JPH04345966A - Recording controller - Google Patents

Abstract

PURPOSE:To attain the synchronization between the operations of a recording device and a reproducing device when the digital. signal outputted from the reproducing device is recorded to the recording device by using an identification signal which shows the validity of the digital signal of the reproducing device. CONSTITUTION:When a DAT system B is set in a reproduction state, a digital interface demodulation circuit 20A outputs an identification signal showing the validity of date with the V (validity) bit signal of a digital audio interface. A synchronization control circuit 14A receives the V bit from the circuit 20 and secures the synchronization between the start of the recording operation of a DAT system A and the start of the reproducing operation of the system B. Thus the synchronization is easily secured between both operations without transmitting especially a synchronizing signal. Then the digital-signal received from the system B can be surely recorded to the system A.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording control device for digital signals such as digital audio signals.

0002

2. Description of the Related Art Conventionally, two digital audio devices such as digital audio tape recorders (hereinafter abbreviated as DAT) for recording and reproducing digital audio signals are provided, and both are connected via digital input/output terminals and cables. One of the devices is placed in a playback state while the other is placed in a recording state, and digital audio signals are transferred between the two to perform digital copying.

0003

[Problem to be Solved by the Invention] In the above conventional method, if one cannot be set to the playback state and the other to be set to the record state at the same time, the beginning of the digital signal output from the playback side is not recorded. This causes problems such as the beginning of a song being cut off, or a digital signal from the playback side arriving at the recording side after the recording side has started, resulting in a no-signal state at the beginning of the song.

The present invention has been made to solve these conventional problems, and when recording a digital signal output from a playback device onto a recording device, the operation of the recording device can be easily adapted to the operation of the playback device. The purpose of the present invention is to provide a recording control device that can be synchronized with the following.

[0005]

[Means for Solving the Problem] A recording control device according to claim 1 is a recording control device that controls recording of a digital signal output by a playback device to a recording device, wherein the playback device outputs the digital signal together with the digital signal. The apparatus is characterized by comprising a synchronization control means for synchronizing the operation of the recording apparatus with the operation of the reproducing apparatus in accordance with an identification signal indicating whether or not the digital signal is valid.

[0006] In the recording control device according to claim 2, both the playback device and the recording device are digital audio equipment that records and plays back digital audio signals, and the identification signal is a V bit of a digital audio interface. It is characterized by

[0007]

In the recording control device according to the first aspect of the invention, the synchronization control means synchronizes the operation of the recording device with the operation of the reproducing device in accordance with the identification signal output from the reproducing device. Therefore, the operation of the recording device can be synchronized with the operation of the reproducing device without the need for troublesome operations or the need to generate a special synchronization signal.

[0008] In the recording control device having the structure of claim 2, since synchronization is achieved using the V bit of the already standardized digital audio interface, synchronization between digital audio devices compliant with the standard can be easily realized. can.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of an embodiment of a recording control apparatus according to the present invention. This embodiment is an example in which the present invention is applied to a digital audio tape (hereinafter abbreviated as DAT) recorder. The digital output terminal ADO of the DAT system A is connected to the DAT system A via the digital interface cable C2.
Connected to AT system B's digital input terminal BDI. Digital input terminal ADI of DAT system A is connected to digital output terminal BDO of DAT system B via digital interface cable C4. D.A.
T-systems A and B have the same configuration, and the same components have the same reference numbers appended with A and B, respectively. Therefore, only the configuration of DAT system A will be explained, and the explanation of the configuration of DAT system B will be omitted.

DAT recorder 2A reads digital audio data to or from tape under the control of control circuit 4A. The control circuit 4A controls the DAT recorder 2A according to the mode signal output from the recording/reproduction mode setting circuit 6A and the Q output signal from the flip-flop (hereinafter abbreviated as F/F) circuit 8A. High level (“1”) and low level (“0”) of mode signal
indicate recording and playback modes, respectively. The high and low levels of the Q output signal of the F/F circuit 8A are respectively
Operation and non-operation instructions for the control circuit 4A are shown.

The set input S of the F/F circuit 8A is connected to the output of the start circuit 12A and the output of the synchronous control circuit 14 (that is, the AND gate 28A) via the OR gate 10A.
output). The reset input of the F/F circuit 8A is connected to the stop circuit 16 via the OR gate 18A.
A and the output of the synchronous control circuit 14A. The start circuit 12A outputs a high level start signal when the start button is pressed. The stop circuit 16A outputs a high level stop signal when the stop button is pressed.

[0012] The synchronous control circuit 14A is a DAT system B.
In accordance with the identification signal indicating whether or not the data is valid, which is output together with the digital audio data when the is in the playback state, that is, the V (validity) bit signal of the digital audio interface outputted by the digital interface demodulation circuit 20A, The recording operation of DAT system A is synchronized with the reproducing operation of the DAT system.

Before explaining the specific configuration of the synchronization control circuit 14A, the signal format of the digital audio interface will be explained with reference to FIG. In a digital audio interface, L channel and R channel
The signals of the channels are not transmitted separately, L, R, L, R
It is transmitted in the order of time division multiplexing. Frames of the L and R channel signals are composed of three types of synchronization patterns, that is, M, W, and B synchronization patterns, and 192 frames are transmitted as one frame. One frame (which corresponds to one sampling period) consists of two subframes. One subframe consists of one periodic pattern and an L or R channel signal, and consists of three
Consists of 2 bits.

Bits 0 to 3 are used for subframe and frame synchronization extraction. Bits 4 to 7 are used to transmit audio error information or an extended portion of audio sampling. Bits 8 to 27 are assigned digital audio data in two's complement representation. Bit 28 is assigned to the V bit. The V bit is at a low level (0) when the digital audio data is valid, that is, there is no error, and when there is no digital audio data, and when the digital audio data is not a true value, that is, data interpolation is performed. muting data or intentional muting data.
Validity at a high level (“1”)
It's a flag. Bit 29 is assigned to the U bit or user bit. The U bit can be used as a start ID indicating the beginning of a song. Bit 30 is assigned to the C bit. The C bit is used in combination with the C bits of other subframes to indicate channel status information such as audio sampling word length, sampling frequency, etc.

The synchronous control circuit 14A is connected to the continuous/detection circuit 2.
2A, a falling detection circuit 24A, and two AND gates 26A and 28A. The continuous/detection circuit 22A receives the V bit output of the digital interface demodulation circuit 20A which returns the digital signal in the digital interface format of FIG. It detects that two or more are included in succession and outputs a high level (“1”) signal. Fall detection circuit 24
A receives the V bit output of the digital interface circuit 20A and outputs a high level ("1") signal when the V bit changes from high level ("1") to low level ("0").

Two inputs of the AND gate 26A are connected to the output of the recording/reproduction mode setting circuit 6A and the output of the continuity/detection circuit 22A, respectively. AND gate 26A
The output is sent to the F/F circuit 8A via the OR gate 18A.
is applied to the reset input of AND gate 28A 2
The two inputs are respectively connected to the output of the recording/reproducing mode setting circuit 6A and the output of the falling edge detection circuit 24A. The output of the AND gate 28A is applied to the set input of the F/F circuit 8A via the OR gate 10A. Therefore, when valid digital audio data starts to be generated in the recording or playback mode, "1" is given to the set input of the F/F circuit 8A, and the F/F circuit 8A receives "1" indicating an operation command. ” is given to the control circuit 4A. Furthermore, when valid digital audio data is lost while in the recording or playback mode, "1" is given to the reset input of the F/F circuit 8A, and the F/F circuit 8A outputs "0" indicating a non-operation command. is given to the control circuit 4A.

The reason why the output of the continuous/detection circuit 22A is supplied to the reset input of the F/F circuit 8A is that even if the DAT system B is in the reproducing state, as described above,
V for data interpolation and intentional muting data
Since the bit sometimes becomes "1", the end of playback in DAT system B can only be confirmed by two or more consecutive "1"s.

Digital interface demodulation circuit 20A
The digital audio data, C bit and U bit outputted from the DAT recorder 2A are supplied to the DAT recorder 2A and recorded on tape under the control of the control circuit 4A. The signal detected from the tape of the DAT recorder 2A is sent to the digital interface modulation circuit 32 via the mute circuit 30A.
A is supplied. Further, a signal indicating an operation or non-operation command outputted from the F/F circuit 8A is inverted by an inverter 34A and then supplied to the V bit input of the digital interface modulation circuit 32A via an OR gate 36A. , "1" is supplied from the DAT recorder 2A via the OR gate 36A during data interpolation or intentional muting. Furthermore, the U bit and C bit indicating status information are respectively supplied from the DAT recorder 2A to the U and C bit inputs of the digital interface modulation circuit 32A. Digital interface modulation circuit 32
A converts the above input signal into the format shown in FIG. 2 and outputs it to the digital output terminal ADO.

Next, the operation of the embodiment of FIG. 1 configured as described above will be explained with reference to the time chart of FIG. 3. It is assumed that DAT systems A and B are set to recording and reproduction modes by recording and reproduction mode setting circuits 6A and 6B, respectively, and DAT system A records the digital signal reproduced by DAT system B.

First, in the stopped state, the V bit remains "1", so the continuity/detection circuits 22A and 2
Since the output of F/F circuit 2B is "1" and the output of falling detection circuits 24A and 24B is "0", F/F circuits 8A and 8B are in the reset state and output "0" indicating a non-operation command.
'' is output to the control circuits 4A and 4B, both DAT recorders 2A and 2B are in an inactive state.

When the start button of the DAT system B is pressed and "1" is supplied from the start circuit 12B to the set input of the F/F circuit 8B, the output of the F/F circuit 8B becomes "1".
1". As a result, the control circuit 4B causes the DAT recorder 2B to read the tape, and the read signal is supplied to the digital interface modulation circuit 32B. Also, the "0" signal from the inverter 34B becomes V The circuit 32B outputs the input signal containing the V bit, which is "0", in the format shown in FIG. 2 through the digital output terminal BDO, the digital interface cable C4, and the digital input terminal ADI. The signal is sent to the digital interface demodulation circuit 20A.The demodulation circuit 20A sets its V bit output to "0".As a result, the output of the falling detection circuit 24A becomes "1", and this "1"
F/F via D gate 28A and OR gate 10A
It is supplied to the set input of circuit 8A. Therefore, the F/F circuit 8A provides the control circuit 4A with a "1" signal that instructs the operation. The control circuit 4A records the digital audio data, C bit, and U bit output from the digital interface demodulation circuit 20A onto the tape of the DAT recorder 2A. In this way, the synchronous control circuit 14A
The start of the recording operation of DAT system A is synchronized with the start of the reproducing operation of DAT system B. Therefore, D on the playback side
To reliably and efficiently record a digital signal output from an AT system B to a DAT system B.

During the playback operation of DAT system B, even if the V bit sent from DAT system B becomes "1" singly due to data interpolation or intentional muting, the output of the continuous detection circuit 22A also becomes "0". Therefore, F/F circuit 8A
continues to output "1" indicating an operation command, and the control circuit 4A continues to perform the recording operation.

When the stop button of DAT system B is pressed and "1" is output from the stop circuit 16B, F
/F circuit circuit 8B outputs "0" indicating a non-operation command,
The control circuit 4B stops the reading operation of the DAT recorder 2B. Further, the output "0" of the F/F circuit 8B is inverted by the inverter 34B and supplied to the digital interface modulation circuit 32B. Therefore, modulation circuit 32B
then continues to send successive V bits with a value of "1" to the DAT system A in the format of FIG. As a result, the continuity/detection circuit 22A outputs "1",
The F/F circuit 8A outputs "0" indicating a non-operation command. Therefore, the control circuit 4A stops the recording operation of the DAT recorder 2A. In this way, the synchronous control circuit 14A
The end of the recording operation of DAT system A can be synchronized with the end of the reproducing operation of DAT system B.

Although the above embodiment relates to a DAT recorder, the present invention is not limited thereto and can be applied to various digital audio devices such as compact discs.

Furthermore, the present invention can be applied not only to the recording of digital audio signals but also to the recording of digital signals in general.

[0026]

As described above, according to the recording control device according to claim 1, the recording device Since the recording operation of the playback device is synchronized with the playback operation of the playback device, synchronization can be easily achieved without the need to issue a special synchronization signal.

According to the recording control device according to claim 2,
Since synchronization is achieved using the V bit of a digital audio interface that has already been standardized, it is possible to easily synchronize digital audio devices that comply with the standard without providing any new signals.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of a recording control device of the present invention.

[Figure 2] Explanatory diagram showing the signal format of a digital audio interface

[Fig. 3] Flowchart showing the operation of the embodiment shown in Fig. 1.

[Explanation of symbols]

14A, 14B Synchronous control circuit 20A, 20B Digital interface demodulation circuit 22A, 22B Continuation/detection circuit 24A, 22B Fall detection circuit

Claims (2)

[Claims] 1. A recording control device that controls recording of a digital signal output by a playback device to a recording device, the device comprising an identification device that indicates whether or not the digital signal output by the playback device together with the digital signal is valid. A recording control device comprising: synchronization control means for synchronizing the operation of the recording device with the operation of the reproducing device according to a signal. 2. The playback device and the recording device include:
2. The recording control device according to claim 1, wherein both are digital audio devices that record and reproduce digital audio signals, and wherein the identification signal is a V bit of a digital audio interface.