diff options
Diffstat (limited to 'src/codec/gsm620.c')
| -rw-r--r-- | src/codec/gsm620.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/src/codec/gsm620.c b/src/codec/gsm620.c index f4ac9ad8..6f1a95bb 100644 --- a/src/codec/gsm620.c +++ b/src/codec/gsm620.c @@ -22,6 +22,10 @@ */ #include <stdint.h> +#include <stdbool.h> + +#include <osmocom/core/bitvec.h> +#include <osmocom/core/utils.h> /* GSM HR unvoiced (mode=0) frames - subjective importance bit ordering */ /* This array encode mapping between GSM 05.03 Table 3a (bits @@ -260,3 +264,31 @@ const uint16_t gsm620_voiced_bitorder[112] = { 82, /* Code 3:6 */ 81, /* Code 3:7 */ }; + +static inline uint16_t mask(const uint8_t msb) +{ + const uint16_t m = (uint16_t)1 << (msb - 1); + return (m - 1) ^ m; +} + +/*! \brief Check whether RTP frame contains HR SID code word according to + * TS 101 318 ยง5.2.2 + * \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_hr_check_sid(uint8_t *rtp_payload, size_t payload_len) +{ + uint8_t i, bits[] = { 1, 2, 8, 9, 5, 4, 9, 5, 4, 9, 5, 4, 9, 5 }; + struct bitvec bv; + bv.data = rtp_payload; + bv.data_len = payload_len; + bv.cur_bit = 33; + + /* code word is all 1 at given bits, numbered from 1, MODE is always 3 */ + for (i = 0; i < ARRAY_SIZE(bits); i++) + if (bitvec_get_uint(&bv, bits[i]) != mask(bits[i])) + return false; + + return true; +} |