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codecs_match 

Change-Id: I5975519e04472b5fd6bf447950c0f8a4147c8d00
This commit is contained in:
Neels Hofmeyr 2024-02-08 23:40:52 +01:00
parent 9d7aa7fcbc
commit 992baaf205
2 changed files with 22 additions and 8 deletions
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28
src/libmsc/gsm_04_08_cc.c
View File

@ -768,6 +768,19 @@ void gsm48_cc_rx_setup_cn_local_rtp_port_known(struct gsm_trans *trans)
mncc_recvmsg(trans->net, trans, MNCC_SETUP_IND, &setup);
}
static bool codecs_match(const struct sdp_audio_codec *a, const struct sdp_audio_codec *b)
{
if (!sdp_audio_codec_cmp(a, b, true, false))
return true;
/* Codecs are not identical. But will the MGW be able to transcode? */
if (!strcmp("AMR", a->subtype_name) && !strcmp("AMR", b->subtype_name)) {
/* TODO: compare matching mode-set. */
return true;
}
return false;
}
static void rx_mncc_sdp(struct gsm_trans *trans, uint32_t mncc_msg_type, const char *sdp,
const struct gsm_mncc_bearer_cap *bcap)
{
@ -814,15 +827,14 @@ static void rx_mncc_sdp(struct gsm_trans *trans, uint32_t mncc_msg_type, const c
/* Assume that the remote side put its actually assigned codec in first place. If our assigned codec doesn't
* match that, continue re-assignment below. If they do match, exit here to leave as-is.
* I'm not sure if this is common practice, or just a workaround: we cannot dynamically switch between all of
* the payload types, but we still want to communicate all supported codecs. Maybe the proper way to tell the
* other side to use a single codec is to leave only that single codec in the SDP; but at least MO *must* send
* all possible codecs along, to give MT a chance to find a good match. Maybe MO should offer all supported
* codecs, but MT should limit to a single pick -- but what do other SDP peers do, say via SIP? */
if (!sdp_audio_codec_cmp(&trans->cc.remote.audio_codecs.codec[0], &codecs->assignment, true, false)) {
/* remote's first codec matches our assigned codec. All is well. */
* I'm not sure if assuming the special role for the codec that is listed first is common practice, or just a
* workaround: we cannot dynamically switch between all of the payload types, but we still want to communicate
* all supported codecs. Maybe the proper way to tell the other side to use a single codec is to leave only that
* single codec in the SDP; but at least MO *must* send all possible codecs along, to give MT a chance to find a
* good match. Maybe MO should offer all supported codecs, but MT should limit to a single pick -- but what do
* other SDP peers do, say via SIP? */
if (codecs_match(&trans->cc.remote.audio_codecs.codec[0], &codecs->assignment))
return;
}
/* We've already completed Assignment of a voice channel (some time ago), and now the remote side has changed
* to a mismatching codec (list). Try to re-assign this side to a matching codec. */

2
tests/msc_vlr/msc_vlr_test_call.c
View File

@ -1258,10 +1258,12 @@ static const struct codec_test codec_tests[] = {
.mt_tx_sdp_mncc_alert_ind = SDP_CODECS_ALL_GSM_AMR_HR_FIRST,
/* mo_rx_sdp_mncc_alert_req == mt_tx_sdp_mncc_alert_ind */
/*
.mo_expect_reassignment = true,
.mo_tx_reassignment_perm_speech = PERM_SPEECH_ALL_GSM_HR3_FIRST,
.mo_rx_reassigned_codec_fr = false,
.mo_rx_reassigned_codec = "AMR:octet-align=1;mode-set=0,2,4",
*/
.mt_tx_sdp_mncc_setup_cnf = SDP_CODECS_ALL_GSM_AMR_HR_FIRST,
.mo_tx_sdp_mncc_setup_compl_ind = {},