[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Bug#638250: Needs to be adapted for libav/0.7



* Reinhard Tartler [110904 08:47 +0200]:

> tags 638250 help
> stop
> 
> On Sun, Sep 04, 2011 at 06:45:36 (CEST), Elimar Riesebieter wrote:
> 
> > block 638250 by 639948
> > thanks
> 
> I strongly disagree that this arch specific defect on ppc is in any way
> a blocking bug for recompiling moc-ffmpeg-plugin against the new libav
> libraries.

moc-ffmpeg-plugin on ppc compiles well against libav 0.7.1 libraries
but produces exactly the same backtraces as ffplay 0.7.1 on ppc. So
this is surely a libav bug.

> It only affects (some?) altivec enabled machines and can be
> easily avoided by disabling the altivec variant.

What do you mean with only? PPC is an officialy supported
architecture in Debian!

Most of the powerpc machines are altivev capable. Apple's G4 and G5,
IBM's Power6 and Power7 are all have altivec which is very useful to
accelerate multimedia applications. And please notice, that altivec
was working well on ffmpeg 0.6.2-5 so it turns out that #639948 is a
regression!

> [...]
> 
> > Thanks again for the patch but there is no solution for #639948 yet.
> > Please advice me what to do? I filed the ppc bug to libav-upstream
> > http://bugzilla.libav.org/show_bug.cgi?id=40 but there is no
> > response either from Debian-multimedia. Removing ppc from supported
> > archs isn't practicable as 639948 is a regression.
> 
> Ideally, we find a porter that can identify the bug and provide a patch
> for fixing the segmentation fault. I've copied the powerpc porters and
> ask them hereby for their assistance.

I'll check the CC settings in libav package, but as far as I can see
they are equal for ppc. Hmmm. Compiling ith gcc-4.5 would be a first
attempt to eleminate a compiler bug.

> Or, if porters approached me, I also could disable the altivec builds in
> libav completely, penalizing potential altivec users that do not
> experience this issue.

This might not be a very intelligent solution.

Elimar

-- 
  Alles was viel bedacht wird ist bedenklich!;-)
         Friedrich Nietzsche

Attachment: signature.asc
Description: Digital signature


Reply to: