低延迟音频编码及应用  

Low delay audio coding and it's applications

作　　者：唐骏[1] 

机构地区：[1]厦门理工学院电子与电气工程系,厦门361024

出　　处：《信息技术》2009年第9期1-3,15,共4页Information Technology

基　　金：厦门市科技计划指导项目(3502Z20077006)

摘　　要：通用的感知音频编码技术能在很低码率下提供透明的音质,但编解码算法延迟大,难以满足两地实时通信的要求,语音编码技术能以低延迟提供良好的语音服务,但不适合处理复杂的音频信号。分析了影响感知音频编解码算法延迟的主要因素,并给出了定量的计算方法,着重论述了MPEG-4 AAC-LD的关键技术、性能及其应用。General perceptual coding can deliver high sound quality even at low bit rates. However, the total delay of the encoder/decoder chain is usually considerably higher than acceptable delay for two-way communication. On the other hand, the algorithmic delay of speech coding schemes is small enough to make them suitable for two-way communication. However, such schemes only provide good quality for speech signals and usually fail when they are used for more complex audio signals like music. This paper discusses the sources of algorithmic delay in a perceptual codec and gives the method of calculating. Finally, the key technology, performance and applications of MPEG-4 AAC-LD are discussed.

关 键 词：低延迟 感知音频编码 变换编码 预回声 

分 类 号：TN912[电子电信—通信与信息系统]