Example #1
0
/*! \brief function for incoming RTP via TCH.req
 *  \param[in] rtp_pl buffer containing RTP payload
 *  \param[in] rtp_pl_len length of \a rtp_pl
 *  \param[in] use_cache Use cached payload instead of parsing RTP
 *  \param[in] marker RTP header Marker bit (indicates speech onset)
 *  \returns 0 if encoding result can be sent further to L1 without extra actions
 *           positive value if data is ready AND extra actions are required
 *           negative value otherwise (no data for L1 encoded)
 *
 * This function prepares a msgb with a L1 PH-DATA.req primitive and
 * queues it into lchan->dl_tch_queue.
 *
 * Note that the actual L1 primitive header is not fully initialized
 * yet, as things like the frame number, etc. are unknown at the time we
 * pre-fill the primtive.
 */
int l1if_tch_encode(struct gsm_lchan *lchan, uint8_t *data, uint8_t *len,
		    const uint8_t *rtp_pl, unsigned int rtp_pl_len, uint32_t fn,
		    bool use_cache, bool marker)
{
	uint8_t *payload_type;
	uint8_t *l1_payload, ft;
	int rc = 0;
	bool is_sid = false;

	DEBUGP(DRTP, "%s RTP IN: %s\n", gsm_lchan_name(lchan),
		osmo_hexdump(rtp_pl, rtp_pl_len));

	payload_type = &data[0];
	l1_payload = &data[1];

	switch (lchan->tch_mode) {
	case GSM48_CMODE_SPEECH_V1:
		if (lchan->type == GSM_LCHAN_TCH_F) {
			*payload_type = GsmL1_TchPlType_Fr;
			rc = rtppayload_to_l1_fr(l1_payload,
						 rtp_pl, rtp_pl_len);
			if (rc && lchan->ts->trx->bts->dtxd)
				is_sid = osmo_fr_check_sid(rtp_pl, rtp_pl_len);
		} else{
			*payload_type = GsmL1_TchPlType_Hr;
			rc = rtppayload_to_l1_hr(l1_payload,
						 rtp_pl, rtp_pl_len);
			if (rc && lchan->ts->trx->bts->dtxd)
				is_sid = osmo_hr_check_sid(rtp_pl, rtp_pl_len);
		}
		if (is_sid)
			dtx_cache_payload(lchan, rtp_pl, rtp_pl_len, fn, -1);
		break;
#if defined(L1_HAS_EFR) && defined(USE_L1_RTP_MODE)
	case GSM48_CMODE_SPEECH_EFR:
		*payload_type = GsmL1_TchPlType_Efr;
		rc = rtppayload_to_l1_efr(l1_payload, rtp_pl,
					  rtp_pl_len);
		/* FIXME: detect and save EFR SID */
		break;
#endif
	case GSM48_CMODE_SPEECH_AMR:
		if (use_cache) {
			*payload_type = GsmL1_TchPlType_Amr;
			rtppayload_to_l1_amr(l1_payload, lchan->tch.dtx.cache,
					     lchan->tch.dtx.len, ft);
			*len = lchan->tch.dtx.len + 1;
			return 0;
		}

		rc = dtx_dl_amr_fsm_step(lchan, rtp_pl, rtp_pl_len, fn,
					 l1_payload, marker, len, &ft);
		if (rc < 0)
			return rc;
		if (!dtx_dl_amr_enabled(lchan)) {
			*payload_type = GsmL1_TchPlType_Amr;
			rtppayload_to_l1_amr(l1_payload + 2, rtp_pl, rtp_pl_len,
					     ft);
			return 0;
		}

		/* DTX DL-specific logic below: */
		switch (lchan->tch.dtx.dl_amr_fsm->state) {
		case ST_ONSET_V:
			*payload_type = GsmL1_TchPlType_Amr_Onset;
			dtx_cache_payload(lchan, rtp_pl, rtp_pl_len, fn, 0);
			*len = 3;
			return 1;
		case ST_VOICE:
			*payload_type = GsmL1_TchPlType_Amr;
			rtppayload_to_l1_amr(l1_payload + 2, rtp_pl, rtp_pl_len,
					     ft);
			return 0;
		case ST_SID_F1:
			if (lchan->type == GSM_LCHAN_TCH_H) { /* AMR HR */
				*payload_type = GsmL1_TchPlType_Amr_SidFirstP1;
				rtppayload_to_l1_amr(l1_payload + 2, rtp_pl,
						     rtp_pl_len, ft);
				return 0;
			}
			/* AMR FR */
			*payload_type = GsmL1_TchPlType_Amr;
			rtppayload_to_l1_amr(l1_payload + 2, rtp_pl, rtp_pl_len,
					     ft);
			return 0;
		case ST_SID_F2:
			*payload_type = GsmL1_TchPlType_Amr;
			rtppayload_to_l1_amr(l1_payload + 2, rtp_pl, rtp_pl_len,
					     ft);
			return 0;
		case ST_F1_INH:
			*payload_type = GsmL1_TchPlType_Amr_SidFirstInH;
			*len = 3;
			dtx_cache_payload(lchan, rtp_pl, rtp_pl_len, fn, 0);
			return 1;
		case ST_U_INH:
			*payload_type = GsmL1_TchPlType_Amr_SidUpdateInH;
			*len = 3;
			dtx_cache_payload(lchan, rtp_pl, rtp_pl_len, fn, 0);
			return 1;
		case ST_SID_U:
			return -EAGAIN;
		case ST_FACCH:
			return -EBADMSG;
		default:
			LOGP(DRTP, LOGL_ERROR, "Unhandled DTX DL AMR FSM state "
			     "%d\n", lchan->tch.dtx.dl_amr_fsm->state);
			return -EINVAL;
		}
		break;
	default:
		/* we don't support CSD modes */
		rc = -1;
		break;
	}

	if (rc < 0) {
		LOGP(DRTP, LOGL_ERROR, "%s unable to parse RTP payload\n",
		     gsm_lchan_name(lchan));
		return -EBADMSG;
	}

	*len = rc + 1;

	DEBUGP(DRTP, "%s RTP->L1: %s\n", gsm_lchan_name(lchan),
		osmo_hexdump(data, *len));
	return 0;
}
Example #2
0
/*! \brief Check current state of DTX DL AMR FSM and dispatch necessary events
 *  \param[in] lchan Logical channel on which we check scheduling
 *  \param[in] rtp_pl buffer with RTP data
 *  \param[in] rtp_pl_len length of rtp_pl
 *  \param[in] fn Frame Number for which we check scheduling
 *  \param[in] l1_payload buffer where CMR and CMI prefix should be added
 *  \param[in] marker RTP Marker bit
 *  \param[out] len Length of expected L1 payload
 *  \param[out] ft_out Frame Type to be populated after decoding
 *  \returns 0 in case of success; negative on error
 */
int dtx_dl_amr_fsm_step(struct gsm_lchan *lchan, const uint8_t *rtp_pl,
			size_t rtp_pl_len, uint32_t fn, uint8_t *l1_payload,
			bool marker, uint8_t *len, uint8_t *ft_out)
{
	uint8_t cmr;
	enum osmo_amr_type ft;
	enum osmo_amr_quality bfi;
	int8_t sti, cmi;
	int rc;

	if (dtx_dl_amr_enabled(lchan)) {
		if (lchan->type == GSM_LCHAN_TCH_H &&
		    lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F2 && !rtp_pl) {
			*len = 3; /* SID-FIRST P1 -> P2 completion */
			memcpy(l1_payload, lchan->tch.dtx.cache, 2);
			dtx_dispatch(lchan, E_SID_U);
			return 0;
		}
	}

	if (!rtp_pl_len)
		return -EBADMSG;

	rc = osmo_amr_rtp_dec(rtp_pl, rtp_pl_len, &cmr, &cmi, &ft, &bfi, &sti);
	if (rc < 0) {
		LOGP(DRTP, LOGL_ERROR, "failed to decode AMR RTP (length %zu)\n",
		     rtp_pl_len);
		return rc;
	}

	/* only needed for old sysmo firmware: */
	*ft_out = ft;

	/* CMI in downlink tells the L1 encoder which encoding function
	 * it will use, so we have to use the frame type */
	if (osmo_amr_is_speech(ft))
		cmi = ft;

	/* populate L1 payload with CMR/CMI - might be ignored by caller: */
	amr_set_mode_pref(l1_payload, &lchan->tch.amr_mr, cmi, cmr);

	/* populate DTX cache with CMR/CMI - overwrite cache which will be
	   either updated or invalidated by caller anyway: */
	amr_set_mode_pref(lchan->tch.dtx.cache, &lchan->tch.amr_mr, cmi, cmr);
	*len = 3 + rtp_pl_len;

	/* DTX DL is not enabled, move along */
	if (!lchan->ts->trx->bts->dtxd)
		return 0;

	if (osmo_amr_is_speech(ft)) {
		/* AMR HR - Inhibition */
		if (lchan->type == GSM_LCHAN_TCH_H && marker &&
		    lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F1)
			return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
						      E_INHIB, (void *)lchan);
		/* AMR FR & HR - generic */
		if (marker && (lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F1 ||
			       lchan->tch.dtx.dl_amr_fsm->state == ST_SID_F2 ||
			       lchan->tch.dtx.dl_amr_fsm->state == ST_SID_U ))
			return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
						      E_ONSET, (void *)lchan);
		return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm, E_VOICE,
					      (void *)lchan);
	}

	if (ft == AMR_SID) {
		if (lchan->tch.dtx.dl_amr_fsm->state == ST_VOICE) {
			/* SID FIRST/UPDATE scheduling logic relies on SID FIRST
			   being sent first hence we have to force caching of SID
			   as FIRST regardless of actually decoded type */
			dtx_cache_payload(lchan, rtp_pl, rtp_pl_len, fn, false);
			return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
						      E_SID_F, (void *)lchan);
		} else
			dtx_cache_payload(lchan, rtp_pl, rtp_pl_len, fn, sti);
		return osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm,
					      sti ? E_SID_U : E_SID_F,
					      (void *)lchan);
	}

	if (ft != AMR_NO_DATA) {
		LOGP(DRTP, LOGL_ERROR, "unsupported AMR FT 0x%02x\n", ft);
		return -ENOTSUP;
	}

	if (marker)
		osmo_fsm_inst_dispatch(lchan->tch.dtx.dl_amr_fsm, E_VOICE,
				       (void *)lchan);
	*len = 0;
	return 0;
}