Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 1 | /* egprs_rlc_compression.h |
| 2 | * Routines for EGPRS RLC bitmap compression handling |
| 3 | */ |
| 4 | #include <errno.h> |
| 5 | #include <decoding.h> |
| 6 | #include <arpa/inet.h> |
| 7 | #include <string.h> |
| 8 | #include <gprs_debug.h> |
| 9 | #include <gprs_rlcmac.h> |
| 10 | #include <egprs_rlc_compression.h> |
| 11 | |
| 12 | extern "C" { |
| 13 | #include <osmocom/core/talloc.h> |
| 14 | #include <osmocom/core/msgb.h> |
| 15 | #include <osmocom/core/stats.h> |
| 16 | } |
| 17 | |
| 18 | #define EGPRS_CODEWORDS 79 /* total number of codewords */ |
| 19 | |
| 20 | struct egprs_compress_node{ |
| 21 | struct egprs_compress_node *left; |
| 22 | struct egprs_compress_node *right; |
| 23 | int run_length; |
| 24 | }; |
| 25 | |
| 26 | extern void *tall_pcu_ctx; |
| 27 | |
| 28 | egprs_compress *egprs_compress::s_instance = 0; |
| 29 | |
| 30 | egprs_compress_node *egprs_compress::create_tree_node(void *parent) |
| 31 | { |
| 32 | egprs_compress_node *new_node; |
| 33 | |
| 34 | new_node = talloc_zero(parent, egprs_compress_node); |
| 35 | new_node->left = NULL; |
| 36 | new_node->right = NULL; |
| 37 | new_node->run_length = -1; |
| 38 | return new_node; |
| 39 | } |
| 40 | |
| 41 | egprs_compress *egprs_compress::instance() |
| 42 | { |
| 43 | if (!egprs_compress::s_instance) |
| 44 | egprs_compress::s_instance = new egprs_compress; |
| 45 | return egprs_compress::s_instance; |
| 46 | } |
| 47 | |
| 48 | /* Expands the given tree by incorporating |
| 49 | * the given codewords. |
| 50 | * \param root[in] Root of ones or zeros tree |
| 51 | * \param cdwd[in] Array of code words |
| 52 | * number of codewords is EGPRS_CODEWORDS |
| 53 | */ |
| 54 | void egprs_compress::build_codewords(egprs_compress_node *root, const char *cdwd[]) |
| 55 | { |
| 56 | egprs_compress_node *iter; |
| 57 | int len; |
| 58 | int i; |
| 59 | int idx; |
| 60 | |
| 61 | for (idx = 0; idx < EGPRS_CODEWORDS; idx++) { |
| 62 | len = strlen((const char *)cdwd[idx]); |
| 63 | iter = root; |
| 64 | for (i = 0; i < len; i++) { |
| 65 | if (cdwd[idx][i] == '0') { |
| 66 | if (!iter->left) |
| 67 | iter->left = create_tree_node(root); |
| 68 | iter = iter->left; |
| 69 | } else { |
| 70 | if (!iter->right) |
| 71 | iter->right = create_tree_node(root); |
| 72 | iter = iter->right; |
| 73 | } |
| 74 | } |
| 75 | if (iter) { |
| 76 | /* The first 64 run lengths are 0, 1, 2, ..., 63 |
| 77 | * and the following ones are 64, 128, 192 described in |
| 78 | * section 9.1.10 of 3gpp 44.060 */ |
| 79 | if (idx < 64) |
| 80 | iter->run_length = idx; |
| 81 | else |
| 82 | iter->run_length = (idx - 63) * 64; |
| 83 | } |
| 84 | } |
| 85 | } |
| 86 | |
sivasankari | 8adfcd0 | 2017-01-16 15:41:21 +0530 | [diff] [blame] | 87 | /* |
| 88 | * Terminating codes for uninterrupted sequences of 0 and 1 up to 64 bit length |
| 89 | * according to TS 44.060 9.1.10 |
| 90 | */ |
| 91 | static const unsigned t4_term[2][64] = { |
| 92 | { |
| 93 | 0b0000110111, |
| 94 | 0b10, |
| 95 | 0b11, |
| 96 | 0b010, |
| 97 | 0b011, |
| 98 | 0b0011, |
| 99 | 0b0010, |
| 100 | 0b00011, |
| 101 | 0b000101, |
| 102 | 0b000100, |
| 103 | 0b0000100, |
| 104 | 0b0000101, |
| 105 | 0b0000111, |
| 106 | 0b00000100, |
| 107 | 0b00000111, |
| 108 | 0b000011000, |
| 109 | 0b0000010111, |
| 110 | 0b0000011000, |
| 111 | 0b0000001000, |
| 112 | 0b00001100111, |
| 113 | 0b00001101000, |
| 114 | 0b00001101100, |
| 115 | 0b00000110111, |
| 116 | 0b00000101000, |
| 117 | 0b00000010111, |
| 118 | 0b00000011000, |
| 119 | 0b000011001010, |
| 120 | 0b000011001011, |
| 121 | 0b000011001100, |
| 122 | 0b000011001101, |
| 123 | 0b000001101000, |
| 124 | 0b000001101001, |
| 125 | 0b000001101010, |
| 126 | 0b000001101011, |
| 127 | 0b000011010010, |
| 128 | 0b000011010011, |
| 129 | 0b000011010100, |
| 130 | 0b000011010101, |
| 131 | 0b000011010110, |
| 132 | 0b000011010111, |
| 133 | 0b000001101100, |
| 134 | 0b000001101101, |
| 135 | 0b000011011010, |
| 136 | 0b000011011011, |
| 137 | 0b000001010100, |
| 138 | 0b000001010101, |
| 139 | 0b000001010110, |
| 140 | 0b000001010111, |
| 141 | 0b000001100100, |
| 142 | 0b000001100101, |
| 143 | 0b000001010010, |
| 144 | 0b000001010011, |
| 145 | 0b000000100100, |
| 146 | 0b000000110111, |
| 147 | 0b000000111000, |
| 148 | 0b000000100111, |
| 149 | 0b000000101000, |
| 150 | 0b000001011000, |
| 151 | 0b000001011001, |
| 152 | 0b000000101011, |
| 153 | 0b000000101100, |
| 154 | 0b000001011010, |
| 155 | 0b000001100110, |
| 156 | 0b000001100111 |
| 157 | |
| 158 | }, |
| 159 | { |
| 160 | 0b00110101, |
| 161 | 0b000111, |
| 162 | 0b0111, |
| 163 | 0b1000, |
| 164 | 0b1011, |
| 165 | 0b1100, |
| 166 | 0b1110, |
| 167 | 0b1111, |
| 168 | 0b10011, |
| 169 | 0b10100, |
| 170 | 0b00111, |
| 171 | 0b01000, |
| 172 | 0b001000, |
| 173 | 0b000011, |
| 174 | 0b110100, |
| 175 | 0b110101, |
| 176 | 0b101010, |
| 177 | 0b101011, |
| 178 | 0b0100111, |
| 179 | 0b0001100, |
| 180 | 0b0001000, |
| 181 | 0b0010111, |
| 182 | 0b0000011, |
| 183 | 0b0000100, |
| 184 | 0b0101000, |
| 185 | 0b0101011, |
| 186 | 0b0010011, |
| 187 | 0b0100100, |
| 188 | 0b0011000, |
| 189 | 0b00000010, |
| 190 | 0b00000011, |
| 191 | 0b00011010, |
| 192 | 0b00011011, |
| 193 | 0b00010010, |
| 194 | 0b00010011, |
| 195 | 0b00010100, |
| 196 | 0b00010101, |
| 197 | 0b00010110, |
| 198 | 0b00010111, |
| 199 | 0b00101000, |
| 200 | 0b00101001, |
| 201 | 0b00101010, |
| 202 | 0b00101011, |
| 203 | 0b00101100, |
| 204 | 0b00101101, |
| 205 | 0b00000100, |
| 206 | 0b00000101, |
| 207 | 0b00001010, |
| 208 | 0b00001011, |
| 209 | 0b01010010, |
| 210 | 0b01010011, |
| 211 | 0b01010100, |
| 212 | 0b01010101, |
| 213 | 0b00100100, |
| 214 | 0b00100101, |
| 215 | 0b01011000, |
| 216 | 0b01011001, |
| 217 | 0b01011010, |
| 218 | 0b01011011, |
| 219 | 0b01001010, |
| 220 | 0b01001011, |
| 221 | 0b00110010, |
| 222 | 0b00110011, |
| 223 | 0b00110100 |
| 224 | } |
| 225 | }; |
| 226 | static const unsigned t4_term_length[2][64] = { |
| 227 | {10, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 7, 7, 8, 8, 9, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12}, |
| 228 | {8, 6, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8} |
| 229 | }; |
| 230 | |
| 231 | static const unsigned t4_min_term_length[] = {2, 4}; |
| 232 | static const unsigned t4_min_make_up_length[] = {10, 5}; |
| 233 | |
| 234 | static const unsigned t4_max_term_length[] = {12, 8}; |
| 235 | static const unsigned t4_max_make_up_length[] = {13, 9}; |
| 236 | |
| 237 | static const unsigned t4_make_up_length[2][15] = { |
| 238 | {10, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13}, |
| 239 | {5, 5, 6, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9} |
| 240 | }; |
| 241 | |
| 242 | static const unsigned t4_make_up_ind[15] = {64, 128, 192, 256, 320, 384, 448, 512, 576, 640, 704, 768, 832, 896, 960}; |
| 243 | |
| 244 | static const unsigned t4_make_up[2][15] = { |
| 245 | { |
| 246 | 0b0000001111, |
| 247 | 0b000011001000, |
| 248 | 0b000011001001, |
| 249 | 0b000001011011, |
| 250 | 0b000000110011, |
| 251 | 0b000000110100, |
| 252 | 0b000000110101, |
| 253 | 0b0000001101100, |
| 254 | 0b0000001101101, |
| 255 | 0b0000001001010, |
| 256 | 0b0000001001011, |
| 257 | 0b0000001001100, |
| 258 | 0b0000001001101, |
| 259 | 0b0000001110010, |
| 260 | 0b0000001110011 |
| 261 | }, |
| 262 | { |
| 263 | 0b11011, |
| 264 | 0b10010, |
| 265 | 0b010111, |
| 266 | 0b0110111, |
| 267 | 0b00110110, |
| 268 | 0b00110111, |
| 269 | 0b01100100, |
| 270 | 0b01100101, |
| 271 | 0b01101000, |
| 272 | 0b01100111, |
| 273 | 0b011001100, |
| 274 | 0b011001101, |
| 275 | 0b011010010, |
| 276 | 0b011010011, |
| 277 | 0b011010100 |
| 278 | } |
| 279 | }; |
| 280 | |
| 281 | /* The code words for one run length and zero |
| 282 | * run length are described in table 9.1.10.1 |
| 283 | * of 3gpp 44.060 |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 284 | */ |
| 285 | const char *one_run_len_code_list[EGPRS_CODEWORDS] = { |
| 286 | "00110101", |
| 287 | "000111", |
| 288 | "0111", |
| 289 | "1000", |
| 290 | "1011", |
| 291 | "1100", |
| 292 | "1110", |
| 293 | "1111", |
| 294 | "10011", |
| 295 | "10100", |
| 296 | "00111", |
| 297 | "01000", |
| 298 | "001000", |
| 299 | "000011", |
| 300 | "110100", |
| 301 | "110101", |
| 302 | "101010", |
| 303 | "101011", |
| 304 | "0100111", |
| 305 | "0001100", |
| 306 | "0001000", |
| 307 | "0010111", |
| 308 | "0000011", |
| 309 | "0000100", |
| 310 | "0101000", |
| 311 | "0101011", |
| 312 | "0010011", |
| 313 | "0100100", |
| 314 | "0011000", |
| 315 | "00000010", |
| 316 | "00000011", |
| 317 | "00011010", |
| 318 | "00011011", |
| 319 | "00010010", |
| 320 | "00010011", |
| 321 | "00010100", |
| 322 | "00010101", |
| 323 | "00010110", |
| 324 | "00010111", |
| 325 | "00101000", |
| 326 | "00101001", |
| 327 | "00101010", |
| 328 | "00101011", |
| 329 | "00101100", |
| 330 | "00101101", |
| 331 | "00000100", |
| 332 | "00000101", |
| 333 | "00001010", |
| 334 | "00001011", |
| 335 | "01010010", |
| 336 | "01010011", |
| 337 | "01010100", |
| 338 | "01010101", |
| 339 | "00100100", |
| 340 | "00100101", |
| 341 | "01011000", |
| 342 | "01011001", |
| 343 | "01011010", |
| 344 | "01011011", |
| 345 | "01001010", |
| 346 | "01001011", |
| 347 | "00110010", |
| 348 | "00110011", |
| 349 | "00110100", |
| 350 | "11011", |
| 351 | "10010", |
| 352 | "010111", |
| 353 | "0110111", |
| 354 | "00110110", |
| 355 | "00110111", |
| 356 | "01100100", |
| 357 | "01100101", |
| 358 | "01101000", |
| 359 | "01100111", |
| 360 | "011001100", |
| 361 | "011001101", |
| 362 | "011010010", |
| 363 | "011010011", |
| 364 | "011010100" |
| 365 | }; |
| 366 | |
| 367 | const char *zero_run_len_code_list[EGPRS_CODEWORDS] = { |
| 368 | "0000110111", |
| 369 | "10", |
| 370 | "11", |
| 371 | "010", |
| 372 | "011", |
| 373 | "0011", |
| 374 | "0010", |
| 375 | "00011", |
| 376 | "000101", |
| 377 | "000100", |
| 378 | "0000100", |
| 379 | "0000101", |
| 380 | "0000111", |
| 381 | "00000100", |
| 382 | "00000111", |
| 383 | "000011000", |
| 384 | "0000010111", |
| 385 | "0000011000", |
| 386 | "0000001000", |
| 387 | "00001100111", |
| 388 | "00001101000", |
| 389 | "00001101100", |
| 390 | "00000110111", |
| 391 | "00000101000", |
| 392 | "00000010111", |
| 393 | "00000011000", |
| 394 | "000011001010", |
| 395 | "000011001011", |
| 396 | "000011001100", |
| 397 | "000011001101", |
| 398 | "000001101000", |
| 399 | "000001101001", |
| 400 | "000001101010", |
| 401 | "000001101011", |
| 402 | "000011010010", |
| 403 | "000011010011", |
| 404 | "000011010100", |
| 405 | "000011010101", |
| 406 | "000011010110", |
| 407 | "000011010111", |
| 408 | "000001101100", |
| 409 | "000001101101", |
| 410 | "000011011010", |
| 411 | "000011011011", |
| 412 | "000001010100", |
| 413 | "000001010101", |
| 414 | "000001010110", |
| 415 | "000001010111", |
| 416 | "000001100100", |
| 417 | "000001100101", |
| 418 | "000001010010", |
| 419 | "000001010011", |
| 420 | "000000100100", |
| 421 | "000000110111", |
| 422 | "000000111000", |
| 423 | "000000100111", |
| 424 | "000000101000", |
| 425 | "000001011000", |
| 426 | "000001011001", |
| 427 | "000000101011", |
| 428 | "000000101100", |
| 429 | "000001011010", |
| 430 | "000001100110", |
| 431 | "000001100111", |
| 432 | "0000001111", |
| 433 | "000011001000", |
| 434 | "000011001001", |
| 435 | "000001011011", |
| 436 | "000000110011", |
| 437 | "000000110100", |
| 438 | "000000110101", |
| 439 | "0000001101100", |
| 440 | "0000001101101", |
| 441 | "0000001001010", |
| 442 | "0000001001011", |
| 443 | "0000001001100", |
| 444 | "0000001001101", |
| 445 | "0000001110010", |
| 446 | "0000001110011" |
| 447 | }; |
| 448 | |
| 449 | /* Calculate runlength of a codeword |
| 450 | * \param root[in] Root of Ones or Zeros tree |
| 451 | * \param bmbuf[in] Received compressed bitmap buf |
Alexander Couzens | 2d24eba | 2019-06-17 01:41:29 +0200 | [diff] [blame] | 452 | * \param length[in] Length of bitmap buf in bits |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 453 | * \param bit_pos[in] The start bit pos to read codeword |
| 454 | * \param len_codewd[in] Length of code word |
| 455 | * \param rlen[out] Calculated run length |
| 456 | */ |
| 457 | static int search_runlen( |
| 458 | egprs_compress_node *root, |
| 459 | const uint8_t *bmbuf, |
Alexander Couzens | 2d24eba | 2019-06-17 01:41:29 +0200 | [diff] [blame] | 460 | uint8_t length, |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 461 | uint8_t bit_pos, |
| 462 | uint8_t *len_codewd, |
| 463 | uint16_t *rlen) |
| 464 | { |
| 465 | egprs_compress_node *iter; |
| 466 | uint8_t dir; |
| 467 | |
| 468 | iter = root; |
| 469 | *len_codewd = 0; |
| 470 | |
| 471 | while (iter->run_length == -1) { |
| 472 | if ((!iter->left) && (!iter->right)) |
| 473 | return -1; |
Alexander Couzens | 2d24eba | 2019-06-17 01:41:29 +0200 | [diff] [blame] | 474 | if (bit_pos >= length) |
| 475 | return -1; |
| 476 | |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 477 | /* get the bit value at the bitpos and put it in right most of dir */ |
| 478 | dir = (bmbuf[bit_pos/8] >> (7 - (bit_pos & 0x07))) & 0x01; |
| 479 | bit_pos++; |
| 480 | (*len_codewd)++; |
| 481 | if (!dir && (iter->left != NULL)) |
| 482 | iter = iter->left; |
| 483 | else if (dir && (iter->right != NULL)) |
| 484 | iter = iter->right; |
| 485 | else |
| 486 | return -1; |
| 487 | } |
| 488 | LOGP(DRLCMACUL, LOGL_DEBUG, "Run_length = %d\n", iter->run_length); |
| 489 | *rlen = iter->run_length; |
| 490 | return 1; |
| 491 | } |
| 492 | |
| 493 | /* Decompress received block bitmap |
| 494 | * \param compress_bmap_len[in] Compressed bitmap length |
| 495 | * \param start[in] Starting Color Code, true if bitmap starts with a run |
| 496 | * length of ones, false if zeros; see 9.1.10, 3GPP 44.060. |
| 497 | * \param orig_crbb_buf[in] Received block crbb bitmap |
| 498 | * \param dest[out] Uncompressed bitvector |
| 499 | */ |
| 500 | int egprs_compress::decompress_crbb( |
| 501 | int8_t compress_bmap_len, |
| 502 | bool start, |
| 503 | const uint8_t *orig_crbb_buf, |
| 504 | bitvec *dest) |
| 505 | { |
Alexander Couzens | 2d24eba | 2019-06-17 01:41:29 +0200 | [diff] [blame] | 506 | int8_t remaining_bmap_len = compress_bmap_len; |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 507 | uint8_t bit_pos = 0; |
| 508 | uint8_t data; |
| 509 | egprs_compress_node *list = NULL; |
| 510 | uint8_t nbits = 0; /* number of bits of codeword */ |
| 511 | uint16_t run_length = 0; |
| 512 | uint16_t cbmaplen = 0; /* compressed bitmap part after decompression */ |
| 513 | unsigned wp = dest->cur_bit; |
| 514 | int rc = 0; |
| 515 | egprs_compress *compress = instance(); |
| 516 | |
Alexander Couzens | 2d24eba | 2019-06-17 01:41:29 +0200 | [diff] [blame] | 517 | while (remaining_bmap_len > 0) { |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 518 | if (start) { |
| 519 | data = 0xff; |
| 520 | list = compress->ones_list; |
| 521 | } else { |
| 522 | data = 0x00; |
| 523 | list = compress->zeros_list; |
| 524 | } |
Alexander Couzens | 2d24eba | 2019-06-17 01:41:29 +0200 | [diff] [blame] | 525 | rc = search_runlen(list, orig_crbb_buf, compress_bmap_len, |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 526 | bit_pos, &nbits, &run_length); |
| 527 | if (rc == -1) |
| 528 | return -1; |
| 529 | /* If run length > 64, need makeup and terminating code */ |
| 530 | if (run_length < 64) |
| 531 | start = !start; |
| 532 | cbmaplen = cbmaplen + run_length; |
Alexander Couzens | 2d24eba | 2019-06-17 01:41:29 +0200 | [diff] [blame] | 533 | |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 534 | /* put run length of Ones in uncompressed bitmap */ |
| 535 | while (run_length != 0) { |
| 536 | if (run_length > 8) { |
Alexander Couzens | ccde5c9 | 2017-02-04 03:10:08 +0100 | [diff] [blame] | 537 | bitvec_write_field(dest, &wp, data, 8); |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 538 | run_length = run_length - 8; |
| 539 | } else { |
Alexander Couzens | ccde5c9 | 2017-02-04 03:10:08 +0100 | [diff] [blame] | 540 | bitvec_write_field(dest, &wp, data, run_length); |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 541 | run_length = 0; |
| 542 | } |
| 543 | } |
| 544 | bit_pos = bit_pos + nbits; |
Alexander Couzens | 2d24eba | 2019-06-17 01:41:29 +0200 | [diff] [blame] | 545 | remaining_bmap_len = remaining_bmap_len - nbits; |
Pravin Kumarvel | 0a4a6c1 | 2016-10-17 11:00:57 +0530 | [diff] [blame] | 546 | } |
| 547 | return 0; |
| 548 | } |
| 549 | |
| 550 | void egprs_compress::decode_tree_init() |
| 551 | { |
| 552 | ones_list = create_tree_node(tall_pcu_ctx); |
| 553 | zeros_list = create_tree_node(tall_pcu_ctx); |
| 554 | build_codewords(ones_list, one_run_len_code_list); |
| 555 | build_codewords(zeros_list, zero_run_len_code_list); |
| 556 | } |
| 557 | |
| 558 | egprs_compress::egprs_compress() |
| 559 | { |
| 560 | decode_tree_init(); |
| 561 | } |
| 562 | |
sivasankari | 8adfcd0 | 2017-01-16 15:41:21 +0530 | [diff] [blame] | 563 | /* Compress received block bitmap |
| 564 | * \param run_len_cnt[in] Count of number of 1's and 0's |
| 565 | * \param codewrd_bitmap[in] Code word for coresponding run length. |
| 566 | * \param crbb_vec[out] compressed bitvector. |
| 567 | */ |
| 568 | static void compress_bitmap( |
| 569 | uint16_t *run_len_cnt, /* cnt: run length count */ |
| 570 | uint16_t *codewrd_bitmap, /* code word */ |
| 571 | int16_t *codewrd_len, /* number of bits in the code word */ |
| 572 | bitvec *crbb_vec, /* bitmap buffer to put code word in */ |
| 573 | bool start) |
| 574 | { |
| 575 | int i = 0; |
| 576 | unsigned writeIndex = crbb_vec->cur_bit; |
| 577 | *codewrd_bitmap = 0; |
| 578 | *codewrd_len = 0; |
| 579 | if (*run_len_cnt >= 64) { |
| 580 | for (i = 0; i < 15; i++) { |
| 581 | if (t4_make_up_ind[i] == *run_len_cnt) { |
| 582 | *codewrd_bitmap = t4_make_up[start][i]; |
| 583 | *codewrd_len = t4_make_up_length[start][i]; |
| 584 | } |
| 585 | } |
| 586 | } else { |
| 587 | *codewrd_bitmap = t4_term[start][*run_len_cnt]; |
| 588 | *codewrd_len = t4_term_length[start][*run_len_cnt]; |
| 589 | } |
Alexander Couzens | ccde5c9 | 2017-02-04 03:10:08 +0100 | [diff] [blame] | 590 | bitvec_write_field(crbb_vec, &writeIndex, *codewrd_bitmap, *codewrd_len); |
sivasankari | 8adfcd0 | 2017-01-16 15:41:21 +0530 | [diff] [blame] | 591 | } |
| 592 | |
| 593 | /* Compress received block bitmap */ |
| 594 | int egprs_compress::osmo_t4_compress(struct bitvec *bv) |
| 595 | { |
| 596 | uint8_t crbb_len = 0; |
| 597 | uint8_t uclen_crbb = 0; |
| 598 | uint8_t crbb_bitmap[127] = {'\0'}; |
| 599 | bool start = (bv->data[0] & 0x80)>>7; |
| 600 | struct bitvec crbb_vec; |
| 601 | |
| 602 | crbb_vec.data = crbb_bitmap; |
| 603 | crbb_vec.cur_bit = 0; |
| 604 | crbb_vec.data_len = 127; |
| 605 | bv->data_len = bv->cur_bit; |
| 606 | bv->cur_bit = 0; |
| 607 | if (egprs_compress::compress_rbb(bv, &crbb_vec, &uclen_crbb, 23*8)) { |
| 608 | memcpy(bv->data, crbb_bitmap, (crbb_len+7)/8); |
| 609 | bv->cur_bit = crbb_len; |
| 610 | bv->data_len = (crbb_len+7)/8; |
| 611 | return start; |
| 612 | } |
| 613 | else |
| 614 | printf("Encode failed\n"); |
| 615 | return -1; |
| 616 | } |
| 617 | |
| 618 | /*! \brief compression algorithm using T4 encoding |
| 619 | * the compressed bitmap's are copied in crbb_bitmap |
| 620 | * \param[in] rbb_vec bit vector to be encoded |
| 621 | * \return 1 if compression is success or 0 for failure |
| 622 | */ |
| 623 | int egprs_compress::compress_rbb( |
| 624 | struct bitvec *urbb_vec, |
| 625 | struct bitvec *crbb_vec, |
| 626 | uint8_t *uclen_crbb, /* Uncompressed bitmap len in CRBB */ |
Alexander Couzens | 6d73205 | 2019-06-16 16:13:42 +0200 | [diff] [blame] | 627 | uint8_t max_bits) /* max remaining bits */ |
sivasankari | 8adfcd0 | 2017-01-16 15:41:21 +0530 | [diff] [blame] | 628 | { |
| 629 | bool run_len_bit; |
| 630 | int buflen = urbb_vec->cur_bit; |
| 631 | int total_bits = urbb_vec->cur_bit; |
| 632 | uint16_t rlen; |
| 633 | uint16_t temprl = 0; |
| 634 | uint16_t cbmap = 0; /* Compressed code word */ |
| 635 | int16_t nbits; /* Length of code word */ |
| 636 | uint16_t uclen = 0; |
| 637 | int16_t clen = 0; |
| 638 | bool start; /* Starting color code see 9.1.10, 3GPP 44.060 */ |
| 639 | urbb_vec->cur_bit = 0; |
| 640 | run_len_bit = (urbb_vec->data[0] & 0x80)>>7; |
| 641 | while (buflen > 0) { |
| 642 | temprl = 0; |
| 643 | /* Find Run length */ |
| 644 | if (run_len_bit == 1) |
| 645 | rlen = bitvec_rl_curbit(urbb_vec, true, total_bits); |
| 646 | else |
| 647 | rlen = bitvec_rl_curbit(urbb_vec, false, total_bits); |
| 648 | buflen = buflen - rlen; |
| 649 | /* if rlen > 64 need Makeup code word */ |
| 650 | /*Compress the bits */ |
| 651 | if (run_len_bit == 0) { |
| 652 | start = 0; |
| 653 | if (rlen >= 64) { |
| 654 | temprl = (rlen/64)*64; |
| 655 | compress_bitmap(&temprl, &cbmap, &nbits, |
| 656 | crbb_vec, start); |
| 657 | clen = clen + nbits; |
| 658 | } |
| 659 | temprl = MOD64(rlen); |
| 660 | compress_bitmap(&temprl, &cbmap, &nbits, |
| 661 | crbb_vec, start); |
| 662 | /* next time the run length will be Ones */ |
| 663 | run_len_bit = 1; |
| 664 | } else { |
| 665 | start = 1; |
| 666 | if (rlen >= 64) { |
| 667 | temprl = (rlen/64)*64; |
| 668 | compress_bitmap(&temprl, &cbmap, &nbits, |
| 669 | crbb_vec, start); |
| 670 | clen = clen + nbits; |
| 671 | } |
| 672 | temprl = MOD64(rlen); |
| 673 | compress_bitmap(&temprl, &cbmap, &nbits, |
| 674 | crbb_vec, start); |
| 675 | |
| 676 | /* next time the run length will be Zeros */ |
| 677 | run_len_bit = 0; |
| 678 | } |
| 679 | uclen = uclen + rlen; |
| 680 | clen = clen + nbits; |
| 681 | /*compressed bitmap exceeds the buffer space */ |
| 682 | if (clen > max_bits) { |
| 683 | uclen = uclen - rlen; |
| 684 | clen = clen - nbits; |
| 685 | break; |
| 686 | } |
| 687 | } |
| 688 | crbb_vec->cur_bit = clen; |
| 689 | *uclen_crbb = uclen; |
| 690 | if (clen >= uclen) |
| 691 | /* No Gain is observed, So no need to compress */ |
| 692 | return 0; |
| 693 | else |
| 694 | LOGP(DRLCMACUL, LOGL_DEBUG, "CRBB bitmap = %s\n", osmo_hexdump(crbb_vec->data, (crbb_vec->cur_bit+7)/8)); |
| 695 | /* Add compressed bitmap to final buffer */ |
| 696 | return 1; |
| 697 | } |