[FFmpeg-devel] ff_log2_tab defined multiple times in the fmpeg 1.1 libraries, bug or feature ??

Reimar Döffinger Reimar.Doeffinger at gmx.de
Sat Feb 16 12:00:42 CET 2013

On 14 Feb 2013, at 22:53, Lars Hammarstrand <lars.hammarstrand at gmail.com> wrote:

> Hello folks!
> I found the original patch: avutil: Duplicate ff_log2_tab instead of
> sharing it across
> libs<http://ffmpeg.org/pipermail/ffmpeg-cvslog/2012-October/055604.html>
> .
> The objectives for this patch was: "*The table is so small that the space
> gain is not worth the performance overhead of cross-library access*"
> (:uhu:). I have never heard of such a thing as "*cross-library access*"
> that "auto-magic" gives you a performance gain when you allocate the exact
> same object file to different link libraries in the same distribution
> package.

Then read up on PIC, -Bsymbolic, dynamic symbol lookup etc.
Of course this only applies to linking against dynamic FFmpeg libraries.

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