JPH0812742B2 - Information signal transmission device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information signal transmission device for reproducing and transmitting a signal recorded by compressing information on an optical disk or the like.

[0002]

2. Description of the Related Art In recent years, a CD player for reproducing a compact disc (CD) in which audio signals are recorded as digital signals and a digital audio tape recorder (DAT) capable of recording audio signals in digital signals have been commercialized. , The time has come to record and reproduce audio signals by digital signals. Along with this, the International Electrotechnical Commission (hereinafter abbreviated as IEC), the Japan Electronic Machinery Manufacturers Association, etc. are discussing digital audio interface standards so that digital signals can be transmitted and received between various digital audio devices.
Current CDs, CD players, and DATs are all IEC IEs
It complies with the standard of C958.

Further, recently, after converting a voice signal into a digital signal, the amount of information is reduced to about 1/4 by utilizing the auditory characteristics.
Digital compact cassette recorders (DCC), optical discs, etc., which are compressed and recorded on a disc have been developed. These digital audio devices are also DAT, C.
I / D so that it can be transmitted / received to / from the D player by digital signals
It is considered to comply with EC958.

The above-mentioned information signal transmission device will be described below with reference to the drawings. 8 is a block diagram of a conventional information signal transmission device, FIG. 9 is a disk track pattern, FIG. 10 is an output waveform diagram of each block, and FIG. 11 is an IE.
C digital audio interface standard I
It shows EC958.

In FIG. 9, 1 is a disk, 1a is a spiral track formed on the disk, and 2 is a reproducing head. The track 1a is divided into, for example, sectors having a predetermined length, and a compressed audio signal obtained by information compression is recorded in each sector. The compressed audio signal recorded in one sector is, for example, an audio signal of R channel, L channel, 384 samples each (total of 768 samples), and after being converted into a digital signal with a sampling frequency of 48 kHz and a quantization bit number of 16 bits. , Information is compressed to 1/4 in sector units.

Each part will be described with reference to FIG. The reproducing head 2 converges the light beam on the track 1a of the disk 1, photoelectrically converts the reflected light from the track 1a, reproduces the information recorded on the track 1a, and the reproducing processing circuit 5
Output to. A motor 3 rotates the disk 1 so that the relative speed between the reproducing head 2 and the track 1a on which the light beam of the reproducing head 2 is converged is always constant (CLV method). Reference numeral 4 is a reproducing head moving circuit, which has a time of 8 msec (48 kHz, 3
It is a circuit for appropriately moving the reproducing head 2 to the head of each sector for every 84 samples. Reference numeral 5 denotes a reproduction processing circuit, which is a circuit for demodulating information obtained by the reproducing head 2 and performing error correction to obtain a compressed audio signal. Reference numeral 6 denotes an information decompression circuit, which is a circuit for decompressing the compressed audio signal output from the reproduction processing circuit 5. 7 is digital audio
An interface circuit (hereinafter abbreviated as a DIO circuit), for example, a circuit conforming to the IEC digital audio interface standard IEC958. The output of the information expansion circuit 6 is generated into a signal conforming to IEC958, and then output from the output terminal 8 to the outside.

Here, the digital audio interface standard of IEC958 will be briefly described. There are two types of methods for transmitting digital signals: a parallel transmission method in which all bits of data are simultaneously sent and a serial transmission method in which bits are sequentially sent one bit at a time. IEC958 adopts a serial transmission method.

As shown in FIG. 11, the basic unit of data is one frame (one sample for each of the L channel and the R channel), and one frame is composed of two subframes. Each subframe is composed of 32 bits, and a preamble for synchronization is set in the first 4 bits of the subframe. The preamble code is B,
Three types, M and W, are prepared for identifying blocks and channels. The following 24 bits are audio signal data, and the first 8 bits are set to 0 when the data such as CD is 16 bits for transmission from the LSB side.

The last symbols V, U, C and P indicate various control codes. V is a validity flag, which is a bit for determining whether or not the data of the audio signal is correct. U is a subcode signal also called user's bit. C
Is called the channel status and defines the nature of the data being transmitted. P is a parity bit such that the number of 1's and the number of 0's excluding the sync signal are even numbers.

Further, 192 frames make up one block, and user bits and status bits are
It is standardized so that it can be used in units of 192 frames / block.

The operation of the information signal transmitting apparatus configured as above will be described below. As described above, 384 samples of the audio signal sampled at 48 kHz, that is, an audio signal of 8 msec is recorded in each sector. Therefore, the audio signal is output from the output terminal 8
In order to continuously output from, each sector may be reproduced every 8 msec.

In FIG. 9, the reproducing head 2 reproducing the sector 0 of the track 1a continues the pause at the head of the sector 1. There are various methods of temporary stop, but an example will be described here. For example, the reproduction head 2 that reproduced sector 0
Is moved to the previous track 1a. The reproducing head 2 that has moved to the previous track advances along the track 1a. Then, when passing the beginning of sector 0 and reaching the end of sector 0, it is moved again to track 1a one track before. This operation is repeated until the reproduction of the sector 1 is started.

Then, when 8 msec has elapsed from the start of reproduction of sector 0, reproduction from sector 1 is restarted. Then, after the reproduction of the sector 1 is completed, the pause is continued again at the head of the sector 2. As for the output of the reproducing head 2 thus reproduced, sector information is intermittently output as shown in FIG. The output of the playback head 2 is
The data is input to the reproduction processing circuit 5, information is demodulated, errors are corrected, and the like, and the information is output to the information expansion circuit 6 at the timing of (b) in FIG. The information expansion circuit 6 expands the compressed audio signal in sector units. Data of 384 samples of the expanded L and R channels are shown in FIG. 10 (c).

The output of the information decompression circuit 6 is input to the DIO circuit 7 and converted into a signal conforming to IEC958, and then the signal shown in FIG.
Output from the output terminal 8 to the outside at the timing of 0 (d).

[0015]

However, the above-mentioned conventional transmission format is limited to a voice signal without information compression, and when transmitting an information-compressed voice signal, the information is expanded and then transmitted. I had to.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an information signal transmitting apparatus capable of transmitting an information-compressed audio signal in a compressed state.

Further, in the above-mentioned conventional configuration, the information-compressed audio signal must be transmitted after decompressing the information, and even if the information is compressed to 1/4 and recorded on the disc,
There is a problem that it takes 60 minutes to transmit a voice signal of 60 minutes.

The present invention solves the above-mentioned conventional problems, and an object thereof is to provide an information signal transmitting apparatus capable of transmitting an information-compressed audio signal in a short time.

[0019]

In order to achieve this object, an information signal transmission apparatus of the present invention comprises a transfer means for outputting a compressed information signal obtained by compressing an information signal of 1 sample m bits into 1 / k. It is provided with a dividing means for dividing the compressed information signal into m-bit words, and a transmission format conversion means for adding auxiliary information relating to the compressed information signal to the word and then converting it into a predetermined transmission format.

Further, the transfer means of the information signal transmitting apparatus of the present invention has k sectors each of which is composed of a compressed information signal obtained by compressing the information signal of x samples into 1 / k during the time length of the information signal of x samples. It is what is output.

Further, the transmission format conversion means of the information signal transmission device of the present invention is a code generation means for generating a code defining additional information related to the compressed information signal in an undefined area of the IEC digital audio interface standard IEC958. , A conversion means for adding the code to the word and converting the word as one sample of the information signal into a transmission format conforming to IEC958 and outputting the converted information.

[0022]

According to the present invention, the compressed information signal can be transmitted in a compressed state by dividing the compressed information signal in units of m bits and using the same bits as the transmission of the expanded information signal.

Further, according to the present invention, according to the above-mentioned constitution, 1 /
If it is a compressed information signal compressed to 4, the transmission speed of the information signal becomes four times. As a result, it becomes possible to transmit the information signal in the time required for 1/4 of the conventional time.

Further, according to the present invention, the above-mentioned configuration makes it possible to use the conventional transmission format. This can be achieved by simply adding a simple circuit.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an information signal transmitting apparatus according to the first embodiment of the present invention, and FIG. 2 is an output waveform diagram of each block.

In FIG. 1, reference numeral 9 denotes a transfer means for transferring a compressed audio signal obtained by compressing information of a 1-sample 16-bit audio signal (see FIG. 2 (a)) to 1/4. The output is shown in FIG. The output of the transfer unit 9 is input to the dividing unit 10 and divides the compressed audio signal into 16-bit units (see FIG. 2C). The output of the dividing means 10 is
It is input to the transmission format conversion means 11. The transmission format conversion means 11 adds an identification code for identifying the characteristics of the compressed audio signal such as the compression rate and the compression method to the compressed audio signal divided in units of 16 bits, converts it into a predetermined transmission format, and outputs it. Output from 8.

As described above, according to this embodiment, by dividing the compressed audio signal in units of 16 bits, the audio signal can be transmitted in the compressed audio signal state. As a result, when transmitting the compressed audio signal as it is to a device for recording, a circuit for compressing information on the receiving side becomes unnecessary.

FIG. 3 is a block diagram of an information signal transmission apparatus according to the second embodiment of the present invention, FIG. 4 is a track pattern of a disk, and FIG. 5 is an output waveform diagram of each block.

In FIG. 3, the same operations as those in the conventional example are designated by the same reference numerals as those in FIG. 8, and the description thereof will be omitted.

Reference numeral 12 is a reproducing head moving circuit, which is a circuit for moving the reproducing head 2 so as to continuously reproduce the sectors along the track 1a. 13 is a motor. The relative speed between the reproducing head 2 and the track 1a on which the light beam of the reproducing head 2 is converged is kept at a predetermined value, and the reproducing head 2 outputs four sectors during an audio signal length of 8 msec recorded in the sector. The disk 1 is being rotated. 1
Reference numeral 4 is a division circuit, which is a total of 76 recorded in one sector.
It is a circuit that divides a compressed audio signal of 8 samples (384 samples of 2 channels) into 16-bit units. The division circuit 13 divides the sector into 192 sectors, and the divided 1
The unit will be referred to as a word hereinafter. Reference numeral 15 is a transmission format conversion circuit, which adds an "identification code for identifying the property (compression rate, compression method, etc.) of the compressed audio signal" to the output of the division circuit 14, and converts it into a predetermined transmission format for output. Is. Here, as an example, the identification code A is added to the head of each word.

The operation of the information signal transmission apparatus configured as described above will be described below.

In FIG. 4, the reproducing head 2 for reproducing the sector 0 of the track 1a successively reproduces sector 1, sector 2, sector 3, ... As a result, as shown in FIG. 5A, the reproducing head 2 continuously outputs four sectors each during the time length of 8 msec of the audio signal recorded in the sector. The output of the reproducing head 2 is input to the reproducing processing circuit 5, demodulates information, performs error correction, etc., and outputs it to the dividing circuit 14 at the timing of FIG. The division circuit 14 divides the sector into 16-bit unit words as shown in FIG. 5C, and outputs the words to the transmission format conversion circuit 15. Transmission format conversion circuit 1
Reference numeral 5 adds an identification code A indicating the characteristics of the compressed audio signal such as the compression method and the compression ratio to each word, and outputs it from the output terminal 8 to the outside.

As described above, according to this embodiment, by reproducing 4 sectors within the time length of the audio signal recorded in one sector, it is possible to output the audio signal at a speed four times faster than usual. Therefore, it is possible to transmit the audio signal in the time required for 1/4 of the conventional time.

Further, since the audio signal can be transmitted in the state of the compressed audio signal, when transmitting the compressed audio signal to the device for recording as it is, a circuit for compressing information on the receiving side becomes unnecessary. .

FIG. 6 is a block diagram of an information signal transmitting apparatus according to the third embodiment of the present invention, and FIG. 7 is an output waveform diagram of each block. In FIG. 6, the same operations as those in the conventional example and the second embodiment are denoted by the same reference numerals as those in FIGS. 8 and 3, and the description thereof will be omitted. Here, the transmission format conversion circuit 16 will be described. .

The transmission format conversion circuit 16 is composed of a control code generation circuit 16a and a DIO circuit 16b. The control code generation circuit 16a is, for example, U of the digital audio interface standard IEC958.
It is a circuit that generates an identification code for defining the properties (compression ratio, compression method, etc.) of the compressed information signal in the undefined area of bits and C bits. The DIO circuit 16b is a circuit conforming to IEC958, like the DIO circuit 7 of the conventional example of FIG.

The operation of the information signal transmission apparatus configured as described above will be described below. The operation of the reproducing head 2 is exactly the same as that of the second embodiment, and the description thereof is omitted, but the output of the reproducing head 2 (see FIG. 7A) is
Similar to FIG. 5A, 4 sectors are output within 8 msec. The output of the reproducing head 2 is input to the reproducing processing circuit 5, demodulates information, corrects errors, etc., and outputs it to the dividing circuit 14 at the timing of FIG. 7B. The division circuit 14 divides the sector into 16-bit units. As shown in FIG. 7C, one sector is divided into 192 words and output to the transmission format conversion circuit 16. In the DIO circuit 16b, the control code generation circuit 16a is added to the word output from the division circuit 14.
The identification code generated by is added, converted into a transmission format compliant with IEC958, and output from the output terminal 8.

As described above, according to this embodiment, not only the transmission time can be shortened to 1/4 of the conventional one, but also the conventional digital audio interface circuit can be used by utilizing the IEC958. is there. This can be realized by adding a simple circuit.

Further, since the audio signal is transmitted in the state of the compressed audio signal, when transmitting the compressed audio signal to the device for recording as it is, the circuit for compressing the information on the receiving side becomes unnecessary.

Although the information signal is an audio signal in the above embodiment, it may be a signal such as a video signal.

[0042]

As described above, according to the present invention, it is possible to transmit a compressed information signal in a compressed state by dividing the compressed information signal into transmission units of the expanded information signal. As a result, it is possible to transmit in a shorter time than in the past.

If an undefined area of a standardized transmission format such as IEC958 is used, it can be realized by adding a simple circuit.

Further, when the information compression signal is transmitted to the recording device, the information compression circuit on the receiving side becomes unnecessary.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an information signal transmission device according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram showing an output waveform of each block in the embodiment.

FIG. 3 is a block diagram showing a configuration of an information signal transmission device according to a second embodiment of the present invention.

FIG. 4 is a schematic diagram showing a track pattern of the disc of the embodiment.

FIG. 5 is a waveform diagram showing the output waveform of each block in the same example.

FIG. 6 is a block diagram showing a configuration of an information signal transmission device according to a third embodiment of the present invention.

FIG. 7 is a waveform diagram showing an output waveform of each block in the embodiment.

FIG. 8 is a block diagram showing a configuration of a conventional information signal transmission device.

FIG. 9 is a schematic diagram showing a track pattern of a conventional disc.

FIG. 10 is a waveform diagram showing an output waveform of each block in the conventional example.

FIG. 11 is a schematic diagram showing a transmission format of IEC958.

[Explanation of Codes] 1 disc 2 reproducing head 5 reproducing processing circuit 8 output terminal 9 transfer means 10 dividing means 11 transmission format converting means 12 reproducing head moving circuit 13 motor 14 dividing circuit 15, 16 transmission format converting circuit 16a control code generating circuit 16b DIO circuit

Front page continued (72) Inventor Satoshi Izumi, Osaka Prefecture Kadoma City 1006 Kadoma, Matsushita Electric Industrial Co., Ltd. (72) Inventor Hiroo Oikawa Osaka Kadoma City, Kadoma 1006 Matsushita Electric Industrial Co., Ltd. (56) References JP 64-73560 (JP, A) JP 2-94174 (JP, A)

Claims (2)

[Claims] 1. An information signal of 1 sample m bits is x sampled.
Information is compressed to 1 / k in pull units and time-axis compressed to 1 / k
And the storage means stored as follows, and for each time length of the information signal of x samples from the storage means.
The compressed information signal of (x × k) samples is continuously read.
Reproducing means; dividing means for dividing the output of the reproducing means into m-bit words; and transmission format converting means for adding auxiliary information relating to the compressed information signal to the words and then converting it into a predetermined transmission format. An information signal transmission device provided. 2. The transmission format converting means is a digital audio interface standard IEC of IEC.
Code generating means for generating a code defining additional information related to the compressed information signal in an undefined area of 958, and adding the code to a word and converting the word into a transmission format conforming to the IEC958 as one sample of the information signal. The information signal transmitting apparatus according to claim 1, further comprising: a converting unit that outputs the information.