【摘要】 MPEG- 4音频编码标准不仅对码率和音质提出了更高的要求 ,而且还要求编码器具有多种功能以满足各种不同应用的需要 .该文利用不同尺度小波系数间的自相似特性和人耳的掩蔽效应 ,提出了一种基于心理声学模型的零树小波音频编码算法 .该算法不仅可在低码率 (5 6 kb/ s)上得到透明质量的 CD音频信号 ,而且可产生嵌入式码流 ,在最优意义上支持多码率的可分级编码 ,是一种很有前途的适用于多媒体通信等领域的编码方案 .更多还原

【Abstract】 The MPEG 4 audio coding standard has not only more requirements to bit rate and sound quality, but also requires the coder to offer manifold functionalities to satisfy various applications. A zerotree wavelet audio coding algorithm based on psychoacoustic model is proposed in this paper, which takes advantage of the self similarities among different scale wavelet coefficients and the masking effect in human hearing. Transparent quality audio can be achieved at lower bit rate (56kb/s) using this algorithm, and the bitstream produced is embedded and able to support multirate scalable coding. It is a promising coding scheme suitable to multimedia communications, and so on.更多还原