[MPlayer-dev-eng] [PATCH] v4l2 interface

[Carsten Schultz]

Hi Jindrich!

On Mon, Jan 13, 2003 at 06:09:22PM +0100, Jindrich Makovicka wrote:
> There's a well known problem that the timestamps of the video stream and 
> sample counts are related to different timebases. It took me a while to 
> make the a/v sync work and it required a lot of tedious hacking (see the 
> *skew* stuff in tvi_v4l.c). If tvi_v4l2 isn't still capable to do 
> internal a/v sync, it has to be compensated for in mencoder. tvi_v4l2 
> corrects the video timestamps by the difference between theoretical and 
> real audio sample count. On my hardware the difference does about 1s pes 
> hour so it's not negligible.

How important are the timestamps reported to mencoder?  If frames
should come at intervals of 0.04 secs, but we come a bit late to grab
one of the frames and we measure timestamps of, say

1.000, 1.040, 1.115, 1.120,

(but no frame was really lost) should that be smoothed out or be
reported to MEncoder as is?  I had written this kind of smoothing code
before realising that a problem I was trying to solve was lying
somewhere else.  It's not perfect, though.

Greetings,

Carsten

-- 
Carsten Schultz (2:40, 33:47), FB Mathematik, FU Berlin
http://www.math.fu-berlin.de/~cschultz/
PGP/GPG key on the pgp.net key servers, 
fingerprint on my home page.
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