title: libx264 not found FFmpeg?
body: <p>I am trying to make a build of ffmpeg with libx264 enabled. However when I run the following command in MSYS</p>
  
  <pre><code>./configure --prefix=ffmpeg/ --enable-gpl --enable-libx264
  </code></pre>
  
  <p>I get an error saying </p>
  
  <pre><code>ERROR: libx264 not found
  </code></pre>
  
  <p>I am using MSYS on windows 10. I also have installed NASM. Here is the config.log file</p>
  
  <pre><code>BEGIN /tmp/ffconf.TRVJWfGe/test.c
      1   #include &lt;stdint.h&gt;
      2   #include &lt;x264.h&gt;
      3   #include &lt;stdint.h&gt;
      4   long check_x264_encoder_encode(void) { return (long) x264_encoder_encode; }
      5   int main(void) { int ret = 0;
      6    ret |= ((intptr_t)check_x264_encoder_encode) &amp; 0xFFFF;
      7   return ret; }
  END /tmp/ffconf.TRVJWfGe/test.c
  gcc -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -U__STRICT_ANSI__ -D__USE_MINGW_ANSI_STDIO=1 -D__MSVCRT_VERSION__=0x0700 -D_WIN32_WINNT=0x0600 -D__printf__=__gnu_printf__ -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600 -std=c11 -fomit-frame-pointer -c -o /tmp/ffconf.TRVJWfGe/test.o /tmp/ffconf.TRVJWfGe/test.c
  In file included from c:\mingw\include\stdint.h:46,
                   from c:\mingw\lib\gcc\mingw32\9.2.0\include\stdint.h:9,
                   from C:/Users/pawel/AppData/Local/Temp/ffconf.TRVJWfGe/test.c:1:
  c:\mingw\include\_mingw.h:413:3: warning: #warning "Direct definition of __USE_MINGW_ANSI_STDIO is deprecated." [-Wcpp]
    413 | # warning "Direct definition of __USE_MINGW_ANSI_STDIO is deprecated."
        |   ^~~~~~~
  c:\mingw\include\_mingw.h:414:10: note: #pragma message: See &lt;_mingw.h&gt; for preferred feature activation methods.
    414 | # pragma message "See &lt;_mingw.h&gt; for preferred feature activation methods."
        |          ^~~~~~~
  C:/Users/pawel/AppData/Local/Temp/ffconf.TRVJWfGe/test.c:2:10: fatal error: x264.h: No such file or directory
      2 | #include &lt;x264.h&gt;
        |          ^~~~~~~~
  compilation terminated.
  ERROR: libx264 not found
  </code></pre>
  
  <p>Could you tell me how to fix the error, or is there a prebuilt package with libx264 already inside?</p>