JPS61216167A - Digital signal recorder - Google Patents

Abstract

PURPOSE:To record correctly the input digital audio signals by supplying these audio signals asynchronous with video signals to a signal recording system via a memory means. CONSTITUTION:The input digital audio signals asynchronous with video signals are written to a memory 4 and then read out and recorded by the reading address data produced according to the synchronizing signal of the video signal. Thus it is possible to record correctly said digital audio signals through a signal recording system which is synchronous with the synchronizing signal of the video signal and underwent the servo control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital signal recording device that records digital audio signals using a signal recording system that performs servo control in synchronization with a synchronizing signal of a video signal.

[Summary of the invention]

The present invention provides a digital signal recording device equipped with a signal recording system that performs servo control in synchronization with a synchronization signal of a video signal, in which an input digital audio signal that is asynchronous with the video signal is stored in the signal recording system via a storage means. By controlling the writing and reading of signals to and from the storage means, the input digital audio signal can be correctly recorded in a signal recording system that is servo-controlled in synchronization with the synchronization signal of the video signal. This is how it was done.

[Conventional technology]

Generally, pulse code modulation (PCM: Pulse
Audio signals with extremely good sound quality are being transmitted using digital technologies such as (Code Modulation), and various devices for digital audio such as PCM digital audio processors and digital audio disc players are being provided. There is. Also 1
, digital audio disc players, PCM relays of FM stereo broadcasts, etc., use PCM digital audio signals with different sampling frequencies, such as 44.1 KHz, 48 KHz, or 32 KH.
It was designed to handle digital audio signals digitized at a sampling frequency of z.

Furthermore, videotape recorders have been widely used to record digital audio signals, and usually digital audio signals are digitized at a sampling frequency of 44.056 KHz, which is synchronized with the synchronization signal of the video signal. The audio signal was supplied to a video tape recorder.

[Problem that the invention seeks to solve]

By the way, in order to record digital audio signals in a signal recording system that performs servo control in synchronization with the synchronization signal of the video signal, such as a video tape recorder, word sync synchronized with the synchronization signal must be performed from the video tape recorder side. It is necessary to provide the PCM digital audio processor or the like on the sending side so that the sending side sends out a digital audio signal with a sampling frequency synchronized with the synchronization signal of the video signal. However, the digital audio signals provided by audio-only equipment without an external synchronization input function and devices that operate with their own synchronization signals, such as digital audio mixers and consoles, cannot be transmitted to video tape recorders. In the past, it was not possible to record correctly because the data had to be asynchronous to the other side.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a digital signal recording apparatus equipped with a signal recording system that performs servo control in synchronization with a synchronization signal of a video signal. It is an object of the present invention to provide a digital signal recording device with a new configuration that enables accurate recording of signals.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a storage means for temporarily storing an input digital audio signal in a digital signal recording apparatus equipped with a signal recording system that performs servo control in synchronization with a synchronization signal of a video signal. and write address data generation means for forming write address data corresponding to the sampling frequency of the input digital audio signal, and read address data generation means for forming read address data synchronized with a synchronization signal of the video signal. It is characterized by

[Effect]

In the digital signal recording apparatus according to the present invention, the above-mentioned 1. temporarily records an input digital audio signal. The a means writes and writes data by the write address data generating means and the read address data generating means.
The readout is controlled, and the input digital audio signal is written in accordance with the write address data given by the write address data generation means, and read out from the storage means in accordance with the read address data given by the read address data generation means. A digital audio signal is recorded by the signal recording system.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a digital signal recording device according to the present invention will be described in detail below with reference to the drawings.

In the embodiment shown in the block diagram of FIG. 1, the first input terminal 1 is supplied with a pi-phase modulated digital audio signal having a sampling frequency of 48 KHz, and this input digital audio signal is connected to the first input terminal 1. 1 is supplied to the reso modulator 2 from the input terminal 1 of the signal generator 1.

The de-modulator 2 performs synchronization separation processing on the input digital audio signal to form a word clock pulse, and also performs high-phase demodulation processing to convert the input digital audio signal from serial data. Convert to 16 bit parallel data.

The 16-bit parallel data of the input digital audio signal obtained by the de-modulator 2 is supplied to the memory 4. Further, the word clock pulse obtained by the demodulator 2 is supplied to a write address data generation circuit 3.

The write address data generating circuit 3 forms write address data and a write clock pulse corresponding to the sampling frequency of the input digital audio signal based on the word clock pulse and supplies the generated write clock pulse to the memory 4.

The memory 4 stores 16 bits of the input digital audio signal supplied from the de-modulator 2.
Parallel data is written in accordance with write address data and write clock pulses provided by the write address data generation circuit 3.

Further, the second signal input terminal 5 is connected to the same jlJ of the video signal.
] signal, for example, a horizontal synchronization signal, and this horizontal synchronization signal is supplied from the second signal input terminal 5 to the clock generation circuit 6.

The clock generation circuit 6 forms a word clock pulse synchronized with the horizontal synchronization signal and supplies it to the 8'fEh output address data generation circuit 7. It also forms a control pulse synchronized with the horizontal synchronization signal. The signal is then supplied to an analog-to-digital converter 10, a Michisa switcher 11, an encoder 12, etc., which will be described later. The read address data generation circuit 7 uses the word clock pulse to form read address data and a read clock pulse synchronized with the synchronization signal of the two-part video signal and supplies them to the memory 4. 16-bit parallel data synchronized with the synchronization signal of the video signal is read out from the memory 4 in accordance with the read address data and read clock pulses given by the read address data generation circuit 7.

The 16-bit parallel data synchronized with the synchronization signal of the video signal read from the memory 4 is sent to the mixer switcher 11, and is supplied from the encoder 12 to the recording head 14 via the recording amplifier 13, where it is sent to the magnetic tape 15. recorded in

Note that in this embodiment, the mixer/switcher 1
1 has an analog signal supplied to the fourth signal input terminal 9.
The audio signal can be digitized by an analog-to-digital converter 10 and then supplied.

Here, the memory 4 is an asynchronous compatible memory in which writing and reading operations are performed almost simultaneously at the word clock rate, and the memory 4 operates at least two write cycles and one or more read cycles in time division with respect to one word clock. It is now possible. Further, the write address data generation circuit 3 and the read address data generation circuit 7 are controlled by the operation control signal supplied from the third signal input terminal 8 when the apparatus of this embodiment is set to the recording operation mode. Initial setting of addresses is performed at the start of mode operation, and the difference between the write address and read address is set to half the window of the memory 4.

Furthermore, in this embodiment, a reproducing head 16 is provided preceding the recording head 14, and the reproduced data obtained by this reproducing head 16 is transmitted from a reproducing amplifier 17 to a decoder 10 via an equalizer/sync separator 18.
is being supplied to. The decoded output data from the decoder 19 is transmitted to the mixer/switcher 11.
is supplied to the digital-to-analog converter 20 and the output camosulator 21 via the above-mentioned digital-to-analog converter 2.
0, the signal is converted into an analog signal and output from the first signal output terminal 22, and the output camosulator 21 again outputs a pi-phase modulated serial digital audio signal from the second signal output terminal 23. ing.

In the time chart of FIG. 2 showing the operation of the embodiment configured as described above, ■-■ is the system delay from the reproducing head 16 to the recording head 14;
This is the advance amount of the playback head 16 relative to the above, and the input/output timing of the digital audio signal corresponds to (2). Furthermore, ■−■ is the delay amount of the decoder 19, and ■−〇 is the delay amount of the encoder 10.
is the delay amount, and ■−〇 is the above memo + J
The delay amount is 4. Note that the operation timing of the encoder 12 with respect to the input from the analog-to-digital converter 10 and the output of the decoder 10 is processed by a delay circuit built in the mixer/switcher 11. Furthermore, ■-〇 is a window corresponding to the memory size of the above-mentioned memory 4, and half of the timing ■ corresponds to the input/output timing of the above-mentioned digital audio signal due to the initial setting of the address at the start of the recording mode operation. Become.

As in this embodiment, a human-powered digital audio signal asynchronous with the video signal is written in the memory 4, and the digital audio signal is read out from the memory 4 using read address data formed based on the synchronization signal of the video signal. By recording the input digital audio signal asynchronously with the video signal, it becomes possible to correctly record the input digital audio signal asynchronously with the video signal using a signal recording system that is servo-controlled and synchronized with the synchronization signal of the video signal. If the difference between the clock frequency of the recording system and the sampling frequency of the input digital audio signal is 10-6 or less, the memory size for one hour of recording is ±3.6ms.
For example, the sampling frequency is 48K.
In the case of Hz, ±173 samples is practical.

〔Effect of the invention〕

As is clear from the description of the embodiments described above, in the digital signal recording device according to the present invention, an input digital audio signal is written into the storage means according to the write address data given by the write address data generation means, and the read address data is written into the storage means. Since the digital audio signal is read from the storage means according to the read address data given by the generation means and recorded by the signal recording system, the input digital audio signal, which is asynchronous to the video signal, is transferred to the servo which is synchronized with the synchronization signal of the video signal. A controlled signal recording system enables accurate recording, and the intended purpose can be fully achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a digital signal recording apparatus according to the present invention, and FIG. 2 is a time chart showing the operation of the above embodiment. 1.5... Signal input terminal 3... Write address data generation circuit 4... Memory 7... Read address data generation circuit 14... Recording head 15... Magnetic tape

Claims (1)

[Scope of Claim] A digital signal recording device equipped with a signal recording system that performs servo control in synchronization with a synchronization signal of a video signal, comprising: a storage means for temporarily storing an input digital audio signal; and a storage means for temporarily storing an input digital audio signal; write address data generation means for forming write address data corresponding to a sampling frequency of , and read address data generation means for forming read address data synchronized with a synchronization signal of a video signal, A digital audio signal is written into the storage means according to the write address data given by the write address data generation means, and read out from the storage means according to the read address data given by the read address data generation means. A digital signal recording device, characterized in that the signal is recorded by the signal recording system described above.