[MPlayer-advusers] [BUG] -sws 10 -vf screenshot leads to hang up

[Michael Niedermayer]

On Sun, Sep 28, 2008 at 05:52:51PM +0400, Andrew Savchenko wrote:
> Hi,
> 
> On Sunday 28 September 2008 15:43, Andrew Savchenko wrote:
> > Hello, all,
> >
> > With revision 27668 and some earlier ones (haven't perform
> > regression search yet) mplayer hangs when playing certain types
> > of video if -sws 10 and -vf screenshot options are used
> > together. This happens only with some video files, regardless to
> > their codec type.
> 
> According to regression test the reason is r27612:
> ------------------------------------------------------------------------
> r27612 | michael | 2008-09-15 07:33:09 +0400 (Пнд, 15 Сен 2008) | 2 
> lines
> 
> Avoid using floating point for calculating filter coefficients.
> 
> ------------------------------------------------------------------------
> 
> FP dropping leads to precision loss and to eternal recursion in 
> swscale.c: getSplineCoeff(). Values of b,c,d variables are changed 
> for the file in question, leading to singularity series an NAN 
> values (log is too long to post here and is easily reproducible).
> 
> Perhaps, it is reasonable to revert 27612, 'cause it broke things 
> down.

no that would not be reasonable.

ive fixed it, if you find more regressions please report them as well!
ive tested swscale quite extensively when i worked on it but there
are too many scalers and special cases ...

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In a rich man's house there is no place to spit but his face.
-- Diogenes of Sinope
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