低码率下CBC算法中位平面编码的新方法

CBC是AV3音频编码中的核心算法，它以编码带为单位，采用位平面编码方法对量化后的频谱系数进行Huffman熵编码，但在码率比较低的情况下，CBC可能因可用比特数不够而无法对那些低比特层的信息进行编码，从而造成那些量化值比较小的频谱系数中重要性最大的位信息没有被编码．为此，论文提出了一种比特平移的方法，将量化系数中重要性最大的位平移到最高比特层，再对平移后的量化系数进行编码．数值分析结果表明：在码率相当的情况下，经比特平移后解码出来的音频信号产生的相对误差比未经移位操作解码出来的音频信号产生的相对误差平均减小了6．28dB．

New method for bit-plane coding in CBC algorithm at low bitrate.

CBC is the core algorithm of AVS part3 audio coding,which applies bit-plane coding to codes the quantized spectrum coefficients by Huffman coding.But in low bitrate,the MSB of the small coefficients may be ignored because of inadequate available bits.Therefore,a new method is proposed in this paper,which is to shift the most significant bits to the highest bit-plane and then code the rearranged coefficients.By analyzing experiments,the results indicated that the error in the new method has decreased about 6...