[FFmpeg-user] [EXTERNAL] Re: Cannot build ffmpeg with libx264

[Carl Eugen Hoyos]

2017-11-20 22:15 GMT+01:00 Moritz Barsnick <barsnick at gmx.net>:
> On Mon, Nov 20, 2017 at 18:17:22 +0000, Peterson, David J wrote:

>> ffmpeg_installation/ffmpeg_build/lib/libx264.a(mc-c.o): In function `x264_plane_copy_avx':mc-c.c:(.text+0x11ac):
>> undefined reference to `_intel_fast_memcpy'
>> collect2: error: ld returned 1 exit status
>> ERROR: libx264 not found
>
> From my humble experience, this probably means your
> x264 was built with icc (the Intel Compiler Suite), but is
> missing some essential flag in x264.pc.

No, x264 (which is responsible for this file) cannot know
that icc links against its own libraries for optimization.
The user who wants to build static binaries with icc and
gcc needs to supply the needed libraries.

> Is that what you did?

> If so, and if you compile ffmpeg with ggc, I believe you need
> to set Intel's linker as the linker. Something like "--ld=ild"

Something like:
--extra-libs=/opt/intel/lib/intel64/libintlc.a

Carl Eugen