11a in the same way as in the normal state.

After that, the audio data stored in the first address space 11-1 is DA converted one symbol at a time in the same order as the storage order (1→4→5→8→...) in the first address space at the time of recording. Then, the audio data stored in the second address space 11-2 is outputted to the second address space 11-2 one symbol at a time in the order of storage in the second address space at the time of recording (2→3→6→7→...). Output to the DA converter in the same order.

<Example> FIG. 1 is a schematic explanatory diagram of the present invention.

MT is magnetic tape, 1+ and 5 (i=L# 2p...
) are a group of audio data for one track recorded on magnetic tape during recording, lla is RAM, and 11-1 is the first audio data group.
Address space 11-2 is a second address space.

As shown in FIG. 1(A), on the magnetic tape MT, audio data groups i and i- are sequentially and continuously stored one track at a time by the first and second heads during recording.

Now, during triple speed playback in which the magnetic tape MT is fed and played back at a speed of 3@ during normal playback, audio data can only be read from the magnetic tape MT for every 3 tracks. Therefore, as shown in FIG. 1(B), the first head reads the 1+ track audio data group, then the second head reads the 2- track audio data group, and then the first and second heads read the audio data group of 2-track. 4+ alternately with
j.

The audio data groups 7+, 8-, etc. are successively read (FIG. 1(C)).

Then, two consecutive audio data groups (temporally discontinuous audio data groups) are combined into a first address space 11-1 and a second address space 11-2 of the RAM 11a.
is memorized. For example, as shown in Figure 1(D), 1
+ and 2- form a pair, and 1+ is the first address space 11-1
A temporally discontinuous audio data group 2- is stored in the second address space 11-2.

After that, the audio data 1+ stored in the first address space 11-1 is illustrated one symbol at a time in the same order as the storage order (1-4→5→8→...) in the first address space at the time of recording. Then, the audio data 2- stored in the second address space 11-2 is stored symbol by symbol in the order of storage in the second address space at the time of recording (2→3→6→
7→...) are output to the DA converter in the same order.

As a result, the 1+ audio data group is first successively output to the DA converter, and then the 2- audio data group is successively output. FIG. 2 is an explanatory diagram showing this situation, and SDa and SDb are the audio signal waveforms at 1° and 2-, respectively, and the audio signal waveforms in the present invention at 5Dol and 3x speed reproduction.

That is, the 1+ voice signal waveform SDa is compressed to 1/2 time and output first, and then the 2- voiced signal waveform SDb is compressed to 1/2 time and output.

It should be noted that during the first rotation of the head, data read from the magnetic tape MT is stored in the first RAM 11a, and during the next second rotation, audio data is read from the first RAM IIa and output to the DA converter. And the first R.A.
While the audio data is being output from M11a to the DA converter, the next data read from the magnetic tape MT is stored in the second RAM, and is output to the DA converter in the next cycle. Thereafter, data is alternately stored in the first and second RAMs, and audio data is output from the first and second RAMs to the DA converter.

FIG. 3 is a block diagram of essential parts of a signal processing circuit that implements the method of the present invention.

11a and llb are first and second RAMs 112 are address selectors; 13 is a timing signal generator; 14 is an address generator that generates an address when writing audio data;
5 is an address generator that generates an address for Q parity storage/reading, 16 is an address generator that generates an address for P parity storage/reading, and 17 is a read address for reading audio data from RAM during normal playback. 18 is a trick play address generator that generates a read address when audio data is read from RAM during triple-speed playback; 19 is a switching unit that selects between normal and normal playback (signal T
RP=”O”), 3x speed playback (signal TRP=71″)
(7) Outputs the address from a predetermined address generator among the address generators 17 and 18 (7).

The timing signal generation unit 13 is configured to: fa) the high level of the first drum signal DRR (FIG. 6);
Depending on the low level, i.e. every rotation of the head,
, second RAM 11a, Ilb read/write switching signal RW
I, RW2, (blm I F Ram signal DRR1 second drum signal CLC, segment signal H
It outputs an address selection signal ASS that outputs an address generated by a predetermined address generator 14 to 18 using the TC, P parity/Q parity signal PQS.

The first and second RAMs 11 a and 1 l b operate to alternately store data or read data based on read/write switching signals RW'l and RW2, respectively.

Further, the address selector 12 is connected to a timing signal generator 13.
The address generators 14 to 18 are activated as appropriate by the signal ASS from
The audio data is stored in the first and second RAMs lla and llb, and audio data is read from the predetermined address or stored in the predetermined address.

The switching unit 19 indicates that normal playback is (No. 48 T RP = ”
0"), triple-speed playback (signal TRP="l"), outputs an address from a predetermined address generator among the address generators 17.1g. During normal playback, the address generator 17 outputs an address during recording. During triple speed playback, the address generator 18 generates addresses in the same order as the symbols are stored in the first address space during recording, and then generates addresses in the same order as the symbols are stored in the first address space during recording. Addresses are generated in the same order as the symbols are stored in the second address space.

Therefore, during normal playback, audio data is read out one symbol at a time (1→2→3→4→5→...) from the RAM in the numerical order shown in FIG.
Audio data is read symbol by symbol (l→4→5→8→...) from the first AM address space 11-1 in the numerical order shown in FIG. 1(D), and then read out from the second address space 11-2.
In order of numbers in Figure 1 (D) (2-3→6→7-...
) The audio data is read out symbol by symbol.

Although the present invention is applied to triple speed playback above, the present invention is not limited to triple speed playback, but can also be applied to trick plays such as 5x playback.

<Effects of the Invention> According to the present invention, during trick play such as triple speed playback, the audio data read from the magnetic tape by the first and second heads is stored in the first and second address spaces in the same way as in normal mode. After that, the audio data stored in the first address space is output in the same order as the storage order in the first address space at the time of recording, and then the audio data stored in the second address space is outputted in the same order as the storage order in the first address space at the time of recording. Since the configuration is configured so that the audio data is output in the same order as the storage order in the second address space, the audio data can be output to the DA converter in a temporally continuous state. However, it is possible to perform playback at three times the speed better than before.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the present invention; FIG. 2 is an explanatory diagram of audio signal waveforms during triple-speed playback according to the present invention; FIG. 3 is a block diagram of main parts of a signal processing section that realizes the present invention; Figures 9 through 9 are explanatory diagrams of the R-DAT device, Figure 10 is an explanatory diagram of the drawbacks of conventional 3x speed playback, and Figure 11 is an explanatory diagram of the conventional 3x speed playback.
FIG. 3 is an explanatory diagram of signal waveforms due to double speed reproduction. MT...Magnetic tape, i, i-(i=1,2....)...One track worth of audio data recorded on magnetic tape during recording, 11
・ ・ RAM. 11-1... 1st address space 11-2... 2nd address space Patent applicant Alpine Co., Ltd. agent Patent attorney Chiki Saito Figure 2 Figure 4 Figure 5 Figure 3

Claims (2)

[Claims] (1) 2·n per sampling each during recording
Separate L-channel and R-channel audio data consisting of bits into upper n bits and lower n bits data, arrange them chronologically in the order of sampling, and store them sequentially in the first address space and second address space of the RAM, and then 1st
The head records the audio data stored in the first address space on the magnetic tape, then the second head records the audio data stored in the second address space on the magnetic tape, and the first head reads it during playback. RAM
At the same time, the audio data read by the second head is stored in the first address space of In a trick play method for an output R-DAT device, during trick play, the audio data read from the magnetic tape by the first and second heads is stored in the first and second address spaces of the RAM in the same way as in normal mode, and then After that, the audio data stored in the first address space is transferred to the first address space at the time of recording.
Output the audio data in the same order as the storage order in the address space, and then output the audio data stored in the second address space.
A trick play method in an R-DAT device, characterized in that output is performed in the same order as the storage order in a second address space during recording. (2) A trick play method in an R-DAT device according to claim (1), wherein the trick play is triple speed playback.