[Ffmpeg-devel] Re: [RFC] X11 device demuxer

Edouard Gomez ed.gomez
Thu Nov 16 17:11:02 CET 2006


Luca Abeni <lucabe72 <at> email.it> writes:
> Can you ask the xvidcap authors for the permission to reuse this part of
> their code under the LGPL license (of course, if you are ok with LGPL)?
> Maybe they will agree...

I'll do. My priority is to not let this code get dead. I think it's a usefull
feature (eg: Ubuntu wiki advertises it as an efficient way to do screencasts)

> [...]
> > +	st = av_new_stream(s1, 0);
> > +	if (!st) {
> > +		return -ENOMEM;
> > +	}
> > +	av_set_pts_info(st, 48, 1, 1000000); /* 48 bits pts in us */
> I think this should be 64, not 48. grab.c used to generate 48bit
> timestamps, but we changed it to 64bit some time ago.
> If you use 48, I think you will not be able to synchronize this video
> with audio captured from OSS...

Yep, it's quite probable 48b comes from ffmpeg legacy grab.c because original
patch is ~1 year old. I'll put 64k.

> My experience with this code in grab.c is that it is very fragile... It
> risks to end up with a lot of skipped frames. Is it working ok for
> capturing from x11 ?
> Of course, if you are capturing video without synchronizing it with any
> audio you will not see problems...

Never tried with sound, seems i have to also test with sound now.

-- 
Edouard Gomez







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