diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/codec/gsm610.c | 39 | ||||
| -rw-r--r-- | src/codec/gsm620.c | 32 |
2 files changed, 71 insertions, 0 deletions
diff --git a/src/codec/gsm610.c b/src/codec/gsm610.c index 35f6011d..47faea21 100644 --- a/src/codec/gsm610.c +++ b/src/codec/gsm610.c @@ -22,6 +22,10 @@ */ #include <stdint.h> +#include <stdbool.h> + +#include <osmocom/core/bitvec.h> +#include <osmocom/core/utils.h> /* GSM FR - subjective importance bit ordering */ /* This array encodes GSM 05.03 Table 2. @@ -292,3 +296,38 @@ const uint16_t gsm610_bitorder[260] = { 11, /* LARc1:0 */ 29, /* LARc5:0 */ }; + +/*! \brief Check whether RTP frame contains FR SID code word according to + * TS 101 318 §5.1.2 + * \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_fr_check_sid(uint8_t *rtp_payload, size_t payload_len) +{ + struct bitvec bv; + uint16_t i, z_bits[] = { 59, 60, 62, 63, 65, 66, 68, 69, 71, 72, 74, 75, + 77, 78, 80, 81, 83, 84, 86, 87, 89, 90, 92, 93, + 95, 96, 115, 116, 118, 119, 121, 122, 124, 125, + 127, 128, 130, 131, 133, 134, 136, 137, 139, + 140, 142, 143, 145, 146, 148, 149, 151, 152, + 171, 172, 174, 175, 177, 178, 180, 181, 183, + 184, 186, 187, 189, 190, 192, 193, 195, 196, + 198, 199, 201, 202, 204, 205, 207, 208, 227, + 228, 230, 231, 233, 234, 236, 237, 239, 242, + 245, 248, 251, 254, 257, 260, 263 }; + + /* signature does not match Full Rate SID */ + if ((rtp_payload[0] >> 4) != 0xD) + return false; + + bv.data = rtp_payload; + bv.data_len = payload_len; + + /* code word is all 0 at given bits, numbered from 1 */ + for (i = 0; i < ARRAY_SIZE(z_bits); i++) + if (bitvec_get_bit_pos(&bv, z_bits[i]) != ZERO) + return false; + + return true; +} 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 §5.2.2 + * \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; +} |