<div dir="ltr">Hello folks!<div><br></div><div>I found the original patch: <a href="http://ffmpeg.org/pipermail/ffmpeg-cvslog/2012-October/055604.html" target="_blank">avutil: Duplicate ff_log2_tab instead of sharing it<span style="white-space:pre-wrap"> </span>across libs</a>.</div>
<div><br></div><div>The objectives for this patch was: "<i>The table is so small that the space gain is not worth the performance overhead of cross-library access</i>" (:uhu:). I have never heard of such a thing as "<i>cross-library access</i>" 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.</div>
<div><br></div><div>Looking forward to have this "unpatched" ...<br></div><div><div>--</div><div><div><div class="gmail_extra"><br><div class="gmail_quote">2013/2/13 Michael Niedermayer <span dir="ltr"><<a href="mailto:michaelni@gmx.at" target="_blank">michaelni@gmx.at</a>></span><br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">Hi<br>
<div><br>
On Wed, Feb 13, 2013 at 04:36:38PM +0100, Lars Hammarstrand wrote:<br>
</div>> Hello, can someone please explain the reason (and how to cope with) that *<br>
> ff_log2_tab* is defined multiple times with *#include "libavutil/log2_tab.c*"<br>
<div>> in the ffmpeg v1.1 libraries like libavcodec 54.91.102 and companions ??<br>
<br>
</div>duplicating the tables causes a small performance increase in some<br>
linking configurations.<br>
<div><br>
<br>
><br>
> This results in "duplicate symbols" while linking as listed below. To get<br>
> ride of the problem we need to delete the duplicated entries by hand with<br>
> "ar -d libxxx.a log2_tab.o" for all libraries but one, not a very smooth<br>
> solution. Will this behavior change in the future or do weed need to<br>
> automate a duplicate removal process while building the ffmpeg libraries<br>
> for XBMC?<br>
<br>
</div>Ive posted a patch to ffmpeg-dev, which may fix this:<br>
0213 19:51 To FFmpeg devel (3.0K) [FFmpeg-devel] [PATCH] buildsys: only include log2_tab per library for shared builds<br>
<br>
please test and comments welcome<br>
<br>
note, some linkers can also be configured to ignore duplicate symbols<br>
<br>
Thanks for the bug report<br>
<br>
[...]<br>
<span><font color="#888888">--<br>
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB<br>
<br>
Concerning the gods, I have no means of knowing whether they exist or not<br>
or of what sort they may be, because of the obscurity of the subject, and<br>
the brevity of human life -- Protagoras<br>
</font></span></blockquote></div><br></div></div></div></div></div>