[Live-devel] Possible bug in liveMedia + info request about H263 / H263plus compatibility

[Ross Finlayson]

>As I explained in the previous emails, I'm trying to set up an rtsp
>server that streams h263 video, taken from a process that writes the
>stream on a unix named pipe.

I suggest that you first get your server to stream from a file 
(containing pre-encoded H.263 video data).  Only once you have that 
working properly, should you move to the more difficult step of 
streaming from a live encoder.


>The "encoder" process sets up ffmpeg libraries, takes video frames from
>an analog camera and encodes them in h263 format, writing them on a
>named pipe (fifo) on the filesystem.

Because you are streaming from a live source, be sure to set the 
"reuseFirstSource" parameter to True.


>Then I start the server, and start an rtsp client to do the right request.
>
>The server then open()s the fifo for reading. Consequently the encoder
>process unblocks and starts encoding frames and writing them on the fifo.
>
>The odd thing is that, then, the server close()s the fifo, only to re -
>open() it after a bit.

The server code does the initial 'open'+'close' on the source object 
in order to generate a SDP description for the stream.  (This SDP 
description, which can - in general - depend upon properties of the 
source data, is then returned to the client as the response to its 
RTSP "DESCRIBE" command.)  The server then does another 'open' on the 
source in order to do the actual streaming.

The good news is that because you set "reuseFirstSource" to True, 
this 'close+reopen' will happen only once, regardless of the number 
of ciients that you have.  However, it's unavoidable (and not a bug), 
so you're going to have to find a way to live with it.

Also, we can't really help you with any problems that you might be 
having with the 'RealPlayer' client; you'd need to ask RealNetworks 
for help with that.  However, I suggest that you first debug your 
server usng VLC and QuickTime Player as clients.  They should both be 
able to decode/play H.263 RTP streams OK.
-- 

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