libx264 recently started mangling the name of x264_encoder_open() to
prevent version mismatches, breaking our test. Checking for another
function instead makes it work again.
Originally committed as revision 19754 to svn://svn.ffmpeg.org/ffmpeg/trunk
enabled libspeex && require libspeex speex/speex.h speex_decoder_init -lspeex
enabled libtheora && require libtheora theora/theora.h theora_info_init -ltheora -logg
enabled libvorbis && require libvorbis vorbis/vorbisenc.h vorbis_info_init -lvorbisenc -lvorbis -logg
-enabled libx264 && require libx264 x264.h x264_encoder_open -lx264 -lm &&
+enabled libx264 && require libx264 x264.h x264_encoder_encode -lx264 -lm &&
{ check_cpp_condition x264.h "X264_BUILD >= 65" ||
die "ERROR: libx264 version must be >= 0.65."; }
enabled libxvid && require libxvid xvid.h xvid_global -lxvidcore