On Tue, Dec 18, 2001 at 12:40:26PM +0100, Zdenek Kabelac wrote: > I've read your post - but WITHOUT modified picture itself (e.g. some > method of blending images together) there is no better way. Yes there is and I wrote about it.
> > wait for #VBI 1 1 1 1 1 1 1 2 1 1 1 1 1 .....
> Which is the best we can do without unmodified picture... :(
No, this is the best we can do without modifying picture or SPEED.
> > wait for #VBI 1 0 1 1 1 1 1 0 1 1 1 1 1 0 1
> 0 zero frame should be skiped...
> Again the best we could do with unmodified picture...
This was only for comparison, to explain the problem. Getting an occasional 0
isn't perceived as a distortion. Getting occasional 2 is.
> > the "2 wait for VBI" never occurs. This is what I'm trying to say: a method of
> > ensuring a "x x x x x y x x x x" pattern that is calculated by comparing video
> > and display fps, but we have to consider sound card speed.
> Well the sound card speed is considered - don't worry :)
Yeah sure I remember how this happened and how I had to play with sound card
sound driver to get sync working with "fscked" aviplay :-)
> > Please reread my original post, I think I explained my proposals for solutions
> > more precisely there.
> I've read that - but as I said - we would have to do some telecine
> transformation in realtime
You probably didn't read it. My proposal is to add an option that will modify
playback speed (both video and audio of course) to match video display fps,
and to be able to maintain a fixed VBI count pattern. In case of 23.98, it
will be played about 4% faster.
So that no picture is modified and we get a 1 1 1 1 1 1 1 1 1 (with occasional
0 if calculations show it is a good idea). That's why I said it should be
slightly faster (this may produce an occational 0) rather than slightly slower
(which would produce occasional 2 which is exactly what I want to avoid).
No big magic or horsepower needed and will imho look better. Don't forget that
aviplay ALREADY DOES modify playback speed to match soundcard clock (your
ideas about matching to cpu clock proved wrong), so there is no strong
precedent not to make another step to fix specific problems (especially if
it's an option that can be turned on/off)
I don't have time to work on aviplay in foreseeable future, but if noone does
it I may do it anyway.
Bye,
Peter Surda (Shurdeek) <[EMAIL PROTECTED]>, ICQ 10236103, +436505122023
--
Secret hacker rule #11: hackers read manuals.
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