All-digital sound card multi-channel playback system and playback method with low bandwidth occupancy

Abstract

The invention discloses an all-digital multichannel playing system having no sound card and a low bandwidth occupancy rate. The system comprises a computer control end and a PWM signal receiving end, wherein the computer control end converts all kinds of files in digital audio formats into at least one PWM file with high fidelity and transmits the PWM file to the PWM signal receiving end, the PWM file is composed of signals with different switching time lengths, the length of a high level or low level duration of each switching signal is in direct proportion to a corresponding amplitude of the audio file, and the length of the duration is controlled by a duration control module of the computer control end; and the PWM signal receiving end is provided with N ports that can work at the same time and can output high levels or low levels according to the length of the duration of the duration control module of the computer control end. According to the all-digital multichannel playing system disclosed by the invention, the digital audio file only needs to be converted by software into the PWM file with high fidelity to directly drive a D type power amplifier, the play of the music with high fidelity can be guaranteed, the equipment is simple, the cost is low, the extensibility is very strong, and the practicability is very strong. The PWM file is composed of signals with different switching time lengths, and thus the requirements on the network bandwidth are very low.

Description

technical field [0001] The invention relates to the technical field of audio playback, in particular to an all-digital soundless card multi-channel playback system and a playback method with low bandwidth occupancy. Background technique [0002] At present, the mainstream audio playback mode is to use sound card hardware D / A conversion to decode audio data files to output analog audio signals, mainly using Class AB or Class A power amplifiers. also like figure 1 The traditional Class D power amplifier shown converts the analog audio signal into a PWM signal through a comparator for power amplification and filtering. The above method is to amplify the power of the audio analog signal, and the presence of nonlinear distortion and intermodulation distortion will lead to sound deterioration. . To solve the problem of sound distortion, such as figure 2 As shown, Texas Instruments uses pure hardware circuits to realize D / D high-precision conversion, uses digital interpolation ...

AI Technical Summary

Problems solved by technology

This method requires the purchase of additional hardware, the cost of the power amplifier increases, and its accuracy is fixed by the hardware and cannot be improved at will; in addition, it can only support one class D power amplifier. Since it does not support the network, there are complicated connections and no networking when multiple sets are used. The basis for in-depth development of sound systems

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