AMR(Adaptive Multi Rate)自适应多速率语音算法
AMR是ETSI和3GPP等组织规定的GSM,3G,W-CDMA等无线通信系统必须支持的一种标准语音处理算法(标准见附),它的编码速率范围是从4.75-12.2kbps,采样率8KHz,编码延时一帧20ms。可以根据网络条件在不同的速率之间切换。手机彩铃,彩信,录音,3GP格式等一般都是使用这种算法,与MP3格式可以互相转换。
算法应用的硬件平台主要是ARM和DSP,例如TI C54 OMAP DM642和Intel的XScale等。
[附]:
(1) GSM 06.90, Digital cellular telecommunication
system (Phase 2+); Adaptive Multi-Rate (AMR) speech transcoding.
(2) GSM 06.91, Substitution and muting of lost frame for AMR speech
traffic channels.
(3) GSM 06.92, Comfort noise aspects for AMR speech traffic channels.
(4) GSM 06.93, Discontinuous transmission (DTX) for AMR speech traffic
channels.
(5) GSM 06.94, Voice Activity Detector (VAD) for AMR.
(6) GSM 06.74, Test sequences for the AMR speech codec.
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