decode.c 22.5 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 50 51 52
 * @section DESCRIPTION
 *
 * Adaptive Entropy Decoder
 * Based on CCSDS documents 121.0-B-2 and 120.0-G-2
 *
 */
53

54 55 56 57 58 59
#include <config.h>

#if HAVE_STDINT_H
# include <stdint.h>
#endif

60 61 62 63 64
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
65
#include "libaec.h"
66
#include "decode.h"
67

68 69 70 71 72
#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
73
#define FLUSH(KIND)                                                     \
74 75
    static void flush_##KIND(struct aec_stream *strm)                   \
    {                                                                   \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
76
        uint32_t *bp, *flush_end;                                       \
77
        int64_t d, m;                                                   \
Moritz Hanke's avatar
Moritz Hanke committed
78
        int64_t data, med, half_d, xmin, xmax;                          \
79 80
        struct internal_state *state = strm->state;                     \
                                                                        \
81
        flush_end = state->rsip;                                        \
82
        if (state->pp) {                                                \
83 84 85
            if (state->flush_start == state->rsi_buffer                 \
                && state->rsip > state->rsi_buffer) {                   \
                state->last_out = *state->rsi_buffer;                   \
86 87
                                                                        \
                if (strm->flags & AEC_DATA_SIGNED) {                    \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
88
                    m = 1ULL << (strm->bits_per_sample - 1);            \
89
                    /* Reference samples have to be sign extended */    \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
90
                    state->last_out = (state->last_out ^ m) - m;        \
91
                }                                                       \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
92
                put_##KIND(strm, state->last_out);                      \
93
                state->flush_start++;                                   \
94 95
            }                                                           \
                                                                        \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
96 97 98 99 100 101
            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
102 103 104
            xmin = state->xmin;                                         \
            xmax = state->xmax;                                         \
                                                                        \
105 106
            for (bp = state->flush_start; bp < flush_end; bp++) {       \
                d = *bp;                                                \
Moritz Hanke's avatar
Moritz Hanke committed
107 108 109 110 111 112 113 114 115 116 117
                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;                                \
                    }                                                   \
118
                } else {                                                \
Moritz Hanke's avatar
Moritz Hanke committed
119 120 121 122 123 124 125 126
                    if (half_d <= xmax - data) {                        \
                        if (d & 1)                                      \
                            data -= half_d;                             \
                        else                                            \
                            data += half_d;                             \
                    } else {                                            \
                        data = xmax - d;                                \
                    }                                                   \
127
                }                                                       \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
128
                put_##KIND(strm, data);                                 \
129
            }                                                           \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
130
            state->last_out = data;                                     \
131
        } else {                                                        \
132 133
            for (bp = state->flush_start; bp < flush_end; bp++)         \
                put_##KIND(strm, *bp);                                  \
134
        }                                                               \
135
        state->flush_start = state->rsip;                               \
136
    }
137

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192

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);
193

194
static inline void check_rsi_end(struct aec_stream *strm)
195
{
196
    /**
197
       Flush output if end of RSI reached
198
     */
199
    struct internal_state *state = strm->state;
200

201
    if (state->rsip - state->rsi_buffer == state->rsi_size) {
202
        state->flush_output(strm);
203 204
        state->flush_start = state->rsi_buffer;
        state->rsip = state->rsi_buffer;
205 206
        if (strm->flags & AEC_PAD_RSI)
            state->bitp -= state->bitp % 8;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
207
    }
208 209
}

210
static inline void put_sample(struct aec_stream *strm, uint32_t s)
211 212 213
{
    struct internal_state *state = strm->state;

214
    *state->rsip++ = s;
215
    strm->avail_out -= state->bytes_per_sample;
216
    check_rsi_end(strm);
217 218
}

219 220 221 222 223 224
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
225 226 227 228 229 230 231 232 233

    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):
234
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
Moritz Hanke's avatar
Moritz Hanke committed
235 236 237 238 239 240 241 242
      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++;
    };

243 244 245
}

static inline uint32_t direct_get(struct aec_stream *strm, unsigned int n)
246 247
{
    /**
248
       Get n bit from input stream
249 250 251 252

       No checking whatsoever. Read bits are dumped.
     */

253
    struct internal_state *state = strm->state;
254

255 256
    if (state->bitp < n)
        fill_acc(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
257

258 259 260 261
    state->bitp -= n;
    return (state->acc >> state->bitp) & ((1ULL << n) - 1);
}

262
static inline uint32_t direct_get_fs(struct aec_stream *strm)
263 264 265 266
{
    /**
       Interpret a Fundamental Sequence from the input buffer.

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
267
       Essentially counts the number of 0 bits until a 1 is
268
       encountered.
269 270
     */

271
    uint32_t fs = 0;
272
#ifdef HAVE_DECL___BUILTIN_CLZLL
273
    uint32_t lz;
274
#endif
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
275
    struct internal_state *state = strm->state;
276

277 278
    state->acc &= ((1ULL << state->bitp) - 1);

279 280 281
    while (state->acc == 0) {
        fs += state->bitp;
        state->bitp = 0;
282
        fill_acc(strm);
283
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
284

285
#ifdef HAVE_DECL___BUILTIN_CLZLL
286 287 288
    lz = __builtin_clzll(state->acc);
    fs += lz + state->bitp - 64;
    state->bitp = 63 - lz;
289
#else
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
290 291 292
    state->bitp--;
    while ((state->acc & (1ULL << state->bitp)) == 0) {
        state->bitp--;
293
        fs++;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
294
    }
295
#endif
296 297 298
    return fs;
}

299
static inline uint32_t bits_ask(struct aec_stream *strm, int n)
300 301 302 303 304 305 306 307 308 309 310 311
{
    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;
}

312
static inline uint32_t bits_get(struct aec_stream *strm, int n)
313 314 315 316 317
{
    return (strm->state->acc >> (strm->state->bitp - n))
        & ((1ULL << n) - 1);
}

318
static inline void bits_drop(struct aec_stream *strm, int n)
319 320 321 322
{
    strm->state->bitp -= n;
}

323
static inline uint32_t fs_ask(struct aec_stream *strm)
324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341
{
    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;
}

342
static inline void fs_drop(struct aec_stream *strm)
343 344 345 346 347
{
    strm->state->fs = 0;
    strm->state->bitp--;
}

348
static inline uint32_t copysample(struct aec_stream *strm)
349
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
350
    if (bits_ask(strm, strm->bits_per_sample) == 0
351 352
        || strm->avail_out == 0)
        return 0;
353

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
354 355
    put_sample(strm, bits_get(strm, strm->bits_per_sample));
    bits_drop(strm, strm->bits_per_sample);
356 357
    return 1;
}
358 359 360 361 362

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

363
    if (state->pp && state->rsip == state->rsi_buffer)
364 365 366 367
        state->ref = 1;
    else
        state->ref = 0;

368 369 370 371
    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);
372 373 374 375 376 377 378 379 380 381 382
    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 {
383
        if (bits_ask(strm, k) == 0 || strm->avail_out == 0)
384
            return M_EXIT;
385 386
        *state->rsip++ += bits_get(strm, k);
        strm->avail_out -= state->bytes_per_sample;
387
        bits_drop(strm, k);
388
    } while(++state->i < state->n);
389

390
    check_rsi_end(strm);
391 392 393 394 395 396 397
    state->mode = m_id;
    return M_CONTINUE;
}

static int m_split_fs(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;
398
    int k = state->id - 1;
399 400

    do {
401 402
        if (fs_ask(strm) == 0)
            return M_EXIT;
403
        state->rsip[state->i] = state->fs << k;
404
        fs_drop(strm);
405
    } while(++state->i < state->n);
406

407
    state->i = 0;
408 409 410 411 412 413
    state->mode = m_split_output;
    return M_CONTINUE;
}

static int m_split(struct aec_stream *strm)
{
414
    int i, k;
415 416
    struct internal_state *state = strm->state;

417 418 419 420
    if (BUFFERSPACE(strm)) {
        k = state->id - 1;

        if (state->ref)
421
            *state->rsip++ = direct_get(strm, strm->bits_per_sample);
422

423
        for (i = 0; i < strm->block_size - state->ref; i++)
424
            state->rsip[i] = direct_get_fs(strm) << k;
425

426
        for (i = state->ref; i < strm->block_size; i++)
427
            *state->rsip++ += direct_get(strm, k);
428

429
        strm->avail_out -= state->out_blklen;
430
        check_rsi_end(strm);
431

432 433 434 435 436
        state->mode = m_id;
        return M_CONTINUE;
    }

    if (state->ref) {
437 438
        if (copysample(strm) == 0)
            return M_EXIT;
439 440 441 442 443
        state->n = strm->block_size - 1;
    } else {
        state->n = strm->block_size;
    }

444
    state->i = 0;
445 446 447 448 449 450 451 452
    state->mode = m_split_fs;
    return M_CONTINUE;
}

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

453 454 455 456 457
    do {
        if (strm->avail_out == 0)
            return M_EXIT;
        put_sample(strm, 0);
    } while(--state->i);
458 459 460 461 462 463 464

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_zero_block(struct aec_stream *strm)
{
465
    int i, zero_blocks, b, zero_bytes;
466 467
    struct internal_state *state = strm->state;

468 469
    if (fs_ask(strm) == 0)
        return M_EXIT;
470
    zero_blocks = state->fs + 1;
471
    fs_drop(strm);
472 473

    if (zero_blocks == ROS) {
474
        b = (state->rsip - state->rsi_buffer) / strm->block_size;
475 476 477 478 479 480
        zero_blocks = MIN(strm->rsi - b, 64 - (b % 64));
    } else if (zero_blocks > ROS) {
        zero_blocks--;
    }

    if (state->ref)
481
        i = zero_blocks * strm->block_size - 1;
482
    else
483
        i = zero_blocks * strm->block_size;
484

485
    zero_bytes = i * state->bytes_per_sample;
486

487
    if (strm->avail_out >= zero_bytes) {
488 489 490
        if (state->rsi_size - (state->rsip - state->rsi_buffer) < i)
            return M_ERROR;

491 492
        memset(state->rsip, 0, i * sizeof(uint32_t));
        state->rsip += i;
493
        strm->avail_out -= zero_bytes;
494
        check_rsi_end(strm);
495

496 497 498 499
        state->mode = m_id;
        return M_CONTINUE;
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
500
    state->i = i;
501 502 503 504 505 506
    state->mode = m_zero_output;
    return M_CONTINUE;
}

static int m_se_decode(struct aec_stream *strm)
{
507
    int32_t m, d1;
508 509 510
    struct internal_state *state = strm->state;

    while(state->i < strm->block_size) {
511 512
        if (fs_ask(strm) == 0)
            return M_EXIT;
513
        m = state->fs;
514
        d1 = m - state->se_table[2 * m + 1];
515 516

        if ((state->i & 1) == 0) {
517 518 519
            if (strm->avail_out == 0)
                return M_EXIT;
            put_sample(strm, state->se_table[2 * m] - d1);
520 521 522
            state->i++;
        }

523 524 525
        if (strm->avail_out == 0)
            return M_EXIT;
        put_sample(strm, d1);
526
        state->i++;
527
        fs_drop(strm);
528 529 530 531 532 533 534 535
    }

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_se(struct aec_stream *strm)
{
536 537
    int i;
    int32_t m, d1;
538 539
    struct internal_state *state = strm->state;

540 541 542 543 544 545 546 547 548 549 550 551 552 553
    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++;
        }
554 555 556 557 558 559 560 561 562 563 564 565 566
        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;

567 568
    if (state->ref && copysample(strm) == 0)
        return M_EXIT;
569 570 571 572 573 574 575 576 577 578 579 580 581 582

    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;

583 584 585 586
    if (bits_ask(strm, 1) == 0)
        return M_EXIT;
    state->id = bits_get(strm, 1);
    bits_drop(strm, 1);
587 588 589 590 591 592 593 594
    state->mode = m_low_entropy_ref;
    return M_CONTINUE;
}

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

595 596 597 598
    do {
        if (copysample(strm) == 0)
            return M_EXIT;
    } while(--state->i);
599 600 601 602 603 604 605

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_uncomp(struct aec_stream *strm)
{
606
    int i;
607 608
    struct internal_state *state = strm->state;

609
    if (BUFFERSPACE(strm)) {
610
        for (i = 0; i < strm->block_size; i++)
611
            *state->rsip++ = direct_get(strm, strm->bits_per_sample);
612
        strm->avail_out -= state->out_blklen;
613
        check_rsi_end(strm);
614

615 616 617 618 619 620 621 622 623
        state->mode = m_id;
        return M_CONTINUE;
    }

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

624 625 626 627 628 629 630 631 632 633 634 635 636 637 638
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
639
int aec_decode_init(struct aec_stream *strm)
640
{
641
    int i, modi;
642
    struct internal_state *state;
643

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
644
    if (strm->bits_per_sample > 32 || strm->bits_per_sample == 0)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
645
        return AEC_CONF_ERROR;
646

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
647
    state = malloc(sizeof(struct internal_state));
648
    if (state == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
649
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
650

651 652
    create_se_table(state->se_table);

653 654
    strm->state = state;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
655
    if (strm->bits_per_sample > 16) {
656
        state->id_len = 5;
657

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
658 659
        if (strm->bits_per_sample <= 24 && strm->flags & AEC_DATA_3BYTE) {
            state->bytes_per_sample = 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
660
            if (strm->flags & AEC_DATA_MSB)
661
                state->flush_output = flush_msb_24;
662
            else
663
                state->flush_output = flush_lsb_24;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
664
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
665
            state->bytes_per_sample = 4;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
666
            if (strm->flags & AEC_DATA_MSB)
667
                state->flush_output = flush_msb_32;
668
            else
669
                state->flush_output = flush_lsb_32;
670 671
        }
        state->out_blklen = strm->block_size
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
672
            * state->bytes_per_sample;
673
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
674 675
    else if (strm->bits_per_sample > 8) {
        state->bytes_per_sample = 2;
676
        state->id_len = 4;
677
        state->out_blklen = strm->block_size * 2;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
678
        if (strm->flags & AEC_DATA_MSB)
679
            state->flush_output = flush_msb_16;
680
        else
681
            state->flush_output = flush_lsb_16;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
682
    } else {
683
        if (strm->flags & AEC_RESTRICTED) {
684 685 686 687 688 689 690 691 692 693 694 695
            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
696
        state->bytes_per_sample = 1;
697
        state->out_blklen = strm->block_size;
698
        state->flush_output = flush_8;
699 700
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
701
    if (strm->flags & AEC_DATA_SIGNED) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
702 703
        state->xmin = -(1ULL << (strm->bits_per_sample - 1));
        state->xmax = (1ULL << (strm->bits_per_sample - 1)) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
704
    } else {
705
        state->xmin = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
706
        state->xmax = (1ULL << strm->bits_per_sample) - 1;
707
    }
708

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
709
    state->in_blklen = (strm->block_size * strm->bits_per_sample
710
                        + state->id_len) / 8 + 9;
711 712

    modi = 1UL << state->id_len;
713
    state->id_table = malloc(modi * sizeof(int (*)(struct aec_stream *)));
714
    if (state->id_table == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
715
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
716

717
    state->id_table[0] = m_low_entropy;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
718
    for (i = 1; i < modi - 1; i++) {
719
        state->id_table[i] = m_split;
720
    }
721
    state->id_table[modi - 1] = m_uncomp;
722

723 724 725
    state->rsi_size = strm->rsi * strm->block_size;
    state->rsi_buffer = malloc(state->rsi_size * sizeof(uint32_t));
    if (state->rsi_buffer == NULL)
726 727
        return AEC_MEM_ERROR;

728 729 730
    strm->total_in = 0;
    strm->total_out = 0;

731 732
    state->rsip = state->rsi_buffer;
    state->flush_start = state->rsi_buffer;
733
    state->bitp = 0;
734
    state->fs = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
735
    state->pp = strm->flags & AEC_DATA_PREPROCESS;
736
    state->mode = m_id;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
737
    return AEC_OK;
738 739
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
740
int aec_decode(struct aec_stream *strm, int flush)
741
{
742 743 744 745 746 747 748 749 750
    /**
       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
751
    struct internal_state *state = strm->state;
752
    int status;
753

754 755 756
    strm->total_in += strm->avail_in;
    strm->total_out += strm->avail_out;

757 758 759 760 761 762 763
    do {
        status = state->mode(strm);
    } while (status == M_CONTINUE);

    if (status == M_ERROR)
        return AEC_DATA_ERROR;

764
    state->flush_output(strm);
765 766 767 768

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

769 770
    return AEC_OK;
}
771

772 773
int aec_decode_end(struct aec_stream *strm)
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
774
    struct internal_state *state = strm->state;
775

776
    free(state->id_table);
777
    free(state->rsi_buffer);
778
    free(state);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
779
    return AEC_OK;
780
}
781

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
782
int aec_buffer_decode(struct aec_stream *strm)
783 784 785 786 787 788 789 790 791 792 793
{
    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;
}