PT encoding audio/video clock rate channels name (A/V) (Hz) (audio) _______________________________________________________________ 0 PCMU A 8000 1 [RFC1890] 1 1016 A 8000 1 [RFC1890] 2 G721 A 8000 1 [RFC1890] 3 GSM A 8000 1 [RFC1890] 4 G723 A 8000 1 [Kumar] 5 DVI4 A 8000 1 [RFC1890] 6 DVI4 A 16000 1 [RFC1890] 7 LPC A 8000 1 [RFC1890] 8 PCMA A 8000 1 [RFC1890] 9 G722 A 8000 1 [RFC1890] 10 L16 A 44100 2 [RFC1890] 11 L16 A 44100 1 [RFC1890] 12 reserved A 13 reserved A 14 MPA A 90000 ?[RFC1890,2250] 15 G728 A 8000 1 [RFC1890] 16 DVI4 A 11025 1 [DiPol] 17 DVI4 A 22050 1 [DiPol] 18--22 unassigned A 23 reserved A 24 reserved V 25 CelB V 90000 [RFC2029] 26 JPEG V 90000 [RFC2435] 27 reserved V 28 nv V 90000 [RFC1890] 29 reserved V 30 reserved V 31 H261 V 90000 [RFC2032] 32 MPV V 90000 [RFC2250] 33 MP2T AV 90000 [RFC2250] 34 H263 V 90000 [Zhu] 35--71 unassigned ? 72--76 reserved for RTCP conflict avoidance [RFC1889] 77--95 unassigned ? 96--127 dynamic ? [RFC1890]The more common types are 0 (as generated by rat, e.g.) and 31; furthermore 3 (GSM), 14 (MPA = MPEG-I or -II audio encapsulated as elementary streams), 32 (MPV = MPEG-I or -II video encapsulated as elementary streams). The first two can be played with the Real player, as far as I know, don't know about the others. A short
grep AVP *.sdp | perl -pe 's/.* //' | sort -n | uniq -con 78 cache files gave once:
29 0 (i.e., 29 times PT=0, etc.) 3 3 1 5 7 14 29 31 7 32 2 121
See also:
RTP Transport Protocol for Real-Time Apps Elective 1889 RTP-AV RTP Audio/Video Profile Elective 1890 RTP-CELLB RTP Payload Format of Sun's CellB Elective 2029 RTP-H.261 RTP Payload Format for H.261 Elective 2032 RTP-JPEG RTP Payload Format for JPEG-compressed Elective 2035 --------- RTP Payload Format for H.263 Video ST Elective 2190 RTP-RAD RTP Payload for Redundant Audio Data Elective 2198 RTP-MPEG RTP Payload Format for MPEG1/MPEG2 Elective 2250 RTP-MPEG RTP Payload Format for Bundled MPEG 2343 -------- RTP Payload Format for H.263+ 2429 -------- RTP Payload Format for BT.656 Video Encoding 2431 -------- RTP Payload Format for JPEG-compressed Video 2435 -------- Compressing IP/UDP/RTP Headers 2508See also Henning Schulzrinne's very helpful RTP FAQ.