[Live-devel] Problem of new support for unicastRTSP/RTPstreaming from a single input source

[Ross Finlayson]

>>The problem with this file is that a "VisualObjectSequence" header - 
>>i.e., beginning with 0x000001B0 - does not appear anywhere.  Such a 
>>header *must* occur in the stream.  (When streaming from a file, it's OK 
>>for there to be only one such header, at the start of the file.
>>When streaming from stdin, such a header must appear throughout the 
>>stream (e.g., every 1 second or so).)
>
>Could you explain why you need the VOS header?

Short answer: Because the RTP payload format for MPEG-4 ES Video requires 
it.  (See RFC 3014, section 3).

Longer answer: Because this header is necessary in order for the RTSP 
server to determine the "config" string that gets included in the SDP 
description that gets passed to each client (in response to the RTSP 
"DESCRIBE" command).

So, if your input stream doesn't already include a VOS header, then you 
will need to add one periodically (once every second or so should be 
sufficient).

(Alternatively, if you know what the VOS header ("config" string) *would* 
be (if you sent it), I could conceivably update the LIVE.COM code to take 
that string as a parameter (instead of trying to extract it from the input 
stream).  Then, media player clients will still get the "config" 
information OK (in the SDP description), and then *might* be able to play 
the stream, even though it won't contain VOS headers.)


	Ross Finlayson
	LIVE.COM
	<http://www.live.com/>