Improving the performance of ITU-T G.729A for VoIP

The authors propose a novel method for improving the performance of ITU-T G.729A for Voice-over-IP (VoIP) applications. One of the most important features for a speech compression algorithm that is to be used for VoIP is that it be resistant to packet loss. Because of the memory that resides in the G.729A algorithm, a packet loss will not only cause degradations during the period of the loss but also following the packet loss due to the differing states of the encoder and decoder. The G.729A algorithm deals quite well with the packet loss period through error concealment, but it does not deal with the state error that follows the packet loss. The paper introduces a new scheme called recovery by reinitialization (RbR) that reduces this state error at minimal cost