I foresee that 24bit input and output will be the most popular usage scenario for Opus because in most cases there is a need to resample input and output for the codec.Hmm, for playback, I would imagine you would just decode to whatver your hardware supports, so that could well be 24-bit/48 kHz on most devices with no resampling (unless you have native 44.1kHz DSP like Rockbox).