diff options
| -rw-r--r-- | include/osmocom/codec/codec.h | 1 | ||||
| -rw-r--r-- | src/codec/gsm660.c | 44 |
2 files changed, 45 insertions, 0 deletions
diff --git a/include/osmocom/codec/codec.h b/include/osmocom/codec/codec.h index 58e3a296..65de20da 100644 --- a/include/osmocom/codec/codec.h +++ b/include/osmocom/codec/codec.h @@ -83,6 +83,7 @@ static inline bool osmo_amr_is_speech(enum osmo_amr_type ft) bool osmo_fr_check_sid(const uint8_t *rtp_payload, size_t payload_len); bool osmo_hr_check_sid(const uint8_t *rtp_payload, size_t payload_len); +bool osmo_efr_check_sid(const uint8_t *rtp_payload, size_t payload_len); int osmo_amr_rtp_enc(uint8_t *payload, uint8_t cmr, enum osmo_amr_type ft, enum osmo_amr_quality bfi); int osmo_amr_rtp_dec(const uint8_t *payload, int payload_len, uint8_t *cmr, diff --git a/src/codec/gsm660.c b/src/codec/gsm660.c index 34b10dea..46ecdac3 100644 --- a/src/codec/gsm660.c +++ b/src/codec/gsm660.c @@ -20,6 +20,10 @@ */ #include <stdint.h> +#include <stdbool.h> + +#include <osmocom/core/bitvec.h> +#include <osmocom/core/utils.h> #include <osmocom/codec/codec.h> /* GSM EFR - subjective importance bit ordering */ @@ -253,3 +257,43 @@ const uint16_t gsm660_bitorder[260] = { 243, /* 258 -> PULSE 4_9: b0 */ 246, /* 259 -> PULSE 4_10: b0 */ }; + +/*! Check whether RTP frame contains EFR SID code word according to + * TS 101 318 ยง5.3.2 + * \param[in] rtp_payload Buffer with RTP payload + * \param[in] payload_len Length of payload + * \returns true if code word is found, false otherwise + */ +bool osmo_efr_check_sid(const uint8_t *rtp_payload, size_t payload_len) +{ + struct bitvec bv; + uint16_t i; + static const uint8_t sid_code_word_bits[95] = { + /* bit numbers relative to "pure" EFR frame beginning, + * not counting the signature bits. */ + 45, 46, 48, 49, 50, 51, 52, 53, 54, 55, + 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, + 66, 67, 68, 94, 95, 96, 98, 99, 100, 101, + 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, + 112, 113, 114, 115, 116, 117, 118, 148, 149, 150, + 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, + 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, + 171, 196, 197, 198, 199, 200, 201, 202, 203, 204, + 205, 206, 207, 208, 209, 212, 213, 214, 215, 216, + 217, 218, 219, 220, 221 }; + + /* signature does not match Enhanced Full Rate SID */ + if ((rtp_payload[0] >> 4) != 0xC) + return false; + + bv.data = (uint8_t *) rtp_payload; + bv.data_len = payload_len; + + /* code word is all 1 at given bits */ + for (i = 0; i < ARRAY_SIZE(sid_code_word_bits); i++) { + if (bitvec_get_bit_pos(&bv, sid_code_word_bits[i]+4) != ONE) + return false; + } + + return true; +} |