摘要
在AMR-WB中,固定码本搜索是影响性能和复杂度的关键模块,约占总复杂度的40%。为了降低计算量,提出了一种码字分裂、子码字脉冲取代的高效码本搜索算法。该算法包括四步:一个初始码字分裂为两个或更多的子码字;每个子码字通过最不重要脉冲取代法进行更新;更新后的子码字合成一个候选的码字;比较初始码字和候选码字,选择优者作为最后的码字。实验表明,与传统方法相比,编码时间减小约16%。
In AMR-WB, the fixed codebook search is the crucial part in both performance and complexity, and it takes up about 40% of total complexity. To reduce the computational load, this paper proposes an efficient codebook search algorithm based on sub-codeword pulse replacement. The proposed algorithm consists of four steps. Firstly, an initial codeword is divided into two or more sub-codewords. Secondly, each sub-codeword is updated using the least important pulse replacement method. Thirdly, the updated sub-codewords are combined as a candidate code- word. Finally, by comparing the candidate codeword and the initial codeword, better one is selected as the final codeword. Experimental results show that the proposed algorithm reduces the overall complexity by about 16% with minor degradation in speech quality, when compared to the traditional algorithms.
出处
《计算机工程与应用》
CSCD
2012年第36期14-18,共5页
Computer Engineering and Applications
基金
福建省教育厅科技计划(No.JB10148)
厦门市科技计划(No.3502Z20103038)
