diff options
| -rw-r--r-- | src/common/msg_utils.c | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/src/common/msg_utils.c b/src/common/msg_utils.c index 393ae908..9c6f20f1 100644 --- a/src/common/msg_utils.c +++ b/src/common/msg_utils.c @@ -116,8 +116,11 @@ void dtx_cache_payload(struct gsm_lchan *lchan, const uint8_t *l1_payload, ARRAY_SIZE(lchan->tch.dtx.cache) - amr); lchan->tch.dtx.len = copy_len + amr; - lchan->tch.dtx.fn = fn; - lchan->tch.dtx.is_update = update; + /* SID FIRST is special because it's both sent and cached: */ + if (update == 0) { + lchan->tch.dtx.fn = fn; + lchan->tch.dtx.is_update = false; /* Mark SID FIRST explicitly */ + } memcpy(lchan->tch.dtx.cache + amr, l1_payload, copy_len); } @@ -128,6 +131,7 @@ void dtx_cache_payload(struct gsm_lchan *lchan, const uint8_t *l1_payload, * \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 @@ -219,18 +223,18 @@ int dtx_dl_amr_fsm_step(struct gsm_lchan *lchan, const uint8_t *rtp_pl, static inline bool dtx_amr_sid_optional(const struct gsm_lchan *lchan, uint32_t fn) { - /* Compute approx. time delta based on Fn duration */ - uint32_t delta = GSM_FN_TO_MS(fn - lchan->tch.dtx.fn); + /* Compute approx. time delta x26 based on Fn duration */ + uint32_t dx26 = 120 * (fn - lchan->tch.dtx.fn); - /* according to 3GPP TS 26.093 A.5.1.1: */ - if (lchan->tch.dtx.is_update) { - /* SID UPDATE should be repeated every 8th RTP frame */ - if (delta < GSM_RTP_FRAME_DURATION_MS * 8) + /* according to 3GPP TS 26.093 A.5.1.1: + (*26) to avoid float math, add 1 FN tolerance (-120) */ + if (lchan->tch.dtx.is_update) { /* SID UPDATE: every 8th RTP frame */ + if (dx26 < GSM_RTP_FRAME_DURATION_MS * 8 * 26 - 120) return true; return false; } /* 3rd frame after SID FIRST should be SID UPDATE */ - if (delta < GSM_RTP_FRAME_DURATION_MS * 3) + if (dx26 < GSM_RTP_FRAME_DURATION_MS * 3 * 26 - 120) return true; return false; } @@ -289,6 +293,7 @@ uint8_t repeat_last_sid(struct gsm_lchan *lchan, uint8_t *dst, uint32_t fn) if (lchan->tch.dtx.len) { memcpy(dst, lchan->tch.dtx.cache, lchan->tch.dtx.len); lchan->tch.dtx.fn = fn; + lchan->tch.dtx.is_update = true; /* SID UPDATE sent */ return lchan->tch.dtx.len + 1; } |