encode.c 24.3 KB
Newer Older
1
/**
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
2
 * @file encode.c
3
 *
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.
 *
47 48 49
 * @section DESCRIPTION
 *
 * Adaptive Entropy Encoder
50
 * Based on CCSDS documents 121.0-B-2 and 120.0-G-2
51 52
 *
 */
53

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

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

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

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
65 66 67
#include "libaec.h"
#include "encode.h"
#include "encode_accessors.h"
68

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
69 70 71 72
static int m_get_block(struct aec_stream *strm);

static inline void emit(struct internal_state *state,
                        uint32_t data, int bits)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
73
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
74 75 76 77
    /**
       Emit sequence of bits.
     */

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
78 79 80
    if (bits <= state->bits) {
        state->bits -= bits;
        *state->cds += data << state->bits;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
81
    } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
82 83
        bits -= state->bits;
        *state->cds++ += (uint64_t)data >> bits;
84

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
85
        while (bits & ~7) {
86
            bits -= 8;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
87
            *state->cds++ = data >> bits;
88
        }
89

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
90 91
        state->bits = 8 - bits;
        *state->cds = data << state->bits;
92
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
93 94
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
95
static inline void emitfs(struct internal_state *state, int fs)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
96
{
97 98
    /**
       Emits a fundamental sequence.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
99

100 101
       fs zero bits followed by one 1 bit.
     */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
102

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
103
    for(;;) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
104 105 106
        if (fs < state->bits) {
            state->bits -= fs + 1;
            *state->cds += 1U << state->bits;
107
            break;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
108
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
109 110 111
            fs -= state->bits;
            *++state->cds = 0;
            state->bits = 8;
112 113
        }
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
114
}
115

116 117 118 119 120 121 122 123 124 125 126 127
static inline void copy64(uint8_t *dst, uint64_t src)
{
    dst[0] = src >> 56;
    dst[1] = src >> 48;
    dst[2] = src >> 40;
    dst[3] = src >> 32;
    dst[4] = src >> 24;
    dst[5] = src >> 16;
    dst[6] = src >> 8;
    dst[7] = src;
}

128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146
static inline void emitblock_fs(struct aec_stream *strm, int k, int ref)
{
    int i;
    int used; /* used bits in 64 bit accumulator */
    uint64_t acc; /* accumulator */
    struct internal_state *state = strm->state;

    acc = (uint64_t)*state->cds << 56;
    used = 7 - state->bits;

    for (i = ref; i < strm->block_size; i++) {
        used += (state->block[i] >> k) + 1;
        if (used > 63) {
            copy64(state->cds, acc);
            state->cds += 8;
            acc = 0;
            used &= 0x3f;
        }
        acc |= 1ULL << (63 - used);
147 148
    }

149 150 151 152
    copy64(state->cds, acc);
    state->cds += used >> 3;
    state->bits = 7 - (used & 7);
}
153

154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237
static inline void emitblock(struct aec_stream *strm, int k, int ref)
{
    /**
       Emit the k LSB of a whole block of input data.
    */

    uint64_t a;
    struct internal_state *state = strm->state;
    uint32_t *in = state->block + ref;
    uint32_t *in_end = state->block + strm->block_size;
    uint64_t mask = (1ULL << k) - 1;
    uint8_t *o = state->cds;
    int p = state->bits;

    a = *o;

    while(in < in_end) {
        a <<= 56;
        p = (p % 8) + 56;

        while (p > k && in < in_end) {
            p -= k;
            a += ((uint64_t)(*in++) & mask) << p;
        }

        switch (p & ~ 7) {
        case 0:
            o[0] = a >> 56;
            o[1] = a >> 48;
            o[2] = a >> 40;
            o[3] = a >> 32;
            o[4] = a >> 24;
            o[5] = a >> 16;
            o[6] = a >> 8;
            o += 7;
            break;
        case 8:
            o[0] = a >> 56;
            o[1] = a >> 48;
            o[2] = a >> 40;
            o[3] = a >> 32;
            o[4] = a >> 24;
            o[5] = a >> 16;
            a >>= 8;
            o += 6;
            break;
        case 16:
            o[0] = a >> 56;
            o[1] = a >> 48;
            o[2] = a >> 40;
            o[3] = a >> 32;
            o[4] = a >> 24;
            a >>= 16;
            o += 5;
            break;
        case 24:
            o[0] = a >> 56;
            o[1] = a >> 48;
            o[2] = a >> 40;
            o[3] = a >> 32;
            a >>= 24;
            o += 4;
            break;
        case 32:
            o[0] = a >> 56;
            o[1] = a >> 48;
            o[2] = a >> 40;
            a >>= 32;
            o += 3;
            break;
        case 40:
            o[0] = a >> 56;
            o[1] = a >> 48;
            a >>= 40;
            o += 2;
            break;
        case 48:
            *o++ = a >> 56;
            a >>= 48;
            break;
        default:
            a >>= 56;
            break;
        }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
238 239
    }

240 241 242 243
    *o = a;
    state->cds = o;
    state->bits = p % 8;
}
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
244

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
245
static void preprocess_unsigned(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
246
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
247 248
    /**
       Preprocess RSI of unsigned samples.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
249 250 251

       Combining preprocessing and converting to uint32_t in one loop
       is slower due to the data dependance on x_i-1.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
252 253
    */

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
254
    uint32_t D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
255
    struct internal_state *state = strm->state;
256 257
    const uint32_t *x = state->data_raw;
    uint32_t *d = state->data_pp;
258 259
    uint32_t xmax = state->xmax;
    uint32_t rsi = strm->rsi * strm->block_size - 1;
260
    int i;
261

262 263 264 265 266 267
    d[0] = x[0];
    for (i = 0; i < rsi; i++) {
        if (x[i+1] >= x[i]) {
            D = x[i+1] - x[i];
            if (D <= x[i])
                d[i+1] = 2 * D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
268
            else
269
                d[i+1] = x[i+1];
270
        } else {
271 272 273
            D = x[i] - x[i+1];
            if (D <= xmax - x[i])
                d[i+1] = 2 * D - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
274
            else
275
                d[i+1] = xmax - x[i+1];
276
        }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
277
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
278
    state->ref = 1;
279
    state->uncomp_len = (strm->block_size - 1) * strm->bits_per_sample;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
280 281
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
282
static void preprocess_signed(struct aec_stream *strm)
283
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
284 285 286 287
    /**
       Preprocess RSI of signed samples.
    */

288
    int64_t D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
289
    struct internal_state *state = strm->state;
290 291
    uint32_t *d = state->data_pp;
    int32_t *x = (int32_t *)state->data_raw;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
292
    uint64_t m = 1ULL << (strm->bits_per_sample - 1);
293 294 295
    int64_t xmax = state->xmax;
    int64_t xmin = state->xmin;
    uint32_t rsi = strm->rsi * strm->block_size - 1;
296
    int i;
297

298
    d[0] = (uint32_t)x[0];
299 300
    x[0] = (x[0] ^ m) - m;

301 302 303 304 305 306
    for (i = 0; i < rsi; i++) {
        x[i+1] = (x[i+1] ^ m) - m;
        if (x[i+1] < x[i]) {
            D = (int64_t)x[i] - x[i+1];
            if (D <= xmax - x[i])
                d[i + 1] = 2 * D - 1;
307
            else
308
                d[i + 1] = xmax - x[i+1];
309
        } else {
310 311 312
            D = (int64_t)x[i+1] - x[i];
            if (D <= x[i] - xmin)
                d[i + 1] = 2 * D;
313
            else
314
                d[i + 1] = x[i+1] - xmin;
315
        }
316
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
317
    state->ref = 1;
318
    state->uncomp_len = (strm->block_size - 1) * strm->bits_per_sample;
319
}
320

321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347
static uint64_t block_fs(struct aec_stream *strm, int k)
{
    /**
       Sum FS of all samples in block for given splitting position.
    */

    int i;
    uint64_t fs = 0;
    struct internal_state *state = strm->state;

    for (i = 0; i < strm->block_size; i += 8)
        fs +=
            (uint64_t)(state->block[i + 0] >> k)
            + (uint64_t)(state->block[i + 1] >> k)
            + (uint64_t)(state->block[i + 2] >> k)
            + (uint64_t)(state->block[i + 3] >> k)
            + (uint64_t)(state->block[i + 4] >> k)
            + (uint64_t)(state->block[i + 5] >> k)
            + (uint64_t)(state->block[i + 6] >> k)
            + (uint64_t)(state->block[i + 7] >> k);

    if (state->ref)
        fs -= (uint64_t)(state->block[0] >> k);

    return fs;
}

348
static uint32_t assess_splitting_option(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
349 350 351 352 353
{
    /**
       Length of CDS encoded with splitting option and optimal k.

       In Rice coding each sample in a block of samples is split at
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
354
       the same position into k LSB and bits_per_sample - k MSB. The
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374
       LSB part is left binary and the MSB part is coded as a
       fundamental sequence a.k.a. unary (see CCSDS 121.0-B-2). The
       function of the length of the Coded Data Set (CDS) depending on
       k has exactly one minimum (see A. Kiely, IPN Progress Report
       42-159).

       To find that minimum with only a few costly evaluations of the
       CDS length, we start with the k of the previous CDS. K is
       increased and the CDS length evaluated. If the CDS length gets
       smaller, then we are moving towards the minimum. If the length
       increases, then the minimum will be found with smaller k.

       For increasing k we know that we will gain block_size bits in
       length through the larger binary part. If the FS lenth is less
       than the block size then a reduced FS part can't compensate the
       larger binary part. So we know that the CDS for k+1 will be
       larger than for k without actually computing the length. An
       analogue check can be done for decreasing k.
     */

375
    int k;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
376 377 378 379 380 381 382 383 384 385 386 387 388
    int k_min;
    int this_bs; /* Block size of current block */
    int no_turn; /* 1 if we shouldn't reverse */
    int dir; /* Direction, 1 means increasing k, 0 decreasing k */
    uint64_t len; /* CDS length for current k */
    uint64_t len_min; /* CDS length minimum so far */
    uint64_t fs_len; /* Length of FS part (not including 1s) */

    struct internal_state *state = strm->state;

    this_bs = strm->block_size - state->ref;
    len_min = UINT64_MAX;
    k = k_min = state->k;
389
    no_turn = k == 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
390 391 392
    dir = 1;

    for (;;) {
393
        fs_len = block_fs(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430
        len = fs_len + this_bs * (k + 1);

        if (len < len_min) {
            if (len_min < UINT64_MAX)
                no_turn = 1;

            len_min = len;
            k_min = k;

            if (dir) {
                if (fs_len < this_bs || k >= state->kmax) {
                    if (no_turn)
                        break;
                    k = state->k - 1;
                    dir = 0;
                    no_turn = 1;
                } else {
                    k++;
                }
            } else {
                if (fs_len >= this_bs || k == 0)
                    break;
                k--;
            }
        } else {
            if (no_turn)
                break;
            k = state->k - 1;
            dir = 0;
            no_turn = 1;
        }
    }
    state->k = k_min;

    return len_min;
}

431
static uint32_t assess_se_option(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
432 433 434 435
{
    /**
       Length of CDS encoded with Second Extension option.

436
       If length is above limit just return UINT32_MAX.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
437 438 439 440
    */

    int i;
    uint64_t d;
441
    uint32_t len;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
442 443 444 445 446 447 448 449
    struct internal_state *state = strm->state;

    len = 1;

    for (i = 0; i < strm->block_size; i+= 2) {
        d = (uint64_t)state->block[i]
            + (uint64_t)state->block[i + 1];
        /* we have to worry about overflow here */
450 451
        if (d > state->uncomp_len) {
            len = UINT32_MAX;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
452 453
            break;
        } else {
454
            len += d * (d + 1) / 2 + state->block[i + 1];
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
455 456 457 458 459
        }
    }
    return len;
}

460 461 462 463 464 465 466 467 468
static void init_output(struct aec_stream *strm)
{
    /**
       Direct output to next_out if next_out can hold a Coded Data
       Set, use internal buffer otherwise.
    */

    struct internal_state *state = strm->state;

469
    if (strm->avail_out > CDSLEN) {
470 471 472 473 474 475 476 477 478 479 480 481 482 483 484
        if (!state->direct_out) {
            state->direct_out = 1;
            *strm->next_out = *state->cds;
            state->cds = strm->next_out;
        }
    } else {
        if (state->zero_blocks == 0 || state->direct_out) {
            /* copy leftover from last block */
            *state->cds_buf = *state->cds;
            state->cds = state->cds_buf;
        }
        state->direct_out = 0;
    }
}

485 486 487 488 489 490
/*
 *
 * FSM functions
 *
 */

491
static int m_flush_block_resumable(struct aec_stream *strm)
492
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
493
    /**
494
       Slow and restartable flushing
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
495
    */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
496
    struct internal_state *state = strm->state;
497

498 499 500 501 502 503 504 505 506 507 508
    int n = MIN(state->cds - state->cds_buf - state->i, strm->avail_out);
    memcpy(strm->next_out, state->cds_buf + state->i, n);
    strm->next_out += n;
    strm->avail_out -= n;
    state->i += n;

    if (strm->avail_out == 0) {
        return M_EXIT;
    } else {
        state->mode = m_get_block;
        return M_CONTINUE;
509 510 511
    }
}

512
static int m_flush_block(struct aec_stream *strm)
513
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
514
    /**
515
       Flush block in direct_out mode by updating counters.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
516

517
       Fall back to slow flushing if in buffered mode.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
518
    */
519
    int n;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
520
    struct internal_state *state = strm->state;
521

522 523 524 525
    if (state->direct_out) {
        n = state->cds - strm->next_out;
        strm->next_out += n;
        strm->avail_out -= n;
526 527
        state->mode = m_get_block;
        return M_CONTINUE;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
528
    }
529

530 531 532
    state->i = 0;
    state->mode = m_flush_block_resumable;
    return M_CONTINUE;
533
}
534

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
535
static int m_encode_splitting(struct aec_stream *strm)
536
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
537
    struct internal_state *state = strm->state;
538
    int k = state->k;
539

540
    emit(state, k + 1, state->id_len);
541

542
    if (state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
543
        emit(state, state->block[0], strm->bits_per_sample);
544 545 546 547

    emitblock_fs(strm, k, state->ref);
    if (k)
        emitblock(strm, k, state->ref);
548

549 550
    return m_flush_block(strm);
}
551

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
552
static int m_encode_uncomp(struct aec_stream *strm)
553
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
554
    struct internal_state *state = strm->state;
555

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
556
    emit(state, (1U << state->id_len) - 1, state->id_len);
557
    emitblock(strm, strm->bits_per_sample, 0);
558

559 560
    return m_flush_block(strm);
}
561

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
562
static int m_encode_se(struct aec_stream *strm)
563 564
{
    int i;
565
    uint32_t d;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
566
    struct internal_state *state = strm->state;
567

568 569
    emit(state, 1, state->id_len + 1);
    if (state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
570
        emit(state, state->block[0], strm->bits_per_sample);
571

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
572
    for (i = 0; i < strm->block_size; i+= 2) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
573 574
        d = state->block[i] + state->block[i + 1];
        emitfs(state, d * (d + 1) / 2 + state->block[i + 1]);
575
    }
576

577 578
    return m_flush_block(strm);
}
579

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
580
static int m_encode_zero(struct aec_stream *strm)
581
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
582
    struct internal_state *state = strm->state;
583

584
    emit(state, 0, state->id_len + 1);
585

586
    if (state->zero_ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
587
        emit(state, state->zero_ref_sample, strm->bits_per_sample);
588

589 590 591 592 593 594
    if (state->zero_blocks == ROS)
        emitfs(state, 4);
    else if (state->zero_blocks >= 5)
        emitfs(state, state->zero_blocks);
    else
        emitfs(state, state->zero_blocks - 1);
595

596 597 598
    state->zero_blocks = 0;
    return m_flush_block(strm);
}
599

600
static int m_select_code_option(struct aec_stream *strm)
601
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
602
    /**
603 604
       Decide which code option to use.
    */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
605

606 607
    uint32_t split_len;
    uint32_t se_len;
608 609 610
    struct internal_state *state = strm->state;

    split_len = assess_splitting_option(strm);
611
    se_len = assess_se_option(strm);
612

613
    if (split_len < state->uncomp_len) {
614 615 616 617 618
        if (split_len < se_len)
            return m_encode_splitting(strm);
        else
            return m_encode_se(strm);
    } else {
619
        if (state->uncomp_len <= se_len)
620 621 622 623 624 625 626 627 628 629 630 631 632
            return m_encode_uncomp(strm);
        else
            return m_encode_se(strm);
    }
}

static int m_check_zero_block(struct aec_stream *strm)
{
    /**
       Check if input block is all zero.

       Aggregate consecutive zero blocks until we find !0 or reach the
       end of a segment or RSI.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
633
    */
634

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
635
    struct internal_state *state = strm->state;
636 637
    uint32_t *p = state->block + state->ref;
    uint32_t *end = state->block + strm->block_size;
638

639 640 641 642 643 644 645
    while(p < end && *p == 0)
        p++;

    if (p < end) {
        if (state->zero_blocks) {
            /* The current block isn't zero but we have to emit a
             * previous zero block first. The current block will be
646
             * flagged and handled later.
647
             */
648
            state->block_nonzero = 1;
649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666
            state->mode = m_encode_zero;
            return M_CONTINUE;
        }
        state->mode = m_select_code_option;
        return M_CONTINUE;
    } else {
        state->zero_blocks++;
        if (state->zero_blocks == 1) {
            state->zero_ref = state->ref;
            state->zero_ref_sample = state->block[0];
        }
        if (state->blocks_avail == 0
            || (strm->rsi - state->blocks_avail) % 64 == 0) {
            if (state->zero_blocks > 4)
                state->zero_blocks = ROS;
            state->mode = m_encode_zero;
            return M_CONTINUE;
        }
667 668 669
        state->mode = m_get_block;
        return M_CONTINUE;
    }
670
}
671

672 673 674 675 676 677 678 679 680 681 682 683
static int m_get_rsi_resumable(struct aec_stream *strm)
{
    /**
       Get RSI while input buffer is short.

       Let user provide more input. Once we got all input pad buffer
       to full RSI.
    */

    struct internal_state *state = strm->state;

    do {
684
        if (strm->avail_in >= state->bytes_per_sample) {
685 686 687 688
            state->data_raw[state->i] = state->get_sample(strm);
        } else {
            if (state->flush == AEC_FLUSH) {
                if (state->i > 0) {
689 690 691 692
                    do
                        state->data_raw[state->i] =
                            state->data_raw[state->i - 1];
                    while(++state->i < strm->rsi * strm->block_size);
693 694
                } else {
                    emit(state, 0, state->bits);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
695
                    if (strm->avail_out > 0) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
696
                        if (!state->direct_out)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
697 698 699
                            *strm->next_out++ = *state->cds;
                        strm->avail_out--;
                    }
700 701 702 703 704 705 706 707
                    return M_EXIT;
                }
            } else {
                return M_EXIT;
            }
        }
    } while (++state->i < strm->rsi * strm->block_size);

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
708
    if (strm->flags & AEC_DATA_PREPROCESS)
709 710 711
        state->preprocess(strm);

    return m_check_zero_block(strm);
712 713
}

714
static int m_get_block(struct aec_stream *strm)
715
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
716
    /**
717 718 719 720
       Provide the next block of preprocessed input data.

       Pull in a whole Reference Sample Interval (RSI) of data if
       block buffer is empty.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
721
    */
722

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
723
    struct internal_state *state = strm->state;
724

725 726 727 728 729 730
    init_output(strm);

    if (state->block_nonzero) {
        state->block_nonzero = 0;
        state->mode = m_select_code_option;
        return M_CONTINUE;
731
    }
732

733
    if (state->blocks_avail == 0) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
734
        state->blocks_avail = strm->rsi - 1;
735 736
        state->block = state->data_pp;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
737
        if (strm->avail_in >= state->rsi_len) {
738
            state->get_rsi(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
739
            if (strm->flags & AEC_DATA_PREPROCESS)
740
                state->preprocess(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
741

742 743 744 745 746 747
            return m_check_zero_block(strm);
        } else {
            state->i = 0;
            state->mode = m_get_rsi_resumable;
        }
    } else {
748 749 750 751
        if (state->ref) {
            state->ref = 0;
            state->uncomp_len = strm->block_size * strm->bits_per_sample;
        }
752 753 754
        state->block += strm->block_size;
        state->blocks_avail--;
        return m_check_zero_block(strm);
755 756 757 758 759 760 761 762 763
    }
    return M_CONTINUE;
}

/*
 *
 * API functions
 *
 */
764

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
765
int aec_encode_init(struct aec_stream *strm)
766
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
767
    struct internal_state *state;
768

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
769
    if (strm->bits_per_sample > 32 || strm->bits_per_sample == 0)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
770
        return AEC_CONF_ERROR;
771 772 773 774 775

    if (strm->block_size != 8
        && strm->block_size != 16
        && strm->block_size != 32
        && strm->block_size != 64)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
776
        return AEC_CONF_ERROR;
777 778

    if (strm->rsi > 4096)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
779
        return AEC_CONF_ERROR;
780

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
781
    state = malloc(sizeof(struct internal_state));
782
    if (state == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
783
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
784 785

    memset(state, 0, sizeof(struct internal_state));
786 787
    strm->state = state;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
788
    if (strm->bits_per_sample > 16) {
789
        /* 24/32 input bit settings */
790 791
        state->id_len = 5;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
792
        if (strm->bits_per_sample <= 24
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
793
            && strm->flags & AEC_DATA_3BYTE) {
794
            state->bytes_per_sample = 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
795
            if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
796 797
                state->get_sample = aec_get_msb_24;
                state->get_rsi = aec_get_rsi_msb_24;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
798
            } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
799 800
                state->get_sample = aec_get_lsb_24;
                state->get_rsi = aec_get_rsi_lsb_24;
801
            }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
802
        } else {
803
            state->bytes_per_sample = 4;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
804
            if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
805 806
                state->get_sample = aec_get_msb_32;
                state->get_rsi = aec_get_rsi_msb_32;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
807
            } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
808 809
                state->get_sample = aec_get_lsb_32;
                state->get_rsi = aec_get_rsi_lsb_32;
810 811
            }
        }
812
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
813
    else if (strm->bits_per_sample > 8) {
814 815
        /* 16 bit settings */
        state->id_len = 4;
816
        state->bytes_per_sample = 2;
817

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
818
        if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
819 820
            state->get_sample = aec_get_msb_16;
            state->get_rsi = aec_get_rsi_msb_16;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
821
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
822 823
            state->get_sample = aec_get_lsb_16;
            state->get_rsi = aec_get_rsi_lsb_16;
824
        }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
825
    } else {
826 827
        /* 8 bit settings */
        state->id_len = 3;
828
        state->bytes_per_sample = 1;
829

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
830 831
        state->get_sample = aec_get_8;
        state->get_rsi = aec_get_rsi_8;
832
    }
833
    state->rsi_len = strm->rsi * strm->block_size * state->bytes_per_sample;
834

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
835
    if (strm->flags & AEC_DATA_SIGNED) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
836 837
        state->xmin = -(1ULL << (strm->bits_per_sample - 1));
        state->xmax = (1ULL << (strm->bits_per_sample - 1)) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
838
        state->preprocess = preprocess_signed;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
839
    } else {
840
        state->xmin = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
841
        state->xmax = (1ULL << strm->bits_per_sample) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
842
        state->preprocess = preprocess_unsigned;
843 844
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
845 846
    state->kmax = (1U << state->id_len) - 3;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
847 848 849
    state->data_pp = malloc(strm->rsi
                            * strm->block_size
                            * sizeof(uint32_t));
850
    if (state->data_pp == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
851
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
852

853
    if (strm->flags & AEC_DATA_PREPROCESS) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
854 855 856
        state->data_raw = malloc(strm->rsi
                                 * strm->block_size
                                 * sizeof(uint32_t));
857 858 859 860 861 862
        if (state->data_raw == NULL)
            return AEC_MEM_ERROR;
    } else {
        state->data_raw = state->data_pp;
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
863
    state->block = state->data_pp;
864 865 866 867

    strm->total_in = 0;
    strm->total_out = 0;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
868 869 870
    state->cds = state->cds_buf;
    *state->cds = 0;
    state->bits = 8;
871 872
    state->mode = m_get_block;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
873
    return AEC_OK;
874 875
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
876
int aec_encode(struct aec_stream *strm, int flush)
877 878 879 880 881
{
    /**
       Finite-state machine implementation of the adaptive entropy
       encoder.
    */
882
    int n;
883 884
    struct internal_state *state = strm->state;

885
    state->flush = flush;
886 887
    strm->total_in += strm->avail_in;
    strm->total_out += strm->avail_out;
888 889 890

    while (state->mode(strm) == M_CONTINUE);

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
891
    if (state->direct_out) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
892
        n = state->cds - strm->next_out;
893 894 895
        strm->next_out += n;
        strm->avail_out -= n;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
896 897
        *state->cds_buf = *state->cds;
        state->cds = state->cds_buf;
898
        state->direct_out = 0;
899
    }
900 901
    strm->total_in -= strm->avail_in;
    strm->total_out -= strm->avail_out;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
902
    return AEC_OK;
903 904
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
905
int aec_encode_end(struct aec_stream *strm)
906
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
907
    struct internal_state *state = strm->state;
908

909 910 911
    if (strm->flags & AEC_DATA_PREPROCESS)
        free(state->data_raw);
    free(state->data_pp);
912
    free(state);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
913
    return AEC_OK;
914
}
915

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
916
int aec_buffer_encode(struct aec_stream *strm)
917 918 919 920 921 922 923
{
    int status;

    status = aec_encode_init(strm);
    if (status != AEC_OK)
        return status;
    status = aec_encode(strm, AEC_FLUSH);
924
    if (strm->avail_in > 0)
925 926 927 928 929
        status = AEC_DATA_ERROR;

    aec_encode_end(strm);
    return status;
}