[FFmpeg-devel] [PATCH] avoid floating point for -t endtime

[Michael Niedermayer]

On Sun, Feb 07, 2010 at 04:18:32PM +0100, Reimar D?ffinger wrote:
> On Sun, Feb 07, 2010 at 09:51:29AM +0100, Michael Niedermayer wrote:
> > On Sun, Feb 07, 2010 at 08:56:14AM +0100, Reimar D?ffinger wrote:
> > > On Sun, Feb 07, 2010 at 01:22:57AM +0100, Michael Niedermayer wrote:
> > > > > +    a = ts_a * tb_a.num * tb_b.den;
> > > > > +    b = ts_b * tb_b.num * tb_a.den;
> > > > 
> > > > read the nut spec again about compare_ts() this overflows for rather small
> > > > numbers
> > > 
> > > Here is an attempt to fix compare_ts first.
> > > It assumes that av_rescale_q does the right thing, although it does at least
> > > use a different algorithm that convert_ts in nut.txt.
> > > "make test" for it is still in progress.
> > [...]
> > > +    if (av_rescale_q(ts_a, tb_a, tb_b) < ts_b) return -1;
> > > +    if (av_rescale_q(ts_b, tb_b, tb_a) < ts_a) return  1;
> > > +    return 0;
> > 
> > av_rescale_q is 
> >  return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
> > 
> > thats not rounding correctly for us
> 
> In that case I suggest someone first fixes the mess - either change
> the convert_ts name in the nut spec, or change it to be an actually
> appropriate method for timestamp conversion as the name suggests,
> or if it already is change av_rescale_q to do that way.
> Pointing me to a spec that either is broken or alternatively means half
> of FFmpeg is doing it wrong is not much of a help.

ive added av_convert_ts() you should be able to use it

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

It is not what we do, but why we do it that matters.
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