Hi, all
The osmocomBB no AMR support yet now (only FR, HR and EFR).
/* no AMR yet */ void dsp_load_tch_param(struct gsm_time *next_time,
if (tch_mode) { switch (l1s.tch_mode) { case GSM48_CMODE_SPEECH_V1: *tch_mode = *tch_f_hn ? TCH_FS_MODE : TCH_HS_MODE; break; case GSM48_CMODE_SPEECH_EFR: *tch_mode = *tch_f_hn ? TCH_EFR_MODE : SIG_ONLY_MODE; break; default: *tch_mode = SIG_ONLY_MODE; } }
i checked the product datasheet, the C123 can support AMR from the beginning. does anyone can give me some information to patch it? BTW, i havn't 30 source, so i can't reference it.
Best regards Aegean Chou
Hi Aegean,
On Sat, Oct 22, 2011 at 07:32:20PM +0800, Aegean Chou wrote:
The osmocomBB no AMR support yet now (only FR, HR and EFR).
this is correct.
i checked the product datasheet, the C123 can support AMR from the beginning. does anyone can give me some information to patch it?
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
baseband-devel@lists.osmocom.org
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Aegean Chou -
Harald Welte