[FFmpeg-devel] [PATCH] Support Bandwidth header in RTSP requests

Ronald S. Bultje rsbultje
Wed Jan 19 12:16:41 CET 2011


On Wed, Jan 19, 2011 at 2:55 AM, John Wimer <john at god.vtic.net> wrote:
>>> This patch allows the Bandwidth header to be set in RTSP requests. This
>>> allows
>>> RTSP clients to specify the maximum bit rate that the RTSP server should
>>> stream to them.
>>> Refer to RFC 2326 section 12.6
>> Except for the issue on how to pass the option - this does sound useful.
>> What servers/setups do support this?
> I think Real server does but I have never tested it. I was/am planning to
> add support to Feng to allow choosing different encodings of the same video
> -- client support was the first step.

Some real servers send multiple stream descriptions in the MDPR header
(per RTSP stream), and then the client selects one (or multiple) in
the SETUP phase... This doesn't exclude what you say but it's
significantly easier client-side: we can simply advertise multiple
streams to the application, which can then pick whichever it likes
best (and we stop serving the others). This also allows
bandwidth-switching (simply re-SETUP) and requires no prior knowledge
of "what will the server serve if I ask for X". If you're going to
implement this, I'd suggest to consider going for this type of feature
instead of the max-bandwidth thing...

(Then again, Luca knows what he's doing so if you guys believe this is
better that's totally fine of course, but please do the FFmpeg-side as
a AVOption in rtsp*.c.)


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