Piotr Krysik | 70c25a1 | 2017-01-03 08:01:23 +0100 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2013 by Andreas Eversberg <jolly@eversberg.eu> |
| 3 | * (C) 2015 by Alexander Chemeris <Alexander.Chemeris@fairwaves.co> |
| 4 | * (C) 2016 by Tom Tsou <tom.tsou@ettus.com> |
| 5 | * |
| 6 | * All Rights Reserved |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License along |
| 19 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 20 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 21 | */ |
| 22 | |
| 23 | #include <stdio.h> |
| 24 | #include <stdint.h> |
| 25 | #include <string.h> |
| 26 | #include <stdlib.h> |
| 27 | |
| 28 | #ifdef __cplusplus |
| 29 | extern "C" { |
| 30 | #endif |
| 31 | |
| 32 | #include <osmocom/core/bits.h> |
| 33 | #include <osmocom/core/conv.h> |
| 34 | #include <osmocom/core/utils.h> |
| 35 | #include <osmocom/core/crcgen.h> |
| 36 | #include <osmocom/core/endian.h> |
| 37 | |
| 38 | #include <osmocom/gsm/protocol/gsm_04_08.h> |
| 39 | #include "gsm0503.h" |
| 40 | #include <osmocom/codec/codec.h> |
| 41 | |
| 42 | #include "gsm0503_interleaving.h" |
| 43 | #include "gsm0503_mapping.h" |
| 44 | #include "gsm0503_tables.h" |
| 45 | #include "gsm0503_coding.h" |
| 46 | #include "gsm0503_parity.h" |
| 47 | |
| 48 | #ifdef __cplusplus |
| 49 | } |
| 50 | #endif |
| 51 | |
| 52 | |
| 53 | /* |
| 54 | * EGPRS coding limits |
| 55 | */ |
| 56 | |
| 57 | /* Max header size with parity bits */ |
| 58 | #define EGPRS_HDR_UPP_MAX 54 |
| 59 | |
| 60 | /* Max encoded header size */ |
| 61 | #define EGPRS_HDR_C_MAX 162 |
| 62 | |
| 63 | /* Max punctured header size */ |
| 64 | #define EGPRS_HDR_HC_MAX 160 |
| 65 | |
| 66 | /* Max data block size with parity bits */ |
| 67 | #define EGPRS_DATA_U_MAX 612 |
| 68 | |
| 69 | /* Max encoded data block size */ |
| 70 | #define EGPRS_DATA_C_MAX 1836 |
| 71 | |
| 72 | /* Max single block punctured data size */ |
| 73 | #define EGPRS_DATA_DC_MAX 1248 |
| 74 | |
| 75 | /* Dual block punctured data size */ |
| 76 | #define EGPRS_DATA_C1 612 |
| 77 | #define EGPRS_DATA_C2 EGPRS_DATA_C1 |
| 78 | |
| 79 | /* TS 101318 Chapter 5.1: 260 bits + 4bit sig */ |
| 80 | #define GSM_FR_BYTES 33 |
| 81 | /* TS 101318 Chapter 5.2: 112 bits, no sig */ |
| 82 | #define GSM_HR_BYTES 14 |
| 83 | /* TS 101318 Chapter 5.3: 244 bits + 4bit sig */ |
| 84 | #define GSM_EFR_BYTES 31 |
| 85 | |
| 86 | struct gsm0503_mcs_code { |
| 87 | uint8_t mcs; |
| 88 | uint8_t usf_len; |
| 89 | |
| 90 | /* Header coding */ |
| 91 | uint8_t hdr_len; |
| 92 | uint8_t hdr_code_len; |
| 93 | uint8_t hdr_punc_len; |
| 94 | const struct osmo_conv_code *hdr_conv; |
| 95 | const uint8_t *hdr_punc; |
| 96 | |
| 97 | /* Data coding */ |
| 98 | uint16_t data_len; |
| 99 | uint16_t data_code_len; |
| 100 | uint16_t data_punc_len; |
| 101 | const struct osmo_conv_code *data_conv; |
| 102 | const uint8_t *data_punc[3]; |
| 103 | }; |
| 104 | |
| 105 | static int osmo_conv_decode_ber(const struct osmo_conv_code *code, |
| 106 | const sbit_t *input, ubit_t *output, |
| 107 | int *n_errors, int *n_bits_total) |
| 108 | { |
| 109 | int res, i, coded_len; |
| 110 | ubit_t recoded[EGPRS_DATA_C_MAX]; |
| 111 | |
| 112 | res = osmo_conv_decode(code, input, output); |
| 113 | |
| 114 | if (n_bits_total || n_errors) { |
| 115 | coded_len = osmo_conv_encode(code, output, recoded); |
| 116 | OSMO_ASSERT(sizeof(recoded) / sizeof(recoded[0]) >= coded_len); |
| 117 | } |
| 118 | |
| 119 | /* Count bit errors */ |
| 120 | if (n_errors) { |
| 121 | *n_errors = 0; |
| 122 | for (i = 0; i < coded_len; i++) { |
| 123 | if (!((recoded[i] && input[i] < 0) || |
| 124 | (!recoded[i] && input[i] > 0)) ) |
| 125 | *n_errors += 1; |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | if (n_bits_total) |
| 130 | *n_bits_total = coded_len; |
| 131 | |
| 132 | return res; |
| 133 | } |
| 134 | |
| 135 | static int _xcch_decode_cB(uint8_t *l2_data, sbit_t *cB, |
| 136 | int *n_errors, int *n_bits_total) |
| 137 | { |
| 138 | ubit_t conv[224]; |
| 139 | int rv; |
| 140 | |
| 141 | osmo_conv_decode_ber(&gsm0503_xcch, cB, |
| 142 | conv, n_errors, n_bits_total); |
| 143 | |
| 144 | rv = osmo_crc64gen_check_bits(&gsm0503_fire_crc40, |
| 145 | conv, 184, conv + 184); |
| 146 | if (rv) |
| 147 | return -1; |
| 148 | |
| 149 | osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 184, 1); |
| 150 | |
| 151 | return 0; |
| 152 | } |
| 153 | |
| 154 | static int _xcch_encode_cB(ubit_t *cB, uint8_t *l2_data) |
| 155 | { |
| 156 | ubit_t conv[224]; |
| 157 | |
| 158 | osmo_pbit2ubit_ext(conv, 0, l2_data, 0, 184, 1); |
| 159 | |
| 160 | osmo_crc64gen_set_bits(&gsm0503_fire_crc40, conv, 184, conv + 184); |
| 161 | |
| 162 | osmo_conv_encode(&gsm0503_xcch, conv, cB); |
| 163 | |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | /* |
| 168 | * GSM xCCH block transcoding |
| 169 | */ |
| 170 | int gsm0503_xcch_decode(uint8_t *l2_data, sbit_t *bursts, |
| 171 | int *n_errors, int *n_bits_total) |
| 172 | { |
| 173 | sbit_t iB[456], cB[456]; |
| 174 | int i; |
| 175 | |
| 176 | for (i = 0; i < 4; i++) |
| 177 | gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, NULL); |
| 178 | |
| 179 | gsm0503_xcch_deinterleave(cB, iB); |
| 180 | |
| 181 | return _xcch_decode_cB(l2_data, cB, n_errors, n_bits_total); |
| 182 | } |
| 183 | |
| 184 | int gsm0503_xcch_encode(ubit_t *bursts, uint8_t *l2_data) |
| 185 | { |
| 186 | ubit_t iB[456], cB[456], hl = 1, hn = 1; |
| 187 | int i; |
| 188 | |
| 189 | _xcch_encode_cB(cB, l2_data); |
| 190 | |
| 191 | gsm0503_xcch_interleave(cB, iB); |
| 192 | |
| 193 | for (i = 0; i < 4; i++) |
| 194 | gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], &hl, &hn); |
| 195 | |
| 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | |
| 200 | |
| 201 | /* |
| 202 | * GSM PDTCH block transcoding |
| 203 | */ |
| 204 | |
| 205 | int gsm0503_pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p, |
| 206 | int *n_errors, int *n_bits_total) |
| 207 | { |
| 208 | sbit_t iB[456], cB[676], hl_hn[8]; |
| 209 | ubit_t conv[456]; |
| 210 | int i, j, k, rv, best = 0, cs = 0, usf = 0; /* make GCC happy */ |
| 211 | |
| 212 | for (i = 0; i < 4; i++) |
| 213 | gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], |
| 214 | hl_hn + i * 2, hl_hn + i * 2 + 1); |
| 215 | |
| 216 | for (i = 0; i < 4; i++) { |
| 217 | for (j = 0, k = 0; j < 8; j++) |
| 218 | k += abs(((int)gsm0503_pdtch_hl_hn_sbit[i][j]) - ((int)hl_hn[j])); |
| 219 | |
| 220 | if (i == 0 || k < best) { |
| 221 | best = k; |
| 222 | cs = i+1; |
| 223 | } |
| 224 | } |
| 225 | |
| 226 | gsm0503_xcch_deinterleave(cB, iB); |
| 227 | |
| 228 | switch (cs) { |
| 229 | case 1: |
| 230 | osmo_conv_decode_ber(&gsm0503_xcch, cB, |
| 231 | conv, n_errors, n_bits_total); |
| 232 | |
| 233 | rv = osmo_crc64gen_check_bits(&gsm0503_fire_crc40, |
| 234 | conv, 184, conv + 184); |
| 235 | if (rv) |
| 236 | return -1; |
| 237 | |
| 238 | osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 184, 1); |
| 239 | |
| 240 | return 23; |
| 241 | case 2: |
| 242 | for (i = 587, j = 455; i >= 0; i--) { |
| 243 | if (!gsm0503_puncture_cs2[i]) |
| 244 | cB[i] = cB[j--]; |
| 245 | else |
| 246 | cB[i] = 0; |
| 247 | } |
| 248 | |
| 249 | osmo_conv_decode_ber(&gsm0503_cs2, cB, |
| 250 | conv, n_errors, n_bits_total); |
| 251 | |
| 252 | for (i = 0; i < 8; i++) { |
| 253 | for (j = 0, k = 0; j < 6; j++) |
| 254 | k += abs(((int)gsm0503_usf2six[i][j]) - ((int)conv[j])); |
| 255 | |
| 256 | if (i == 0 || k < best) { |
| 257 | best = k; |
| 258 | usf = i; |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | conv[3] = usf & 1; |
| 263 | conv[4] = (usf >> 1) & 1; |
| 264 | conv[5] = (usf >> 2) & 1; |
| 265 | if (usf_p) |
| 266 | *usf_p = usf; |
| 267 | |
| 268 | rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, |
| 269 | conv + 3, 271, conv + 3 + 271); |
| 270 | if (rv) |
| 271 | return -1; |
| 272 | |
| 273 | osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 271, 1); |
| 274 | |
| 275 | return 34; |
| 276 | case 3: |
| 277 | for (i = 675, j = 455; i >= 0; i--) { |
| 278 | if (!gsm0503_puncture_cs3[i]) |
| 279 | cB[i] = cB[j--]; |
| 280 | else |
| 281 | cB[i] = 0; |
| 282 | } |
| 283 | |
| 284 | osmo_conv_decode_ber(&gsm0503_cs3, cB, |
| 285 | conv, n_errors, n_bits_total); |
| 286 | |
| 287 | for (i = 0; i < 8; i++) { |
| 288 | for (j = 0, k = 0; j < 6; j++) |
| 289 | k += abs(((int)gsm0503_usf2six[i][j]) - ((int)conv[j])); |
| 290 | |
| 291 | if (i == 0 || k < best) { |
| 292 | best = k; |
| 293 | usf = i; |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | conv[3] = usf & 1; |
| 298 | conv[4] = (usf >> 1) & 1; |
| 299 | conv[5] = (usf >> 2) & 1; |
| 300 | if (usf_p) |
| 301 | *usf_p = usf; |
| 302 | |
| 303 | rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, |
| 304 | conv + 3, 315, conv + 3 + 315); |
| 305 | if (rv) |
| 306 | return -1; |
| 307 | |
| 308 | osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 315, 1); |
| 309 | |
| 310 | return 40; |
| 311 | case 4: |
| 312 | for (i = 12; i < 456; i++) |
| 313 | conv[i] = (cB[i] < 0) ? 1 : 0; |
| 314 | |
| 315 | for (i = 0; i < 8; i++) { |
| 316 | for (j = 0, k = 0; j < 12; j++) |
| 317 | k += abs(((int)gsm0503_usf2twelve_sbit[i][j]) - ((int)cB[j])); |
| 318 | |
| 319 | if (i == 0 || k < best) { |
| 320 | best = k; |
| 321 | usf = i; |
| 322 | } |
| 323 | } |
| 324 | |
| 325 | conv[9] = usf & 1; |
| 326 | conv[10] = (usf >> 1) & 1; |
| 327 | conv[11] = (usf >> 2) & 1; |
| 328 | if (usf_p) |
| 329 | *usf_p = usf; |
| 330 | |
| 331 | rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, |
| 332 | conv + 9, 431, conv + 9 + 431); |
| 333 | if (rv) { |
| 334 | *n_bits_total = 456 - 12; |
| 335 | *n_errors = *n_bits_total; |
| 336 | return -1; |
| 337 | } |
| 338 | |
| 339 | *n_bits_total = 456 - 12; |
| 340 | *n_errors = 0; |
| 341 | |
| 342 | osmo_ubit2pbit_ext(l2_data, 0, conv, 9, 431, 1); |
| 343 | |
| 344 | return 54; |
| 345 | default: |
| 346 | *n_bits_total = 0; |
| 347 | *n_errors = 0; |
| 348 | break; |
| 349 | } |
| 350 | |
| 351 | return -1; |
| 352 | } |
| 353 | |
| 354 | int gsm0503_pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len) |
| 355 | { |
| 356 | ubit_t iB[456], cB[676]; |
| 357 | const ubit_t *hl_hn; |
| 358 | ubit_t conv[334]; |
| 359 | int i, j, usf; |
| 360 | |
| 361 | switch (l2_len) { |
| 362 | case 23: |
| 363 | osmo_pbit2ubit_ext(conv, 0, l2_data, 0, 184, 1); |
| 364 | |
| 365 | osmo_crc64gen_set_bits(&gsm0503_fire_crc40, conv, 184, conv + 184); |
| 366 | |
| 367 | osmo_conv_encode(&gsm0503_xcch, conv, cB); |
| 368 | |
| 369 | hl_hn = gsm0503_pdtch_hl_hn_ubit[0]; |
| 370 | |
| 371 | break; |
| 372 | case 34: |
| 373 | osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 271, 1); |
| 374 | usf = l2_data[0] & 0x7; |
| 375 | |
| 376 | osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, conv + 3, |
| 377 | 271, conv + 3 + 271); |
| 378 | |
| 379 | memcpy(conv, gsm0503_usf2six[usf], 6); |
| 380 | |
| 381 | osmo_conv_encode(&gsm0503_cs2, conv, cB); |
| 382 | |
| 383 | for (i = 0, j = 0; i < 588; i++) |
| 384 | if (!gsm0503_puncture_cs2[i]) |
| 385 | cB[j++] = cB[i]; |
| 386 | |
| 387 | hl_hn = gsm0503_pdtch_hl_hn_ubit[1]; |
| 388 | |
| 389 | break; |
| 390 | case 40: |
| 391 | osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 315, 1); |
| 392 | usf = l2_data[0] & 0x7; |
| 393 | |
| 394 | osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, conv + 3, |
| 395 | 315, conv + 3 + 315); |
| 396 | |
| 397 | memcpy(conv, gsm0503_usf2six[usf], 6); |
| 398 | |
| 399 | osmo_conv_encode(&gsm0503_cs3, conv, cB); |
| 400 | |
| 401 | for (i = 0, j = 0; i < 676; i++) |
| 402 | if (!gsm0503_puncture_cs3[i]) |
| 403 | cB[j++] = cB[i]; |
| 404 | |
| 405 | hl_hn = gsm0503_pdtch_hl_hn_ubit[2]; |
| 406 | |
| 407 | break; |
| 408 | case 54: |
| 409 | osmo_pbit2ubit_ext(cB, 9, l2_data, 0, 431, 1); |
| 410 | usf = l2_data[0] & 0x7; |
| 411 | |
| 412 | osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, cB + 9, |
| 413 | 431, cB + 9 + 431); |
| 414 | |
| 415 | memcpy(cB, gsm0503_usf2twelve_ubit[usf], 12); |
| 416 | |
| 417 | hl_hn = gsm0503_pdtch_hl_hn_ubit[3]; |
| 418 | |
| 419 | break; |
| 420 | default: |
| 421 | return -1; |
| 422 | } |
| 423 | |
| 424 | gsm0503_xcch_interleave(cB, iB); |
| 425 | |
| 426 | for (i = 0; i < 4; i++) { |
| 427 | gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], |
| 428 | hl_hn + i * 2, hl_hn + i * 2 + 1); |
| 429 | } |
| 430 | |
| 431 | return GSM0503_GPRS_BURSTS_NBITS; |
| 432 | } |
| 433 | |
| 434 | /* |
| 435 | * GSM TCH/F FR/EFR transcoding |
| 436 | */ |
| 437 | |
| 438 | static void tch_fr_reassemble(uint8_t *tch_data, |
| 439 | ubit_t *b_bits, int net_order) |
| 440 | { |
| 441 | int i, j, k, l, o; |
| 442 | |
| 443 | tch_data[0] = 0xd << 4; |
| 444 | memset(tch_data + 1, 0, 32); |
| 445 | |
| 446 | if (net_order) { |
| 447 | for (i = 0, j = 4; i < 260; i++, j++) |
| 448 | tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7))); |
| 449 | |
| 450 | return; |
| 451 | } |
| 452 | |
| 453 | /* reassemble d-bits */ |
| 454 | i = 0; /* counts bits */ |
| 455 | j = 4; /* counts output bits */ |
| 456 | k = gsm0503_gsm_fr_map[0]-1; /* current number bit in element */ |
| 457 | l = 0; /* counts element bits */ |
| 458 | o = 0; /* offset input bits */ |
| 459 | while (i < 260) { |
| 460 | tch_data[j >> 3] |= (b_bits[k + o] << (7 - (j & 7))); |
| 461 | if (--k < 0) { |
| 462 | o += gsm0503_gsm_fr_map[l]; |
| 463 | k = gsm0503_gsm_fr_map[++l]-1; |
| 464 | } |
| 465 | i++; |
| 466 | j++; |
| 467 | } |
| 468 | } |
| 469 | |
| 470 | static void tch_fr_disassemble(ubit_t *b_bits, |
| 471 | uint8_t *tch_data, int net_order) |
| 472 | { |
| 473 | int i, j, k, l, o; |
| 474 | |
| 475 | if (net_order) { |
| 476 | for (i = 0, j = 4; i < 260; i++, j++) |
| 477 | b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| 478 | |
| 479 | return; |
| 480 | } |
| 481 | |
| 482 | i = 0; /* counts bits */ |
| 483 | j = 4; /* counts input bits */ |
| 484 | k = gsm0503_gsm_fr_map[0] - 1; /* current number bit in element */ |
| 485 | l = 0; /* counts element bits */ |
| 486 | o = 0; /* offset output bits */ |
| 487 | while (i < 260) { |
| 488 | b_bits[k + o] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| 489 | if (--k < 0) { |
| 490 | o += gsm0503_gsm_fr_map[l]; |
| 491 | k = gsm0503_gsm_fr_map[++l] - 1; |
| 492 | } |
| 493 | i++; |
| 494 | j++; |
| 495 | } |
| 496 | } |
| 497 | |
| 498 | static void tch_hr_reassemble(uint8_t *tch_data, ubit_t *b_bits) |
| 499 | { |
| 500 | int i, j; |
| 501 | |
| 502 | tch_data[0] = 0x00; /* F = 0, FT = 000 */ |
| 503 | memset(tch_data + 1, 0, 14); |
| 504 | |
| 505 | for (i = 0, j = 8; i < 112; i++, j++) |
| 506 | tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7))); |
| 507 | } |
| 508 | |
| 509 | static void tch_hr_disassemble(ubit_t *b_bits, uint8_t *tch_data) |
| 510 | { |
| 511 | int i, j; |
| 512 | |
| 513 | for (i = 0, j = 8; i < 112; i++, j++) |
| 514 | b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| 515 | } |
| 516 | |
| 517 | static void tch_efr_reassemble(uint8_t *tch_data, ubit_t *b_bits) |
| 518 | { |
| 519 | int i, j; |
| 520 | |
| 521 | tch_data[0] = 0xc << 4; |
| 522 | memset(tch_data + 1, 0, 30); |
| 523 | |
| 524 | for (i = 0, j = 4; i < 244; i++, j++) |
| 525 | tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7))); |
| 526 | } |
| 527 | |
| 528 | static void tch_efr_disassemble(ubit_t *b_bits, uint8_t *tch_data) |
| 529 | { |
| 530 | int i, j; |
| 531 | |
| 532 | for (i = 0, j = 4; i < 244; i++, j++) |
| 533 | b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| 534 | } |
| 535 | |
| 536 | static void tch_amr_reassemble(uint8_t *tch_data, ubit_t *d_bits, int len) |
| 537 | { |
| 538 | int i, j; |
| 539 | |
| 540 | memset(tch_data, 0, (len + 7) >> 3); |
| 541 | |
| 542 | for (i = 0, j = 0; i < len; i++, j++) |
| 543 | tch_data[j >> 3] |= (d_bits[i] << (7 - (j & 7))); |
| 544 | } |
| 545 | |
| 546 | static void tch_amr_disassemble(ubit_t *d_bits, uint8_t *tch_data, int len) |
| 547 | { |
| 548 | int i, j; |
| 549 | |
| 550 | for (i = 0, j = 0; i < len; i++, j++) |
| 551 | d_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| 552 | } |
| 553 | |
| 554 | static void tch_fr_d_to_b(ubit_t *b_bits, ubit_t *d_bits) |
| 555 | { |
| 556 | int i; |
| 557 | |
| 558 | for (i = 0; i < 260; i++) |
| 559 | b_bits[gsm610_bitorder[i]] = d_bits[i]; |
| 560 | } |
| 561 | |
| 562 | static void tch_fr_b_to_d(ubit_t *d_bits, ubit_t *b_bits) |
| 563 | { |
| 564 | int i; |
| 565 | |
| 566 | for (i = 0; i < 260; i++) |
| 567 | d_bits[i] = b_bits[gsm610_bitorder[i]]; |
| 568 | } |
| 569 | |
| 570 | static void tch_hr_d_to_b(ubit_t *b_bits, ubit_t *d_bits) |
| 571 | { |
| 572 | int i; |
| 573 | |
| 574 | const uint16_t *map; |
| 575 | |
| 576 | if (!d_bits[93] && !d_bits[94]) |
| 577 | map = gsm620_unvoiced_bitorder; |
| 578 | else |
| 579 | map = gsm620_voiced_bitorder; |
| 580 | |
| 581 | for (i = 0; i < 112; i++) |
| 582 | b_bits[map[i]] = d_bits[i]; |
| 583 | } |
| 584 | |
| 585 | static void tch_hr_b_to_d(ubit_t *d_bits, ubit_t *b_bits) |
| 586 | { |
| 587 | int i; |
| 588 | const uint16_t *map; |
| 589 | |
| 590 | if (!b_bits[34] && !b_bits[35]) |
| 591 | map = gsm620_unvoiced_bitorder; |
| 592 | else |
| 593 | map = gsm620_voiced_bitorder; |
| 594 | |
| 595 | for (i = 0; i < 112; i++) |
| 596 | d_bits[i] = b_bits[map[i]]; |
| 597 | } |
| 598 | |
| 599 | static void tch_efr_d_to_w(ubit_t *b_bits, ubit_t *d_bits) |
| 600 | { |
| 601 | int i; |
| 602 | |
| 603 | for (i = 0; i < 260; i++) |
| 604 | b_bits[gsm660_bitorder[i]] = d_bits[i]; |
| 605 | } |
| 606 | |
| 607 | static void tch_efr_w_to_d(ubit_t *d_bits, ubit_t *b_bits) |
| 608 | { |
| 609 | int i; |
| 610 | |
| 611 | for (i = 0; i < 260; i++) |
| 612 | d_bits[i] = b_bits[gsm660_bitorder[i]]; |
| 613 | } |
| 614 | |
| 615 | static void tch_efr_protected(ubit_t *s_bits, ubit_t *b_bits) |
| 616 | { |
| 617 | int i; |
| 618 | |
| 619 | for (i = 0; i < 65; i++) |
| 620 | b_bits[i] = s_bits[gsm0503_gsm_efr_protected_bits[i] - 1]; |
| 621 | } |
| 622 | |
| 623 | static void tch_fr_unreorder(ubit_t *d, ubit_t *p, ubit_t *u) |
| 624 | { |
| 625 | int i; |
| 626 | |
| 627 | for (i = 0; i < 91; i++) { |
| 628 | d[i << 1] = u[i]; |
| 629 | d[(i << 1) + 1] = u[184 - i]; |
| 630 | } |
| 631 | |
| 632 | for (i = 0; i < 3; i++) |
| 633 | p[i] = u[91 + i]; |
| 634 | } |
| 635 | |
| 636 | static void tch_fr_reorder(ubit_t *u, ubit_t *d, ubit_t *p) |
| 637 | { |
| 638 | int i; |
| 639 | |
| 640 | for (i = 0; i < 91; i++) { |
| 641 | u[i] = d[i << 1]; |
| 642 | u[184 - i] = d[(i << 1) + 1]; |
| 643 | } |
| 644 | |
| 645 | for (i = 0; i < 3; i++) |
| 646 | u[91 + i] = p[i]; |
| 647 | } |
| 648 | |
| 649 | static void tch_hr_unreorder(ubit_t *d, ubit_t *p, ubit_t *u) |
| 650 | { |
| 651 | memcpy(d, u, 95); |
| 652 | memcpy(p, u + 95, 3); |
| 653 | } |
| 654 | |
| 655 | static void tch_hr_reorder(ubit_t *u, ubit_t *d, ubit_t *p) |
| 656 | { |
| 657 | memcpy(u, d, 95); |
| 658 | memcpy(u + 95, p, 3); |
| 659 | } |
| 660 | |
| 661 | static void tch_efr_reorder(ubit_t *w, ubit_t *s, ubit_t *p) |
| 662 | { |
| 663 | memcpy(w, s, 71); |
| 664 | w[71] = w[72] = s[69]; |
| 665 | memcpy(w + 73, s + 71, 50); |
| 666 | w[123] = w[124] = s[119]; |
| 667 | memcpy(w + 125, s + 121, 53); |
| 668 | w[178] = w[179] = s[172]; |
| 669 | memcpy(w + 180, s + 174, 50); |
| 670 | w[230] = w[231] = s[222]; |
| 671 | memcpy(w + 232, s + 224, 20); |
| 672 | memcpy(w + 252, p, 8); |
| 673 | } |
| 674 | |
| 675 | static void tch_efr_unreorder(ubit_t *s, ubit_t *p, ubit_t *w) |
| 676 | { |
| 677 | int sum; |
| 678 | |
| 679 | memcpy(s, w, 71); |
| 680 | sum = s[69] + w[71] + w[72]; |
| 681 | s[69] = (sum > 2); |
| 682 | memcpy(s + 71, w + 73, 50); |
| 683 | sum = s[119] + w[123] + w[124]; |
| 684 | s[119] = (sum > 2); |
| 685 | memcpy(s + 121, w + 125, 53); |
| 686 | sum = s[172] + w[178] + w[179]; |
| 687 | s[172] = (sum > 2); |
| 688 | memcpy(s + 174, w + 180, 50); |
| 689 | sum = s[220] + w[230] + w[231]; |
| 690 | s[222] = (sum > 2); |
| 691 | memcpy(s + 224, w + 232, 20); |
| 692 | memcpy(p, w + 252, 8); |
| 693 | } |
| 694 | |
| 695 | static void tch_amr_merge(ubit_t *u, ubit_t *d, ubit_t *p, int len, int prot) |
| 696 | { |
| 697 | memcpy(u, d, prot); |
| 698 | memcpy(u + prot, p, 6); |
| 699 | memcpy(u + prot + 6, d + prot, len - prot); |
| 700 | } |
| 701 | |
| 702 | static void tch_amr_unmerge(ubit_t *d, ubit_t *p, |
| 703 | ubit_t *u, int len, int prot) |
| 704 | { |
| 705 | memcpy(d, u, prot); |
| 706 | memcpy(p, u+prot, 6); |
| 707 | memcpy(d + prot, u + prot + 6, len - prot); |
| 708 | } |
| 709 | |
| 710 | int gsm0503_tch_fr_decode(uint8_t *tch_data, sbit_t *bursts, |
| 711 | int net_order, int efr, int *n_errors, int *n_bits_total) |
| 712 | { |
| 713 | sbit_t iB[912], cB[456], h; |
| 714 | ubit_t conv[185], s[244], w[260], b[65], d[260], p[8]; |
| 715 | int i, rv, len, steal = 0; |
| 716 | |
| 717 | for (i=0; i<8; i++) { |
| 718 | gsm0503_tch_burst_unmap(&iB[i * 114], |
| 719 | &bursts[i * 116], &h, i >> 2); |
| 720 | steal -= h; |
| 721 | } |
| 722 | |
| 723 | gsm0503_tch_fr_deinterleave(cB, iB); |
| 724 | |
| 725 | if (steal > 0) { |
| 726 | rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); |
| 727 | if (rv) { |
| 728 | /* Error decoding FACCH frame */ |
| 729 | return -1; |
| 730 | } |
| 731 | |
| 732 | return 23; |
| 733 | } |
| 734 | |
| 735 | osmo_conv_decode_ber(&gsm0503_tch_fr, cB, conv, n_errors, n_bits_total); |
| 736 | |
| 737 | tch_fr_unreorder(d, p, conv); |
| 738 | |
| 739 | for (i = 0; i < 78; i++) |
| 740 | d[i + 182] = (cB[i + 378] < 0) ? 1 : 0; |
| 741 | |
| 742 | rv = osmo_crc8gen_check_bits(&gsm0503_tch_fr_crc3, d, 50, p); |
| 743 | if (rv) { |
| 744 | /* Error checking CRC8 for the FR part of an EFR/FR frame */ |
| 745 | return -1; |
| 746 | } |
| 747 | |
| 748 | if (efr) { |
| 749 | tch_efr_d_to_w(w, d); |
| 750 | |
| 751 | tch_efr_unreorder(s, p, w); |
| 752 | |
| 753 | tch_efr_protected(s, b); |
| 754 | |
| 755 | rv = osmo_crc8gen_check_bits(&gsm0503_tch_efr_crc8, b, 65, p); |
| 756 | if (rv) { |
| 757 | /* Error checking CRC8 for the EFR part of an EFR frame */ |
| 758 | return -1; |
| 759 | } |
| 760 | |
| 761 | tch_efr_reassemble(tch_data, s); |
| 762 | |
| 763 | len = GSM_EFR_BYTES; |
| 764 | } else { |
| 765 | tch_fr_d_to_b(w, d); |
| 766 | |
| 767 | tch_fr_reassemble(tch_data, w, net_order); |
| 768 | |
| 769 | len = GSM_FR_BYTES; |
| 770 | } |
| 771 | |
| 772 | return len; |
| 773 | } |
| 774 | |
| 775 | int gsm0503_tch_fr_encode(ubit_t *bursts, uint8_t *tch_data, |
| 776 | int len, int net_order) |
| 777 | { |
| 778 | ubit_t iB[912], cB[456], h; |
| 779 | ubit_t conv[185], w[260], b[65], s[244], d[260], p[8]; |
| 780 | int i; |
| 781 | |
| 782 | switch (len) { |
| 783 | case GSM_EFR_BYTES: /* TCH EFR */ |
| 784 | |
| 785 | tch_efr_disassemble(s, tch_data); |
| 786 | |
| 787 | tch_efr_protected(s, b); |
| 788 | |
| 789 | osmo_crc8gen_set_bits(&gsm0503_tch_efr_crc8, b, 65, p); |
| 790 | |
| 791 | tch_efr_reorder(w, s, p); |
| 792 | |
| 793 | tch_efr_w_to_d(d, w); |
| 794 | |
| 795 | goto coding_efr_fr; |
| 796 | case GSM_FR_BYTES: /* TCH FR */ |
| 797 | tch_fr_disassemble(w, tch_data, net_order); |
| 798 | |
| 799 | tch_fr_b_to_d(d, w); |
| 800 | |
| 801 | coding_efr_fr: |
| 802 | osmo_crc8gen_set_bits(&gsm0503_tch_fr_crc3, d, 50, p); |
| 803 | |
| 804 | tch_fr_reorder(conv, d, p); |
| 805 | |
| 806 | memcpy(cB + 378, d + 182, 78); |
| 807 | |
| 808 | osmo_conv_encode(&gsm0503_tch_fr, conv, cB); |
| 809 | |
| 810 | h = 0; |
| 811 | |
| 812 | break; |
| 813 | case GSM_MACBLOCK_LEN: /* FACCH */ |
| 814 | _xcch_encode_cB(cB, tch_data); |
| 815 | |
| 816 | h = 1; |
| 817 | |
| 818 | break; |
| 819 | default: |
| 820 | return -1; |
| 821 | } |
| 822 | |
| 823 | gsm0503_tch_fr_interleave(cB, iB); |
| 824 | |
| 825 | for (i = 0; i < 8; i++) { |
| 826 | gsm0503_tch_burst_map(&iB[i * 114], |
| 827 | &bursts[i * 116], &h, i >> 2); |
| 828 | } |
| 829 | |
| 830 | return 0; |
| 831 | } |
| 832 | |
| 833 | int gsm0503_tch_hr_decode(uint8_t *tch_data, sbit_t *bursts, int odd, |
| 834 | int *n_errors, int *n_bits_total) |
| 835 | { |
| 836 | sbit_t iB[912], cB[456], h; |
| 837 | ubit_t conv[98], b[112], d[112], p[3]; |
| 838 | int i, rv, steal = 0; |
| 839 | |
| 840 | /* Only unmap the stealing bits */ |
| 841 | if (!odd) { |
| 842 | for (i = 0; i < 4; i++) { |
| 843 | gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 0); |
| 844 | steal -= h; |
| 845 | } |
| 846 | |
| 847 | for (i = 2; i < 5; i++) { |
| 848 | gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 1); |
| 849 | steal -= h; |
| 850 | } |
| 851 | } |
| 852 | |
| 853 | /* If we found a stole FACCH, but only at correct alignment */ |
| 854 | if (steal > 0) { |
| 855 | for (i = 0; i < 6; i++) { |
| 856 | gsm0503_tch_burst_unmap(&iB[i * 114], |
| 857 | &bursts[i * 116], NULL, i >> 2); |
| 858 | } |
| 859 | |
| 860 | for (i = 2; i < 4; i++) { |
| 861 | gsm0503_tch_burst_unmap(&iB[i * 114 + 456], |
| 862 | &bursts[i * 116], NULL, 1); |
| 863 | } |
| 864 | |
| 865 | gsm0503_tch_fr_deinterleave(cB, iB); |
| 866 | |
| 867 | rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); |
| 868 | if (rv) { |
| 869 | /* Error decoding FACCH frame */ |
| 870 | return -1; |
| 871 | } |
| 872 | |
| 873 | return GSM_MACBLOCK_LEN; |
| 874 | } |
| 875 | |
| 876 | for (i = 0; i < 4; i++) { |
| 877 | gsm0503_tch_burst_unmap(&iB[i * 114], |
| 878 | &bursts[i * 116], NULL, i >> 1); |
| 879 | } |
| 880 | |
| 881 | gsm0503_tch_hr_deinterleave(cB, iB); |
| 882 | |
| 883 | osmo_conv_decode_ber(&gsm0503_tch_hr, cB, conv, n_errors, n_bits_total); |
| 884 | |
| 885 | tch_hr_unreorder(d, p, conv); |
| 886 | |
| 887 | for (i = 0; i < 17; i++) |
| 888 | d[i + 95] = (cB[i + 211] < 0) ? 1 : 0; |
| 889 | |
| 890 | rv = osmo_crc8gen_check_bits(&gsm0503_tch_fr_crc3, d + 73, 22, p); |
| 891 | if (rv) { |
| 892 | /* Error checking CRC8 for an HR frame */ |
| 893 | return -1; |
| 894 | } |
| 895 | |
| 896 | tch_hr_d_to_b(b, d); |
| 897 | |
| 898 | tch_hr_reassemble(tch_data, b); |
| 899 | |
| 900 | return 15; |
| 901 | } |
| 902 | |
| 903 | int gsm0503_tch_hr_encode(ubit_t *bursts, uint8_t *tch_data, int len) |
| 904 | { |
| 905 | ubit_t iB[912], cB[456], h; |
| 906 | ubit_t conv[98], b[112], d[112], p[3]; |
| 907 | int i; |
| 908 | |
| 909 | switch (len) { |
| 910 | case 15: /* TCH HR */ |
| 911 | tch_hr_disassemble(b, tch_data); |
| 912 | |
| 913 | tch_hr_b_to_d(d, b); |
| 914 | |
| 915 | osmo_crc8gen_set_bits(&gsm0503_tch_fr_crc3, d + 73, 22, p); |
| 916 | |
| 917 | tch_hr_reorder(conv, d, p); |
| 918 | |
| 919 | osmo_conv_encode(&gsm0503_tch_hr, conv, cB); |
| 920 | |
| 921 | memcpy(cB + 211, d + 95, 17); |
| 922 | |
| 923 | h = 0; |
| 924 | |
| 925 | gsm0503_tch_hr_interleave(cB, iB); |
| 926 | |
| 927 | for (i = 0; i < 4; i++) { |
| 928 | gsm0503_tch_burst_map(&iB[i * 114], |
| 929 | &bursts[i * 116], &h, i >> 1); |
| 930 | } |
| 931 | |
| 932 | break; |
| 933 | case GSM_MACBLOCK_LEN: /* FACCH */ |
| 934 | _xcch_encode_cB(cB, tch_data); |
| 935 | |
| 936 | h = 1; |
| 937 | |
| 938 | gsm0503_tch_fr_interleave(cB, iB); |
| 939 | |
| 940 | for (i=0; i<6; i++) { |
| 941 | gsm0503_tch_burst_map(&iB[i * 114], |
| 942 | &bursts[i * 116], &h, i >> 2); |
| 943 | } |
| 944 | |
| 945 | for (i=2; i<4; i++) { |
| 946 | gsm0503_tch_burst_map(&iB[i * 114 + 456], |
| 947 | &bursts[i * 116], &h, 1); |
| 948 | } |
| 949 | |
| 950 | break; |
| 951 | default: |
| 952 | return -1; |
| 953 | } |
| 954 | |
| 955 | return 0; |
| 956 | } |
| 957 | |
| 958 | int gsm0503_tch_afs_decode(uint8_t *tch_data, sbit_t *bursts, |
| 959 | int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft, |
| 960 | uint8_t *cmr, int *n_errors, int *n_bits_total) |
| 961 | { |
| 962 | sbit_t iB[912], cB[456], h; |
| 963 | ubit_t d[244], p[6], conv[250]; |
| 964 | int i, j, k, best = 0, rv, len, steal = 0, id = 0; |
| 965 | *n_errors = 0; *n_bits_total = 0; |
| 966 | |
| 967 | for (i=0; i<8; i++) { |
| 968 | gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], &h, i >> 2); |
| 969 | steal -= h; |
| 970 | } |
| 971 | |
| 972 | gsm0503_tch_fr_deinterleave(cB, iB); |
| 973 | |
| 974 | if (steal > 0) { |
| 975 | rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); |
| 976 | if (rv) { |
| 977 | /* Error decoding FACCH frame */ |
| 978 | return -1; |
| 979 | } |
| 980 | |
| 981 | return GSM_MACBLOCK_LEN; |
| 982 | } |
| 983 | |
| 984 | for (i = 0; i < 4; i++) { |
| 985 | for (j = 0, k = 0; j < 8; j++) |
| 986 | k += abs(((int)gsm0503_afs_ic_sbit[i][j]) - ((int)cB[j])); |
| 987 | |
| 988 | if (i == 0 || k < best) { |
| 989 | best = k; |
| 990 | id = i; |
| 991 | } |
| 992 | } |
| 993 | |
| 994 | /* Check if indicated codec fits into range of codecs */ |
| 995 | if (id >= codecs) { |
| 996 | /* Codec mode out of range, return id */ |
| 997 | return id; |
| 998 | } |
| 999 | |
| 1000 | switch ((codec_mode_req) ? codec[*ft] : codec[id]) { |
| 1001 | case 7: /* TCH/AFS12.2 */ |
| 1002 | osmo_conv_decode_ber(&gsm0503_tch_afs_12_2, cB + 8, |
| 1003 | conv, n_errors, n_bits_total); |
| 1004 | |
| 1005 | tch_amr_unmerge(d, p, conv, 244, 81); |
| 1006 | |
| 1007 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 81, p); |
| 1008 | if (rv) { |
| 1009 | /* Error checking CRC8 for an AMR 12.2 frame */ |
| 1010 | return -1; |
| 1011 | } |
| 1012 | |
| 1013 | tch_amr_reassemble(tch_data, d, 244); |
| 1014 | |
| 1015 | len = 31; |
| 1016 | |
| 1017 | break; |
| 1018 | case 6: /* TCH/AFS10.2 */ |
| 1019 | osmo_conv_decode_ber(&gsm0503_tch_afs_10_2, cB + 8, |
| 1020 | conv, n_errors, n_bits_total); |
| 1021 | |
| 1022 | tch_amr_unmerge(d, p, conv, 204, 65); |
| 1023 | |
| 1024 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 65, p); |
| 1025 | if (rv) { |
| 1026 | /* Error checking CRC8 for an AMR 10.2 frame */ |
| 1027 | return -1; |
| 1028 | } |
| 1029 | |
| 1030 | tch_amr_reassemble(tch_data, d, 204); |
| 1031 | |
| 1032 | len = 26; |
| 1033 | |
| 1034 | break; |
| 1035 | case 5: /* TCH/AFS7.95 */ |
| 1036 | osmo_conv_decode_ber(&gsm0503_tch_afs_7_95, cB + 8, |
| 1037 | conv, n_errors, n_bits_total); |
| 1038 | |
| 1039 | tch_amr_unmerge(d, p, conv, 159, 75); |
| 1040 | |
| 1041 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 75, p); |
| 1042 | if (rv) { |
| 1043 | /* Error checking CRC8 for an AMR 7.95 frame */ |
| 1044 | return -1; |
| 1045 | } |
| 1046 | |
| 1047 | tch_amr_reassemble(tch_data, d, 159); |
| 1048 | |
| 1049 | len = 20; |
| 1050 | |
| 1051 | break; |
| 1052 | case 4: /* TCH/AFS7.4 */ |
| 1053 | osmo_conv_decode_ber(&gsm0503_tch_afs_7_4, cB + 8, |
| 1054 | conv, n_errors, n_bits_total); |
| 1055 | |
| 1056 | tch_amr_unmerge(d, p, conv, 148, 61); |
| 1057 | |
| 1058 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 61, p); |
| 1059 | if (rv) { |
| 1060 | /* Error checking CRC8 for an AMR 7.4 frame */ |
| 1061 | return -1; |
| 1062 | } |
| 1063 | |
| 1064 | tch_amr_reassemble(tch_data, d, 148); |
| 1065 | |
| 1066 | len = 19; |
| 1067 | |
| 1068 | break; |
| 1069 | case 3: /* TCH/AFS6.7 */ |
| 1070 | osmo_conv_decode_ber(&gsm0503_tch_afs_6_7, cB + 8, |
| 1071 | conv, n_errors, n_bits_total); |
| 1072 | |
| 1073 | tch_amr_unmerge(d, p, conv, 134, 55); |
| 1074 | |
| 1075 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); |
| 1076 | if (rv) { |
| 1077 | /* Error checking CRC8 for an AMR 6.7 frame */ |
| 1078 | return -1; |
| 1079 | } |
| 1080 | |
| 1081 | tch_amr_reassemble(tch_data, d, 134); |
| 1082 | |
| 1083 | len = 17; |
| 1084 | |
| 1085 | break; |
| 1086 | case 2: /* TCH/AFS5.9 */ |
| 1087 | osmo_conv_decode_ber(&gsm0503_tch_afs_5_9, cB + 8, |
| 1088 | conv, n_errors, n_bits_total); |
| 1089 | |
| 1090 | tch_amr_unmerge(d, p, conv, 118, 55); |
| 1091 | |
| 1092 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); |
| 1093 | if (rv) { |
| 1094 | /* Error checking CRC8 for an AMR 5.9 frame */ |
| 1095 | return -1; |
| 1096 | } |
| 1097 | |
| 1098 | tch_amr_reassemble(tch_data, d, 118); |
| 1099 | |
| 1100 | len = 15; |
| 1101 | |
| 1102 | break; |
| 1103 | case 1: /* TCH/AFS5.15 */ |
| 1104 | osmo_conv_decode_ber(&gsm0503_tch_afs_5_15, cB + 8, |
| 1105 | conv, n_errors, n_bits_total); |
| 1106 | |
| 1107 | tch_amr_unmerge(d, p, conv, 103, 49); |
| 1108 | |
| 1109 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 49, p); |
| 1110 | if (rv) { |
| 1111 | /* Error checking CRC8 for an AMR 5.15 frame */ |
| 1112 | return -1; |
| 1113 | } |
| 1114 | |
| 1115 | tch_amr_reassemble(tch_data, d, 103); |
| 1116 | |
| 1117 | len = 13; |
| 1118 | |
| 1119 | break; |
| 1120 | case 0: /* TCH/AFS4.75 */ |
| 1121 | osmo_conv_decode_ber(&gsm0503_tch_afs_4_75, cB + 8, |
| 1122 | conv, n_errors, n_bits_total); |
| 1123 | |
| 1124 | tch_amr_unmerge(d, p, conv, 95, 39); |
| 1125 | |
| 1126 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 39, p); |
| 1127 | if (rv) { |
| 1128 | /* Error checking CRC8 for an AMR 4.75 frame */ |
| 1129 | return -1; |
| 1130 | } |
| 1131 | |
| 1132 | tch_amr_reassemble(tch_data, d, 95); |
| 1133 | |
| 1134 | len = 12; |
| 1135 | |
| 1136 | break; |
| 1137 | default: |
| 1138 | /* Unknown frame type */ |
| 1139 | *n_bits_total = 448; |
| 1140 | *n_errors = *n_bits_total; |
| 1141 | return -1; |
| 1142 | } |
| 1143 | |
| 1144 | /* Change codec request / indication, if frame is valid */ |
| 1145 | if (codec_mode_req) |
| 1146 | *cmr = id; |
| 1147 | else |
| 1148 | *ft = id; |
| 1149 | |
| 1150 | return len; |
| 1151 | } |
| 1152 | |
| 1153 | int gsm0503_tch_afs_encode(ubit_t *bursts, uint8_t *tch_data, int len, |
| 1154 | int codec_mode_req, uint8_t *codec, int codecs, uint8_t ft, |
| 1155 | uint8_t cmr) |
| 1156 | { |
| 1157 | ubit_t iB[912], cB[456], h; |
| 1158 | ubit_t d[244], p[6], conv[250]; |
| 1159 | int i; |
| 1160 | uint8_t id; |
| 1161 | |
| 1162 | if (len == GSM_MACBLOCK_LEN) { /* FACCH */ |
| 1163 | _xcch_encode_cB(cB, tch_data); |
| 1164 | |
| 1165 | h = 1; |
| 1166 | |
| 1167 | goto facch; |
| 1168 | } |
| 1169 | |
| 1170 | h = 0; |
| 1171 | |
| 1172 | if (codec_mode_req) { |
| 1173 | if (cmr >= codecs) { |
| 1174 | /* FIXME: CMR ID is not in codec list! */ |
| 1175 | return -1; |
| 1176 | } |
| 1177 | id = cmr; |
| 1178 | } else { |
| 1179 | if (ft >= codecs) { |
| 1180 | /* FIXME: FT ID is not in codec list! */ |
| 1181 | return -1; |
| 1182 | } |
| 1183 | id = ft; |
| 1184 | } |
| 1185 | |
| 1186 | switch (codec[ft]) { |
| 1187 | case 7: /* TCH/AFS12.2 */ |
| 1188 | if (len != 31) |
| 1189 | goto invalid_length; |
| 1190 | |
| 1191 | tch_amr_disassemble(d, tch_data, 244); |
| 1192 | |
| 1193 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 81, p); |
| 1194 | |
| 1195 | tch_amr_merge(conv, d, p, 244, 81); |
| 1196 | |
| 1197 | osmo_conv_encode(&gsm0503_tch_afs_12_2, conv, cB + 8); |
| 1198 | |
| 1199 | break; |
| 1200 | case 6: /* TCH/AFS10.2 */ |
| 1201 | if (len != 26) |
| 1202 | goto invalid_length; |
| 1203 | |
| 1204 | tch_amr_disassemble(d, tch_data, 204); |
| 1205 | |
| 1206 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 65, p); |
| 1207 | |
| 1208 | tch_amr_merge(conv, d, p, 204, 65); |
| 1209 | |
| 1210 | osmo_conv_encode(&gsm0503_tch_afs_10_2, conv, cB + 8); |
| 1211 | |
| 1212 | break; |
| 1213 | case 5: /* TCH/AFS7.95 */ |
| 1214 | if (len != 20) |
| 1215 | goto invalid_length; |
| 1216 | |
| 1217 | tch_amr_disassemble(d, tch_data, 159); |
| 1218 | |
| 1219 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 75, p); |
| 1220 | |
| 1221 | tch_amr_merge(conv, d, p, 159, 75); |
| 1222 | |
| 1223 | osmo_conv_encode(&gsm0503_tch_afs_7_95, conv, cB + 8); |
| 1224 | |
| 1225 | break; |
| 1226 | case 4: /* TCH/AFS7.4 */ |
| 1227 | if (len != 19) |
| 1228 | goto invalid_length; |
| 1229 | |
| 1230 | tch_amr_disassemble(d, tch_data, 148); |
| 1231 | |
| 1232 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 61, p); |
| 1233 | |
| 1234 | tch_amr_merge(conv, d, p, 148, 61); |
| 1235 | |
| 1236 | osmo_conv_encode(&gsm0503_tch_afs_7_4, conv, cB + 8); |
| 1237 | |
| 1238 | break; |
| 1239 | case 3: /* TCH/AFS6.7 */ |
| 1240 | if (len != 17) |
| 1241 | goto invalid_length; |
| 1242 | |
| 1243 | tch_amr_disassemble(d, tch_data, 134); |
| 1244 | |
| 1245 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); |
| 1246 | |
| 1247 | tch_amr_merge(conv, d, p, 134, 55); |
| 1248 | |
| 1249 | osmo_conv_encode(&gsm0503_tch_afs_6_7, conv, cB + 8); |
| 1250 | |
| 1251 | break; |
| 1252 | case 2: /* TCH/AFS5.9 */ |
| 1253 | if (len != 15) |
| 1254 | goto invalid_length; |
| 1255 | |
| 1256 | tch_amr_disassemble(d, tch_data, 118); |
| 1257 | |
| 1258 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); |
| 1259 | |
| 1260 | tch_amr_merge(conv, d, p, 118, 55); |
| 1261 | |
| 1262 | osmo_conv_encode(&gsm0503_tch_afs_5_9, conv, cB + 8); |
| 1263 | |
| 1264 | break; |
| 1265 | case 1: /* TCH/AFS5.15 */ |
| 1266 | if (len != 13) |
| 1267 | goto invalid_length; |
| 1268 | |
| 1269 | tch_amr_disassemble(d, tch_data, 103); |
| 1270 | |
| 1271 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 49, p); |
| 1272 | |
| 1273 | tch_amr_merge(conv, d, p, 103, 49); |
| 1274 | |
| 1275 | osmo_conv_encode(&gsm0503_tch_afs_5_15, conv, cB + 8); |
| 1276 | |
| 1277 | break; |
| 1278 | case 0: /* TCH/AFS4.75 */ |
| 1279 | if (len != 12) |
| 1280 | goto invalid_length; |
| 1281 | |
| 1282 | tch_amr_disassemble(d, tch_data, 95); |
| 1283 | |
| 1284 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 39, p); |
| 1285 | |
| 1286 | tch_amr_merge(conv, d, p, 95, 39); |
| 1287 | |
| 1288 | osmo_conv_encode(&gsm0503_tch_afs_4_75, conv, cB + 8); |
| 1289 | |
| 1290 | break; |
| 1291 | default: |
| 1292 | /* FIXME: FT %ft is not supported */ |
| 1293 | return -1; |
| 1294 | } |
| 1295 | |
| 1296 | memcpy(cB, gsm0503_afs_ic_ubit[id], 8); |
| 1297 | |
| 1298 | facch: |
| 1299 | gsm0503_tch_fr_interleave(cB, iB); |
| 1300 | |
| 1301 | for (i = 0; i < 8; i++) { |
| 1302 | gsm0503_tch_burst_map(&iB[i * 114], |
| 1303 | &bursts[i * 116], &h, i >> 2); |
| 1304 | } |
| 1305 | |
| 1306 | return 0; |
| 1307 | |
| 1308 | invalid_length: |
| 1309 | /* FIXME: payload length %len does not comply with codec type %ft */ |
| 1310 | return -1; |
| 1311 | } |
| 1312 | |
| 1313 | int gsm0503_tch_ahs_decode(uint8_t *tch_data, sbit_t *bursts, int odd, |
| 1314 | int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft, |
| 1315 | uint8_t *cmr, int *n_errors, int *n_bits_total) |
| 1316 | { |
| 1317 | sbit_t iB[912], cB[456], h; |
| 1318 | ubit_t d[244], p[6], conv[135]; |
| 1319 | int i, j, k, best = 0, rv, len, steal = 0, id = 0; |
| 1320 | |
| 1321 | /* only unmap the stealing bits */ |
| 1322 | if (!odd) { |
| 1323 | for (i = 0; i < 4; i++) { |
| 1324 | gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 0); |
| 1325 | steal -= h; |
| 1326 | } |
| 1327 | for (i = 2; i < 5; i++) { |
| 1328 | gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 1); |
| 1329 | steal -= h; |
| 1330 | } |
| 1331 | } |
| 1332 | |
| 1333 | /* if we found a stole FACCH, but only at correct alignment */ |
| 1334 | if (steal > 0) { |
| 1335 | for (i = 0; i < 6; i++) { |
| 1336 | gsm0503_tch_burst_unmap(&iB[i * 114], |
| 1337 | &bursts[i * 116], NULL, i >> 2); |
| 1338 | } |
| 1339 | |
| 1340 | for (i = 2; i < 4; i++) { |
| 1341 | gsm0503_tch_burst_unmap(&iB[i * 114 + 456], |
| 1342 | &bursts[i * 116], NULL, 1); |
| 1343 | } |
| 1344 | |
| 1345 | gsm0503_tch_fr_deinterleave(cB, iB); |
| 1346 | |
| 1347 | rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); |
| 1348 | if (rv) { |
| 1349 | /* Error decoding FACCH frame */ |
| 1350 | return -1; |
| 1351 | } |
| 1352 | |
| 1353 | return GSM_MACBLOCK_LEN; |
| 1354 | } |
| 1355 | |
| 1356 | for (i = 0; i < 4; i++) { |
| 1357 | gsm0503_tch_burst_unmap(&iB[i * 114], |
| 1358 | &bursts[i * 116], NULL, i >> 1); |
| 1359 | } |
| 1360 | |
| 1361 | gsm0503_tch_hr_deinterleave(cB, iB); |
| 1362 | |
| 1363 | for (i = 0; i < 4; i++) { |
| 1364 | for (j = 0, k = 0; j < 4; j++) |
| 1365 | k += abs(((int)gsm0503_ahs_ic_sbit[i][j]) - ((int)cB[j])); |
| 1366 | |
| 1367 | if (i == 0 || k < best) { |
| 1368 | best = k; |
| 1369 | id = i; |
| 1370 | } |
| 1371 | } |
| 1372 | |
| 1373 | /* Check if indicated codec fits into range of codecs */ |
| 1374 | if (id >= codecs) { |
| 1375 | /* Codec mode out of range, return id */ |
| 1376 | return id; |
| 1377 | } |
| 1378 | |
| 1379 | switch ((codec_mode_req) ? codec[*ft] : codec[id]) { |
| 1380 | case 5: /* TCH/AHS7.95 */ |
| 1381 | osmo_conv_decode_ber(&gsm0503_tch_ahs_7_95, cB + 4, |
| 1382 | conv, n_errors, n_bits_total); |
| 1383 | |
| 1384 | tch_amr_unmerge(d, p, conv, 123, 67); |
| 1385 | |
| 1386 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 67, p); |
| 1387 | if (rv) { |
| 1388 | /* Error checking CRC8 for an AMR 7.95 frame */ |
| 1389 | return -1; |
| 1390 | } |
| 1391 | |
| 1392 | for (i = 0; i < 36; i++) |
| 1393 | d[i + 123] = (cB[i + 192] < 0) ? 1 : 0; |
| 1394 | |
| 1395 | tch_amr_reassemble(tch_data, d, 159); |
| 1396 | |
| 1397 | len = 20; |
| 1398 | |
| 1399 | break; |
| 1400 | case 4: /* TCH/AHS7.4 */ |
| 1401 | osmo_conv_decode_ber(&gsm0503_tch_ahs_7_4, cB + 4, |
| 1402 | conv, n_errors, n_bits_total); |
| 1403 | |
| 1404 | tch_amr_unmerge(d, p, conv, 120, 61); |
| 1405 | |
| 1406 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 61, p); |
| 1407 | if (rv) { |
| 1408 | /* Error checking CRC8 for an AMR 7.4 frame */ |
| 1409 | return -1; |
| 1410 | } |
| 1411 | |
| 1412 | for (i = 0; i < 28; i++) |
| 1413 | d[i + 120] = (cB[i + 200] < 0) ? 1 : 0; |
| 1414 | |
| 1415 | tch_amr_reassemble(tch_data, d, 148); |
| 1416 | |
| 1417 | len = 19; |
| 1418 | |
| 1419 | break; |
| 1420 | case 3: /* TCH/AHS6.7 */ |
| 1421 | osmo_conv_decode_ber(&gsm0503_tch_ahs_6_7, cB + 4, |
| 1422 | conv, n_errors, n_bits_total); |
| 1423 | |
| 1424 | tch_amr_unmerge(d, p, conv, 110, 55); |
| 1425 | |
| 1426 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); |
| 1427 | if (rv) { |
| 1428 | /* Error checking CRC8 for an AMR 6.7 frame */ |
| 1429 | return -1; |
| 1430 | } |
| 1431 | |
| 1432 | for (i = 0; i < 24; i++) |
| 1433 | d[i + 110] = (cB[i + 204] < 0) ? 1 : 0; |
| 1434 | |
| 1435 | tch_amr_reassemble(tch_data, d, 134); |
| 1436 | |
| 1437 | len = 17; |
| 1438 | |
| 1439 | break; |
| 1440 | case 2: /* TCH/AHS5.9 */ |
| 1441 | osmo_conv_decode_ber(&gsm0503_tch_ahs_5_9, cB + 4, |
| 1442 | conv, n_errors, n_bits_total); |
| 1443 | |
| 1444 | tch_amr_unmerge(d, p, conv, 102, 55); |
| 1445 | |
| 1446 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); |
| 1447 | if (rv) { |
| 1448 | /* Error checking CRC8 for an AMR 5.9 frame */ |
| 1449 | return -1; |
| 1450 | } |
| 1451 | |
| 1452 | for (i = 0; i < 16; i++) |
| 1453 | d[i + 102] = (cB[i + 212] < 0) ? 1 : 0; |
| 1454 | |
| 1455 | tch_amr_reassemble(tch_data, d, 118); |
| 1456 | |
| 1457 | len = 15; |
| 1458 | |
| 1459 | break; |
| 1460 | case 1: /* TCH/AHS5.15 */ |
| 1461 | osmo_conv_decode_ber(&gsm0503_tch_ahs_5_15, cB + 4, |
| 1462 | conv, n_errors, n_bits_total); |
| 1463 | |
| 1464 | tch_amr_unmerge(d, p, conv, 91, 49); |
| 1465 | |
| 1466 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 49, p); |
| 1467 | if (rv) { |
| 1468 | /* Error checking CRC8 for an AMR 5.15 frame */ |
| 1469 | return -1; |
| 1470 | } |
| 1471 | |
| 1472 | for (i = 0; i < 12; i++) |
| 1473 | d[i + 91] = (cB[i + 216] < 0) ? 1 : 0; |
| 1474 | |
| 1475 | tch_amr_reassemble(tch_data, d, 103); |
| 1476 | |
| 1477 | len = 13; |
| 1478 | |
| 1479 | break; |
| 1480 | case 0: /* TCH/AHS4.75 */ |
| 1481 | osmo_conv_decode_ber(&gsm0503_tch_ahs_4_75, cB + 4, |
| 1482 | conv, n_errors, n_bits_total); |
| 1483 | |
| 1484 | tch_amr_unmerge(d, p, conv, 83, 39); |
| 1485 | |
| 1486 | rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 39, p); |
| 1487 | if (rv) { |
| 1488 | /* Error checking CRC8 for an AMR 4.75 frame */ |
| 1489 | return -1; |
| 1490 | } |
| 1491 | |
| 1492 | for (i = 0; i < 12; i++) |
| 1493 | d[i + 83] = (cB[i + 216] < 0) ? 1 : 0; |
| 1494 | |
| 1495 | tch_amr_reassemble(tch_data, d, 95); |
| 1496 | |
| 1497 | len = 12; |
| 1498 | |
| 1499 | break; |
| 1500 | default: |
| 1501 | /* Unknown frame type */ |
| 1502 | *n_bits_total = 159; |
| 1503 | *n_errors = *n_bits_total; |
| 1504 | return -1; |
| 1505 | } |
| 1506 | |
| 1507 | /* Change codec request / indication, if frame is valid */ |
| 1508 | if (codec_mode_req) |
| 1509 | *cmr = id; |
| 1510 | else |
| 1511 | *ft = id; |
| 1512 | |
| 1513 | return len; |
| 1514 | } |
| 1515 | |
| 1516 | int gsm0503_tch_ahs_encode(ubit_t *bursts, uint8_t *tch_data, int len, |
| 1517 | int codec_mode_req, uint8_t *codec, int codecs, uint8_t ft, |
| 1518 | uint8_t cmr) |
| 1519 | { |
| 1520 | ubit_t iB[912], cB[456], h; |
| 1521 | ubit_t d[244], p[6], conv[135]; |
| 1522 | int i; |
| 1523 | uint8_t id; |
| 1524 | |
| 1525 | if (len == GSM_MACBLOCK_LEN) { /* FACCH */ |
| 1526 | _xcch_encode_cB(cB, tch_data); |
| 1527 | |
| 1528 | h = 1; |
| 1529 | |
| 1530 | gsm0503_tch_fr_interleave(cB, iB); |
| 1531 | |
| 1532 | for (i = 0; i < 6; i++) |
| 1533 | gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], |
| 1534 | &h, i >> 2); |
| 1535 | for (i = 2; i < 4; i++) |
| 1536 | gsm0503_tch_burst_map(&iB[i * 114 + 456], |
| 1537 | &bursts[i * 116], &h, 1); |
| 1538 | |
| 1539 | return 0; |
| 1540 | } |
| 1541 | |
| 1542 | h = 0; |
| 1543 | |
| 1544 | if (codec_mode_req) { |
| 1545 | if (cmr >= codecs) { |
| 1546 | /* FIXME: CMR ID %d not in codec list */ |
| 1547 | return -1; |
| 1548 | } |
| 1549 | id = cmr; |
| 1550 | } else { |
| 1551 | if (ft >= codecs) { |
| 1552 | /* FIXME: FT ID %d not in codec list */ |
| 1553 | return -1; |
| 1554 | } |
| 1555 | id = ft; |
| 1556 | } |
| 1557 | |
| 1558 | switch (codec[ft]) { |
| 1559 | case 5: /* TCH/AHS7.95 */ |
| 1560 | if (len != 20) |
| 1561 | goto invalid_length; |
| 1562 | |
| 1563 | tch_amr_disassemble(d, tch_data, 159); |
| 1564 | |
| 1565 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 67, p); |
| 1566 | |
| 1567 | tch_amr_merge(conv, d, p, 123, 67); |
| 1568 | |
| 1569 | osmo_conv_encode(&gsm0503_tch_ahs_7_95, conv, cB + 4); |
| 1570 | |
| 1571 | memcpy(cB + 192, d + 123, 36); |
| 1572 | |
| 1573 | break; |
| 1574 | case 4: /* TCH/AHS7.4 */ |
| 1575 | if (len != 19) |
| 1576 | goto invalid_length; |
| 1577 | |
| 1578 | tch_amr_disassemble(d, tch_data, 148); |
| 1579 | |
| 1580 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 61, p); |
| 1581 | |
| 1582 | tch_amr_merge(conv, d, p, 120, 61); |
| 1583 | |
| 1584 | osmo_conv_encode(&gsm0503_tch_ahs_7_4, conv, cB + 4); |
| 1585 | |
| 1586 | memcpy(cB + 200, d + 120, 28); |
| 1587 | |
| 1588 | break; |
| 1589 | case 3: /* TCH/AHS6.7 */ |
| 1590 | if (len != 17) |
| 1591 | goto invalid_length; |
| 1592 | |
| 1593 | tch_amr_disassemble(d, tch_data, 134); |
| 1594 | |
| 1595 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); |
| 1596 | |
| 1597 | tch_amr_merge(conv, d, p, 110, 55); |
| 1598 | |
| 1599 | osmo_conv_encode(&gsm0503_tch_ahs_6_7, conv, cB + 4); |
| 1600 | |
| 1601 | memcpy(cB + 204, d + 110, 24); |
| 1602 | |
| 1603 | break; |
| 1604 | case 2: /* TCH/AHS5.9 */ |
| 1605 | if (len != 15) |
| 1606 | goto invalid_length; |
| 1607 | |
| 1608 | tch_amr_disassemble(d, tch_data, 118); |
| 1609 | |
| 1610 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); |
| 1611 | |
| 1612 | tch_amr_merge(conv, d, p, 102, 55); |
| 1613 | |
| 1614 | osmo_conv_encode(&gsm0503_tch_ahs_5_9, conv, cB + 4); |
| 1615 | |
| 1616 | memcpy(cB + 212, d + 102, 16); |
| 1617 | |
| 1618 | break; |
| 1619 | case 1: /* TCH/AHS5.15 */ |
| 1620 | if (len != 13) |
| 1621 | goto invalid_length; |
| 1622 | |
| 1623 | tch_amr_disassemble(d, tch_data, 103); |
| 1624 | |
| 1625 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 49, p); |
| 1626 | |
| 1627 | tch_amr_merge(conv, d, p, 91, 49); |
| 1628 | |
| 1629 | osmo_conv_encode(&gsm0503_tch_ahs_5_15, conv, cB + 4); |
| 1630 | |
| 1631 | memcpy(cB + 216, d + 91, 12); |
| 1632 | |
| 1633 | break; |
| 1634 | case 0: /* TCH/AHS4.75 */ |
| 1635 | if (len != 12) |
| 1636 | goto invalid_length; |
| 1637 | |
| 1638 | tch_amr_disassemble(d, tch_data, 95); |
| 1639 | |
| 1640 | osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 39, p); |
| 1641 | |
| 1642 | tch_amr_merge(conv, d, p, 83, 39); |
| 1643 | |
| 1644 | osmo_conv_encode(&gsm0503_tch_ahs_4_75, conv, cB + 4); |
| 1645 | |
| 1646 | memcpy(cB + 216, d + 83, 12); |
| 1647 | |
| 1648 | break; |
| 1649 | default: |
| 1650 | /* FIXME: FT %ft is not supported */ |
| 1651 | return -1; |
| 1652 | } |
| 1653 | |
| 1654 | memcpy(cB, gsm0503_afs_ic_ubit[id], 4); |
| 1655 | |
| 1656 | gsm0503_tch_hr_interleave(cB, iB); |
| 1657 | |
| 1658 | for (i = 0; i < 4; i++) |
| 1659 | gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i >> 1); |
| 1660 | |
| 1661 | return 0; |
| 1662 | |
| 1663 | invalid_length: |
| 1664 | /* FIXME: payload length %len does not comply with codec type %ft */ |
| 1665 | return -1; |
| 1666 | } |
| 1667 | |
| 1668 | /* |
| 1669 | * GSM RACH transcoding |
| 1670 | */ |
| 1671 | |
| 1672 | /* |
| 1673 | * GSM RACH apply BSIC to parity |
| 1674 | * |
| 1675 | * p(j) = p(j) xor b(j) j = 0, ..., 5 |
| 1676 | * b(0) = MSB of PLMN colour code |
| 1677 | * b(5) = LSB of BS colour code |
| 1678 | */ |
| 1679 | static int rach_apply_bsic(ubit_t *d, uint8_t bsic) |
| 1680 | { |
| 1681 | int i; |
| 1682 | |
| 1683 | /* Apply it */ |
| 1684 | for (i = 0; i < 6; i++) |
| 1685 | d[8 + i] ^= ((bsic >> (5 - i)) & 1); |
| 1686 | |
| 1687 | return 0; |
| 1688 | } |
| 1689 | |
| 1690 | int gsm0503_rach_decode(uint8_t *ra, sbit_t *burst, uint8_t bsic) |
| 1691 | { |
| 1692 | ubit_t conv[14]; |
| 1693 | int rv; |
| 1694 | |
| 1695 | osmo_conv_decode(&gsm0503_rach, burst, conv); |
| 1696 | |
| 1697 | rach_apply_bsic(conv, bsic); |
| 1698 | |
| 1699 | rv = osmo_crc8gen_check_bits(&gsm0503_rach_crc6, conv, 8, conv + 8); |
| 1700 | if (rv) |
| 1701 | return -1; |
| 1702 | |
| 1703 | osmo_ubit2pbit_ext(ra, 0, conv, 0, 8, 1); |
| 1704 | |
| 1705 | return 0; |
| 1706 | } |
| 1707 | |
| 1708 | int gsm0503_rach_encode(ubit_t *burst, uint8_t *ra, uint8_t bsic) |
| 1709 | { |
| 1710 | ubit_t conv[14]; |
| 1711 | |
| 1712 | osmo_pbit2ubit_ext(conv, 0, ra, 0, 8, 1); |
| 1713 | |
| 1714 | osmo_crc8gen_set_bits(&gsm0503_rach_crc6, conv, 8, conv + 8); |
| 1715 | |
| 1716 | rach_apply_bsic(conv, bsic); |
| 1717 | |
| 1718 | osmo_conv_encode(&gsm0503_rach, conv, burst); |
| 1719 | |
| 1720 | return 0; |
| 1721 | } |
| 1722 | |
| 1723 | /* |
| 1724 | * GSM SCH transcoding |
| 1725 | */ |
| 1726 | int gsm0503_sch_decode(uint8_t *sb_info, sbit_t *burst) |
| 1727 | { |
| 1728 | ubit_t conv[35]; |
| 1729 | int rv; |
| 1730 | |
| 1731 | osmo_conv_decode(&gsm0503_sch, burst, conv); |
| 1732 | |
| 1733 | rv = osmo_crc16gen_check_bits(&gsm0503_sch_crc10, conv, 25, conv + 25); |
| 1734 | if (rv) |
| 1735 | return -1; |
| 1736 | |
| 1737 | osmo_ubit2pbit_ext(sb_info, 0, conv, 0, 25, 1); |
| 1738 | |
| 1739 | return 0; |
| 1740 | } |
| 1741 | |
| 1742 | int gsm0503_sch_encode(ubit_t *burst, uint8_t *sb_info) |
| 1743 | { |
| 1744 | ubit_t conv[35]; |
| 1745 | |
| 1746 | osmo_pbit2ubit_ext(conv, 0, sb_info, 0, 25, 1); |
| 1747 | |
| 1748 | osmo_crc16gen_set_bits(&gsm0503_sch_crc10, conv, 25, conv + 25); |
| 1749 | |
| 1750 | osmo_conv_encode(&gsm0503_sch, conv, burst); |
| 1751 | |
| 1752 | return 0; |
| 1753 | } |