encode.c 24.2 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

261
    *d++ = x[0];
262
    while (rsi--) {
263 264
        if (x[1] >= x[0]) {
            D = x[1] - x[0];
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
265
            if (D <= x[0])
266
                *d = 2 * D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
267
            else
268
                *d = x[1];
269
        } else {
270
            D = x[0] - x[1];
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
271
            if (D <= xmax - x[0])
272
                *d = 2 * D - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
273
            else
274
                *d = xmax - x[1];
275
        }
276
        d++;
277
        x++;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
278
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
279
    state->ref = 1;
280
    state->uncomp_len = (strm->block_size - 1) * strm->bits_per_sample;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
281 282
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
283
static void preprocess_signed(struct aec_stream *strm)
284
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
285 286 287 288
    /**
       Preprocess RSI of signed samples.
    */

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

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

301
    while (rsi--) {
302 303 304 305 306
        x[1] = (x[1] ^ m) - m;
        if (x[1] < x[0]) {
            D = (int64_t)x[0] - x[1];
            if (D <= xmax - x[0])
                *d = 2 * D - 1;
307
            else
308
                *d = xmax - x[1];
309
        } else {
310 311 312
            D = (int64_t)x[1] - x[0];
            if (D <= x[0] - xmin)
                *d = 2 * D;
313
            else
314
                *d = x[1] - xmin;
315
        }
316 317
        x++;
        d++;
318
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
319
    state->ref = 1;
320
    state->uncomp_len = (strm->block_size - 1) * strm->bits_per_sample;
321
}
322

323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349
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;
}

350
static uint32_t assess_splitting_option(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
351 352 353 354 355
{
    /**
       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
356
       the same position into k LSB and bits_per_sample - k MSB. The
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376
       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.
     */

377
    int k;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
378 379 380 381 382 383 384 385 386 387 388 389 390
    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;
391
    no_turn = k == 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
392 393 394
    dir = 1;

    for (;;) {
395
        fs_len = block_fs(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432
        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;
}

433
static uint32_t assess_se_option(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
434 435 436 437
{
    /**
       Length of CDS encoded with Second Extension option.

438
       If length is above limit just return UINT32_MAX.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
439 440 441 442
    */

    int i;
    uint64_t d;
443
    uint32_t len;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
444 445 446 447 448 449 450 451
    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 */
452 453
        if (d > state->uncomp_len) {
            len = UINT32_MAX;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
454 455
            break;
        } else {
456
            len += d * (d + 1) / 2 + state->block[i + 1];
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
457 458 459 460 461
        }
    }
    return len;
}

462 463 464 465 466 467 468 469 470
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;

471
    if (strm->avail_out > CDSLEN) {
472 473 474 475 476 477 478 479 480 481 482 483 484 485 486
        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;
    }
}

487 488 489 490 491 492
/*
 *
 * FSM functions
 *
 */

493
static int m_flush_block_resumable(struct aec_stream *strm)
494
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
495
    /**
496
       Slow and restartable flushing
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
497
    */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
498
    struct internal_state *state = strm->state;
499

500 501 502 503 504 505 506 507 508 509 510
    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;
511 512 513
    }
}

514
static int m_flush_block(struct aec_stream *strm)
515
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
516
    /**
517
       Flush block in direct_out mode by updating counters.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
518

519
       Fall back to slow flushing if in buffered mode.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
520
    */
521
    int n;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
522
    struct internal_state *state = strm->state;
523

524 525 526 527
    if (state->direct_out) {
        n = state->cds - strm->next_out;
        strm->next_out += n;
        strm->avail_out -= n;
528 529
        state->mode = m_get_block;
        return M_CONTINUE;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
530
    }
531

532 533 534
    state->i = 0;
    state->mode = m_flush_block_resumable;
    return M_CONTINUE;
535
}
536

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
537
static int m_encode_splitting(struct aec_stream *strm)
538
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
539
    struct internal_state *state = strm->state;
540
    int k = state->k;
541

542
    emit(state, k + 1, state->id_len);
543

544
    if (state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
545
        emit(state, state->block[0], strm->bits_per_sample);
546 547 548 549

    emitblock_fs(strm, k, state->ref);
    if (k)
        emitblock(strm, k, state->ref);
550

551 552
    return m_flush_block(strm);
}
553

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
554
static int m_encode_uncomp(struct aec_stream *strm)
555
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
556
    struct internal_state *state = strm->state;
557

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
558
    emit(state, (1U << state->id_len) - 1, state->id_len);
559
    emitblock(strm, strm->bits_per_sample, 0);
560

561 562
    return m_flush_block(strm);
}
563

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
564
static int m_encode_se(struct aec_stream *strm)
565 566
{
    int i;
567
    uint32_t d;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
568
    struct internal_state *state = strm->state;
569

570 571
    emit(state, 1, state->id_len + 1);
    if (state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
572
        emit(state, state->block[0], strm->bits_per_sample);
573

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
574
    for (i = 0; i < strm->block_size; i+= 2) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
575 576
        d = state->block[i] + state->block[i + 1];
        emitfs(state, d * (d + 1) / 2 + state->block[i + 1]);
577
    }
578

579 580
    return m_flush_block(strm);
}
581

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
582
static int m_encode_zero(struct aec_stream *strm)
583
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
584
    struct internal_state *state = strm->state;
585

586
    emit(state, 0, state->id_len + 1);
587

588
    if (state->zero_ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
589
        emit(state, state->zero_ref_sample, strm->bits_per_sample);
590

591 592 593 594 595 596
    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);
597

598 599 600
    state->zero_blocks = 0;
    return m_flush_block(strm);
}
601

602
static int m_select_code_option(struct aec_stream *strm)
603
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
604
    /**
605 606
       Decide which code option to use.
    */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
607

608 609
    uint32_t split_len;
    uint32_t se_len;
610 611 612
    struct internal_state *state = strm->state;

    split_len = assess_splitting_option(strm);
613
    se_len = assess_se_option(strm);
614

615
    if (split_len < state->uncomp_len) {
616 617 618 619 620
        if (split_len < se_len)
            return m_encode_splitting(strm);
        else
            return m_encode_se(strm);
    } else {
621
        if (state->uncomp_len <= se_len)
622 623 624 625 626 627 628 629 630 631 632 633 634
            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
635
    */
636

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
637
    struct internal_state *state = strm->state;
638 639
    uint32_t *p = state->block + state->ref;
    uint32_t *end = state->block + strm->block_size;
640

641 642 643 644 645 646 647
    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
648
             * flagged and handled later.
649
             */
650
            state->block_nonzero = 1;
651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668
            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;
        }
669 670 671
        state->mode = m_get_block;
        return M_CONTINUE;
    }
672
}
673

674 675 676 677 678 679 680 681 682 683 684 685
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 {
686
        if (strm->avail_in >= state->bytes_per_sample) {
687 688 689 690
            state->data_raw[state->i] = state->get_sample(strm);
        } else {
            if (state->flush == AEC_FLUSH) {
                if (state->i > 0) {
691 692 693 694
                    do
                        state->data_raw[state->i] =
                            state->data_raw[state->i - 1];
                    while(++state->i < strm->rsi * strm->block_size);
695 696
                } else {
                    emit(state, 0, state->bits);
697
                    if (strm->avail_out > 0) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
698
                        if (!state->direct_out)
699 700 701
                            *strm->next_out++ = *state->cds;
                        strm->avail_out--;
                    }
702 703 704 705 706 707 708 709
                    return M_EXIT;
                }
            } else {
                return M_EXIT;
            }
        }
    } while (++state->i < strm->rsi * strm->block_size);

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
710
    if (strm->flags & AEC_DATA_PREPROCESS)
711 712 713
        state->preprocess(strm);

    return m_check_zero_block(strm);
714 715
}

716
static int m_get_block(struct aec_stream *strm)
717
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
718
    /**
719 720 721 722
       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
723
    */
724

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
725
    struct internal_state *state = strm->state;
726

727 728 729 730 731 732
    init_output(strm);

    if (state->block_nonzero) {
        state->block_nonzero = 0;
        state->mode = m_select_code_option;
        return M_CONTINUE;
733
    }
734

735
    if (state->blocks_avail == 0) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
736
        state->blocks_avail = strm->rsi - 1;
737 738
        state->block = state->data_pp;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
739
        if (strm->avail_in >= state->rsi_len) {
740
            state->get_rsi(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
741
            if (strm->flags & AEC_DATA_PREPROCESS)
742
                state->preprocess(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
743

744 745 746 747 748 749
            return m_check_zero_block(strm);
        } else {
            state->i = 0;
            state->mode = m_get_rsi_resumable;
        }
    } else {
750 751 752 753
        if (state->ref) {
            state->ref = 0;
            state->uncomp_len = strm->block_size * strm->bits_per_sample;
        }
754 755 756
        state->block += strm->block_size;
        state->blocks_avail--;
        return m_check_zero_block(strm);
757 758 759 760 761 762 763 764 765
    }
    return M_CONTINUE;
}

/*
 *
 * API functions
 *
 */
766

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
767
int aec_encode_init(struct aec_stream *strm)
768
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
769
    struct internal_state *state;
770

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
771
    if (strm->bits_per_sample > 32 || strm->bits_per_sample == 0)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
772
        return AEC_CONF_ERROR;
773 774 775 776 777

    if (strm->block_size != 8
        && strm->block_size != 16
        && strm->block_size != 32
        && strm->block_size != 64)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
778
        return AEC_CONF_ERROR;
779 780

    if (strm->rsi > 4096)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
781
        return AEC_CONF_ERROR;
782

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
783
    state = malloc(sizeof(struct internal_state));
784
    if (state == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
785
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
786 787

    memset(state, 0, sizeof(struct internal_state));
788 789
    strm->state = state;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
790
    if (strm->bits_per_sample > 16) {
791
        /* 24/32 input bit settings */
792 793
        state->id_len = 5;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
794
        if (strm->bits_per_sample <= 24
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
795
            && strm->flags & AEC_DATA_3BYTE) {
796
            state->bytes_per_sample = 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
797
            if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
798 799
                state->get_sample = aec_get_msb_24;
                state->get_rsi = aec_get_rsi_msb_24;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
800
            } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
801 802
                state->get_sample = aec_get_lsb_24;
                state->get_rsi = aec_get_rsi_lsb_24;
803
            }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
804
        } else {
805
            state->bytes_per_sample = 4;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
806
            if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
807 808
                state->get_sample = aec_get_msb_32;
                state->get_rsi = aec_get_rsi_msb_32;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
809
            } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
810 811
                state->get_sample = aec_get_lsb_32;
                state->get_rsi = aec_get_rsi_lsb_32;
812 813
            }
        }
814
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
815
    else if (strm->bits_per_sample > 8) {
816 817
        /* 16 bit settings */
        state->id_len = 4;
818
        state->bytes_per_sample = 2;
819

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
820
        if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
821 822
            state->get_sample = aec_get_msb_16;
            state->get_rsi = aec_get_rsi_msb_16;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
823
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
824 825
            state->get_sample = aec_get_lsb_16;
            state->get_rsi = aec_get_rsi_lsb_16;
826
        }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
827
    } else {
828 829
        /* 8 bit settings */
        state->id_len = 3;
830
        state->bytes_per_sample = 1;
831

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
832 833
        state->get_sample = aec_get_8;
        state->get_rsi = aec_get_rsi_8;
834
    }
835
    state->rsi_len = strm->rsi * strm->block_size * state->bytes_per_sample;
836

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
837
    if (strm->flags & AEC_DATA_SIGNED) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
838 839
        state->xmin = -(1ULL << (strm->bits_per_sample - 1));
        state->xmax = (1ULL << (strm->bits_per_sample - 1)) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
840
        state->preprocess = preprocess_signed;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
841
    } else {
842
        state->xmin = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
843
        state->xmax = (1ULL << strm->bits_per_sample) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
844
        state->preprocess = preprocess_unsigned;
845 846
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
847 848
    state->kmax = (1U << state->id_len) - 3;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
849 850 851
    state->data_pp = malloc(strm->rsi
                            * strm->block_size
                            * sizeof(uint32_t));
852
    if (state->data_pp == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
853
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
854

855
    if (strm->flags & AEC_DATA_PREPROCESS) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
856 857 858
        state->data_raw = malloc(strm->rsi
                                 * strm->block_size
                                 * sizeof(uint32_t));
859 860 861 862 863 864
        if (state->data_raw == NULL)
            return AEC_MEM_ERROR;
    } else {
        state->data_raw = state->data_pp;
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
865
    state->block = state->data_pp;
866 867 868 869

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

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
870 871 872
    state->cds = state->cds_buf;
    *state->cds = 0;
    state->bits = 8;
873 874
    state->mode = m_get_block;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
875
    return AEC_OK;
876 877
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
878
int aec_encode(struct aec_stream *strm, int flush)
879 880 881 882 883
{
    /**
       Finite-state machine implementation of the adaptive entropy
       encoder.
    */
884
    int n;
885 886
    struct internal_state *state = strm->state;

887
    state->flush = flush;
888 889
    strm->total_in += strm->avail_in;
    strm->total_out += strm->avail_out;
890 891 892

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

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
893
    if (state->direct_out) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
894
        n = state->cds - strm->next_out;
895 896 897
        strm->next_out += n;
        strm->avail_out -= n;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
898 899
        *state->cds_buf = *state->cds;
        state->cds = state->cds_buf;
900
        state->direct_out = 0;
901
    }
902 903
    strm->total_in -= strm->avail_in;
    strm->total_out -= strm->avail_out;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
904
    return AEC_OK;
905 906
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
907
int aec_encode_end(struct aec_stream *strm)
908
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
909
    struct internal_state *state = strm->state;
910

911 912 913
    if (strm->flags & AEC_DATA_PREPROCESS)
        free(state->data_raw);
    free(state->data_pp);
914
    free(state);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
915
    return AEC_OK;
916
}
917

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
918
int aec_buffer_encode(struct aec_stream *strm)
919 920 921 922 923 924 925
{
    int status;

    status = aec_encode_init(strm);
    if (status != AEC_OK)
        return status;
    status = aec_encode(strm, AEC_FLUSH);
926
    if (strm->avail_in > 0)
927 928 929 930 931
        status = AEC_DATA_ERROR;

    aec_encode_end(strm);
    return status;
}