一种基于优先树脉冲取代的固定码本搜索方法

分析了G.722.2中的固定码本结构及其搜索方法,结合深度优先树与脉冲取代法各自的优点,提出了一种新的方法——基于优先树脉冲取代的固定码本搜索方法,该方法在基本保持语音质量的前提下,可使固定码本搜索计算复杂度降低,从而使G.722.2的编码运行时间进一步减少。实验结果表明,与G.722.2中采用的深度优先树搜索方法相比,基于优先树脉冲取代的固定码本搜索方法可以在不影响语音质量的前提下,使固定码本搜索复杂度降低85%以上。

Fixed Code Searching Algorithm Based on Depth-first Tree Pulse Replacement

The fixed codebook structure and the search method in the G. 722.2 are analyzed, then a new fast search method is proposed, based on first tree pulse replacement, which combined the depth - first tree search method with the pulse replacement method, this method can reduce the computational complexity of the fixed codebook search with equal voice quality, and then the G. 722.2 algorithm running time reduce further more. Experimental results show that the proposed first tree pulse method reduces the fixed codebook search computational complexity by more than 85% with speech quality equivalent, compared with that by the depth - first tree search method adopted in G. 722.2.