i've tested 3 audio formats on the n770. (not checked bitrates, but i think vorbis, mpc are the defaults for the encoder and mp3 > 192kbps) mp3 => 2-4% cpu usage vorbis => 18-22% cpu usage mpc => 94% cpu usage and sounds scratched (i've compiled libmpcdec3 and gstreamer-0.10-plugins-bad) so if you want to keep your cpu usage as low as possible, use mp3 :-/
