JPH05282801A - Digital recording and reproducing device - Google Patents

Abstract

PURPOSE:To allow TV image signals according to different methods and signals according to different processing modes to be recorded and reproduced with the same tape, by recording and reproducing digital information signals of multiple systems of different data rates by a plurality of recording channels of the same data rate in a digital VTR. CONSTITUTION:In a multiplexer 11a, 2-channel recording input signals S12 and S13 having a data rate of R/2 are multiplexed into a signal of a single system, and in a multiplexer 11b, 4-channel recording input signals S14-S17 having a data rate of R/4 are multiplexed into a signal of a single system, with both of the data rates of the outputs being made equal to the rate R of a recording input signal S11. Further, the error correction codes which are output from encoders 12a-12c are input to modulators 13a-13c in a mode suitable for the recording and reproducing system to generate recording data signals. Thereafter, the signals are amplified by recording amplifiers 14a-14c, and recorded on three channels CH1-CH3 on a tape 16 by recording heads 15a-15c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital recording / reproducing apparatus such as a digital VTR (video tape recorder), and more particularly to a recording / reproducing apparatus having a plurality of recording channels.

[0002]

2. Description of the Related Art Generally, in a digital VTR for recording and reproducing a video signal and an audio signal in the form of a digital signal, since the data rate of the signal is high, at least the video signal data is divided into a plurality of recording channels and recorded. Has been taken.

FIG. 4 shows a conventional 2-channel digital V
The structural example of TR is shown. The input digital video signal is divided into two by the demultiplexer 401, the data rate is 1/2 of that of the original digital video signal, error correction coding is performed by the encoders 402a to 402b, and further recorded by the modulators 403a to 403b. Modulation suitable for the reproduction system is applied. On the other hand, the input digital audio signal is error correction coded by the encoder 404 independently of the video signal, and is similarly modulated by the modulator 405. Then, the video signal data from the modulators 403a and 403b and the audio signal data from the modulator 405 are time division multiplexed by the adders 406a and 406b to generate a recording data signal of two channels. The recording signal data of two channels is amplified by the recording amplifiers 407a and 407b, and the recording heads 408a to 408a to
It is sequentially recorded on the helical track on the magnetic tape 409 by 408b.

In the reproducing system, the recording signal data of two channels is read from the magnetic tape 409 by the reproducing heads 410a and 410b, and the preamplifiers 411a to 41a are used.
Amplified by 1b. Preamplifiers 411a to 411
The output of b is branched into two, while the demodulator 412
The video signal data is demodulated by a to 412b and further error-correction-decoded by the decoders 413a to 413b. After that, the multiplexer 414 multiplexes the two-channel digital video signal data and extracts the reproduced video output. On the other hand, the outputs of the preamplifiers 411a to 411b are guided to the selection switch 415, where the audio signal data is separated from the video signal data, and then the demodulator 41
6 and the decoder 417, the reproduced voice output is taken out.

FIG. 5 shows another example of the configuration of a conventional digital VTR. The input digital video signal is band-compressed by the band compressor 501 to be converted into a data series having a lower data rate, then error-correction coded by the encoder 502, and modulated by the modulator 503. On the other hand, the input digital audio signal is similarly encoded by the encoder 504 and is modulated by the modulator 505.
Then, the video signal data from the modulator 503 and the modulator 5
The recording signal data is generated by time-division multiplexing the audio signal data from 04 in the adder 506. The recording signal data is amplified by the recording amplifier 507 and then recorded on the magnetic tape 509 by the recording head 508.

In the reproducing system, the recording signal data on the magnetic tape 509 is read by the reproducing head 510 and amplified by the preamplifier 512. The output of the preamplifier 512 is 2
On the other hand, the demodulator 512 demodulates the video signal data, and the decoder 513 performs error correction decoding. Then, the band decompressor 514 performs the reverse operation of the band compressor 501 to extract the reproduced video output. Be done. On the other hand, the output of the preamplifier 511 is guided to the selection switch 515, where the audio signal data is separated from the video signal data, and then the reproduced audio output is taken out via the demodulator 516 and the decoder 517.

Thus, in the conventional digital VTR,
Regarding the video signal, one system of signals is recorded and reproduced by a plurality of recording channels or a single recording channel. Therefore, in principle, it is impossible to record / reproduce video signals and audio signals of a plurality of different sources or record / reproduce signals of different processing modes on the same magnetic tape.

Specifically, for example, in the current standard television system, there are various systems such as PAL and SECAM in addition to NTSC adopted in Japan.
Regarding the signal format of the video signal, both composite signal and component signal exist. Further, as a high definition television signal, there are an SMPTE240M baseband signal, a MUSE signal and the like. Further, due to the progress of band compression technology, when recording / reproducing or transmitting a video signal, there are video signals processed in various different band compression modes. When a plurality of sources with different signal formats and image qualities and signals with a plurality of different processing modes coexist in this way, if these can be recorded on the same tape and optionally reproduced, various video software can be used. It is considered to be useful in the production of and various service industries.

[0009]

As described above, it would be useful if a video signal and an audio signal of a plurality of different sources or different processing modes can be recorded and reproduced on the same recording medium. However, in the conventional digital VTR, one system is used. Since the video signal of No. 1 is configured to be recorded and reproduced by a plurality of recording channels or a single recording channel, there is a problem that such a thing cannot be performed.

An object of the present invention is to provide a digital recording / reproducing apparatus capable of recording / reproducing information signals such as video signals and audio signals of a plurality of different sources or different processing modes on the same recording medium. To do.

[0011]

In order to solve the above-mentioned problems, the present invention provides a digital recording / reproducing apparatus having two or more recording channels having the same recording data rate, by applying three or more recording input signals having different data rates. The first conversion means converts the signal into a signal having the same data rate as the recording channel and the same number as the recording channel, and then recorded in a plurality of recording channels, and at the time of reproduction, a signal reproduced from the plurality of recording channels is converted into a first signal. It is characterized in that it is converted into a reproduction output signal having the same data rate as that of the recording input signal and the same number of channels as the number of channels of the recording input signal by the conversion means of No. 2 and output.

The first converting means can be realized by using a multiplexer that multiplexes signals of at least two systems among the recording input signals, and the second converting means can be realized by using a demultiplexer that divides the multiplexed signals. it can.

[0013]

As described above, according to the present invention, a plurality of systems of digital information signals having different data rates are recorded and reproduced by a plurality of recording channels having the same data rate in the digital VTR. Therefore, it is possible to record and reproduce, on the same tape, television image signals based on different standard systems and image signals having different processing modes such as high-quality images, band-compressed moving images, and still images.

In this case, since the data rates of the plurality of recording channels may be constant, the number and arrangement of heads and the structure of the mechanical section such as the rotary scanning system can be commonly used for all recording input signals. Is not complicated.

Although error correction is generally performed when recording / reproducing a digital information signal, in the present invention, the error correction capability can be freely set for each recording input signal of the same data rate according to the property of information. Therefore, for example, by assigning a large number of error correction codes to voices or band compressed images, which are easily deteriorated due to data errors, to enhance the error correction capability, uniform data can be obtained for a plurality of sources having different data error characteristics. It is also possible to ensure quality.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a digital recording / reproducing apparatus according to an embodiment of the present invention, showing an example applied to a digital VTR.

Digital information signals S11 to S17 to be recorded (hereinafter referred to as recording input signals) are input to the input terminals 10a to 10g. Here, the recording input signal S11
If the data rate of R is R (bps), the recording input signal S1
The data rate of 2 to S13 is R / 2, the recording input signal S1
The data rate of 4 to S17 is R / 4.

Taking the case where the digital information signal is a video signal as an example, for example, S11 is a high definition television video signal or its band compression signal, and S12 to S13 are video signals of the current standard television system or its band compression signal. ,
Then, S14 to S17 are still images or band-compressed signals thereof. The recording input signals of these respective channels may have different information contents or may be common.

It is also possible to apply different standard television system signals such as NTSC and PAL to the recorded input signals having the same data rate, for example, S12 and S13. Furthermore, S11 and S12-
As recording input signals of each data rate of S13 and S14 to S17, signals of different signal formats (for example, composite and component) with the same information content are applied,
It is also possible to apply band-compressed signals having the same content but different compression rates.

The recording input signal S11 is directly input to the encoder 12a. The recording input signals S12 to S13 are multiplexed by the multiplexer 11a and then input to the encoder 12b. The recording input signals S14 to S17 are sent to the multiplexer 11
After being multiplexed by b, it is input to the encoder 12c. The encoders 12a to 12c respectively perform error correction coding on the input recording input signals.

In the multiplexer 11a, a 2-channel recording input signal S12 having a data rate of R / 2 is used.
To S13 are multiplexed into one system signal, and the multiplexer 11b multiplexes the 4-channel recording input signals S14 to S17 having a data rate of R / 4 into one system signal, so that the output data rate is Also becomes equal to the data rate R of the recording input signal S11.

The error correction code output from the encoders 12a to 12c is input to the modulators 13a to 13c and is modulated by a method suitable for the recording / reproducing system to generate a recording data signal. These recorded data signals are
After being amplified by the recording amplifiers 14a to 14c, the recording heads 15a to 15c perform recording on the three recording channels CH1 to CH3 on the magnetic tape 16, respectively.

FIG. 2 is a diagram showing an example of a recording format on the tape 16 and shows three recording channels CH1 to CH.
Helical tracks respectively corresponding to H3 are periodically formed. Each helical track has a video track 31
And an audio track 32 is provided. Here, the recording data rate of each recording channel CH1 to CH3 is a constant value determined by the format of the digital VTR used.

The recording data signals recorded on the tape 16 are read by the reproducing heads 17a to 17c corresponding to the recording channels CH1 to CH3, respectively. The outputs of the reproducing heads 17a to 17 are amplified by the preamplifiers 18a to 18c and then demodulated by the demodulators 18a to 19c,
Further, error correction decoding is performed by the decoders 20a to 20c to restore the digital information signal.

The output of the decoder 20a is the direct output terminal 22.
The reproduction output signal S21 is sent to a. This reproduction output signal S21 corresponds to the recording input signal S11, and its data rate is R.

The output of the decoder 20b is the demultiplexer 2
1a is divided into two systems, and output terminals 22b to 22c
Are output as reproduction output signals S22 to S23. The reproduction output signals S22 to S23 are the recording input signals S12 to S13.
And the data rate is R / 2.

The output of the decoder 20c is the demultiplexer 2
1b is divided into 4 systems, and output terminals 22d to 22g
Are output as reproduction output signals S24 to S27. The reproduction output signals S24 to S27 are the recording input signals S14 to S17.
And the data rate is R / 4.

As described above, in the present embodiment, the plurality of recording input signals S11 to S17 having different data rates are converted into three-channel signals having the same data rate by using the multiplexers 11a to 11b, and then the encoders 12a to 12b. Recording is performed on three recording channels CH1 to CH3 on the tape 16 by the recording heads 15a to 15b via the modulators 13a to 13b and the recording amplifiers 14a to 14b.

During reproduction, the signals read from the recording channels CH1 to CH3 of the tape 16 by the reproducing heads 17a to 17c are restored through the preamplifiers 18a to 18c, the demodulators 19a to 19c and the decoders 20a to 20c. , The demultiplexers 21a-21b are used to convert to the same data rate as during recording, and the reproduction output signal S
21 to S27 can be obtained.

In the above embodiment, the recording input signal S1
1 and S12 to S13 and S14 to S17 have been described on the assumption that the ratio of the data rates is exactly 4: 2: 1. However, in reality, the data rate has such an integer ratio relationship between sources. Alternatively, signals having different processing modes do not always exist.

FIG. 3 shows an embodiment in which this point is improved,
After the input terminals 10a-10g, the preprocessing circuits 23a-2
3g is arranged respectively. These preprocessing circuits 23
a to 23g perform processing to bring the data rate into the above-described integer ratio relationship by adding appropriate redundant bits to the recording input signals S11 to S17, for example. As a result, even if the data rates are not exactly in the ratio of integers, the signal S is recorded using the plurality of recording channels CH1 to CH3.
Recording / reproduction of 11 to S17 is possible. Preprocessing circuit 23
It is not always necessary to provide all of a to 23 g, and there is 1
Based on the data rate of the recording input signal of the channel,
You may make it match the data rate of another channel. A circuit having the same function as that of the preprocessing circuits 23a to 23g may be provided in the preceding stage or the latter stage of the encoders 12a to 12c, or the encoders 12a to 12c may have the same function.

Further, although the recording / reproducing method of the audio signal is not particularly described in the above embodiment, for example, FIG.
Alternatively, as described with reference to FIG. 5, the video signal may be time-division multiplexed and recorded on the audio track 32 of FIG. Further, since the digital audio signal accompanying the high definition television video signal is planned to be multi-channel, the multi-channel digital audio signal is given as the recording input signals S14 to S17 in FIG. It is also effective to record using the same recording channel (CH3) and record the high-definition video signal using the recording channel CH1 or CH2. Furthermore, the present invention can be applied to a system using an optical disk or the like as a magnetic recording medium.

[0033]

As described above, according to the present invention, a plurality of different sources having different original data rates are provided on the same recording medium with a simple structure having a common mechanism such as a head and a rotary scanning system. Information signals such as video signals and audio signals in different processing modes can be recorded and reproduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of a digital VTR according to an embodiment of the present invention.

FIG. 2 is a diagram showing a recording format on a tape in the embodiment.

FIG. 3 is a block diagram showing a configuration of a main part of another embodiment of the present invention.

FIG. 4 is a block diagram showing an example of a conventional digital VTR.

FIG. 5 is a block diagram showing another example of a conventional digital VTR.

[Explanation of symbols]

S11 to S17 ... Recording input signals 10a to 10c ...
Input terminals 11a to 11b ... Multiplexers 12a to 12c ...
Encoders 13a to 13c ... Modulators 14a to 14c ...
Recording amplifiers 15a to 15c ... Recording head 16 ... Magnetic tapes 17a to 17c ... Reproducing heads 18a to 18c.
Preamplifiers 19a to 19c ... Demodulators 20a to 20c ...
Decoders 21a to 21b ... Demultiplexers 22a to 22g ...
Output terminals S21 to S27 ... Reproduction output signals 23a to 23g ...
Pre-processing circuit 31 ... Video track 32 ... Audio track

Claims (2)

[Claims] 1. A digital recording / reproducing apparatus having two or more recording channels having the same recording data rate, wherein three or more systems of recording input signals having different data rates have the same data rate as the recording channel and the number of recording channels. First to convert the signal of the same number of channels as
Converting means, recording means for recording the signals converted by the first converting means in the plurality of recording channels, reproducing means for reproducing the signals recorded by the recording means, and reproducing means for reproducing the signals. And a second conversion means for converting the reproduced signal into a reproduction output signal having the same data rate as the recording input signal and the same number of channels as the recording input signal system. 2. The first converting means comprises a multiplexer for multiplexing at least two channels of the recording input signal, and the second converting means comprises a demultiplexer for dividing the multiplexed signal. The digital recording / reproducing apparatus according to claim 1, further comprising: