static struct msgb *l1_to_rtppayload_fr(uint8_t *l1_payload, uint8_t payload_len,
struct gsm_lchan *lchan)
{
struct msgb *msg;
uint8_t *cur;
msg = msgb_alloc_headroom(1024, 128, "L1C-to-RTP");
if (!msg)
return NULL;
#ifdef USE_L1_RTP_MODE
/* new L1 can deliver bits like we need them */
cur = msgb_put(msg, GSM_FR_BYTES);
memcpy(cur, l1_payload, GSM_FR_BYTES);
#else
/* step1: reverse the bit-order of each payload byte */
osmo_revbytebits_buf(l1_payload, payload_len);
cur = msgb_put(msg, GSM_FR_BYTES);
/* step2: we need to shift the entire L1 payload by 4 bits right */
osmo_nibble_shift_right(cur, l1_payload, GSM_FR_BITS/4);
cur[0] |= 0xD0;
#endif /* USE_L1_RTP_MODE */
lchan_set_marker(osmo_fr_check_sid(l1_payload, payload_len), lchan);
return msg;
}
static struct msgb *l1_to_rtppayload_fr(uint8_t *l1_payload, uint8_t payload_len,
struct gsm_lchan *lchan)
{
struct msgb *msg;
uint8_t *cur;
msg = msgb_alloc_headroom(1024, 128, "L1P-to-RTP");
if (!msg)
return NULL;
/* new L1 can deliver bits like we need them */
cur = msgb_put(msg, GSM_FR_BYTES);
memcpy(cur, l1_payload, GSM_FR_BYTES);
lchan_set_marker(osmo_fr_check_sid(l1_payload, payload_len), lchan);
return msg;
}
/*! \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;
}
