SPARC optimizations have been removed in
commit b4dd424d96f09f9bafb88e47f37df65dc4529143
The last revission with the optimizations is fb1b70c1ed50951c5fc1a309c3c446b2eaaf564b

If you want to maintain these (or other) SPARC optimizations in ffmpeg, then please
contact ffmpeg-devel@ffmpeg.org
