iLBC语音编解码器核心技术的研究

Research of The Key Technology of iLBC Speech Codec

重点讨论了iLBC编解码器独立于帧的长期预测。独立于帧的长期预测是用来在编码语音没有遭受与传输丢失相关的多帧语音退化情况下,开发斜度标记相关的办法。然后介绍了iLBC,G.729A和G.723.1编解码器的平均主观得分MOS,并用信号为例说明基于独立于帧的长期预测编解码器和CELP编解码器之间的不同,最后用语音重构的例子说明二者语音质量间的差别。

The iLBC（internet low bit rate codec） with an emphasis on the frame-independent long-term prediction is discussed. The frame-independent long-term prediction is a method to exploit pitch-lag correlations in the speech encoding without suffering multlple-frame speech degradation in connection with transmission loss. The MOS（Mean Opinion Scores） for the iLBC codec, G.729A and G.723.1 is introduced. The differences between the predictive codec based on frame-independent long-term prediction and CELP codecs are illuminated by the signal example. Finally, the differences of speech quality by using of the example of speech reconstruction is presented.