diff options
Diffstat (limited to 'src/osmo-bsc/codec_pref.c')
| -rw-r--r-- | src/osmo-bsc/codec_pref.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/src/osmo-bsc/codec_pref.c b/src/osmo-bsc/codec_pref.c index 924f77fe2..c998e6007 100644 --- a/src/osmo-bsc/codec_pref.c +++ b/src/osmo-bsc/codec_pref.c @@ -242,3 +242,68 @@ int match_codec_pref(enum gsm48_chan_mode *chan_mode, return 0; } + +/*! Determine the BSS supported speech codec list that is sent to the MSC with + * the COMPLETE LAYER 3 INFORMATION message. + * \param[out] scl GSM 08.08 speech codec list with BSS supported codecs. + * \param[in] msc associated msc (current codec settings). + * \param[in] bts associated bts (current codec settings). */ +void gen_bss_supported_codec_list(struct gsm0808_speech_codec_list *scl, + const struct bsc_msc_data *msc, const struct gsm_bts *bts) +{ + uint8_t perm_spch; + unsigned int i; + int rc; + uint16_t amr_s15_s0_bts; + uint16_t amr_s15_s0_msc; + uint16_t amr_s15_s0; + const struct gsm48_multi_rate_conf *amr_cfg_bts; + const struct gsm48_multi_rate_conf *amr_cfg_msc; + + memset(scl, 0, sizeof(*scl)); + + for (i = 0; i < msc->audio_length; i++) { + + /* Pick a permitted speech value from the global codec configuration list */ + perm_spch = audio_support_to_gsm88(msc->audio_support[i]); + + /* Check this permitted speech value against the BTS specific parameters. + * if the BTS does not support the codec, try the next one */ + if (!test_codec_support_bts(&bts->codec, perm_spch)) + continue; + + /* Write item into codec list */ + rc = gsm0808_speech_codec_from_chan_type(&scl->codec[scl->len], perm_spch); + if (rc != 0) + continue; + + /* AMR (HR/FR version 3) is the only codec that requires a codec + * configuration (S0-S15). Determine the current configuration and update + * the cfg flag. */ + if (msc->audio_support[i]->ver == 3) { + + /* First lookup the BTS specific AMR rate configuration. Thsi config + * is set via the VTY for each BTS individually. In cases where no + * configuration is set we will assume a safe default */ + if (msc->audio_support[i]->hr) { + amr_cfg_bts = (struct gsm48_multi_rate_conf *)&bts->mr_half.gsm48_ie; + amr_s15_s0_bts = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_bts, false); + } else { + amr_cfg_bts = (struct gsm48_multi_rate_conf *)&bts->mr_full.gsm48_ie; + amr_s15_s0_bts = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_bts, true); + } + + /* At next, lookup the AMR rate configuration that is set for the MSC */ + amr_cfg_msc = &msc->amr_conf; + amr_s15_s0_msc = gsm0808_sc_cfg_from_gsm48_mr_cfg(amr_cfg_msc, true); + + /* Calculate the intersection of the two configurations and update S0-S15 + * in the codec list. */ + amr_s15_s0 = amr_s15_s0_bts & amr_s15_s0_msc; + scl->codec[scl->len].cfg = amr_s15_s0; + } + + scl->len++; + } +} + |