[FFmpeg-devel] [PATCH] Add the frame size attribute to SDP descriptions

Martin Storsjö martin
Thu Jan 7 17:28:25 CET 2010

On Thu, 7 Jan 2010, Luca Abeni wrote:

> Is this attribute described somewhere? (even if not in an RFC...
> Is it part of some other standard such as ISMA, 3GP, or similar?)

I had a quick look but didn't find anything, but I'll give it another go.

> > it seems to be common practice. FFmpeg's H264 rtp parser reads such a line
> Such usage is unfortunately wrong (IMHO).
> > and QuickTime player also seems to benefit from having it available.
> If some client has a sane usage for this attribute, I am ok with the
> patch... How does qt player use the "a=framesize:" line?
> (I am asking because I want to avoid potential misunderstanding like
> the one in rtp_h264.c).

Hmm, I seemed to remember that it was able to open a correctly sized 
window immediately if this was set, but when retesting it now, it doesn't 
actually seem to make any difference.

I'll try to look for mentionings in standards and get back to you if I 
find anything else to back up the need for this attribute.

// Martin

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