[FFmpeg-devel] [PATCH] --enable-libx264 and --enable-libxvid depend on --enable-pthread

Jason Garrett-Glaser darkshikari
Sat Feb 28 01:57:01 CET 2009

On Fri, Feb 27, 2009 at 4:53 PM, M?ns Rullg?rd <mans at mansr.com> wrote:
> Jason Garrett-Glaser <darkshikari at gmail.com> writes:
>> On that note, anyone have any ideas about how to fix ffmpeg's current
>> problem with x264? ?If x264.h is current but the x264 library itself
>> is not, ffmpeg will think the version check succeeded and link itself
>> to an ancient x264, resulting in random weird segfaults and other such
>> things. ?I have seen half a dozen people already with this problem in
>> #ffmpeg.
> How would we detect this situation? ?If the header is present, and the
> library can be linked against, we must assume that the installation is
> correct. ?Users with broken installations can blame themselves.

I think this happens because of the following situation:

1.  User is using $somedistro.  $somedistro keeps a shared x264
library of version X, an old version.
2.  User installs x264 in --prefix=/usr, overwriting their existing
x264.h.  However, they installed a static version.
3.  User configures ffmpeg.  ffmpeg checks the version by checking
x264.h--not by checking the .so--and because shared linking is
preferred to static by the linker (by default), the linker will link
to libx264.X.so instead of libx264.a.
4.  Things fail miserably.

At least that's my theory.

Dark Shikari

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