Bug#693040: libav: Strange build failure on several archs

[Reinhard Tartler]

On Wed, Nov 14, 2012 at 9:29 AM, Fabian Greffrath <fabian at greffrath.com> wrote:
> Am 13.11.2012 16:45, schrieb Reinhard Tartler:
>
>> The problem is upstream and has been identified now. Reverting
>> upstream commit 468ea9d5b14f92fe61f47f034e67066f65163f5f seems to fix
>> the issue, albeit a better solution is currently being worked on.
>
>
> Good to know that you've succeeded to narrow down the problem. But how could
> it ever build on the other archs if the symbol in question isn't exported
> anymore, why does it only break on selected archs?


Because those are the archs that do not have special ASM variants of
the log2 implementation but fall back to the C variant. The C variant
tries to access the ff_log2_tab symbol, to which the access is hidden.

The proper patch to solve this is:

http://patches.libav.org/patch/30530/

-- 
regards,
    Reinhard