JPH0380472A - Method for recording digital voice signal - Google Patents

Abstract

PURPOSE:To improve the ability of correction with respect to a burst error by alternately arranging and recording respective channels on respective tracks in a prescribed block unit after the error correction codes of the digital signals of two channels are generated every channel. CONSTITUTION:The voice signals of the CH1 and the CH2 are respectively converted to the digital signal by A/D conversion circuits 1 and stored in the memory circuits 2 of the respective channels in one field unit. The error correction codes of the stored digital voice signal are generated circuit 3 and stored in the respective circuits 2. Then, recording signals are outputted by the circuits 2 based on a control signal from a memory control circuit 4 according to the formats of the recording signals and the recording signals of both channels are inputted to two switching circuits 5. Based on a signal from the circuit 4, the switching of the CH1 and CH2 is executed every two blocks by the circuit 5. Then, the recording signal to the Y track and the recording signal to the C track are outputted. Thus, the ability of the correction with respect to the burst error is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention converts audio signals into digital signals and converts them into VTRs.
This relates to a recording method for recording.

Conventional technology A method for recording a video signal on a home VTR is to modulate the luminance (Y) signal of the video signal to FM, and also modulate the carrier color (Y) signal to FM.
C) A common method is to convert the frequency of the signal to the lower frequency side, frequency multiplex the signals, and record the signals. In this case, one field of video signals is recorded by one rotating magnetic head using one track diagonally with respect to the longitudinal direction of the magnetic chip.

However, in the field of broadcasting, for the purpose of improving image quality, a method has been devised in which the video signal is divided into a Y signal and a C signal, and each signal is recorded using a separate rotating magnetic head. FIG. 4 shows a recording signal format on a conventional magnetic tape.

The Y signal and C signal are recorded simultaneously on separate tracks, and the Y and C signals are recorded simultaneously on separate tracks.
Two tracks, the signal and the C signal, constitute one field of the video signal.

On the other hand, audio signals were also recorded as analog signals on the edge of magnetic tape using fixed magnetic heads.
For the purpose of improving performance, a method of converting the signal into a digital signal and recording it has also been proposed.

On June 19, 1986, the Institute of Electronics and Communication Engineers Magnetic Recording Research Group M
As announced in R86-5, in the method of converting an audio signal into a digital signal and recording it, the frequency of the recording signal increases due to digitalization, and conventional fixed magnetic heads can no longer perform recording and reproduction. Therefore, recording and reproduction are performed using a rotating magnetic head in the same way as video signals. FIG. 5 shows a configuration diagram of a conventional cylinder section. Fifth
As is clear from the figure, the magnetic tape 2 is wound around the cylinder 1 so that the angle is X degrees larger than the conventional 180 degrees. The audio signal converted into a digital signal is recorded in this enlarged portion of X degrees.

FIG. 6 shows a conventional example of a recording signal format on a magnetic tape. The audio signal converted to a digital signal is
The time axis is compressed in units of one field, and CHI is recorded on the extension line of the Y signal of the video signal and CH2 is recorded on the extension line of the C signal of the video signal by a rotating magnetic head in the same way as the video signal.

FIG. 7 shows the signal format of the digital signal to be recorded. This format shows one channel, and both CHI and CH2 have the same format. The recording signal is composed of blocks, and one block is composed of a synchronization signal, an address signal, a CRC signal, data, and error correction codes C2 and CI. One vertical column in FIG. 7 corresponds to one block, and data is recorded in order starting from the block with address "0". FIG. 8 shows the recording signal.

In the Y track, the digital audio signal of CHI is arranged in order from the block with address "0", and in the C track, the digital audio signal of CH2 is arranged in order from the block with address rOJ.

The error correction code uses the same Reed-Solomon code as that used in compact discs (CDs), and the 7th
The white circles shown in the figure indicate the generation sequence of the C2 error correction code. A four-symbol error correction code is generated from 24 data symbols in one block at a time, and errors of up to two symbols can be corrected independently.

FIG. 9 is a block diagram showing a conventional circuit for generating this recording signal. 1 is an analog-to-digital conversion circuit (hereinafter referred to as an A/D conversion circuit) that converts an analog signal into a digital signal, 2 is a memory circuit that stores the digital signal, 3 is an error correction code generation circuit, and 4 is a memory control circuit. It is a circuit.

The operation will be explained below. The audio signals of CHI and CH2 are each converted into digital signals by an A/D conversion circuit 1, and stored in a memory circuit 2 of each channel in units of one field. The stored digital audio signal for one field undergoes error correction code generation for each channel in the error correction code generation circuit 3, and is stored in the respective memory circuits 2. Then, according to the control signal from the memory control circuit 4, the Y recording signal is sent from the memory circuit 2 of CHI to the memory circuit 2 of CH2 according to the recording signal format.
A recording signal of C is outputted from.

Problems to be Solved by the Invention However, in the recording method described above, when a burst error occurs on a digital audio recording track, it is possible to correct up to 4 blocks of burst errors for each channel; It is impossible to correct burst errors of 5 blocks or more by itself.

The present invention is intended to solve the above-mentioned conventional problems, and aims to improve the ability to correct burst errors.

Means for Solving the Problem To achieve this object, the digital audio signal recording method of the present invention generates an error correction code for each channel when recording two channels of digital signals on separate tracks. After this, each channel is alternately arranged and recorded in each track in predetermined block units.

Effect: With this configuration, even if a burst error occurs on one track, the error is distributed to each channel, and the burst error on each channel can be 172 times the burst error occurring on the track.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a circuit configuration for generating a recording signal in an embodiment of the present invention. 1 is an A/D conversion circuit, 2 is a memory circuit, 3 is an error correction code generation circuit, 4 is a memory control circuit, and 5 is a digital signal switching circuit.

The operation will be explained below. The audio signals CH1 and CH2 are each converted into digital signals by an A/D conversion circuit 1, and stored in the memory circuit 2 of each channel in units of one field. An error correction code is generated for each channel of the stored digital audio signal for one field in an error correction code generation circuit 3, and the error correction code is stored in each memory circuit 2. Then, in response to a control signal from the memory control circuit 4, a recording signal is outputted from the memory circuit 2 of each channel according to the recording signal format, and the recording signals of both channels are inputted to the two switching circuits 5.

In the two switching circuits 5, the signal from the memory control circuit 4
Switching between CHI and CH2 is performed for each block, and a recording signal to the Y track and a recording signal to the C track are output.

FIG. 2 shows the recorded signal. The recording signal of the Y track is the digital audio of CHI when the block addresses are "0" and "1", the digital audio of CH2 when the block addresses are "2" and "3", and so on, alternately every two blocks. The digital audio signals of CHI and CH2 are arranged.

On the other hand, for the recording signal of the C track, digital audio signals of CH2 and CHI are similarly arranged alternately every two blocks in a relationship opposite to that of the Y track.

That is, the digital audio signals of CHI and CH2 are recorded on each track by alternating them every two blocks.

Now, from the block address rOJ of the Y track, "7
'', error correction is performed for each channel during playback, so in CH1, the block address rOJ
, rlJ , r4J , and r5J blocks cause an error. C2 shown by the white circle in the signal format shown in Figure 3
In the series, the block addresses rOJ and "4" indicated by the cross marks are errors, but these are two symbol errors and can be corrected independently. Similarly, all other series are 2
It becomes a symbol error, and all errors can be corrected by itself.

Also, considering the case of CH2, the block address r
Although the blocks 2J, r3J, r6J, and r7J have errors, they all have 2 symbol errors in the error correction series like CHl, and the errors can be corrected independently.

As described above, according to this embodiment, it is possible to perform error correction independently for burst errors of up to 4 blocks, but it is now possible to perform error correction independently for burst errors of up to 8 blocks. can.

Effects of the Invention As described above, the present invention generates an error correction code for each channel and then arranges each channel alternately in blocks on two tracks to configure a recording signal. This makes it possible to realize an excellent digital audio signal recording method that can improve the ability to correct burst errors.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a circuit configuration for generating a recording signal in one embodiment of the present invention, FIG. 2 is a recording signal diagram in the same embodiment, and FIG. 3 is an error correction sequence in the same embodiment. FIG. 4 is a diagram of the signal format recorded on the magnetic tape of a conventional broadcasting VTR. FIG. 5 is a plan view showing the conventional configuration of the serial reader section of a VTR capable of recording digital audio signals. FIG. A recording format diagram on a magnetic tape showing an example of conventional digital audio recording. Figure 7 is a signal format diagram of a conventional digital audio signal. Figure 8 is a diagram of a conventional recording signal. Figure 9 is a diagram of a conventional recording signal. FIG. 2 is a block diagram showing a circuit configuration for generation. 1...A/D conversion circuit, 2...memory circuit, 3
...Error correction code generation circuit, 4.Memory control circuit, 5.Switching circuit.

Claims (1)

[Claims] Converts 2-channel audio signals to digital signals,
When simultaneously recording on separate tracks on a magnetic tape using two rotating magnetic heads, an error correction code is generated for each channel of the digital signals of the two channels, and then each channel is divided into predetermined block units. A method for recording a digital audio signal, characterized in that recording is performed by alternately arranging and recording on each of the tracks.