JPH02158959A - Digital audio tape recorder - Google Patents

Abstract

PURPOSE:To enable the dubbing of a subcode even in the case of inhibition of a digital copy by providing a circuit for receiving a main signal as an analog signal and a circuit for transmitting and receiving an appendant subsignal as a digital signal. CONSTITUTION:The subcode recorded on a recording medium 1 is sent to a system control circuit 6 by a digital audio tape recorder (DAT) on the reproducing side, and when a digital copy inhibit flag is shown as its inhibition, the digital copy inhibit flag is set with a digital interface output. A digital interface is selected by the DAT on the recording side, and when it is detected by a digital interface circuit 5 that the digital copy inhibit flag is set, so far as the subcode is concerned, the channel status for inputting the digital interface and a user's bit are applied and recorded, and an audio signal given to an analog interface circuit 4 is A/D-converted and recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a digital audio tape recorder capable of dubbing sub-signals.

Conventional technology With conventional DATs, when dubbing audio signals between two DATs, the DAT sending the signal converts the main signal, digital audio data, and the sub signal, the subcode, into a predetermined format. transmitted by a digital audio interface. Dubbing using this digital audio interface allows high-quality dubbing without degrading the quality of the data. However, DAT may intentionally prohibit dubbing using a digital audio interface. Therefore, if dubbing using a digital interface is prohibited, the reproduction/transmission side either transmits the copy flag in the channel status to prohibit copying or does not output the output signal itself, and the receiving/recording side transmits the digital interface signal. The situation was handled in such a way that it was not accepted. In this case, on the sending side, the digital audio data is subjected to magnetic/A conversion into an analog signal, and then transmitted through an analog interface, and on the receiving side, the analog signal is A/D converted, converted into a digital signal, and then dubbed.

Problems to be Solved by the Invention However, in the conventional configuration as described above, when dubbing using an analog interface, the audio signal is transmitted and can be dubbed, but the subcode is not transmitted and cannot be dubbed.

In view of the above problems, the present invention provides a digital audio tape recorder that can transmit and dub subcodes even when dubbing by a digital audio interface is prohibited.

Means for Solving the Problems The present invention includes an analog interface circuit that transmits and receives a main signal as an analog signal, and a digital interface circuit that transmits and receives a sub-signal accompanying the main signal as a digital signal.

Effect of the Invention With the above-described configuration, the present invention prevents dubbing of digital audio data using a digital interface, either because the copy code recorded on the tape that is the recording medium used as the dubbing source prohibits copying or intentionally. In this case, the analog audio signal after D/A conversion of the digital audio data is dubbed using an analog interface, and at the same time the subcode (in the case of DAT, the sampling frequency,
PCMID such as copy prohibition information, start ID1
By transmitting and receiving 5UBID (program number, etc., PACK, program time, etc.) via a digital interface, it is also possible to dub subcodes.

That is, when dubbing by the digital interface is prohibited, on the reproduction/transmission side, sub-data such as channel status and user's bits among the data sent from the digital interface are correctly transmitted. The digital audio data is then D/A converted and transmitted as an analog signal through an analog interface.

On the recording side, the reception records subcodes from the digital interface and audio signals from the analog interface. By doing this, audio data and subcodes can be dubbed even when digital copying is prohibited.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of a DAT in one embodiment of the present invention.

In FIG. 1, 1 is a recording medium such as a magnetic tape.

Reference numeral 2 denotes a recording/reproducing circuit that records a recording signal onto the recording medium 1 and reproduces a reproduced signal from the recording medium 1. 3 adds a subcode to the recorded signal and separates the subcode from the reproduced signal, as well as coding and decoding the first error correction code, interleaving,
This is a signal processing circuit that performs processing such as deinterleaving.

Reference numeral 4 denotes an analog interface circuit that interfaces with external equipment and transmits and receives signals using analog signals. 5 is a digital interface circuit that is an interface with external equipment and transmits and receives signals using digital signals.

6 is a recording/reproducing circuit 2. Signal processing circuit 3. Analog interface circuit 4. Digital interface circuit 5
This is a system control circuit that controls the

The operation of the interface installation of this embodiment configured as described above will be described below. When dubbing a signal recorded on the recording medium 1 to another recording medium, two DATs shown in FIG. 1 are used, with the negative one in the playback mode and the other in the recording mode. Figure 2 shows a connection diagram of two DATs.

Two DATs use analog interface cable 25
and 26, each analog interface circuit 22 and 24 by a digital interface cable 27,
Digital interface circuits 21 and 23 are connected. On the playback side DAT, system control circuit 6
The playback mode is instructed by
A decoding process is performed at , and audio data, which is a main signal, and a subcode, which is a sub signal, are obtained. The subcode is sent to the system control circuit 6. If the digital copy prohibition flag in this subcode indicates prohibition, be sure to set the digital copy prohibition flag in the digital interface output as well. Both the digital interface output and the analog interface output are controlled by the system control circuit 6 to output whether or not digital copying is prohibited. Alternatively, if digital copy is not prohibited, only the digital interface output may be output, and if digital copy is prohibited, the digital interface and analog interface may be output as described above.

The digital audio data in the digital interface signal will not be used by the DAT on the receiving side if digital copying is prohibited, so it does not matter whether it is included correctly or not.

FIG. 3 shows the format of the digital audio interface signal. Digital audio data is stored in two audio sample words. Preamble 21 is a 5YNC signal.6 AUX 22 is a pre-slot of an audio digital signal or audio sample word. Validity flag (v) 24
is set when the audio sample word is unreliable.
This is the flag to be sorted. DAT on the regeneration sending side for user data (u) 25 and channel status (c) 26
The subcode of is stored. 27 is an even number/grity from time slot 4 to 31.

FIG. 4 shows the track format of a DAT signal recorded on a magnetic tape. Audio data, which is the main signal, is stored in the audio data area 31, and subcodes, which are sub signals, are stored in the subcode 1 and subcode 2 areas 32.
, 3s and a part of the audio data area 31.

The DAT on the recording side is provided with an input selection switch 7 for audio signals, and the user uses the input selection switch 7 to select whether the source to be recorded is a digital interface input or an analog interface input.

When digital interface input is selected, on the recording side, the digital interface circuit 5 detects whether or not the digital copy prohibition flag is set during the digital interface input that is applied to the digital interface circuit 5. If not, the system control circuit 6 controls the source to be used as a digital interface input and record digital audio data and subcode.

If it is detected that the digital copy prohibition flag is set, the channel status and user bits being input through the digital interface are used and recorded for the subcode. If necessary, the system control circuit 6 generates a subcode, adds or rewrites it, and sends it to the signal processing circuit 3. That is, regarding the subcode, the recording side performs the same processing regardless of whether the digital copy prohibition flag is set or not.

On the other hand, for audio signals, the digital interface input cannot be used, so the analog interface circuit 4
The audio signal added to the computer is A/D converted and recorded. When the analog interface input is selected by the input selection switch 7, the audio signal applied to the analog interface circuit 4 is
/D conversion and recording. If the digital interface circuit 5 detects that the digital interface input is input correctly, the subcode adopts the channel status and user bits in the digital interface input. If it is detected that the input is not correct to the digital interface circuit 5, the subcode is generated independently by the system control circuit 6 and added to the signal processing circuit 3.

Alternatively, the input selection switch 7 may be abolished.

First, the digital interface circuit 5 checks whether the human power is input correctly, and if it is detected that the input is correct, then the digital copy prohibition flag is checked. If the digital copy prohibition flag is not set, the digital audio data and subcode obtained by the digital interface circuit 5 are used as the recording source.

If the digital copy prohibition flag is set, only the subcode uses the channel status and user bits obtained by the digital interface circuit 5, and the audio signal is obtained from the analog interface circuit 4.

Further, if the digital interface circuit 5 detects that the input is not input correctly, the audio signal is obtained from the analog interface circuit 4, and the subcode is generated independently by the system control circuit 6. If the system control circuit 6 controls the input selection switch 7 in this manner, the input selection switch 7 may be omitted.

As described above, according to this embodiment, dubbing of subcodes can be made possible even when digital copying is prohibited by controlling the control algorithm of the system control circuit 6 during dubbing as described above.

As described in detail, according to the present invention, dubbing of subcodes is possible even when digital copying is prohibited, and its practical effects are great.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a DAT according to an embodiment of the present invention, and FIG.
The figure is a connection diagram of two DATs, FIG. 3 is a format diagram of digital interface signals, and FIG. 4 is a track format diagram of signals recorded on the magnetic tape of the DAT. 1... Recording medium, 2... Recording and reproducing circuit, 3
... Signal processing circuit, 4. Analog interface circuit, 5. Digital interface circuit, 6. System control circuit, 21.
23...Digital interface circuit, 22
．． 24...analog interface circuit, 31
...Preamble, 32...AUXl 33
...Audio sample word, 34...Validity flag, 35...User data, 36
...Channel status, 37...Parity bit. Name of agent: Patent attorney Shigetaka Kurino, 1 person Zl, 2
3--Tigital Inter 7 Ace Koro each 22.24-
Analog Inter 7=Isro 25-A Allod Inter 7 Eighth Goofle RCh-26--Analog Inter 7 Nice γ-Full Leh 27"-Ticital Interf-Isro Full Leh 2

Claims (1)

[Claims] An analog interface circuit that converts the digital audio signal, which is the main signal, into an analog signal and sends and receives it, and a digital interface that sends and receives sub-signals such as the program number and program time that accompany the main signal as digital signals. A digital audio tape recorder comprising a circuit.