[Live-devel] RTP timestamp vs presentation timestamp in MPEG2 elementary streams

[Ross Finlayson]

>the RFC says that the RTP timestamp of an MPEG2 RTP packet is *not* the 
>presentation timestamp (PTS)
>of the contained video frame, but the transmission time of the first byte 
>of the packet.
>further on the RFC seems to contradict itself by stating that the 
>timestamp field of the fixed RTP header
>carries the presentation time (PTS). did I misinterpreted the RFC here?

Yes.  (I presume you're referring to RFC 2250.)  Section 2 of the RFC (that 
mentions "transmission time for the first byte of the packet") refers to 
streaming MPEG Transport Streams.  Section 3 of the RFC (that mentions 
"Presentation Time Stamps") refers to streaming MPEG Elementary 
Streams.  These are effectively two different RTP payload formats 
(actually, three, because Audio and Video Elementary Streams also have 
separate formats) that just happen to be written up in the same RFC.