[FFmpeg-devel] [PATCH 10/10] Document how av_cmp_q() deal when one of the values to be compared is 0/0.

[Michael Niedermayer]

On Fri, Oct 01, 2010 at 09:16:55AM +0200, Tomas H?rdin wrote:
> On Thu, 2010-09-30 at 23:58 +0200, Michael Niedermayer wrote:
> > On Thu, Sep 30, 2010 at 09:45:41PM +0200, Stefano Sabatini wrote:
> > > ---
> > >  libavutil/rational.h |    4 ++++
> > >  1 files changed, 4 insertions(+), 0 deletions(-)
> > > 
> > > diff --git a/libavutil/rational.h b/libavutil/rational.h
> > > index 2dd0c2c..bd2e711 100644
> > > --- a/libavutil/rational.h
> > > +++ b/libavutil/rational.h
> > > @@ -41,6 +41,10 @@ typedef struct AVRational{
> > >  
> > >  /**
> > >   * Compare two rationals.
> > > + * If one of the compared values is 0/0, the result of the comparison
> > > + * is always 0, so you should do an explicit check for that case
> > > + * rather than use this function.
> > 
> > is there any return value that would in any case avoid an additional check?
> 
> Perhaps AVERROR_INVALIDDATA?

I think that if we do detect NAN then the most sensible value to return would
be INT_MIN because INT_MIN == -INT_MIN thus in some sense it is the best
non zero element that has both + and -

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

Everything should be made as simple as possible, but not simpler.
-- Albert Einstein
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