I cannot build ffmpeg 0.7.1,1 successfully on my system. I have not been able to figure out the makefile system to get compiler/makefile output that tells me what is being executed from make to the compiler but I suspect an include issue of some sort; running gmake in the work directory manually causes gmake to use 100% on a cpu core but does nothing further. I heard other reports of the trouble with no ideas or fixes. The following errors result (on a repeat make to clean output towards the failure):

===>  Building for ffmpeg-0.7.1,1
LD      ffmpeg_g
LD      ffprobe_g
LD      ffserver_g
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_sse2'
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_blur_line_sse2'
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_filter_line_mmx2'
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_ssse3'
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_sse2'
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_mmx'
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_filter_line_ssse3'
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_blur_line_sse2'
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_filter_line_mmx2'
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_ssse3'
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_mmx'
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_filter_line_ssse3'
gmake: *** [ffprobe_g] Error 1
gmake: *** Waiting for unfinished jobs....
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_sse2'
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_blur_line_sse2'
gmake: *** [ffmpeg_g] Error 1
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_filter_line_mmx2'
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_ssse3'
libavfilter/libavfilter.so: undefined reference to `ff_yadif_filter_line_mmx'
libavfilter/libavfilter.so: undefined reference to `ff_gradfun_filter_line_ssse3'
gmake: *** [ffserver_g] Error 1
*** Error code 1

Stop in /usr/ports/multimedia/ffmpeg.
*** Error code 1

Stop in /usr/ports/multimedia/ffmpeg.

Fix: More of a workaround until I can find out what the compiler is doing:
cd /usr/ports/multimedia/ffmpeg;make CONFIGURE_ARGS+="--disable-filter=yadif --disable-filter=gradfun"

or apply the following diff
How-To-Repeat: cd /usr/ports/multimedia/ffmpeg;make