wget http://asterisk.hosting.lv/bin12/codec_g729-ast12-gcc4-glibc-pentium4.so
cp codec_g729-ast12-gcc4-glibc-pentium4.so /usr/lib/asterisk/modules/codec_g729.so
chmod +x /usr/lib/asterisk/modules/codec_g729.so
stop asterisk (from CLI: stop now)
and restart it by running: /usr/share/astguiclient/start_asterisk_boot.pl
Check whether the codecs where loaded from asterisk CLI:
> show translation