给出了信号压缩通常的变换-量化-编码函数。DHT函数为离散DHT变换，是FFT变换的近似，其正反变换相同，克服了FFT复系数不利于存储的缺点。LLMAX函数给出了某x序列在固定比特下的最佳量化输出。熵编码函数为霍夫曼编码。-Gives the signal compression usually transform- quantitative- coding function. DHT DHT discrete transform function, the FFT transform approximation, the same positive and negative transformation, overcoming complex FFT coefficient is not conducive to storage shortcomings. LLMAX function x is given a fixed bit sequence in the optimum quantized output. Entropy coding function as Huffman coding.