8～64kbit/s超宽带嵌入式语音频编码方法

8～64kbit/s super-wideband embedded speech and audio coding algorithm

基于国际电信联盟标准化组织（ITU—T）编码标准G729．1和改进的调制叠接变换（MLT,modulated lapped transform）编码技术，提出了一种码率在8-64kbit／s的超宽带嵌入式变速率语音与音频编码方法，其中，8．32kbit／s码率的码流由G729．1编码算法生成，编码信号为0—7kHz频段的信息；36、40和48kbit／s码率层及56、64kbiffs码率层码流由MLT变换编码方式生成，编码信号分别为7-14kHz频段的信息和G729．1编码残差的MDCT信息。客观和主观听力测试表明本编码器的性能达到了ITU-T提出的参考指标要求。

Based on the international telecommunication union telecommunication standardization sector （ITU-T） recommendation G729.1 and modified modulated lapped transform （MLT） coding, a super-wideband embedded variable bit-rate speech and audio coding algorithm was proposed, the bit-rates of this codec was from 8kbit/s to 64kbit/s. The information in the frequencies of 0-7 kHz was encoded by G729.1 codec at 8-32kbit/s, the information in the frequencies of 7-14 kHz was encoded by the transform coding at 36, 40 and 48kbit/s, and G729.1 residual signal＇s MDCT （modified discrete cosine transform） was encoded by the transform coding at 56 and 64kbit/s. The objective and subjective listening tests show that this codec has good performance compared with Terms of Reference given by ITU-T.