Standard predefined fixed payload types.
The official list is at:
http://www.iana.org/assignments/rtp-parameters
Audio: reserved: 19 unassigned: 20-23,
Video: unassigned: 24, 27, 29, 30, 35-71, 77-95 Reserved for RTCP conflict avoidance: 72-76
Pcmu = 0ITU-T G.711. mu-law audio (RFC 3551)
_1016 = 1RFC 3551 says reserved
G721 = 2RFC 3551 says reserved
Gsm = 3GSM audio
G723 = 4ITU G.723.1 audio
Dvi48000 = 5IMA ADPCM wave type (RFC 3551)
Dvi416000 = 6IMA ADPCM wave type (RFC 3551)
Lpc = 7experimental linear predictive encoding
Pcma = 8ITU-T G.711 A-law audio (RFC 3551)
G722 = 9ITU-T G.722 (RFC 3551)
L16Stereo = 10stereo PCM
L16Mono = 11mono PCM
Qcelp = 12EIA & TIA standard IS-733
Cn = 13Comfort Noise (RFC 3389)
Mpa = 14Audio MPEG 1-3.
G728 = 15ITU-T G.728 Speech coder (RFC 3551)
Dvi411025 = 16IMA ADPCM wave type (RFC 3551)
Dvi422050 = 17IMA ADPCM wave type (RFC 3551)
G729 = 18ITU-T G.729 Speech coder (RFC 3551)
Cellb = 25See RFC 2029
Jpeg = 26ISO Standards 10918-1 and 10918-2 (RFC 2435)
Nv = 28nv encoding by Ron Frederick
H261 = 31ITU-T Recommendation H.261 (RFC 2032)
Mpv = 32Video MPEG 1 & 2 (RFC 2250)
Mp2t = 33MPEG-2 transport stream (RFC 2250)
H263 = 34Video H263 (RFC 2190)