Method and device for transmitting audio data

Abstract

The invention discloses an audio data transmission method, which is used for carrying out audio data transmission without occupying an extra memory in order to save the memory space and reduce the burden of a CPU (central processing unit). The method includes the following steps that: a decoder writes audio data into a cache unit; when the cache unit is full, the decoder judges whether an interrupt flag exists; after audio transmission is interrupted, the decoder receives an interrupt flag transmitted by an interrupt module; and when a judgement result is yes, the decoder triggers DMA (Direct Memory Access) transmission. The invention also discloses a device used for carrying out the method.

Description

technical field [0001] The invention relates to computer and embedded fields, in particular to a method and device for transmitting audio data. Background technique [0002] With the rapid development of embedded system and multimedia technology, the multimedia playback system based on embedded system is gradually rising. In the embedded multimedia playback system, audio playback is one of the most basic functions. [0003] During audio playback, the output of audio data is output to DAC (Digital-to-Analog Converter, digital-to-analog converter) by means of DMA (Direct Memory Access, direct memory access), and the audio data is converted from digital signal by DAC After it is an analog signal, it is output according to the sampling rate, such as 48K, 44.1K, etc. Among them, DMA refers to an input / output operation mode that realizes automatic batch exchange of data between high-speed peripherals and main memory under special hardware control, and minimizes CPU intervention....

AI Technical Summary

Problems solved by technology

But the defect of this method is that memory is needed to save mute data, which takes up more storage resources

And the storage space of this memory should not be too small, because if it is too small, the audio data may not be ready after the saved silent data is transmitted, and the DMA transmission cannot be started, and the purpose of improving the discontinuous audio playback cannot be achieved.

And since it is judged by DMA interrupt whether there is ready audio data, a judgment must be made every time the silent data is transferred, so DMA interrupts will occur frequently before the DMA transfer is interrupted and the next round of DMA transfer starts.

The frequent DMA interrupts add more burden to the CPU, which in turn aggravates the discontinuity of the sound and seriously affects the user's listening effect

And if the silent data is not transmitted, the interrupt of the end of the DMA transmission cannot continue to come, and the DMA transmission cannot be started again, resulting in the inability to continue playing the audio data

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