MPEG-4AAC的码率失真控制算法需要多次检索霍夫曼码书以获得当前状态比特消耗的参考值。从霍夫曼码书使用概率的分析入手,提出了检索部分码书方案以实现比特消耗参考值的快速计算。客观测试表明该方案能有效降低计算量,且几乎不影响编码器音质。
Rate-distortion control algorithm in MPEG-4 AAC(Advanced Audio Coding) needs to search Huffman code books many times to obtain the reference number of the current consumed bits, Based on the usage probability of different Huffman code books, a fast algorithm for reference consumed bits calculating is proposed from partial searching Huffman code books. Objective tests show that the proposed method can reduce the computational complexity effectively without significant degradation to the audio quality.