[FFmpeg-devel] Fix Altivec detection on Linux.

David Woodhouse dwmw2
Thu Mar 20 12:52:26 CET 2008

On Thu, 2008-03-20 at 12:24 +0100, Reimar D?ffinger wrote:
> In my personal opinion the "right" solution is to choose one single way
> of detecting AltiVec, and tell anyone where it does not work to fix
> their OS. 

That's what we've done, isn't it? We've put it in the AT_HWCAP field of
the ELF auxiliary vector, which is passed to every program as it's
started up and contains all kinds of interesting information about the
system such as cache line sizes, etc. That's the _right_ place for it.

However, glibc makes it hard for a library to get at the auxvec, so the
easiest way to get it is to open /proc/$$/auxv and read it. I'm really
not feeling quixotic enough this week to argue with Uli about that.


More information about the ffmpeg-devel mailing list