[Ffmpeg-devel] [BUG] H.264 + AltiVec == heavy artefacts

Diego Biurrun diego
Wed Oct 12 11:05:44 CEST 2005

On Fri, Oct 07, 2005 at 05:33:13PM +0200, Romain Dolbeau wrote:
> Diego Biurrun wrote:
> >>So now let's try the usual suspects: what compiler, what OS, what CPU(s),
> >>what extra compiler option(s) are you using ?
> >Debian unstable
> >PowerBook G4 7447A processor running at 1500MHz
> >gcc (GCC) 4.0.2 (Debian 4.0.2-2)
> >I get the same results with
> >gcc-3.3 (GCC) 3.3.6 (Debian 1:3.3.6-10)
> >gcc-3.4 (GCC) 3.4.5 20050821 (prerelease) (Debian 3.4.4-8)
> >http://mplayerhq.hu/~diego/bbc-africa_m720p.mov
> This sample works fine for me in OSX. It's completely broken
> under my Debian/ppc stable. Apparently even in linux,
> pointer are aligned on a 16 bytes boundary and strides
> are multiple of 16, but I didn't have the time to check
> in details, so I may have missed a vector.

OK, so now you can reproduce this.  Is there something else I can do to
help you debug this?

> This starts looking like a broken compiler to me ; the hadamard
> functions were known to be broken with some fsf-gcc and are
> disabled in non-darwin OSes already :-(

Yes, might well be possible...


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