SMV(Selectable Mode Vocoder):

SMV(Selectable Mode Vocoder):
Selectable Mode Vocoder (SMV) is variable bitrate speech coding standard used in CDMA2000 networks
full rate at 8.5 kbit/s
half rate at 4 kbit/s
quarter rate at 2 kbit/s
eighth rate at 800 bit/s

全速率下：3.6 MOS分
支持3G2文件