[FFmpeg-devel] [PATCH] correct make test failure from 15261 release until now (15899)

[Siarhei Siamashka]

On Friday 21 November 2008, Michael Niedermayer wrote:
> On Fri, Nov 21, 2008 at 09:15:30PM +0100, Vitor Sessak wrote:
> > David Geldreich wrote:
> > > Hello Guillaume,
> > >
> > > Le 21 nov. 08 ? 17:25, Guillaume POIRIER a ?crit :
> > >> This is not the way to go. Reg tests pass on AMD64/Linux, so the code
> > >> must be fixed to work the same on any plateform. The md5sum should not
> > >> match X plateform results, but all plateforms result.
> > >
> > > That's why I made another post to tell to ignore my proposed patch.
> > >
> > > I found no way of making sin/sinf works the same way on all the
> > > platform. In my case, OSX ppc and intel gives different results.
> > >
> > > So changes r15261 and r14982 are incomplete ... they correct the
> > > problem for AMD64 but breaks in on Intel32.
> > >
> > > We must iterate to find a "stable" sine window generating function.
> >
> > Even if we find a way to generate a sine window in an arch-independent
> > way, the codec still uses floating points in other places, so if it ever
> > is bit-identical across PPC and I32, I don't see any reason not to see a
> > different output when testing on ARM or SH or GCC 6.4 or whatever we'll
> > encounter in future. Unless someone tells me why it is supposed to work
> > as is, I think that this test should be removed...
>
> ratecontrol in video uses floats, and other parts do too, we arent seeing
> problems with these and arent disabling them
>
> If you argue that the wma test should be disabled because it is not
> matching between some important systems, thats something i can understand
>
> but, arguing that itz should be disabled because it might theoretically not
> work on some architecture or not yet existing compiler is well ...
>
> And last, id say disable the float code for the regression tests,
> replacing the whole fft by a memcpy() if it doesnt match beteen archs
> is alot better than removing a regression test.
> These tests are important to catch bugs early ...

Still what about trying to make regression tests resistant to minor acceptable
differences in the generated output?

-- 
Best regards,
Siarhei Siamashka