Re: AMR support

Hi Aegean, On Sat, Oct 22, 2011 at 07:32:20PM +0800, Aegean Chou wrote: this is correct. AMR in general is relatively complex, at least at least if you want to implement it in a compliant way. There is not only the 'adaptive' aspect, i.e. the negotiation of different codec modes with CMR/CMI/CMC and the associated CmiPhase, but also the RATSCCH signalling for TFO. Furthermore, the situation gets slightly more complicated as the Calypso DSP ROM firmware apparently doesn't support AMR out-of-the-box but needs some DSP code patches. While we already have support for applying such patches, we don't have a license to distribute such patches, i.e. we cannot include them in OsmocomBB without being in copyright violation. So the correct way of implementing this is: * decide which DSP patch to use (from original firmware) * write a script that can extract it out of the original firmware image * include such a script in OsmocomBB * implement the DSP API / L1 related aspects for AMR in Calypso (by looking at TSM30 source code, or legal forms of reverse engineering the original firmware of e.g. a C123) If you would like to contribute patches/code for any of this work, we would be more than happy to review and merge them. Regards, Harald -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)