[Ffmpeg-devel] H.264 encoder

[Panagiotis Issaris]

Hi,

On wo, 2006-10-04 at 18:49 +0200, Christian Iversen wrote:
> On Wednesday 04 October 2006 17:51, Panagiotis Issaris wrote:
> 
> > > [...]
> > >
> > > > +                if (val > 0)
> > > > +                    val--;
> > > > +                else // < 0
> > > > +                    val++;
> > >
> > > val -= (val>>31)|1;
> >
> > Fixed.
> 
> Is it because I appearantly don't understand C, or is that a pretty odd 
> expression? 
> 
> You take the sign bit, and "or" it with 1, leaving ... 1, in all cases.
No, the sign bit is still there (arithmetic shift, sign bit gets
propagated), so together with the |1 it results in either -1 or +1.

> Is this expression equiv. to val--; ? 
Yes.

With friendly regards,
Takis