I have a question on the implementation of AMR modes.
AMR NB has 8 different modes depending on bitrates(from 4.75 kbps ~ 12.2 kbps),
and the required computation is different for each mode.
Are the 8 modes must supported in the AMR codec for 3G mobile phones?
Thanks in advance.
I am not sure but I think so, at least for GSM. A bit more uncertain about UMTS (3G). If you con't get a more conclusive answer from someone else I suggest you download the specs from 3gpp.org and find out for yourself, but that is of course quite cumbersome...