Speex has been ported to the Blackfin DSP, for the STAMP development board.

This port has been tested on the STAMP development board and requires the 
toolchain available at http://blackfin.uclinux.org/

In order to cross-compile for uclinux:
export CC=bfin-uclinux-gcc
./configure --enable-blackfin-asm --enable-fixed-point --host=bfin-uclinux
make
make install

The --enable-blackfin-asm option is not required, but it speeds up Speex by
approximately a factor of two.

If you're getting a crash when enabling --enable-blackfin-asm then your
toolchain (assembler in fact) is probably too old (a bug was fixed in the
June 3rd build)