decode.c 22.7 KB
Newer Older
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
1 2
/**
 * @file decode.c
3
 *
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
4
 * @author Mathis Rosenhauer, Deutsches Klimarechenzentrum
5 6 7 8 9
 * @author Moritz Hanke, Deutsches Klimarechenzentrum
 * @author Joerg Behrens, Deutsches Klimarechenzentrum
 * @author Luis Kornblueh, Max-Planck-Institut fuer Meteorologie
 *
 * @section LICENSE
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
10
 * Copyright 2012 - 2014
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
 *
 * Mathis Rosenhauer,                 Luis Kornblueh
 * Moritz Hanke,
 * Joerg Behrens
 *
 * Deutsches Klimarechenzentrum GmbH  Max-Planck-Institut fuer Meteorologie
 * Bundesstr. 45a                     Bundesstr. 53
 * 20146 Hamburg                      20146 Hamburg
 * Germany                            Germany
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer in the documentation and/or other materials provided
 *    with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
47 48 49
 * @section DESCRIPTION
 *
 * Adaptive Entropy Decoder
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
50
 * Based on CCSDS documents 121.0-B-2 and 120.0-G-3
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
51 52
 *
 */
53

54 55 56
#include <config.h>

#if HAVE_STDINT_H
57
#include <stdint.h>
58 59
#endif

60 61 62 63
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

64 65 66 67
#ifdef HAVE_BSR64
#include <intrin.h>
#endif

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
68
#include "libaec.h"
69
#include "decode.h"
70

71 72 73 74 75
#define ROS 5

#define BUFFERSPACE(strm) (strm->avail_in >= strm->state->in_blklen     \
                           && strm->avail_out >= strm->state->out_blklen)

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
76
#define FLUSH(KIND)                                                     \
77 78
    static void flush_##KIND(struct aec_stream *strm)                   \
    {                                                                   \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
79
        uint32_t *bp, *flush_end;                                       \
80
        int64_t d, m;                                                   \
Moritz Hanke's avatar
Moritz Hanke committed
81
        int64_t data, med, half_d, xmin, xmax;                          \
82 83
        struct internal_state *state = strm->state;                     \
                                                                        \
84
        flush_end = state->rsip;                                        \
85
        if (state->pp) {                                                \
86 87 88
            if (state->flush_start == state->rsi_buffer                 \
                && state->rsip > state->rsi_buffer) {                   \
                state->last_out = *state->rsi_buffer;                   \
89 90
                                                                        \
                if (strm->flags & AEC_DATA_SIGNED) {                    \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
91
                    m = 1ULL << (strm->bits_per_sample - 1);            \
92
                    /* Reference samples have to be sign extended */    \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
93
                    state->last_out = (state->last_out ^ m) - m;        \
94
                }                                                       \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
95
                put_##KIND(strm, state->last_out);                      \
96
                state->flush_start++;                                   \
97 98
            }                                                           \
                                                                        \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
99 100 101 102 103 104
            data = state->last_out;                                     \
            if (strm->flags & AEC_DATA_SIGNED)                          \
                med = 0;                                                \
            else                                                        \
                med = (state->xmax - state->xmin) / 2 + 1;              \
                                                                        \
Moritz Hanke's avatar
Moritz Hanke committed
105 106 107
            xmin = state->xmin;                                         \
            xmax = state->xmax;                                         \
                                                                        \
108 109
            for (bp = state->flush_start; bp < flush_end; bp++) {       \
                d = *bp;                                                \
Moritz Hanke's avatar
Moritz Hanke committed
110 111 112 113 114 115 116 117 118 119 120
                half_d = (d + 1) >> 1;                                  \
                                                                        \
                if (data < med) {                                       \
                    if (half_d <= data - xmin) {                        \
                        if (d & 1)                                      \
                            data -= half_d;                             \
                        else                                            \
                            data += half_d;                             \
                    } else {                                            \
                        data = xmin + d;                                \
                    }                                                   \
121
                } else {                                                \
Moritz Hanke's avatar
Moritz Hanke committed
122 123 124 125 126 127 128 129
                    if (half_d <= xmax - data) {                        \
                        if (d & 1)                                      \
                            data -= half_d;                             \
                        else                                            \
                            data += half_d;                             \
                    } else {                                            \
                        data = xmax - d;                                \
                    }                                                   \
130
                }                                                       \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
131
                put_##KIND(strm, data);                                 \
132
            }                                                           \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
133
            state->last_out = data;                                     \
134
        } else {                                                        \
135 136
            for (bp = state->flush_start; bp < flush_end; bp++)         \
                put_##KIND(strm, *bp);                                  \
137
        }                                                               \
138
        state->flush_start = state->rsip;                               \
139
    }
140

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195

static inline void put_msb_32(struct aec_stream *strm, uint32_t data)
{
    *strm->next_out++ = data >> 24;
    *strm->next_out++ = data >> 16;
    *strm->next_out++ = data >> 8;
    *strm->next_out++ = data;
}

static inline void put_msb_24(struct aec_stream *strm, uint32_t data)
{
    *strm->next_out++ = data >> 16;
    *strm->next_out++ = data >> 8;
    *strm->next_out++ = data;
}

static inline void put_msb_16(struct aec_stream *strm, uint32_t data)
{
    *strm->next_out++ = data >> 8;
    *strm->next_out++ = data;
}

static inline void put_lsb_32(struct aec_stream *strm, uint32_t data)
{
    *strm->next_out++ = data;
    *strm->next_out++ = data >> 8;
    *strm->next_out++ = data >> 16;
    *strm->next_out++ = data >> 24;
}

static inline void put_lsb_24(struct aec_stream *strm, uint32_t data)
{
    *strm->next_out++ = data;
    *strm->next_out++ = data >> 8;
    *strm->next_out++ = data >> 16;
}

static inline void put_lsb_16(struct aec_stream *strm, uint32_t data)
{
    *strm->next_out++ = data;
    *strm->next_out++ = data >> 8;
}

static inline void put_8(struct aec_stream *strm, uint32_t data)
{
    *strm->next_out++ = data;
}

FLUSH(msb_32);
FLUSH(msb_24);
FLUSH(msb_16);
FLUSH(lsb_32);
FLUSH(lsb_24);
FLUSH(lsb_16);
FLUSH(8);
196

197
static inline void check_rsi_end(struct aec_stream *strm)
198
{
199
    /**
200
       Flush output if end of RSI reached
201
     */
202
    struct internal_state *state = strm->state;
203

204
    if (state->rsip - state->rsi_buffer == state->rsi_size) {
205
        state->flush_output(strm);
206 207
        state->flush_start = state->rsi_buffer;
        state->rsip = state->rsi_buffer;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
208
    }
209 210
}

211
static inline void put_sample(struct aec_stream *strm, uint32_t s)
212 213 214
{
    struct internal_state *state = strm->state;

215
    *state->rsip++ = s;
216
    strm->avail_out -= state->bytes_per_sample;
217
    check_rsi_end(strm);
218 219
}

220 221 222 223 224 225
static inline void fill_acc(struct aec_stream *strm)
{
    int b = (63 - strm->state->bitp) >> 3;

    strm->avail_in -= b;
    strm->state->bitp += b << 3;
Moritz Hanke's avatar
Moritz Hanke committed
226 227 228 229 230 231 232 233 234

    switch (b) {
      case (7):
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
      case (6):
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
      case (5):
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
      case (4):
235
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
Moritz Hanke's avatar
Moritz Hanke committed
236 237 238 239 240 241 242 243
      case (3):
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
      case (2):
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
      case (1):
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
    };

244 245 246
}

static inline uint32_t direct_get(struct aec_stream *strm, unsigned int n)
247 248
{
    /**
249
       Get n bit from input stream
250 251 252 253

       No checking whatsoever. Read bits are dumped.
     */

254
    struct internal_state *state = strm->state;
255

256 257
    if (state->bitp < n)
        fill_acc(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
258

259 260 261 262
    state->bitp -= n;
    return (state->acc >> state->bitp) & ((1ULL << n) - 1);
}

263
static inline uint32_t direct_get_fs(struct aec_stream *strm)
264 265 266 267
{
    /**
       Interpret a Fundamental Sequence from the input buffer.

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
268
       Essentially counts the number of 0 bits until a 1 is
269
       encountered.
270 271
     */

272
    uint32_t fs = 0;
273
#if HAVE_DECL___BUILTIN_CLZLL||HAVE_BSR64
274
    uint32_t lz;
275
#endif
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
276
    struct internal_state *state = strm->state;
277

278 279
    state->acc &= ((1ULL << state->bitp) - 1);

280 281 282
    while (state->acc == 0) {
        fs += state->bitp;
        state->bitp = 0;
283
        fill_acc(strm);
284
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
285

Thomas Jahns's avatar
Thomas Jahns committed
286
#if HAVE_DECL___BUILTIN_CLZLL
287 288 289
    lz = __builtin_clzll(state->acc);
    fs += lz + state->bitp - 64;
    state->bitp = 63 - lz;
290 291 292 293
#elif HAVE_BSR64
    _BitScanReverse64(&lz, state->acc);
    fs += state->bitp - 1 - lz;
    state->bitp = lz;
294
#else
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
295 296 297
    state->bitp--;
    while ((state->acc & (1ULL << state->bitp)) == 0) {
        state->bitp--;
298
        fs++;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
299
    }
300
#endif
301 302 303
    return fs;
}

304
static inline uint32_t bits_ask(struct aec_stream *strm, int n)
305 306 307 308 309 310 311 312 313 314 315 316
{
    while (strm->state->bitp < n) {
        if (strm->avail_in == 0)
            return 0;
        strm->avail_in--;
        strm->state->acc <<= 8;
        strm->state->acc |= *strm->next_in++;
        strm->state->bitp += 8;
    }
    return 1;
}

317
static inline uint32_t bits_get(struct aec_stream *strm, int n)
318 319 320 321 322
{
    return (strm->state->acc >> (strm->state->bitp - n))
        & ((1ULL << n) - 1);
}

323
static inline void bits_drop(struct aec_stream *strm, int n)
324 325 326 327
{
    strm->state->bitp -= n;
}

328
static inline uint32_t fs_ask(struct aec_stream *strm)
329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346
{
    if (bits_ask(strm, 1) == 0)
        return 0;
    while ((strm->state->acc & (1ULL << (strm->state->bitp - 1))) == 0) {
        if (strm->state->bitp == 1) {
            if (strm->avail_in == 0)
                return 0;
            strm->avail_in--;
            strm->state->acc <<= 8;
            strm->state->acc |= *strm->next_in++;
            strm->state->bitp += 8;
        }
        strm->state->fs++;
        strm->state->bitp--;
    }
    return 1;
}

347
static inline void fs_drop(struct aec_stream *strm)
348 349 350 351 352
{
    strm->state->fs = 0;
    strm->state->bitp--;
}

353
static inline uint32_t copysample(struct aec_stream *strm)
354
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
355
    if (bits_ask(strm, strm->bits_per_sample) == 0
356 357
        || strm->avail_out == 0)
        return 0;
358

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
359 360
    put_sample(strm, bits_get(strm, strm->bits_per_sample));
    bits_drop(strm, strm->bits_per_sample);
361 362
    return 1;
}
363 364 365 366 367

static int m_id(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;

368 369
    if (state->rsip == state->rsi_buffer) {
        if(strm->flags & AEC_PAD_RSI)
370
            state->bitp -= state->bitp % 8;
371 372 373
        if (state->pp)
            state->ref = 1;
    } else {
374
        state->ref = 0;
375
    }
376 377 378 379
    if (bits_ask(strm, state->id_len) == 0)
        return M_EXIT;
    state->id = bits_get(strm, state->id_len);
    bits_drop(strm, state->id_len);
380 381 382 383 384 385 386 387 388 389 390
    state->mode = state->id_table[state->id];

    return M_CONTINUE;
}

static int m_split_output(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;
    int k = state->id - 1;

    do {
391
        if (bits_ask(strm, k) == 0 || strm->avail_out == 0)
392
            return M_EXIT;
393 394
        *state->rsip++ += bits_get(strm, k);
        strm->avail_out -= state->bytes_per_sample;
395
        bits_drop(strm, k);
396
    } while(++state->i < state->n);
397

398
    check_rsi_end(strm);
399 400 401 402 403 404 405
    state->mode = m_id;
    return M_CONTINUE;
}

static int m_split_fs(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;
406
    int k = state->id - 1;
407 408

    do {
409 410
        if (fs_ask(strm) == 0)
            return M_EXIT;
411
        state->rsip[state->i] = state->fs << k;
412
        fs_drop(strm);
413
    } while(++state->i < state->n);
414

415
    state->i = 0;
416 417 418 419 420 421
    state->mode = m_split_output;
    return M_CONTINUE;
}

static int m_split(struct aec_stream *strm)
{
422
    int i, k;
423 424
    struct internal_state *state = strm->state;

425 426 427 428
    if (BUFFERSPACE(strm)) {
        k = state->id - 1;

        if (state->ref)
429
            *state->rsip++ = direct_get(strm, strm->bits_per_sample);
430

431
        for (i = 0; i < strm->block_size - state->ref; i++)
432
            state->rsip[i] = direct_get_fs(strm) << k;
433

434
        for (i = state->ref; i < strm->block_size; i++)
435
            *state->rsip++ += direct_get(strm, k);
436

437
        strm->avail_out -= state->out_blklen;
438
        check_rsi_end(strm);
439

440 441 442 443 444
        state->mode = m_id;
        return M_CONTINUE;
    }

    if (state->ref) {
445 446
        if (copysample(strm) == 0)
            return M_EXIT;
447 448 449 450 451
        state->n = strm->block_size - 1;
    } else {
        state->n = strm->block_size;
    }

452
    state->i = 0;
453 454 455 456 457 458 459 460
    state->mode = m_split_fs;
    return M_CONTINUE;
}

static int m_zero_output(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;

461 462 463 464 465
    do {
        if (strm->avail_out == 0)
            return M_EXIT;
        put_sample(strm, 0);
    } while(--state->i);
466 467 468 469 470 471 472

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_zero_block(struct aec_stream *strm)
{
473
    int i, zero_blocks, b, zero_bytes;
474 475
    struct internal_state *state = strm->state;

476 477
    if (fs_ask(strm) == 0)
        return M_EXIT;
478
    zero_blocks = state->fs + 1;
479
    fs_drop(strm);
480 481

    if (zero_blocks == ROS) {
482
        b = (state->rsip - state->rsi_buffer) / strm->block_size;
483 484 485 486 487 488
        zero_blocks = MIN(strm->rsi - b, 64 - (b % 64));
    } else if (zero_blocks > ROS) {
        zero_blocks--;
    }

    if (state->ref)
489
        i = zero_blocks * strm->block_size - 1;
490
    else
491
        i = zero_blocks * strm->block_size;
492

493
    zero_bytes = i * state->bytes_per_sample;
494

495
    if (strm->avail_out >= zero_bytes) {
496 497 498
        if (state->rsi_size - (state->rsip - state->rsi_buffer) < i)
            return M_ERROR;

499 500
        memset(state->rsip, 0, i * sizeof(uint32_t));
        state->rsip += i;
501
        strm->avail_out -= zero_bytes;
502
        check_rsi_end(strm);
503

504 505 506 507
        state->mode = m_id;
        return M_CONTINUE;
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
508
    state->i = i;
509 510 511 512 513 514
    state->mode = m_zero_output;
    return M_CONTINUE;
}

static int m_se_decode(struct aec_stream *strm)
{
515
    int32_t m, d1;
516 517 518
    struct internal_state *state = strm->state;

    while(state->i < strm->block_size) {
519 520
        if (fs_ask(strm) == 0)
            return M_EXIT;
521
        m = state->fs;
522
        d1 = m - state->se_table[2 * m + 1];
523 524

        if ((state->i & 1) == 0) {
525 526 527
            if (strm->avail_out == 0)
                return M_EXIT;
            put_sample(strm, state->se_table[2 * m] - d1);
528 529 530
            state->i++;
        }

531 532 533
        if (strm->avail_out == 0)
            return M_EXIT;
        put_sample(strm, d1);
534
        state->i++;
535
        fs_drop(strm);
536 537 538 539 540 541 542 543
    }

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_se(struct aec_stream *strm)
{
544 545
    int i;
    int32_t m, d1;
546 547
    struct internal_state *state = strm->state;

548 549 550 551 552 553 554 555 556 557 558 559 560 561
    if (BUFFERSPACE(strm)) {
        i = state->ref;

        while (i < strm->block_size) {
            m = direct_get_fs(strm);
            d1 = m - state->se_table[2 * m + 1];

            if ((i & 1) == 0) {
                put_sample(strm, state->se_table[2 * m] - d1);
                i++;
            }
            put_sample(strm, d1);
            i++;
        }
562 563 564 565 566 567 568 569 570 571 572 573 574
        state->mode = m_id;
        return M_CONTINUE;
    }

    state->mode = m_se_decode;
    state->i = state->ref;
    return M_CONTINUE;
}

static int m_low_entropy_ref(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;

575 576
    if (state->ref && copysample(strm) == 0)
        return M_EXIT;
577 578 579 580 581 582 583 584 585 586 587 588 589 590

    if(state->id == 1) {
        state->mode = m_se;
        return M_CONTINUE;
    }

    state->mode = m_zero_block;
    return M_CONTINUE;
}

static int m_low_entropy(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;

591 592 593 594
    if (bits_ask(strm, 1) == 0)
        return M_EXIT;
    state->id = bits_get(strm, 1);
    bits_drop(strm, 1);
595 596 597 598 599 600 601 602
    state->mode = m_low_entropy_ref;
    return M_CONTINUE;
}

static int m_uncomp_copy(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;

603 604 605 606
    do {
        if (copysample(strm) == 0)
            return M_EXIT;
    } while(--state->i);
607 608 609 610 611 612 613

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_uncomp(struct aec_stream *strm)
{
614
    int i;
615 616
    struct internal_state *state = strm->state;

617
    if (BUFFERSPACE(strm)) {
618
        for (i = 0; i < strm->block_size; i++)
619
            *state->rsip++ = direct_get(strm, strm->bits_per_sample);
620
        strm->avail_out -= state->out_blklen;
621
        check_rsi_end(strm);
622

623 624 625 626 627 628 629 630 631
        state->mode = m_id;
        return M_CONTINUE;
    }

    state->i = strm->block_size;
    state->mode = m_uncomp_copy;
    return M_CONTINUE;
}

632 633 634 635 636 637 638 639 640 641 642 643 644 645 646
static void create_se_table(int *table)
{
    int i, j, k, ms;

    k = 0;
    for (i = 0; i < 13; i++) {
        ms = k;
        for (j = 0; j <= i; j++) {
            table[2 * k] = i;
            table[2 * k + 1] = ms;
            k++;
        }
    }
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
647
int aec_decode_init(struct aec_stream *strm)
648
{
649
    int i, modi;
650
    struct internal_state *state;
651

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
652
    if (strm->bits_per_sample > 32 || strm->bits_per_sample == 0)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
653
        return AEC_CONF_ERROR;
654

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
655
    state = malloc(sizeof(struct internal_state));
656
    if (state == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
657
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
658

659 660
    create_se_table(state->se_table);

661 662
    strm->state = state;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
663
    if (strm->bits_per_sample > 16) {
664
        state->id_len = 5;
665

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
666 667
        if (strm->bits_per_sample <= 24 && strm->flags & AEC_DATA_3BYTE) {
            state->bytes_per_sample = 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
668
            if (strm->flags & AEC_DATA_MSB)
669
                state->flush_output = flush_msb_24;
670
            else
671
                state->flush_output = flush_lsb_24;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
672
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
673
            state->bytes_per_sample = 4;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
674
            if (strm->flags & AEC_DATA_MSB)
675
                state->flush_output = flush_msb_32;
676
            else
677
                state->flush_output = flush_lsb_32;
678 679
        }
        state->out_blklen = strm->block_size
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
680
            * state->bytes_per_sample;
681
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
682 683
    else if (strm->bits_per_sample > 8) {
        state->bytes_per_sample = 2;
684
        state->id_len = 4;
685
        state->out_blklen = strm->block_size * 2;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
686
        if (strm->flags & AEC_DATA_MSB)
687
            state->flush_output = flush_msb_16;
688
        else
689
            state->flush_output = flush_lsb_16;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
690
    } else {
691
        if (strm->flags & AEC_RESTRICTED) {
692 693 694 695 696 697 698 699 700 701 702 703
            if (strm->bits_per_sample <= 4) {
                if (strm->bits_per_sample <= 2)
                    state->id_len = 1;
                else
                    state->id_len = 2;
            } else {
                return AEC_CONF_ERROR;
            }
        } else {
            state->id_len = 3;
        }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
704
        state->bytes_per_sample = 1;
705
        state->out_blklen = strm->block_size;
706
        state->flush_output = flush_8;
707 708
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
709
    if (strm->flags & AEC_DATA_SIGNED) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
710 711
        state->xmin = -(1ULL << (strm->bits_per_sample - 1));
        state->xmax = (1ULL << (strm->bits_per_sample - 1)) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
712
    } else {
713
        state->xmin = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
714
        state->xmax = (1ULL << strm->bits_per_sample) - 1;
715
    }
716

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
717
    state->in_blklen = (strm->block_size * strm->bits_per_sample
718
                        + state->id_len) / 8 + 9;
719 720

    modi = 1UL << state->id_len;
721
    state->id_table = malloc(modi * sizeof(int (*)(struct aec_stream *)));
722
    if (state->id_table == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
723
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
724

725
    state->id_table[0] = m_low_entropy;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
726
    for (i = 1; i < modi - 1; i++) {
727
        state->id_table[i] = m_split;
728
    }
729
    state->id_table[modi - 1] = m_uncomp;
730

731 732 733
    state->rsi_size = strm->rsi * strm->block_size;
    state->rsi_buffer = malloc(state->rsi_size * sizeof(uint32_t));
    if (state->rsi_buffer == NULL)
734 735
        return AEC_MEM_ERROR;

736 737 738
    strm->total_in = 0;
    strm->total_out = 0;

739 740
    state->rsip = state->rsi_buffer;
    state->flush_start = state->rsi_buffer;
741
    state->bitp = 0;
742
    state->fs = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
743
    state->pp = strm->flags & AEC_DATA_PREPROCESS;
744
    state->mode = m_id;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
745
    return AEC_OK;
746 747
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
748
int aec_decode(struct aec_stream *strm, int flush)
749
{
750 751 752 753 754 755 756 757 758
    /**
       Finite-state machine implementation of the adaptive entropy
       decoder.

       Can work with one byte input und one sample output buffers. If
       enough buffer space is available, then faster implementations
       of the states are called. Inspired by zlib.
    */

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
759
    struct internal_state *state = strm->state;
760
    int status;
761

762 763 764
    strm->total_in += strm->avail_in;
    strm->total_out += strm->avail_out;

765 766 767 768 769 770 771
    do {
        status = state->mode(strm);
    } while (status == M_CONTINUE);

    if (status == M_ERROR)
        return AEC_DATA_ERROR;

772
    state->flush_output(strm);
773 774 775 776

    strm->total_in -= strm->avail_in;
    strm->total_out -= strm->avail_out;

777 778
    return AEC_OK;
}
779

780 781
int aec_decode_end(struct aec_stream *strm)
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
782
    struct internal_state *state = strm->state;
783

784
    free(state->id_table);
785
    free(state->rsi_buffer);
786
    free(state);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
787
    return AEC_OK;
788
}
789

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
790
int aec_buffer_decode(struct aec_stream *strm)
791 792 793 794 795 796 797 798 799 800 801
{
    int status;

    status = aec_decode_init(strm);
    if (status != AEC_OK)
        return status;

    status = aec_decode(strm, AEC_FLUSH);
    aec_decode_end(strm);
    return status;
}