[ AC_MSG_ERROR([Could not find ffmpeg on your system: you may get it from http://ffmpeg.sf.net/ (svn version is recommended). Alternatively you can use --disable-ffmpeg to disable the ffmpeg plugins.]) ], [$LDAVUTIL])
AC_CHECK_LIB(postproc, pp_postprocess, [
VLC_ADD_LIBS([ffmpeg],[-lpostproc])],
AC_MSG_ERROR([Could not find libpostproc inside FFmpeg. You should configure FFmpeg with --enable-gpl --enable-pp.]),