See RFC 2029
Comfort Noise (RFC 3389)
IMA ADPCM wave type (RFC 3551)
IMA ADPCM wave type (RFC 3551)
IMA ADPCM wave type (RFC 3551)
IMA ADPCM wave type (RFC 3551)
RFC 3551 says reserved
ITU-T G.722 (RFC 3551)
ITU G.723.1 audio
ITU-T G.728 Speech coder (RFC 3551)
ITU-T G.729 Speech coder (RFC 3551)
GSM audio
ITU-T Recommendation H.261 (RFC 2032)
Video H263 (RFC 2190)
ISO Standards 10918-1 and 10918-2 (RFC 2435)
mono PCM
stereo PCM
experimental linear predictive encoding
MPEG-2 transport stream (RFC 2250)
Audio MPEG 1-3.
Video MPEG 1 & 2 (RFC 2250)
nv encoding by Ron Frederick
ITU-T G.711 A-law audio (RFC 3551)
ITU-T G.711. mu-law audio (RFC 3551)
EIA & TIA standard IS-733
RFC 3551 says reserved
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