diff options
Diffstat (limited to 'src/coding/gsm0503_coding.c')
| -rw-r--r-- | src/coding/gsm0503_coding.c | 193 |
1 files changed, 187 insertions, 6 deletions
diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c index 7385d233..1bec56ea 100644 --- a/src/coding/gsm0503_coding.c +++ b/src/coding/gsm0503_coding.c @@ -47,6 +47,7 @@ #include <osmocom/coding/gsm0503_tables.h> #include <osmocom/coding/gsm0503_coding.h> #include <osmocom/coding/gsm0503_parity.h> +#include <osmocom/coding/gsm0503_amr_dtx.h> /*! \mainpage libosmocoding Documentation * @@ -1168,7 +1169,7 @@ int gsm0503_pdtch_decode(uint8_t *l2_data, const sbit_t *bursts, uint8_t *usf_p, } /* - * EGPRS PDTCH UL block encoding + * EGPRS PDTCH DL block encoding */ static int egprs_type3_map(ubit_t *bursts, const ubit_t *hc, const ubit_t *dc, int usf) { @@ -1176,7 +1177,7 @@ static int egprs_type3_map(ubit_t *bursts, const ubit_t *hc, const ubit_t *dc, i ubit_t iB[456]; const ubit_t *hl_hn = gsm0503_pdtch_hl_hn_ubit[3]; - gsm0503_mcs1_dl_interleave(gsm0503_usf2six[usf], hc, dc, iB); + gsm0503_mcs1_dl_interleave(gsm0503_usf2twelve_ubit[usf], hc, dc, iB); for (i = 0; i < 4; i++) { gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], @@ -1332,7 +1333,7 @@ static int egprs_parse_dl_cps(struct egprs_cps *cps, * \param[out] bursts caller-allocated buffer for unpacked burst bits * \param[in] l2_data L2 (MAC) block to be encoded * \param[in] l2_len length of l2_data in bytes, used to determine MCS - * \returns 0 on success; negative on error */ + * \returns number of bits encoded; negative on error */ int gsm0503_pdtch_egprs_encode(ubit_t *bursts, const uint8_t *l2_data, uint8_t l2_len) { @@ -1427,7 +1428,7 @@ bad_header: * \param[out] bursts caller-allocated buffer for unpacked burst bits * \param[in] l2_data L2 (MAC) block to be encoded * \param[in] l2_len length of l2_data in bytes, used to determine CS - * \returns 0 on success; negative on error */ + * \returns number of bits encoded; negative on error */ int gsm0503_pdtch_encode(ubit_t *bursts, const uint8_t *l2_data, uint8_t l2_len) { ubit_t iB[456], cB[676]; @@ -1635,6 +1636,39 @@ static void tch_amr_disassemble(ubit_t *d_bits, const uint8_t *tch_data, int len d_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; } +/* Append STI and MI bits to the SID_UPDATE frame, see also + * 3GPP TS 26.101, chapter 4.2.3 AMR Core Frame with comfort noise bits */ +static void tch_amr_sid_update_append(ubit_t *sid_update, uint8_t sti, uint8_t mi) +{ + /* Zero out the space that had been used by the CRC14 */ + memset(sid_update + 35, 0, 14); + + /* Append STI and MI parameters */ + sid_update[35] = sti & 1; + sid_update[36] = mi & 1; + sid_update[37] = mi >> 1 & 1; + sid_update[38] = mi >> 2 & 1; +} + +/* Extract a SID UPDATE fram the sbits of an FR AMR frame */ +static void extract_afs_sid_update(sbit_t *sid_update, const sbit_t *sbits) +{ + + unsigned int i; + + sbits += 32; + + for (i = 0; i < 53; i++) { + sid_update[0] = sbits[0]; + sid_update[1] = sbits[1]; + sid_update[2] = sbits[2]; + sid_update[3] = sbits[3]; + sid_update += 4; + sbits += 8; + } + +} + /* re-arrange according to TS 05.03 Table 2 (receiver) */ static void tch_fr_d_to_b(ubit_t *b_bits, const ubit_t *d_bits) { @@ -2101,10 +2135,37 @@ int gsm0503_tch_afs_decode(uint8_t *tch_data, const sbit_t *bursts, int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft, uint8_t *cmr, int *n_errors, int *n_bits_total) { + return gsm0503_tch_afs_decode_dtx(tch_data, bursts, codec_mode_req, + codec, codecs, ft, cmr, n_errors, + n_bits_total, NULL); +} + +/*! Perform channel decoding of a TCH/AFS channel according TS 05.03 + * \param[out] tch_data Codec frame in RTP payload format + * \param[in] bursts buffer containing the symbols of 8 bursts + * \param[in] codec_mode_req is this CMR (1) or CMC (0) + * \param[in] codec array of active codecs (active codec set) + * \param[in] codecs number of codecs in \a codec + * \param ft Frame Type; Input if \a codec_mode_req = 1, Output * otherwise + * \param[out] cmr Output in \a codec_mode_req = 1 + * \param[out] n_errors Number of detected bit errors + * \param[out] n_bits_total Total number of bits + * \param[inout] dtx DTX frame type output, previous DTX frame type input + * \returns (>=4) length of bytes used in \a tch_data output buffer; ([0,3]) + * codec out of range; negative on error + */ +int gsm0503_tch_afs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts, + int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft, + uint8_t *cmr, int *n_errors, int *n_bits_total, uint8_t *dtx) +{ sbit_t iB[912], cB[456], h; ubit_t d[244], p[6], conv[250]; int i, j, k, best = 0, rv, len, steal = 0, id = 0; + ubit_t cBd[456]; *n_errors = 0; *n_bits_total = 0; + static ubit_t sid_first_dummy[64] = { 0 }; + sbit_t sid_update_enc[256]; + uint8_t dtx_prev; for (i=0; i<8; i++) { gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], &h, i >> 2); @@ -2123,6 +2184,50 @@ int gsm0503_tch_afs_decode(uint8_t *tch_data, const sbit_t *bursts, return GSM_MACBLOCK_LEN; } + /* Determine the DTX frame type (SID_UPDATE, ONSET etc...) */ + if (dtx) { + osmo_sbit2ubit(cBd, cB, 456); + dtx_prev = *dtx; + *dtx = gsm0503_detect_afs_dtx_frame(n_errors, n_bits_total, cBd); + + if (dtx_prev == AFS_SID_UPDATE && *dtx == AMR_OTHER) { + /* NOTE: The AFS_SID_UPDATE frame is splitted into + * two half rate frames. If the id marker frame + * (AFS_SID_UPDATE) is detected the following frame + * contains the actual comfort noised data part of + * (AFS_SID_UPDATE_CN). */ + *dtx = AFS_SID_UPDATE_CN; + + extract_afs_sid_update(sid_update_enc, cB); + osmo_conv_decode_ber(&gsm0503_tch_axs_sid_update, + sid_update_enc, conv, n_errors, + n_bits_total); + rv = osmo_crc16gen_check_bits(&gsm0503_amr_crc14, conv, + 35, conv + 35); + if (rv != 0) { + /* Error checking CRC14 for an AMR SID_UPDATE frame */ + return -1; + } + + tch_amr_sid_update_append(conv, 1, + (codec_mode_req) ? codec[*ft] + : codec[id]); + tch_amr_reassemble(tch_data, conv, 39); + len = 5; + goto out; + } else if (*dtx == AFS_SID_FIRST) { + tch_amr_sid_update_append(sid_first_dummy, 0, + (codec_mode_req) ? codec[*ft] + : codec[id]); + tch_amr_reassemble(tch_data, conv, 39); + len = 5; + goto out; + } else if (*dtx == AFS_ONSET) { + len = 0; + goto out; + } + } + for (i = 0; i < 4; i++) { for (j = 0, k = 0; j < 8; j++) k += abs(((int)gsm0503_afs_ic_sbit[i][j]) - ((int)cB[j])); @@ -2283,6 +2388,7 @@ int gsm0503_tch_afs_decode(uint8_t *tch_data, const sbit_t *bursts, return -1; } +out: /* Change codec request / indication, if frame is valid */ if (codec_mode_req) *cmr = id; @@ -2480,9 +2586,36 @@ int gsm0503_tch_ahs_decode(uint8_t *tch_data, const sbit_t *bursts, int odd, int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft, uint8_t *cmr, int *n_errors, int *n_bits_total) { + return gsm0503_tch_ahs_decode_dtx(tch_data, bursts, odd, codec_mode_req, + codec, codecs, ft, cmr, n_errors, + n_bits_total, NULL); +} + +/*! Perform channel decoding of a TCH/AFS channel according TS 05.03 + * \param[out] tch_data Codec frame in RTP payload format + * \param[in] bursts buffer containing the symbols of 8 bursts + * \param[in] odd Is this an odd (1) or even (0) frame number? + * \param[in] codec_mode_req is this CMR (1) or CMC (0) + * \param[in] codec array of active codecs (active codec set) + * \param[in] codecs number of codecs in \a codec + * \param ft Frame Type; Input if \a codec_mode_req = 1, Output * otherwise + * \param[out] cmr Output in \a codec_mode_req = 1 + * \param[out] n_errors Number of detected bit errors + * \param[out] n_bits_total Total number of bits + * \param[inout] dtx DTX frame type output, previous DTX frame type input + * \returns (>=4) length of bytes used in \a tch_data output buffer; ([0,3]) + * codec out of range; negative on error + */ +int gsm0503_tch_ahs_decode_dtx(uint8_t *tch_data, const sbit_t *bursts, int odd, + int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft, + uint8_t *cmr, int *n_errors, int *n_bits_total, uint8_t *dtx) +{ sbit_t iB[912], cB[456], h; ubit_t d[244], p[6], conv[135]; int i, j, k, best = 0, rv, len, steal = 0, id = 0; + ubit_t cBd[456]; + static ubit_t sid_first_dummy[64] = { 0 }; + uint8_t dtx_prev; /* only unmap the stealing bits */ if (!odd) { @@ -2526,6 +2659,52 @@ int gsm0503_tch_ahs_decode(uint8_t *tch_data, const sbit_t *bursts, int odd, gsm0503_tch_hr_deinterleave(cB, iB); + /* Determine the DTX frame type (SID_UPDATE, ONSET etc...) */ + if (dtx) { + osmo_sbit2ubit(cBd, cB, 456); + dtx_prev = *dtx; + *dtx = gsm0503_detect_ahs_dtx_frame(n_errors, n_bits_total, cBd); + + if (dtx_prev == AHS_SID_UPDATE && *dtx == AMR_OTHER) { + /* NOTE: The AHS_SID_UPDATE frame is splitted into + * two half rate frames. If the id marker frame + * (AHS_SID_UPDATE) is detected the following frame + * contains the actual comfort noised data part of + * (AHS_SID_UPDATE_CN). */ + *dtx = AHS_SID_UPDATE_CN; + + osmo_conv_decode_ber(&gsm0503_tch_axs_sid_update, + cB + 16, conv, n_errors, + n_bits_total); + rv = osmo_crc16gen_check_bits(&gsm0503_amr_crc14, conv, + 35, conv + 35); + if (rv != 0) { + /* Error checking CRC14 for an AMR SID_UPDATE frame */ + return -1; + } + + tch_amr_sid_update_append(conv, 1, + (codec_mode_req) ? codec[*ft] + : codec[id]); + tch_amr_reassemble(tch_data, conv, 39); + len = 5; + goto out; + } else if (*dtx == AHS_SID_FIRST_P2) { + tch_amr_sid_update_append(sid_first_dummy, 0, + (codec_mode_req) ? codec[*ft] + : codec[id]); + tch_amr_reassemble(tch_data, sid_first_dummy, 39); + len = 5; + goto out; + } else if (*dtx == AHS_SID_UPDATE || *dtx == AHS_ONSET + || *dtx == AHS_SID_FIRST_INH + || *dtx == AHS_SID_UPDATE_INH + || *dtx == AHS_SID_FIRST_P1) { + len = 0; + goto out; + } + } + for (i = 0; i < 4; i++) { for (j = 0, k = 0; j < 4; j++) k += abs(((int)gsm0503_ahs_ic_sbit[i][j]) - ((int)cB[j])); @@ -2670,6 +2849,7 @@ int gsm0503_tch_ahs_decode(uint8_t *tch_data, const sbit_t *bursts, int odd, return -1; } +out: /* Change codec request / indication, if frame is valid */ if (codec_mode_req) *cmr = id; @@ -2879,7 +3059,7 @@ static inline int16_t rach_decode_ber(const sbit_t *burst, uint8_t bsic, bool is osmo_ubit2pbit_ext(ra, 0, conv, 0, nbits, 1); - return is_11bit ? osmo_load16le(ra) : ra[0]; + return is_11bit ? ((ra[0] << 3) | (ra[1] & 0x07)) : ra[0]; } /*! Decode the Extended (11-bit) RACH according to 3GPP TS 45.003 @@ -2974,7 +3154,8 @@ int gsm0503_rach_ext_encode(ubit_t *burst, uint16_t ra11, uint8_t bsic, bool is_ uint8_t ra[2] = { 0 }, nbits = 8; if (is_11bit) { - osmo_store16le(ra11, ra); + ra[0] = (uint8_t) (ra11 >> 3); + ra[1] = (uint8_t) (ra11 & 0x07); nbits = 11; } else ra[0] = (uint8_t)ra11; |