SU370744A1 - DEVICE FOR INPUT AND ISOLATION OF THE SIGNAL OF SOUND SUPPORT OF TELEVISION - Google Patents

Description

one

The invention relates to digital transmission of analog signals, for example, in the joint transmission of audio signals and television images in the form of a single digital stream.

The known devices for inputting pulse-modulated (PCM) audio signals, IB analog-to-form, to an analog image signal with subsequent processing of both signals by a common encoder do not provide the required quality of audio signal transmission.

To improve the quality of television sound transmissions and sound accompaniment, eliminate mutual influences in the joint transmission of these signals, increase the noise immunity of transmission in the transmitting part of the proposed device, parallel to the input of a television signal encoder, the threshold unit is activated, which controls the operation of the And circuit, a pulse generator, which follows the coding frequency of the television signal, and the output of the circuit "And is connected to the digital stream combining unit, to the other inputs of which A television signal encoder is connected via a key controlled by a threshold unit and a sound guide encoder through a memory block controlled by a signal from the output of the threshold unit, and in the receiving part of the device a synchro-pulse identifier is connected in parallel with the output of the television signal decoder connecting the input of the receiving part

devices to a television signal decoder, with a storage unit and with an output stage, the input of which is connected to the output of a television signal decoder. Fig, 1 shows a signal input circuit.

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FIG. 2 is a diagram of its isolation; in fig. 3 -

expanded block diagram of the transmitting part

the proposed device. .

The signal input circuit consists of a coder /

a television signal, a threshold unit 2, an AND 3 logic circuit, a generator 4, an integration unit 5, a key b, an audio signal encoder 7 and a storage unit 8. The signal extraction circuit includes

decoder 9 of television signals, regenerator 10 clock pulses, threshold block //, output stage 12, pulse shaping unit 13, locking block 14, block 15 of a television digital stream, temporary sum, matrix 16, identifier 17 marker groups, blocks //, 13, .15 and 17 constitute the sync pulse identification unit, block 18, audio decoder 19 and control pulse generator 20.

The device works as follows.

The television signal arrives at the encoder / and the threshold unit 2, which is triggered by a decrease in the television signal below the black level. The signal from block 2 controls the operation of the circuit "And 3," to which another input receives pulses with the frequency of following the code groups of the PCM-signal of the television from generator 4. When block 2 triggers, the output of the circuit "And 3 forms code groups of the type 100000000, corresponding to the minimum signal in the reflex code commonly used in code transmission of the television signal. These code groups are fed to the input of the digital streams combining unit 5. The operation of block 2 causes the key 6 to open, through which the pulses from the encoder output / enter block 5. The signal from block 2 reads and passes the input to block 5 of the code groups of the audio signal formed by encoder 7 and recorded in block 8. At the output of the block 5 combining digital streams, a composite PCM signal is formed, consisting of image signal code groups in group packets of the form 100000000, corresponding to the transmission of clock pulses and audio signal code groups transmitted inside these packages.

In the receiving part of the PCM device, the signal is converted in the decoder 9 of television signals, containing a digital analog converter, the signal from which is fed to one of the inputs of the regenerator 10, to the threshold unit 11 and the output stage 12.

A television analog signal with a reduced level of horizontal (frame, control) clock pulses at the output of the converter in decoder 9 is divided (recognized) in the block // and restored to the normal level ratios in the output stage 12. In block 13, a sequence of pulses of duration t 1 is formed 5 micron / sec following frequency / p and is fed to another input of the regenerator W, where the sync pulses are digitally regenerated using code signals / holes by code groups of the type 100000000, and to the locking block 14 with a block of 15. At the inputs of blocks 14 (the “NO” scheme) and 15 (the “I” scheme) a digital television signal is directly received with an audio signal inserted into it. With this unit 14, the decoder .9 is locked by means of pulses from the regenerator 10 and block 13 through the time adder 16 for the time of regeneration of the clock pulses. The sequence of symbols selected by block 15 is supplied to the input of the identifier 17 and simultaneously with the output signal of the identifier 17 to the inputs of block 18. The identified marker groups serve as a command to start recording two audio signal code groups and to restore the audio signals input to the device by the digital-to-analog converter decoder 19, to the inputs of which recognized signals are detected through the / 8 block and shaper 20, with a frequency of 2 / p, controlling the process of decoding the PCM audio signal .

Each block of the transmitting part of the device. Is represented in FIG. 3 as a complex functional unit. The coding blocks of television and sound contain, respectively, nine-bit coder 21 and

parallel code shaper 22 with memory blocks 23 and 24.

Signals from encoder 21, threshold block 25, and frequency / page extractor 26 are converted to discrete optical sources with sound signals from blocks 23 and 24 using the NET 27 circuit to lock the output of the encoder 21 for horizontal, frame, and equalizing pulses, formers 28 packets code groups (“I” circuits) and an auxiliary pulse train / p that are phase-shifted relative to the leading edge of horizontal sync pulses on a four-bit binary counter 29 and “I 30” circuit. From the output of the pilot pulse former consisting of two frequency multiplier 31, AND 5: 2 and NO 33 circuits, a sequence of pulses of an acoustic signal following the frequency / OECE 2 / p., and sequences of control pulses of a frequency / p section that are shifted one relative to

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television and sound signals before forming a full signal on a temporary adder 34. In the television signal component, before temporal summation, symbols appear in packets of code groups of the form 100,000,000, corresponding to

time for the transfer of audio signal sigal, using successively connected two-bit binary counter 35, trigger 36 and NO 37 circuit. Parallel-connected two-bit binary counter 38 and logic AND AND NO 39 generate marker groups and sequences of read pulses necessary for control (command) input code groups sigpala sound

into a digital stream of a television signal, using alternating characters with a lower frequency.

Subject invention

A device for inputting and extracting a sound signal from a television that is transmitted by pulsed modulation in packets of code groups of horizontal pulses and pulse pulsed modulated

a video signal signal consisting of an encoder and a decoder of a television signal, an encoder and a decoder of an audio signal, a combining and dividing circuit of digital streams corresponding to image signals, sound and sync pulses,

characterized in that, in order to improve the quality of transmission of television signals and sound accompaniment, to eliminate reciprocal; when jointly transmitting these signals, to increase the noise immunity of the transmission, in the transmitting part of the device parallel to the input of the television signal coder, the , the other input of which is connected to a pulse generator, which follows the frequency of encoding the television signal, and the output of the AND circuit is connected to a digital stream combining unit, to other inputs

the television signal encoder is connected via a key controlled by a threshold block and an audio signal encoder through a memory block controlled by a signal from the output of the threshold block, and in the receiving part of the device a sync pulse is connected in parallel to the output of a television signal decoder whose outputs are connected with a key connecting the input of the receiving part of the device to the decoder of the television signal, with a storage unit and with the output stage, the input of which is connected to the output of the decoder of the television signal.

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