Study Of MPEG-1 Audio Coding Algorithm And Application In Sound Record & Playback System

In recent digital audio technique has been widely applied in the fields of consumer electronics, digital broadcasting and communication etc., which brought huge economic and social benefits annually. The digital audio coding, as the most important audio technique, has always absorbed people's attention since it was present. A series of audio coding standards has been produced in the past several years, and the MPEG-1 audio, which is the opening, advanced and grading coding method, gradually became the universal coding standard.The paper firstly introduces the basic theories and methods of audio coding. Afterward, more emphasis has been paid on the implementation of MPEG-1 audio coding standard, and the MPEG-1 layer 1 algorithms have been programmed in C programming language. According to the needs of a sound record &playback system, the subband filterbank and the psychoacoustic model, which need more complex computations, have been simplified and modified, resulting in the rapid decrease of the whole computations. The new algorithms are referred to as simplified layer 1 algorithms, which should be implement real-time in 16 bits fixed-point DSP chip. The fixed-point implementation of simplified layer 1 algorithms is simulated in C programming language, and the results show that the perceptual quality of reconstructing audio is good. In the last part of paper, the analog implementation of sound record &playback system is described in detail, and the solution based on fixed-point DSP chip of digital sound record &playback system is also preliminary proposed.