Patch by Olivier Guilyardi list samalyse com.
See the thread: "[FFmpeg-devel] [PATCH] libavdevice: JACK demuxer".
Originally committed as revision 18322 to svn://svn.ffmpeg.org/ffmpeg/trunk
Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.' to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".
Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk
