[FFmpeg-devel] Realmedia patch

Ronald S. Bultje rsbultje
Mon Sep 8 23:23:04 CEST 2008

Hi Luca,

On Mon, Sep 8, 2008 at 3:51 AM, Luca Abeni <lucabe72 at email.it> wrote:
> Ronald S. Bultje wrote:
>> Once basic playback works, I'll leave you to review the rest and in
>> the mean time I'll start working on MMS or Quicktime's RTSP (or does
>> that work already?)...
> I think qt uses standard RTSP/RTP, so it should be already supported.
> If you know about qt rtsp:// urls that ffplay cannot decode, I am
> interested in them (maybe it's just due to unsupported payloads, I do
> not know...).
> AFAIK, the only not-fully-standard feature provided by qt is in "RTP
> over TCP" handling: qt does not use the standard RTP over RTSP, but
> seems to use RTP over HTTP. I've been told that having it working
> should be fairly easy, but I suspect that some additional work might
> be needed to correctly integrate "RTP over HTTP" in libavformat in a
> clean way.

I can confirm that setup is easy (as you said, just add payloads) and
that RTP over RTSP looks very weird, i.e. I don't understand how to
parse the data. UDP doesn't work, I never receive any data, I'll try
some different URIs, maybe my test is broken [1]...

I tried a second stream, quicktime served by a realmedia server, and
this breaks horribly. Makes me think that maybe this separation within
RTPDynamicPayloadHandler and RTSP_SERVER_* wasn't the best of ideas.
We should separate into multiple layers, where SDP parsing is a
server-dependent thing, whereas data parsing _alone_ is
payload-type-dependent. Right now it's all intermingled in no
particular order and it'll break. Maybe I should rewrite the RTSP/RTP
demuxers after all. :-).


[1] rtsp://quicktime.tc.columbia.edu:554/users/lrf10/movies/sixties.mov

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