JP3497676B2 - AV combine receiver - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
AES / EBU (Audio Engine) used for TV digital equipment used in production and transmitted by using auxiliary signal area of serial interface TV video signal
The present invention relates to an AV combine receiver for receiving audio signals in the ering Society / European Broadcasting Union) format.

[0002]

2. Description of the Related Art Conventionally, AV combine receivers have been
A TV video signal in which an audio signal of ES / EBU format is converted into data and multiplexed in an auxiliary signal area is input, and a video signal and an audio signal are separated and output. Originally, a continuous audio signal of AES / EBU format is packetized by data conversion, and discontinuously time-compressed, and then arranged in the auxiliary signal area. Therefore, the AV combine receiver requires a buffer for reconstructing an audio signal. This buffer size is specified as a minimum of 64 samples per channel.

By the way, in the conventional AV combine receiver as described above, in order to synchronize the audio signal and the TV video signal on the receiving side, it is necessary to reset the write / read address of the buffer every 5 frames of the video. is there. However, if the minimum buffer size is 64, then 8
008/64 = 125 The remainder becomes 8, and the address may be reset to 0 immediately after the audio data is written in the buffer from addresses 0 to 7, and may be overwritten before the contents of addresses 0 to 7 are read. That is, there is a problem that the write address and the read address of the buffer may be overtaken.

[0004]

As described above, in the conventional AV combine receiver, the buffer for reconstructing the audio signal of AES / EBU format is
The minimum value of the buffer size is specified. If the write / read address of the buffer is reset for each specified frame of the video signal in order to synchronize the audio signal and the TV video signal on the receiving side, there will be a remainder and There is a problem that the write address and the read address of the above may pass.

The present invention solves the above problems and provides AES /
For the EBU audio signal reconstructing buffer, the problem of address discontinuity at the time of reset is eliminated, overwriting of its write address and read address does not occur, and the memory capacity of the buffer is set to the necessary minimum to reduce the hardware. It is an object of the present invention to provide an AV combine receiver capable of reducing wear.

[0006]

In order to solve the above-mentioned problems, the present invention takes as input a serial digital video signal in which an audio signal of AES / EBU format is converted into data and multiplexed in an auxiliary signal area. Original AES from input signal
In an AV combine receiver for reconstructing an audio signal of / EBU format, a serial / parallel conversion means for converting the serial digital video signal into a parallel digital video signal, and a parallel digital video signal output from the serial / parallel conversion means Input means for separating the audio data multiplexed in the auxiliary signal area, a buffer for accumulating the audio data separated by this means, a buffer for reconstructing and sequentially outputting, and an output from this buffer. Format conversion means for converting the audio data to the original AES / EBU format audio signal, and the buffer size per audio signal channel of the buffer is defined as a video signal defined for synchronizing video and audio. AES of reference sampling frequency for frame period
/ EBU is a divisor of the number of audio signal samples.

The format conversion means may be arranged in the preceding stage of the buffer. Also, the AES /
The number of EBU format audio signal samples is 8008
When it is (2 × 2 × 2 × 7 × 11 × 13), the buffer size per channel of the audio signal of the buffer is set to a number of 64 or more, which is a divisor of 8008. A cyclic FIFO memory can be used as the buffer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the configuration of an AV combine receiver according to the present invention. The AES / EBU audio signal is converted into data and the serial digital video signal multiplexed in the auxiliary signal area is supplied to the AV combine receiver. This serial digital signal is converted into a parallel digital video signal by a serial / parallel converter (S / P) 1. The parallel digital video signal is supplied to the demultiplexer 2.

The demultiplexer 2 separates the audio data multiplexed in the auxiliary signal area from the parallel digital video signal according to the switching control signal from the controller 5. The separated audio data is buffer 3
Is supplied to.

The buffer 3 accumulates the separated audio data from the demultiplexer 2 based on the address control signal from the controller 5 and sequentially outputs them.
The output is supplied to the format converter 4.

The format converter 4 includes a buffer 3 based on a timing control signal from the controller 5.
Auxiliary signal from is for returning the converted digital audio signal to the original AES / EBU transmission format, and the audio signal reconstructed by this is a digital image in which the digital audio signal is separated by the demultiplexer 2. It is output as a reception signal together with the signal.

The format converter 4 does not necessarily have to be arranged in the subsequent stage of the buffer 3, and the buffer 3
It may be arranged in the preceding stage. Buffer 3 above
Is composed of, for example, a cyclic FIFO memory as shown in FIG. The cyclic type FIFO memory is a first-in first-out type memory in which the write address is incremented by 1 when writing and the read address is incremented by 1 when reading, and then returns to the first address when the final addresses are reached. is there.

The controller 5 instructs the buffer 3 to
The write side has a write pulse signal WR and a write address reset signal WRS synchronized with the video signal on the input side.
A read pulse signal RD and a read address reset signal RRST synchronized with the audio signal on the output side are applied to the read side.

The operation of the above configuration will be described below with reference to a specific example. For example, when the AES / EBU audio signal of 48 kHz sampling is multiplexed in the auxiliary signal area of the TV video signal of 29.97 frames per second, the audio data separated by the demultiplexer 2 synchronizes the video and the audio. In addition, every 5 frames of the video signal is given to the writing side and the reading side with some space.

However, for example, the minimum buffer size is 6
If it is 4, since 8008/64 = 125 remainder 8, the address is reset to 0 immediately after the audio data is written from the buffer addresses 0 to 7, and the data is sequentially overwritten. The data must be read before it can be written.

However, the audio data in the input signal is not always multiplexed evenly, and the write pulse intervals are indefinite. Therefore, in order to continuously output data at equal intervals on the reading side, it is necessary to store some data. Therefore, if the contents of addresses 0 to 7 are read before being overwritten after the address reset, the write address and the read address of the buffer 3 will be overtaken somewhere, and the audio signal must be reconstructed correctly. I can't.

Therefore, in the present invention, the buffer size is set to 8
The divisor of 008 (2 × 2 × 2 × 7 × 11 × 13) is set to 88, for example. In this case, 8008/88 = 91,
The FIFO makes exactly 91 cycles during 5 frames of video,
No address jump occurs at address reset. Therefore, an offset can be added on the read side so as not to overtake the write and read addresses, and the above problem can be solved.

As described above, the buffer size per audio signal channel of the AV combine receiver is set to 80.
If it is a divisor of 08 and is 64 or more, no address jump occurs at the time of address reset. Therefore, it is only necessary to consider the offset of the read address with respect to the write address without considering the limit value of the address at reset, and the memory can be operated efficiently.

In particular, if the buffer size is 88, it is possible to provide a sufficient margin on the reading side for input data at irregular intervals, and it is possible to prevent the memory capacity from being wasted.

[0020]

As described above, according to the present invention, AES /
For the EBU audio signal reconstructing buffer, the problem of address discontinuity at the time of reset is eliminated, overwriting of its write address and read address does not occur, and the memory capacity of the buffer is set to the necessary minimum to reduce the hardware. An AV combine receiver capable of reducing wear can be provided.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a configuration of an embodiment of an AV combine receiver according to the present invention.

FIG. 2 is a block diagram showing an input / output configuration of a buffer and its control signal according to the same embodiment. 1 ... Serial / parallel converter (S / P) 2 ... Demultiplexer 3 ... Buffer (FIFO memory) 4 ... Format converter 5 ... Controller

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-5-130576 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 5/60 101 H04N 7/04 H04N 7 / 045

Claims (4)

(57) [Claims] 1. AES / EBU (Audio Engineering Soci)
An AV combine that reconstructs the original AES / EBU format audio signal from the input digital signal, which is a serial digital video signal that is converted into data of the audio signal of ety / European Broadcasting Union) format and is multiplexed in the auxiliary signal area. In the receiver, a serial / parallel conversion means for converting the serial digital video signal into a parallel digital video signal and a parallel digital video signal output from the serial / parallel conversion means are input and multiplexed in an auxiliary signal area thereof. Means for separating the audio data that is present, a buffer for accumulating the audio data separated by this means, reconstructing and outputting sequentially, and audio data output from this buffer to the original AES /
A format conversion means for converting into an EBU format audio signal, wherein the buffer size per audio signal channel of the buffer is AES of a reference sampling frequency for a video signal frame period defined for synchronizing video and audio. / An AV combine receiver characterized in that it is a divisor of the number of samples of an EBU audio signal. 2. AES / EBU (Audio Engineering Soci)
An AV combine that reconstructs the original AES / EBU format audio signal from the input digital signal, which is a serial digital video signal that is converted into data of the audio signal of ety / European Broadcasting Union) format and is multiplexed in the auxiliary signal area. In the receiver, a serial / parallel conversion means for converting the serial digital video signal into a parallel digital video signal and a parallel digital video signal output from the serial / parallel conversion means are input and multiplexed in an auxiliary signal area thereof. Means for separating the audio data that is present and the audio data output from this means to the original AES / EB
The apparatus comprises a format conversion means for converting into a U format audio signal and a buffer for accumulating the audio data whose format has been converted by this means, reconstructing and outputting sequentially, and a buffer size per audio signal channel of the buffer. An AV combine receiver characterized in that it is a divisor of the number of samples of an AES / EBU audio signal having a reference sampling frequency with respect to a video signal frame period defined for synchronizing video and audio. 3. When the number of samples of the audio signal of the AES / EBU format is 8008, the buffer size per audio signal channel of the buffer is 80.
The AV combine receiver according to any one of claims 1 and 2, wherein the divisor of 08 is 64 or more. 4. The AV combine receiver according to claim 1, wherein the buffer is a cyclic FIFO memory.