decode.c 21.9 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 10 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
 * @author Moritz Hanke, Deutsches Klimarechenzentrum
 * @author Joerg Behrens, Deutsches Klimarechenzentrum
 * @author Luis Kornblueh, Max-Planck-Institut fuer Meteorologie
 *
 * @section LICENSE
 * Copyright 2012
 *
 * 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)                   \
    {                                                                   \
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
            }                                                           \
                                                                        \
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
            }                                                           \
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;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
205
    }
206 207
}

208
static inline void put_sample(struct aec_stream *strm, uint32_t s)
209 210 211
{
    struct internal_state *state = strm->state;

212
    *state->rsip++ = s;
213
    strm->avail_out -= state->bytes_per_sample;
214
    check_rsi_end(strm);
215 216
}

217 218 219 220 221 222
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
223 224 225 226 227 228 229 230 231

    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):
232
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
Moritz Hanke's avatar
Moritz Hanke committed
233 234 235 236 237 238 239 240
      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++;
    };

241 242 243
}

static inline uint32_t direct_get(struct aec_stream *strm, unsigned int n)
244 245
{
    /**
246
       Get n bit from input stream
247 248 249 250

       No checking whatsoever. Read bits are dumped.
     */

251
    struct internal_state *state = strm->state;
252

253 254
    if (state->bitp < n)
        fill_acc(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
255

256 257 258 259
    state->bitp -= n;
    return (state->acc >> state->bitp) & ((1ULL << n) - 1);
}

260
static inline uint32_t direct_get_fs(struct aec_stream *strm)
261 262 263 264
{
    /**
       Interpret a Fundamental Sequence from the input buffer.

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
265 266 267 268
       Essentially counts the number of 0 bits until a 1 is
       encountered. The longest FS we can safely detect is 56 bits. If
       no FS is found in accumulator then we top it up to at least 56
       bits.
269 270
     */

271
    uint32_t fs = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
272
    struct internal_state *state = strm->state;
273

274 275 276
    state->acc &= ((1ULL << state->bitp) - 1);

    if (state->acc == 0)
277
        fill_acc(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
278

279
#ifdef HAVE_DECL___BUILTIN_CLZLL
280 281 282
    fs = __builtin_clzll(state->acc) - (64 - state->bitp);
    state->bitp -= fs + 1;
#else
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
283 284 285
    state->bitp--;
    while ((state->acc & (1ULL << state->bitp)) == 0) {
        state->bitp--;
286
        fs++;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
287
    }
288
#endif
289 290 291
    return fs;
}

292
static inline uint32_t bits_ask(struct aec_stream *strm, int n)
293 294 295 296 297 298 299 300 301 302 303 304
{
    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;
}

305
static inline uint32_t bits_get(struct aec_stream *strm, int n)
306 307 308 309 310
{
    return (strm->state->acc >> (strm->state->bitp - n))
        & ((1ULL << n) - 1);
}

311
static inline void bits_drop(struct aec_stream *strm, int n)
312 313 314 315
{
    strm->state->bitp -= n;
}

316
static inline uint32_t fs_ask(struct aec_stream *strm)
317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334
{
    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;
}

335
static inline void fs_drop(struct aec_stream *strm)
336 337 338 339 340
{
    strm->state->fs = 0;
    strm->state->bitp--;
}

341
static inline uint32_t copysample(struct aec_stream *strm)
342
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
343
    if (bits_ask(strm, strm->bits_per_sample) == 0
344 345
        || strm->avail_out == 0)
        return 0;
346

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
347 348
    put_sample(strm, bits_get(strm, strm->bits_per_sample));
    bits_drop(strm, strm->bits_per_sample);
349 350
    return 1;
}
351 352 353 354 355

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

356
    if (state->pp && state->rsip == state->rsi_buffer)
357 358 359 360
        state->ref = 1;
    else
        state->ref = 0;

361 362 363 364
    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);
365 366 367 368 369 370 371 372 373 374 375
    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 {
376
        if (bits_ask(strm, k) == 0 || strm->avail_out == 0)
377
            return M_EXIT;
378 379
        *state->rsip++ += bits_get(strm, k);
        strm->avail_out -= state->bytes_per_sample;
380
        bits_drop(strm, k);
381
    } while(++state->i < state->n);
382

383
    check_rsi_end(strm);
384 385 386 387 388 389 390
    state->mode = m_id;
    return M_CONTINUE;
}

static int m_split_fs(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;
391
    int k = state->id - 1;
392 393

    do {
394 395
        if (fs_ask(strm) == 0)
            return M_EXIT;
396
        state->rsip[state->i] = state->fs << k;
397
        fs_drop(strm);
398
    } while(++state->i < state->n);
399

400
    state->i = 0;
401 402 403 404 405 406
    state->mode = m_split_output;
    return M_CONTINUE;
}

static int m_split(struct aec_stream *strm)
{
407
    int i, k;
408 409
    struct internal_state *state = strm->state;

410 411 412 413
    if (BUFFERSPACE(strm)) {
        k = state->id - 1;

        if (state->ref)
414
            *state->rsip++ = direct_get(strm, strm->bits_per_sample);
415

416
        for (i = 0; i < strm->block_size - state->ref; i++)
417
            state->rsip[i] = direct_get_fs(strm) << k;
418

419
        for (i = state->ref; i < strm->block_size; i++)
420
            *state->rsip++ += direct_get(strm, k);
421

422
        strm->avail_out -= state->out_blklen;
423
        check_rsi_end(strm);
424

425 426 427 428 429
        state->mode = m_id;
        return M_CONTINUE;
    }

    if (state->ref) {
430 431
        if (copysample(strm) == 0)
            return M_EXIT;
432 433 434 435 436
        state->n = strm->block_size - 1;
    } else {
        state->n = strm->block_size;
    }

437
    state->i = 0;
438 439 440 441 442 443 444 445
    state->mode = m_split_fs;
    return M_CONTINUE;
}

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

446 447 448 449 450
    do {
        if (strm->avail_out == 0)
            return M_EXIT;
        put_sample(strm, 0);
    } while(--state->i);
451 452 453 454 455 456 457

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_zero_block(struct aec_stream *strm)
{
458
    int i, zero_blocks, b, zero_bytes;
459 460
    struct internal_state *state = strm->state;

461 462
    if (fs_ask(strm) == 0)
        return M_EXIT;
463
    zero_blocks = state->fs + 1;
464
    fs_drop(strm);
465 466

    if (zero_blocks == ROS) {
467
        b = (state->rsip - state->rsi_buffer) / strm->block_size;
468 469 470 471 472 473
        zero_blocks = MIN(strm->rsi - b, 64 - (b % 64));
    } else if (zero_blocks > ROS) {
        zero_blocks--;
    }

    if (state->ref)
474
        i = zero_blocks * strm->block_size - 1;
475
    else
476
        i = zero_blocks * strm->block_size;
477

478 479
    zero_bytes = i * state->bytes_per_sample;
    if (strm->avail_out >= zero_bytes) {
480 481
        memset(state->rsip, 0, i * sizeof(uint32_t));
        state->rsip += i;
482
        strm->avail_out -= zero_bytes;
483
        check_rsi_end(strm);
484

485 486 487 488
        state->mode = m_id;
        return M_CONTINUE;
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
489
    state->i = i;
490 491 492 493 494 495
    state->mode = m_zero_output;
    return M_CONTINUE;
}

static int m_se_decode(struct aec_stream *strm)
{
496
    int32_t m, d1;
497 498 499
    struct internal_state *state = strm->state;

    while(state->i < strm->block_size) {
500 501
        if (fs_ask(strm) == 0)
            return M_EXIT;
502
        m = state->fs;
503
        d1 = m - state->se_table[2 * m + 1];
504 505

        if ((state->i & 1) == 0) {
506 507 508
            if (strm->avail_out == 0)
                return M_EXIT;
            put_sample(strm, state->se_table[2 * m] - d1);
509 510 511
            state->i++;
        }

512 513 514
        if (strm->avail_out == 0)
            return M_EXIT;
        put_sample(strm, d1);
515
        state->i++;
516
        fs_drop(strm);
517 518 519 520 521 522 523 524
    }

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_se(struct aec_stream *strm)
{
525 526
    int i;
    int32_t m, d1;
527 528
    struct internal_state *state = strm->state;

529 530 531 532 533 534 535 536 537 538 539 540 541 542
    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++;
        }
543 544 545 546 547 548 549 550 551 552 553 554 555
        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;

556 557
    if (state->ref && copysample(strm) == 0)
        return M_EXIT;
558 559 560 561 562 563 564 565 566 567 568 569 570 571

    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;

572 573 574 575
    if (bits_ask(strm, 1) == 0)
        return M_EXIT;
    state->id = bits_get(strm, 1);
    bits_drop(strm, 1);
576 577 578 579 580 581 582 583
    state->mode = m_low_entropy_ref;
    return M_CONTINUE;
}

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

584 585 586 587
    do {
        if (copysample(strm) == 0)
            return M_EXIT;
    } while(--state->i);
588 589 590 591 592 593 594

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_uncomp(struct aec_stream *strm)
{
595
    int i;
596 597
    struct internal_state *state = strm->state;

598
    if (BUFFERSPACE(strm)) {
599
        for (i = 0; i < strm->block_size; i++)
600
            *state->rsip++ = direct_get(strm, strm->bits_per_sample);
601
        strm->avail_out -= state->out_blklen;
602
        check_rsi_end(strm);
603

604 605 606 607 608 609 610 611 612
        state->mode = m_id;
        return M_CONTINUE;
    }

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

613 614 615 616 617 618 619 620 621 622 623 624 625 626 627
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
628
int aec_decode_init(struct aec_stream *strm)
629
{
630
    int i, modi;
631
    struct internal_state *state;
632

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
633
    if (strm->bits_per_sample > 32 || strm->bits_per_sample == 0)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
634
        return AEC_CONF_ERROR;
635

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
636
    state = malloc(sizeof(struct internal_state));
637
    if (state == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
638
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
639

640 641
    create_se_table(state->se_table);

642 643
    strm->state = state;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
644
    if (strm->bits_per_sample > 16) {
645
        state->id_len = 5;
646

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
647 648
        if (strm->bits_per_sample <= 24 && strm->flags & AEC_DATA_3BYTE) {
            state->bytes_per_sample = 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
649
            if (strm->flags & AEC_DATA_MSB)
650
                state->flush_output = flush_msb_24;
651
            else
652
                state->flush_output = flush_lsb_24;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
653
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
654
            state->bytes_per_sample = 4;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
655
            if (strm->flags & AEC_DATA_MSB)
656
                state->flush_output = flush_msb_32;
657
            else
658
                state->flush_output = flush_lsb_32;
659 660
        }
        state->out_blklen = strm->block_size
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
661
            * state->bytes_per_sample;
662
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
663 664
    else if (strm->bits_per_sample > 8) {
        state->bytes_per_sample = 2;
665
        state->id_len = 4;
666
        state->out_blklen = strm->block_size * 2;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
667
        if (strm->flags & AEC_DATA_MSB)
668
            state->flush_output = flush_msb_16;
669
        else
670
            state->flush_output = flush_lsb_16;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
671
    } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
672
        state->bytes_per_sample = 1;
673
        state->id_len = 3;
674
        state->out_blklen = strm->block_size;
675
        state->flush_output = flush_8;
676 677
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
678
    if (strm->flags & AEC_DATA_SIGNED) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
679 680
        state->xmin = -(1ULL << (strm->bits_per_sample - 1));
        state->xmax = (1ULL << (strm->bits_per_sample - 1)) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
681
    } else {
682
        state->xmin = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
683
        state->xmax = (1ULL << strm->bits_per_sample) - 1;
684
    }
685

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
686
    state->in_blklen = (strm->block_size * strm->bits_per_sample
687
                        + state->id_len) / 8 + 9;
688 689

    modi = 1UL << state->id_len;
690
    state->id_table = malloc(modi * sizeof(int (*)(struct aec_stream *)));
691
    if (state->id_table == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
692
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
693

694
    state->id_table[0] = m_low_entropy;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
695
    for (i = 1; i < modi - 1; i++) {
696
        state->id_table[i] = m_split;
697
    }
698
    state->id_table[modi - 1] = m_uncomp;
699

700 701 702
    state->rsi_size = strm->rsi * strm->block_size;
    state->rsi_buffer = malloc(state->rsi_size * sizeof(uint32_t));
    if (state->rsi_buffer == NULL)
703 704
        return AEC_MEM_ERROR;

705 706 707
    strm->total_in = 0;
    strm->total_out = 0;

708 709
    state->rsip = state->rsi_buffer;
    state->flush_start = state->rsi_buffer;
710
    state->bitp = 0;
711
    state->fs = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
712
    state->pp = strm->flags & AEC_DATA_PREPROCESS;
713
    state->mode = m_id;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
714
    return AEC_OK;
715 716
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
717
int aec_decode(struct aec_stream *strm, int flush)
718
{
719 720 721 722 723 724 725 726 727
    /**
       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
728
    struct internal_state *state = strm->state;
729

730 731 732
    strm->total_in += strm->avail_in;
    strm->total_out += strm->avail_out;

733 734
    while (state->mode(strm) == M_CONTINUE);
    state->flush_output(strm);
735 736 737 738

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

739 740
    return AEC_OK;
}
741

742 743
int aec_decode_end(struct aec_stream *strm)
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
744
    struct internal_state *state = strm->state;
745

746
    free(state->id_table);
747
    free(state->rsi_buffer);
748
    free(state);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
749
    return AEC_OK;
750
}
751

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
752
int aec_buffer_decode(struct aec_stream *strm)
753 754 755 756 757 758 759 760 761 762 763
{
    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;
}