pcmu 0
pcma 8
cn 13
//ipcmwb 97
//eg711u 100
//eg711a 101
ilbc 102
isac 103
isacswb 104
avt 106
red 117
cn_wb 98
cn_swb32 99
pcm16b 93
pcm16b_wb 94
pcm16b_swb32khz 95
//pcm16b_swb48khz 96
//mpeg4aac 122
g722 9
celt32 114
