At medium or long distance （〉 10 kin） underwater acoustic speech communication, information transfer rate is constrained by the complicated, time varying channel and limited bandwidth. The bit rate of speech coding...At medium or long distance （〉 10 kin） underwater acoustic speech communication, information transfer rate is constrained by the complicated, time varying channel and limited bandwidth. The bit rate of speech coding is required to be as low as possible. The time delay of underwater acoustic wave propagation can be used for low bit rate speech coding. After investigating the Mixed Excitation Linear Prediction （MELP） standard and taking account of the auditory perceptual features, a variable and adjustable bit rate speech codec algorithm has been proposed, whose average bit rate is about 600 bps. The average Perceptual Evaluation of Speech Quality Mean Opinion Score （PESQ MOS） of synthesized speeches is about 2.8. It has been proved by the computer simulation and sea trial that the performance of the proposed algorithm is well and robust when bit error rate is no more than 10-3. The synthesized speech is vivid and intelligible, and keeps main individual characteristics of speaker.展开更多
在TMS320C6455上实现了音视频编码标准(Audio and video coding standard,AVS)视频标准标清视频的实时编码,高清视频码流的实时解码。以AVS参考代码RM52i为软件基础,综合考虑TMS320C6455的性能和AVS视频编解码器的实现方式,采用了系统...在TMS320C6455上实现了音视频编码标准(Audio and video coding standard,AVS)视频标准标清视频的实时编码,高清视频码流的实时解码。以AVS参考代码RM52i为软件基础,综合考虑TMS320C6455的性能和AVS视频编解码器的实现方式,采用了系统结构优化、线性汇编优化、存储空间优化、EDMA辅助数据搬移等多种优化措施,最终实现了对720×576分辨率视频的实时编码和1 920×1 080分辨率高清码流的实时解码。展开更多
基金supported by the National Natural Science Foundation of China(61102152)
文摘At medium or long distance （〉 10 kin） underwater acoustic speech communication, information transfer rate is constrained by the complicated, time varying channel and limited bandwidth. The bit rate of speech coding is required to be as low as possible. The time delay of underwater acoustic wave propagation can be used for low bit rate speech coding. After investigating the Mixed Excitation Linear Prediction （MELP） standard and taking account of the auditory perceptual features, a variable and adjustable bit rate speech codec algorithm has been proposed, whose average bit rate is about 600 bps. The average Perceptual Evaluation of Speech Quality Mean Opinion Score （PESQ MOS） of synthesized speeches is about 2.8. It has been proved by the computer simulation and sea trial that the performance of the proposed algorithm is well and robust when bit error rate is no more than 10-3. The synthesized speech is vivid and intelligible, and keeps main individual characteristics of speaker.
文摘在TMS320C6455上实现了音视频编码标准(Audio and video coding standard,AVS)视频标准标清视频的实时编码,高清视频码流的实时解码。以AVS参考代码RM52i为软件基础,综合考虑TMS320C6455的性能和AVS视频编解码器的实现方式,采用了系统结构优化、线性汇编优化、存储空间优化、EDMA辅助数据搬移等多种优化措施,最终实现了对720×576分辨率视频的实时编码和1 920×1 080分辨率高清码流的实时解码。
