[FFmpeg-user] Compiling on a G4, but still runnable on a G3

[Programmingkid]

I'm trying to make a binary of ffmpeg that will run using altivec instructions on a G4 Processor while still being compatible with a G3 processor. I read in the changelog for 0.5.2 that problems with altivec and the PowerPC processor have been fixed. I compiled ffmpeg 0.5.4 on a G4 processor and it worked fine on that computer. When I tried the same binary on a G3 processor, the program crashed with an illegal instruction. So the question is what do I need to do in order to keep altivec instructions, yet still have a binary that works with g3 processors?