Device and method for transmitting audio signals by composite video signals in baseband manner

Abstract

The invention discloses a device and a method for transmitting audio signals by composite video signals in a baseband manner. The device comprises an audio difference module, an audio modulation enabling module and an audio modulation module, inputted base band audio signals enter the audio difference module and are processed to output audio difference signals, the audio modulation enabling modulejudges whether a current position is positioned at an expected line position of a composite video signal field blanking interval or not based on a field counter and a line counter of a composite video and generates enabling signals, and the audio difference signals, composite video signals and audio modulation enabling signals are inputted into the audio modulation module and analyzed and processed to output composite video signals with audios. According to the device, the audio signals are transmitted in the baseband manner, frequency modulation is omitted, cost is reduced, attenuation of long-distance transmission signals is less, noise resistance is high, and crosstalk between signals is avoided.

Description

technical field [0001] The invention relates to the technical field of audio and video signal transmission, in particular to a device and method for transmitting audio signals by using a composite video signal baseband. Background technique [0002] Most of the currently existing methods of transmitting audio signals are to pre-emphasize the baseband audio signal, and then modulate the processed baseband audio signal to a higher frequency carrier by frequency modulation, the frequency is generally tens of megahertz , and then superimpose the modulated audio signal and the modulated composite video signal, so that the audio signal and the video signal are sent to the receiving end together. [0003] The prior art also has the following disadvantages: 1. The audio signal is frequency modulated, the implementation of the sending system and the receiving system is relatively complicated, and the cost of the sending and receiving device is high. 2. The frequency modulation and d...

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Problems solved by technology

[0003] The prior art also has the following deficiencies: 1. The audio signal is frequency modulated, the sending system and the receiving system are complicated to realize, and the cost of the sending and receiving device is high

2. After the audio signal is FM and demodulated, it is easy to cause large distortion

3. The audio and video crosstalk that is easily generated due to the superimposition of the composite video signal after the audio signal is modulated

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