一种基于分裂表扩展的格型矢量量化新方法

A Novel Lattice Vector Quantization Utilizing Division Table Extension

基于分裂表设计了一种适用于低比特率音频编码的格型矢量量化新方法.它将大值矢量分裂为基础码本中的矢量与分裂表中的分裂量之和,然后分别对其进行量化,从而在低计算复杂度下,解决了格型矢量量化中因矢量值过大而产生的过载失真问题.同时,通过仔细挑选RE8格中的子集,设计了适合该分裂表扩展方法的码本.结果表明,与经典的Voronoi扩展矢量量化方法相比,新方法在保持音频编码性能相当的同时,压缩了量化码本的存储空间,降低了计算复杂度.

A novel lattice vector quantization method for low bit-rate audio coding was proposed. This method uses a division table to extend the codebook. It divides large vectors into two smaller ones, one is in the base codebook, the other is in the division table, and then quantizes the two vectors separately to solve overload distortion problem caused by the large value of the vector. And after carefully choosing a subset of lattice in RE8, a codebook which is fit in with the division table extension method was designed. Compared with the classic quantization method with Voronoi extension, the proposed method greatly compresses the size of codebook and reduces computational complexity while achieves similar quality in low bitrate audio coding.