static struct msgb *l1_to_rtppayload_efr(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_EFR_BYTES);
memcpy(cur, l1_payload, GSM_EFR_BYTES);
#else
/* step1: reverse the bit-order of each payload byte */
osmo_revbytebits_buf(l1_payload, payload_len);
cur = msgb_put(msg, GSM_EFR_BYTES);
/* step 2: we need to shift the entire L1 payload by 4 bits right */
osmo_nibble_shift_right(cur, l1_payload, GSM_EFR_BITS/4);
cur[0] |= 0xC0;
#endif /* USE_L1_RTP_MODE */
enum osmo_amr_type ft;
enum osmo_amr_quality bfi;
uint8_t cmr;
int8_t sti, cmi;
osmo_amr_rtp_dec(l1_payload, payload_len, &cmr, &cmi, &ft, &bfi, &sti);
lchan_set_marker(ft == AMR_GSM_EFR_SID, lchan);
return msg;
}
static struct msgb *l1_to_rtppayload_efr(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_EFR_BYTES);
memcpy(cur, l1_payload, GSM_EFR_BYTES);
enum osmo_amr_type ft;
enum osmo_amr_quality bfi;
uint8_t cmr;
int8_t sti, cmi;
osmo_amr_rtp_dec(l1_payload, payload_len, &cmr, &cmi, &ft, &bfi, &sti);
lchan_set_marker(ft == AMR_GSM_EFR_SID, lchan);
return msg;
}
/*! \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;
}