decode.c 22.8 KB
Newer Older
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
1 2
/**
 * @file decode.c
3 4
 *
 * @section LICENSE
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
5
 * Copyright 2012 - 2014
6
 *
7 8 9 10
 * Mathis Rosenhauer, Moritz Hanke, Joerg Behrens
 * Deutsches Klimarechenzentrum GmbH
 * Bundesstr. 45a
 * 20146 Hamburg Germany
11
 *
12 13 14 15 16
 * Luis Kornblueh
 * Max-Planck-Institut fuer Meteorologie
 * Bundesstr. 53
 * 20146 Hamburg
 * Germany
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
 *
 * 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
44 45 46
 * @section DESCRIPTION
 *
 * Adaptive Entropy Decoder
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
47
 * Based on CCSDS documents 121.0-B-2 and 120.0-G-3
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
48 49
 *
 */
50 51 52 53 54

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
55
#include "libaec.h"
56
#include "decode.h"
57

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
58 59 60 61
#if HAVE_BSR64
#  include <intrin.h>
#endif

62 63 64 65 66
#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
67
#define FLUSH(KIND)                                                     \
68 69
    static void flush_##KIND(struct aec_stream *strm)                   \
    {                                                                   \
70
        uint32_t *bp, *flush_end;                                       \
71
        int64_t d, m;                                                   \
Moritz Hanke's avatar
Moritz Hanke committed
72
        int64_t data, med, half_d, xmin, xmax;                          \
73 74
        struct internal_state *state = strm->state;                     \
                                                                        \
75
        flush_end = state->rsip;                                        \
76
        if (state->pp) {                                                \
77 78 79
            if (state->flush_start == state->rsi_buffer                 \
                && state->rsip > state->rsi_buffer) {                   \
                state->last_out = *state->rsi_buffer;                   \
80 81
                                                                        \
                if (strm->flags & AEC_DATA_SIGNED) {                    \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
82
                    m = UINT64_C(1) << (strm->bits_per_sample - 1);     \
83
                    /* Reference samples have to be sign extended */    \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
84
                    state->last_out = (state->last_out ^ m) - m;        \
85
                }                                                       \
86
                put_##KIND(strm, (uint32_t)state->last_out);            \
87
                state->flush_start++;                                   \
88 89
            }                                                           \
                                                                        \
90 91 92 93 94 95
            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
96 97 98
            xmin = state->xmin;                                         \
            xmax = state->xmax;                                         \
                                                                        \
99 100
            for (bp = state->flush_start; bp < flush_end; bp++) {       \
                d = *bp;                                                \
Moritz Hanke's avatar
Moritz Hanke committed
101 102 103 104 105 106 107 108 109 110 111
                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;                                \
                    }                                                   \
112
                } else {                                                \
Moritz Hanke's avatar
Moritz Hanke committed
113 114 115 116 117 118 119 120
                    if (half_d <= xmax - data) {                        \
                        if (d & 1)                                      \
                            data -= half_d;                             \
                        else                                            \
                            data += half_d;                             \
                    } else {                                            \
                        data = xmax - d;                                \
                    }                                                   \
121
                }                                                       \
122
                put_##KIND(strm, (uint32_t)data);                       \
123
            }                                                           \
124
            state->last_out = data;                                     \
125
        } else {                                                        \
126 127
            for (bp = state->flush_start; bp < flush_end; bp++)         \
                put_##KIND(strm, *bp);                                  \
128
        }                                                               \
129
        state->flush_start = state->rsip;                               \
130
    }
131

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
132 133 134

static inline void put_msb_32(struct aec_stream *strm, uint32_t data)
{
135 136 137 138
    *strm->next_out++ = (unsigned char)(data >> 24);
    *strm->next_out++ = (unsigned char)(data >> 16);
    *strm->next_out++ = (unsigned char)(data >> 8);
    *strm->next_out++ = (unsigned char)data;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
139 140 141 142
}

static inline void put_msb_24(struct aec_stream *strm, uint32_t data)
{
143 144 145
    *strm->next_out++ = (unsigned char)(data >> 16);
    *strm->next_out++ = (unsigned char)(data >> 8);
    *strm->next_out++ = (unsigned char)data;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
146 147 148 149
}

static inline void put_msb_16(struct aec_stream *strm, uint32_t data)
{
150 151
    *strm->next_out++ = (unsigned char)(data >> 8);
    *strm->next_out++ = (unsigned char)data;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
152 153 154 155
}

static inline void put_lsb_32(struct aec_stream *strm, uint32_t data)
{
156 157 158 159
    *strm->next_out++ = (unsigned char)data;
    *strm->next_out++ = (unsigned char)(data >> 8);
    *strm->next_out++ = (unsigned char)(data >> 16);
    *strm->next_out++ = (unsigned char)(data >> 24);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
160 161 162 163
}

static inline void put_lsb_24(struct aec_stream *strm, uint32_t data)
{
164 165 166
    *strm->next_out++ = (unsigned char)data;
    *strm->next_out++ = (unsigned char)(data >> 8);
    *strm->next_out++ = (unsigned char)(data >> 16);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
167 168 169 170
}

static inline void put_lsb_16(struct aec_stream *strm, uint32_t data)
{
171 172
    *strm->next_out++ = (unsigned char)data;
    *strm->next_out++ = (unsigned char)(data >> 8);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
173 174 175 176
}

static inline void put_8(struct aec_stream *strm, uint32_t data)
{
177
    *strm->next_out++ = (unsigned char)data;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
178 179
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
180 181 182 183 184 185 186
FLUSH(msb_32)
FLUSH(msb_24)
FLUSH(msb_16)
FLUSH(lsb_32)
FLUSH(lsb_24)
FLUSH(lsb_16)
FLUSH(8)
187

188
static inline void check_rsi_end(struct aec_stream *strm)
189
{
190
    /**
191
       Flush output if end of RSI reached
192
     */
193
    struct internal_state *state = strm->state;
194

195
    if (state->rsi_size == (size_t)(state->rsip - state->rsi_buffer)) {
196
        state->flush_output(strm);
197 198
        state->flush_start = state->rsi_buffer;
        state->rsip = state->rsi_buffer;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
199
    }
200 201
}

202
static inline void put_sample(struct aec_stream *strm, uint32_t s)
203 204 205
{
    struct internal_state *state = strm->state;

206
    *state->rsip++ = s;
207
    strm->avail_out -= state->bytes_per_sample;
208
    check_rsi_end(strm);
209 210
}

211 212 213 214 215 216
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
217 218 219 220 221 222 223 224 225

    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):
226
        strm->state->acc = (strm->state->acc << 8) | *strm->next_in++;
Moritz Hanke's avatar
Moritz Hanke committed
227 228 229 230 231 232 233 234
      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++;
    };

235 236
}

237
static inline uint32_t direct_get(struct aec_stream *strm, int n)
238 239
{
    /**
240
       Get n bit from input stream
241 242 243 244

       No checking whatsoever. Read bits are dumped.
     */

245
    struct internal_state *state = strm->state;
246

247 248
    if (state->bitp < n)
        fill_acc(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
249

250
    state->bitp -= n;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
251
    return (state->acc >> state->bitp) & ((UINT64_C(1) << n) - 1);
252 253
}

254
static inline uint32_t direct_get_fs(struct aec_stream *strm)
255 256 257 258
{
    /**
       Interpret a Fundamental Sequence from the input buffer.

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
259
       Essentially counts the number of 0 bits until a 1 is
260
       encountered.
261 262
     */

263
    uint32_t fs = 0;
264 265 266 267
#if HAVE_DECL___BUILTIN_CLZLL
    int lz;
#elif HAVE_BSR64
    unsigned long lz;
268
#endif
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
269
    struct internal_state *state = strm->state;
270

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
271
    state->acc &= ((UINT64_C(1) << state->bitp) - 1);
272

273 274 275
    while (state->acc == 0) {
        fs += state->bitp;
        state->bitp = 0;
276
        fill_acc(strm);
277
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
278

Thomas Jahns's avatar
Thomas Jahns committed
279
#if HAVE_DECL___BUILTIN_CLZLL
280 281 282
    lz = __builtin_clzll(state->acc);
    fs += lz + state->bitp - 64;
    state->bitp = 63 - lz;
283 284 285 286
#elif HAVE_BSR64
    _BitScanReverse64(&lz, state->acc);
    fs += state->bitp - 1 - lz;
    state->bitp = lz;
287
#else
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
288
    state->bitp--;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
289
    while ((state->acc & (UINT64_C(1) << state->bitp)) == 0) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
290
        state->bitp--;
291
        fs++;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
292
    }
293
#endif
294 295 296
    return fs;
}

297
static inline uint32_t bits_ask(struct aec_stream *strm, int n)
298 299 300 301 302 303 304 305 306 307 308 309
{
    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;
}

310
static inline uint32_t bits_get(struct aec_stream *strm, int n)
311 312
{
    return (strm->state->acc >> (strm->state->bitp - n))
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
313
        & ((UINT64_C(1) << n) - 1);
314 315
}

316
static inline void bits_drop(struct aec_stream *strm, int n)
317 318 319 320
{
    strm->state->bitp -= n;
}

321
static inline uint32_t fs_ask(struct aec_stream *strm)
322 323 324
{
    if (bits_ask(strm, 1) == 0)
        return 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
325
    while ((strm->state->acc & (UINT64_C(1) << (strm->state->bitp - 1))) == 0) {
326 327 328 329 330 331 332 333 334 335 336 337 338 339
        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;
}

340
static inline void fs_drop(struct aec_stream *strm)
341 342 343 344 345
{
    strm->state->fs = 0;
    strm->state->bitp--;
}

346
static inline uint32_t copysample(struct aec_stream *strm)
347
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
348
    if (bits_ask(strm, strm->bits_per_sample) == 0
349 350
        || strm->avail_out == 0)
        return 0;
351

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
352 353
    put_sample(strm, bits_get(strm, strm->bits_per_sample));
    bits_drop(strm, strm->bits_per_sample);
354 355
    return 1;
}
356 357 358 359 360

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

361 362
    if (state->rsip == state->rsi_buffer) {
        if(strm->flags & AEC_PAD_RSI)
363
            state->bitp -= state->bitp % 8;
364 365 366
        if (state->pp)
            state->ref = 1;
    } else {
367
        state->ref = 0;
368
    }
369 370 371 372
    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);
373 374 375 376 377 378 379 380 381 382 383
    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 {
384
        if (bits_ask(strm, k) == 0 || strm->avail_out == 0)
385
            return M_EXIT;
386 387
        *state->rsip++ += bits_get(strm, k);
        strm->avail_out -= state->bytes_per_sample;
388
        bits_drop(strm, k);
389
    } while(++state->i < state->n);
390

391
    check_rsi_end(strm);
392 393 394 395 396 397 398
    state->mode = m_id;
    return M_CONTINUE;
}

static int m_split_fs(struct aec_stream *strm)
{
    struct internal_state *state = strm->state;
399
    int k = state->id - 1;
400 401

    do {
402 403
        if (fs_ask(strm) == 0)
            return M_EXIT;
404
        state->rsip[state->i] = state->fs << k;
405
        fs_drop(strm);
406
    } while(++state->i < state->n);
407

408
    state->i = 0;
409 410 411 412 413 414
    state->mode = m_split_output;
    return M_CONTINUE;
}

static int m_split(struct aec_stream *strm)
{
415
    uint32_t i, k;
416 417
    struct internal_state *state = strm->state;

418 419 420 421
    if (BUFFERSPACE(strm)) {
        k = state->id - 1;

        if (state->ref)
422
            *state->rsip++ = direct_get(strm, strm->bits_per_sample);
423

424
        for (i = 0; i < strm->block_size - state->ref; i++)
425
            state->rsip[i] = direct_get_fs(strm) << k;
426

427
        for (i = state->ref; i < strm->block_size; i++)
428
            *state->rsip++ += direct_get(strm, k);
429

430
        strm->avail_out -= state->out_blklen;
431
        check_rsi_end(strm);
432

433 434 435 436 437
        state->mode = m_id;
        return M_CONTINUE;
    }

    if (state->ref) {
438 439
        if (copysample(strm) == 0)
            return M_EXIT;
440 441 442 443 444
        state->n = strm->block_size - 1;
    } else {
        state->n = strm->block_size;
    }

445
    state->i = 0;
446 447 448 449 450 451 452 453
    state->mode = m_split_fs;
    return M_CONTINUE;
}

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

454 455 456 457 458
    do {
        if (strm->avail_out == 0)
            return M_EXIT;
        put_sample(strm, 0);
    } while(--state->i);
459 460 461 462 463 464 465

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_zero_block(struct aec_stream *strm)
{
466
    uint32_t i, zero_blocks, b, zero_bytes;
467 468
    struct internal_state *state = strm->state;

469 470
    if (fs_ask(strm) == 0)
        return M_EXIT;
471
    zero_blocks = state->fs + 1;
472
    fs_drop(strm);
473 474

    if (zero_blocks == ROS) {
475
        b = (int)(state->rsip - state->rsi_buffer) / strm->block_size;
476 477 478 479 480 481
        zero_blocks = MIN(strm->rsi - b, 64 - (b % 64));
    } else if (zero_blocks > ROS) {
        zero_blocks--;
    }

    if (state->ref)
482
        i = zero_blocks * strm->block_size - 1;
483
    else
484
        i = zero_blocks * strm->block_size;
485

486
    zero_bytes = i * state->bytes_per_sample;
487

488
    if (strm->avail_out >= zero_bytes) {
489 490 491
        if (state->rsi_size - (state->rsip - state->rsi_buffer) < i)
            return M_ERROR;

492 493
        memset(state->rsip, 0, i * sizeof(uint32_t));
        state->rsip += i;
494
        strm->avail_out -= zero_bytes;
495
        check_rsi_end(strm);
496

497 498 499 500
        state->mode = m_id;
        return M_CONTINUE;
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
501
    state->i = i;
502 503 504 505 506 507
    state->mode = m_zero_output;
    return M_CONTINUE;
}

static int m_se_decode(struct aec_stream *strm)
{
508
    int32_t m, d1;
509 510 511
    struct internal_state *state = strm->state;

    while(state->i < strm->block_size) {
512 513
        if (fs_ask(strm) == 0)
            return M_EXIT;
514
        m = state->fs;
515
        d1 = m - state->se_table[2 * m + 1];
516 517

        if ((state->i & 1) == 0) {
518 519 520
            if (strm->avail_out == 0)
                return M_EXIT;
            put_sample(strm, state->se_table[2 * m] - d1);
521 522 523
            state->i++;
        }

524 525 526
        if (strm->avail_out == 0)
            return M_EXIT;
        put_sample(strm, d1);
527
        state->i++;
528
        fs_drop(strm);
529 530 531 532 533 534 535 536
    }

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_se(struct aec_stream *strm)
{
537
    uint32_t i;
538
    int32_t m, d1;
539 540
    struct internal_state *state = strm->state;

541 542 543 544 545 546 547 548 549 550 551 552 553 554
    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++;
        }
555 556 557 558 559 560 561 562 563 564 565 566 567
        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;

568 569
    if (state->ref && copysample(strm) == 0)
        return M_EXIT;
570 571 572 573 574 575 576 577 578 579 580 581 582 583

    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;

584 585 586 587
    if (bits_ask(strm, 1) == 0)
        return M_EXIT;
    state->id = bits_get(strm, 1);
    bits_drop(strm, 1);
588 589 590 591 592 593 594 595
    state->mode = m_low_entropy_ref;
    return M_CONTINUE;
}

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

596 597 598 599
    do {
        if (copysample(strm) == 0)
            return M_EXIT;
    } while(--state->i);
600 601 602 603 604 605 606

    state->mode = m_id;
    return M_CONTINUE;
}

static int m_uncomp(struct aec_stream *strm)
{
607
    uint32_t i;
608 609
    struct internal_state *state = strm->state;

610
    if (BUFFERSPACE(strm)) {
611
        for (i = 0; i < strm->block_size; i++)
612
            *state->rsip++ = direct_get(strm, strm->bits_per_sample);
613
        strm->avail_out -= state->out_blklen;
614
        check_rsi_end(strm);
615

616 617 618 619 620 621 622 623 624
        state->mode = m_id;
        return M_CONTINUE;
    }

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

625 626 627 628 629 630 631 632 633 634 635 636 637 638 639
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
640
int aec_decode_init(struct aec_stream *strm)
641
{
642
    int i, modi;
643
    struct internal_state *state;
644

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
645
    if (strm->bits_per_sample > 32 || strm->bits_per_sample == 0)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
646
        return AEC_CONF_ERROR;
647

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
648
    state = malloc(sizeof(struct internal_state));
649
    if (state == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
650
        return AEC_MEM_ERROR;
651
    memset(state, 0, sizeof(struct internal_state));
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
652

653 654
    create_se_table(state->se_table);

655 656
    strm->state = state;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
657
    if (strm->bits_per_sample > 16) {
658
        state->id_len = 5;
659

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
660 661
        if (strm->bits_per_sample <= 24 && strm->flags & AEC_DATA_3BYTE) {
            state->bytes_per_sample = 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
662
            if (strm->flags & AEC_DATA_MSB)
663
                state->flush_output = flush_msb_24;
664
            else
665
                state->flush_output = flush_lsb_24;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
666
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
667
            state->bytes_per_sample = 4;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
668
            if (strm->flags & AEC_DATA_MSB)
669
                state->flush_output = flush_msb_32;
670
            else
671
                state->flush_output = flush_lsb_32;
672 673
        }
        state->out_blklen = strm->block_size
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
674
            * state->bytes_per_sample;
675
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
676 677
    else if (strm->bits_per_sample > 8) {
        state->bytes_per_sample = 2;
678
        state->id_len = 4;
679
        state->out_blklen = strm->block_size * 2;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
680
        if (strm->flags & AEC_DATA_MSB)
681
            state->flush_output = flush_msb_16;
682
        else
683
            state->flush_output = flush_lsb_16;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
684
    } else {
685
        if (strm->flags & AEC_RESTRICTED) {
686 687 688 689 690 691 692 693 694 695 696 697
            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
698
        state->bytes_per_sample = 1;
699
        state->out_blklen = strm->block_size;
700
        state->flush_output = flush_8;
701 702
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
703
    if (strm->flags & AEC_DATA_SIGNED) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
704 705
        state->xmin = -(INT64_C(1) << (strm->bits_per_sample - 1));
        state->xmax = (UINT64_C(1) << (strm->bits_per_sample - 1)) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
706
    } else {
707
        state->xmin = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
708
        state->xmax = (UINT64_C(1) << strm->bits_per_sample) - 1;
709
    }
710

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
711
    state->in_blklen = (strm->block_size * strm->bits_per_sample
712
                        + state->id_len) / 8 + 9;
713 714

    modi = 1UL << state->id_len;
715
    state->id_table = malloc(modi * sizeof(int (*)(struct aec_stream *)));
716
    if (state->id_table == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
717
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
718

719
    state->id_table[0] = m_low_entropy;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
720
    for (i = 1; i < modi - 1; i++) {
721
        state->id_table[i] = m_split;
722
    }
723
    state->id_table[modi - 1] = m_uncomp;
724

725 726 727
    state->rsi_size = strm->rsi * strm->block_size;
    state->rsi_buffer = malloc(state->rsi_size * sizeof(uint32_t));
    if (state->rsi_buffer == NULL)
728 729
        return AEC_MEM_ERROR;

730
    state->ref = 0;
731 732 733
    strm->total_in = 0;
    strm->total_out = 0;

734 735
    state->rsip = state->rsi_buffer;
    state->flush_start = state->rsi_buffer;
736
    state->bitp = 0;
737
    state->fs = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
738
    state->pp = strm->flags & AEC_DATA_PREPROCESS;
739
    state->mode = m_id;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
740
    return AEC_OK;
741 742
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
743
int aec_decode(struct aec_stream *strm, int flush)
744
{
745 746 747 748 749 750 751 752 753
    /**
       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
754
    struct internal_state *state = strm->state;
755
    int status;
756

757 758 759
    strm->total_in += strm->avail_in;
    strm->total_out += strm->avail_out;

760 761 762 763 764 765 766
    do {
        status = state->mode(strm);
    } while (status == M_CONTINUE);

    if (status == M_ERROR)
        return AEC_DATA_ERROR;

767
    state->flush_output(strm);
768 769 770 771

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

772 773
    return AEC_OK;
}
774

775 776
int aec_decode_end(struct aec_stream *strm)
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
777
    struct internal_state *state = strm->state;
778

779
    free(state->id_table);
780
    free(state->rsi_buffer);
781
    free(state);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
782
    return AEC_OK;
783
}
784

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
785
int aec_buffer_decode(struct aec_stream *strm)
786 787 788 789 790 791 792 793 794 795 796
{
    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;
}