[Live-devel] sanity check: Program Streams

[Ross Finlayson]

>Is it correct to say that MPEG 2 Program Stream format has no RTP payload
>type, and that RTP-encapsulated MPEG 2 data is sent as either TS or ES
>data?

This is not strictly true, but in practice it's true enough.  RFC 
2250 *does* briefly mention the packetization/streaming of MPEG 
Program Stream data, but almost noone implements it.

>   It is my understanding that the Program Stream format is not
>designed for VOD network transmission and that audio/video industry
>practices do not use the PS format in that way.

That's correct.

>   I can't find an RTP
>payload type for Program Stream

Actually, it is defined (using the MIME type "video/MP2P") in RFC 
3555, but, as noted above, it's rarely used.

>Mainly, I think it is very illogical to build a network streaming device
>which reads and writes only PS files, when PS files are not as versatile
>and not designed for use in network environments.  Certainly, implementing
>trick mode in this system will be very confusing for me, and I think I will
>not be able to use much of the LIVE555 trick mode if I have this strange
>system.  My opinion is that a system which reads and writes only Transport
>Streams makes a lot more sense.

Yes, especially if you want to support fast forward and reverse play.
-- 

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/