encode.c 26.2 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

69
/* Marker for Remainder Of Segment condition in zero block encoding */
70
#define ROS -1
71

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
72
73
74
75
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
76
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
77
78
79
80
    /**
       Emit sequence of bits.
     */

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
81
82
83
    if (bits <= state->bits) {
        state->bits -= bits;
        *state->cds += data << state->bits;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
84
    } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
85
86
        bits -= state->bits;
        *state->cds++ += (uint64_t)data >> bits;
87

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
88
        while (bits & ~7) {
89
            bits -= 8;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
90
            *state->cds++ = data >> bits;
91
        }
92

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
93
94
        state->bits = 8 - bits;
        *state->cds = data << state->bits;
95
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
96
97
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
98
static inline void emitfs(struct internal_state *state, int fs)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
99
{
100
101
    /**
       Emits a fundamental sequence.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
102

103
104
       fs zero bits followed by one 1 bit.
     */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
105

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
106
    for(;;) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
107
108
109
        if (fs < state->bits) {
            state->bits -= fs + 1;
            *state->cds += 1U << state->bits;
110
            break;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
111
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
112
113
114
            fs -= state->bits;
            *++state->cds = 0;
            state->bits = 8;
115
116
        }
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
117
}
118

119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
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;
}

#define EMITBLOCK_FS(ref)                                           \
    static inline void emitblock_fs_##ref(struct aec_stream *strm,  \
                                          int k)                    \
    {                                                               \
        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);                             \
        }                                                           \
                                                                    \
        copy64(state->cds, acc);                                    \
        state->cds += used >> 3;                                    \
        state->bits = 7 - (used & 7);                               \
    }

EMITBLOCK_FS(0);
EMITBLOCK_FS(1);

#define EMITBLOCK(ref)                                              \
    static inline void emitblock_##ref(struct aec_stream *strm,     \
                                       int k)                       \
    {                                                               \
        /**                                                         \
           Emit the k LSB of a whole block of input data.           \
        */                                                          \
                                                                    \
        int b;                                                      \
        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;               \
            }                                                       \
                                                                    \
            for (b = 56; b > (p & ~7); b -= 8)                      \
                *o++ = a >> b;                                      \
            a >>= b;                                                \
        }                                                           \
                                                                    \
        *o = a;                                                     \
        state->cds = o;                                             \
        state->bits = p % 8;                                        \
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
198
199
200
201
202
    }

EMITBLOCK(0);
EMITBLOCK(1);

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
203
static void preprocess_unsigned(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
204
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
205
206
    /**
       Preprocess RSI of unsigned samples.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
207
208
209

       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
210
211
    */

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
212
    uint32_t D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
213
    struct internal_state *state = strm->state;
214
215
    const uint32_t *x = state->data_raw;
    uint32_t *d = state->data_pp;
216
217
    uint32_t xmax = state->xmax;
    uint32_t rsi = strm->rsi * strm->block_size - 1;
218

219
    *d++ = x[0];
220
    while (rsi--) {
221
222
        if (x[1] >= x[0]) {
            D = x[1] - x[0];
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
223
            if (D <= x[0])
224
                *d = 2 * D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
225
            else
226
                *d = x[1];
227
        } else {
228
            D = x[0] - x[1];
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
229
            if (D <= xmax - x[0])
230
                *d = 2 * D - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
231
            else
232
                *d = xmax - x[1];
233
        }
234
        d++;
235
        x++;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
236
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
237
    state->ref = 1;
238
    state->uncomp_len = (strm->block_size - 1) * strm->bits_per_sample;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
239
240
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
241
static void preprocess_signed(struct aec_stream *strm)
242
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
243
244
245
246
    /**
       Preprocess RSI of signed samples.
    */

247
    int64_t D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
248
    struct internal_state *state = strm->state;
249
250
    uint32_t *d = state->data_pp;
    int32_t *x = (int32_t *)state->data_raw;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
251
    uint64_t m = 1ULL << (strm->bits_per_sample - 1);
252
253
254
    int64_t xmax = state->xmax;
    int64_t xmin = state->xmin;
    uint32_t rsi = strm->rsi * strm->block_size - 1;
255

256
257
258
    *d++ = (uint32_t)x[0];
    x[0] = (x[0] ^ m) - m;

259
    while (rsi--) {
260
261
262
263
264
        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;
265
            else
266
                *d = xmax - x[1];
267
        } else {
268
269
270
            D = (int64_t)x[1] - x[0];
            if (D <= x[0] - xmin)
                *d = 2 * D;
271
            else
272
                *d = x[1] - xmin;
273
        }
274
275
        x++;
        d++;
276
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
277
    state->ref = 1;
278
    state->uncomp_len = (strm->block_size - 1) * strm->bits_per_sample;
279
}
280

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
281
282
283
284
285
286
static uint64_t block_fs(struct aec_stream *strm, int k)
{
    /**
       Sum FS of all samples in block for given splitting position.
    */

287
288
    int i;
    uint64_t fs = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
289
290
    struct internal_state *state = strm->state;

291
292
293
294
295
296
297
298
299
300
301
302
303
    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);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
304
305
306
307

    return fs;
}

308
static uint32_t assess_splitting_option(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
309
310
311
312
313
{
    /**
       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
314
       the same position into k LSB and bits_per_sample - k MSB. The
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
315
316
317
318
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
348
       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.
     */

    int k;
    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;
349
    no_turn = k == 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
    dir = 1;

    for (;;) {
        fs_len = block_fs(strm, k);
        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;
}

391
static uint32_t assess_se_option(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
392
393
394
395
{
    /**
       Length of CDS encoded with Second Extension option.

396
       If length is above limit just return UINT32_MAX.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
397
398
399
400
    */

    int i;
    uint64_t d;
401
    uint32_t len;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
402
403
404
405
406
407
408
409
    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 */
410
411
        if (d > state->uncomp_len) {
            len = UINT32_MAX;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
412
413
            break;
        } else {
414
            len += d * (d + 1) / 2 + state->block[i + 1];
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
415
416
417
418
419
        }
    }
    return len;
}

420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
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;

    if (strm->avail_out > state->cds_len) {
        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;
    }
}

445
446
447
448
449
450
/*
 *
 * FSM functions
 *
 */

451
static int m_flush_block_resumable(struct aec_stream *strm)
452
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
453
    /**
454
       Slow and restartable flushing
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
455
    */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
456
    struct internal_state *state = strm->state;
457

458
459
460
461
462
463
464
465
466
467
468
    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;
469
470
471
    }
}

472
static int m_flush_block(struct aec_stream *strm)
473
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
474
    /**
475
       Flush block in direct_out mode by updating counters.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
476

477
       Fall back to slow flushing if in buffered mode.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
478
    */
479
    int n;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
480
    struct internal_state *state = strm->state;
481

482
483
484
485
    if (state->direct_out) {
        n = state->cds - strm->next_out;
        strm->next_out += n;
        strm->avail_out -= n;
486
487
        state->mode = m_get_block;
        return M_CONTINUE;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
488
    }
489

490
491
492
    state->i = 0;
    state->mode = m_flush_block_resumable;
    return M_CONTINUE;
493
}
494

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
495
static int m_encode_splitting(struct aec_stream *strm)
496
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
497
    struct internal_state *state = strm->state;
498
    int k = state->k;
499

500
    emit(state, k + 1, state->id_len);
501

502
    if (state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
503
    {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
504
        emit(state, state->block[0], strm->bits_per_sample);
505
        emitblock_fs_1(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
506
507
        if (k)
            emitblock_1(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
508
509
510
    }
    else
    {
511
        emitblock_fs_0(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
512
513
        if (k)
            emitblock_0(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
514
    }
515

516
517
    return m_flush_block(strm);
}
518

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
519
static int m_encode_uncomp(struct aec_stream *strm)
520
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
521
    struct internal_state *state = strm->state;
522

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
523
    emit(state, (1U << state->id_len) - 1, state->id_len);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
524
    emitblock_0(strm, strm->bits_per_sample);
525

526
527
    return m_flush_block(strm);
}
528

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
529
static int m_encode_se(struct aec_stream *strm)
530
531
{
    int i;
532
    uint32_t d;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
533
    struct internal_state *state = strm->state;
534

535
536
    emit(state, 1, state->id_len + 1);
    if (state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
537
        emit(state, state->block[0], strm->bits_per_sample);
538

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
539
    for (i = 0; i < strm->block_size; i+= 2) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
540
541
        d = state->block[i] + state->block[i + 1];
        emitfs(state, d * (d + 1) / 2 + state->block[i + 1]);
542
    }
543

544
545
    return m_flush_block(strm);
}
546

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
547
static int m_encode_zero(struct aec_stream *strm)
548
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
549
    struct internal_state *state = strm->state;
550

551
    emit(state, 0, state->id_len + 1);
552

553
    if (state->zero_ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
554
        emit(state, state->zero_ref_sample, strm->bits_per_sample);
555

556
557
558
559
560
561
    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);
562

563
564
565
    state->zero_blocks = 0;
    return m_flush_block(strm);
}
566

567
static int m_select_code_option(struct aec_stream *strm)
568
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
569
    /**
570
571
       Decide which code option to use.
    */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
572

573
574
    uint32_t split_len;
    uint32_t se_len;
575
576
577
    struct internal_state *state = strm->state;

    split_len = assess_splitting_option(strm);
578
    se_len = assess_se_option(strm);
579

580
    if (split_len < state->uncomp_len) {
581
582
583
584
585
        if (split_len < se_len)
            return m_encode_splitting(strm);
        else
            return m_encode_se(strm);
    } else {
586
        if (state->uncomp_len <= se_len)
587
588
589
590
591
592
593
594
595
596
597
598
599
            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
600
    */
601

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
602
    struct internal_state *state = strm->state;
603
604
    uint32_t *p = state->block + state->ref;
    uint32_t *end = state->block + strm->block_size;
605

606
607
608
609
610
611
612
    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
613
             * flagged and handled later.
614
             */
615
            state->block_nonzero = 1;
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
            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;
        }
634
635
636
        state->mode = m_get_block;
        return M_CONTINUE;
    }
637
}
638

639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
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 {
        if (strm->avail_in > 0) {
            state->data_raw[state->i] = state->get_sample(strm);
        } else {
            if (state->flush == AEC_FLUSH) {
                if (state->i > 0) {
656
657
658
659
                    do
                        state->data_raw[state->i] =
                            state->data_raw[state->i - 1];
                    while(++state->i < strm->rsi * strm->block_size);
660
661
                } else {
                    emit(state, 0, state->bits);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
662
                    if (strm->avail_out > 0) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
663
                        if (!state->direct_out)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
664
665
666
                            *strm->next_out++ = *state->cds;
                        strm->avail_out--;
                    }
667
668
669
670
671
672
673
674
                    return M_EXIT;
                }
            } else {
                return M_EXIT;
            }
        }
    } while (++state->i < strm->rsi * strm->block_size);

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
675
    if (strm->flags & AEC_DATA_PREPROCESS)
676
677
678
        state->preprocess(strm);

    return m_check_zero_block(strm);
679
680
}

681
static int m_get_block(struct aec_stream *strm)
682
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
683
    /**
684
685
686
687
       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
688
    */
689

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
690
    struct internal_state *state = strm->state;
691

692
693
694
695
696
697
    init_output(strm);

    if (state->block_nonzero) {
        state->block_nonzero = 0;
        state->mode = m_select_code_option;
        return M_CONTINUE;
698
    }
699

700
    if (state->blocks_avail == 0) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
701
        state->blocks_avail = strm->rsi - 1;
702
703
        state->block = state->data_pp;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
704
        if (strm->avail_in >= state->rsi_len) {
705
            state->get_rsi(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
706
            if (strm->flags & AEC_DATA_PREPROCESS)
707
                state->preprocess(strm);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
708

709
710
711
712
713
714
            return m_check_zero_block(strm);
        } else {
            state->i = 0;
            state->mode = m_get_rsi_resumable;
        }
    } else {
715
716
717
718
        if (state->ref) {
            state->ref = 0;
            state->uncomp_len = strm->block_size * strm->bits_per_sample;
        }
719
720
721
        state->block += strm->block_size;
        state->blocks_avail--;
        return m_check_zero_block(strm);
722
723
724
725
726
727
728
729
730
    }
    return M_CONTINUE;
}

/*
 *
 * API functions
 *
 */
731

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
732
int aec_encode_init(struct aec_stream *strm)
733
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
734
    struct internal_state *state;
735

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
736
    if (strm->bits_per_sample > 32 || strm->bits_per_sample == 0)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
737
        return AEC_CONF_ERROR;
738
739
740
741
742

    if (strm->block_size != 8
        && strm->block_size != 16
        && strm->block_size != 32
        && strm->block_size != 64)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
743
        return AEC_CONF_ERROR;
744
745

    if (strm->rsi > 4096)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
746
        return AEC_CONF_ERROR;
747

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
748
    state = malloc(sizeof(struct internal_state));
749
    if (state == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
750
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
751
752

    memset(state, 0, sizeof(struct internal_state));
753
754
    strm->state = state;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
755
    if (strm->bits_per_sample > 16) {
756
        /* 24/32 input bit settings */
757
758
        state->id_len = 5;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
759
        if (strm->bits_per_sample <= 24
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
760
            && strm->flags & AEC_DATA_3BYTE) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
761
            state->rsi_len = 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
762
            if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
763
764
                state->get_sample = aec_get_msb_24;
                state->get_rsi = aec_get_rsi_msb_24;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
765
            } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
766
767
                state->get_sample = aec_get_lsb_24;
                state->get_rsi = aec_get_rsi_lsb_24;
768
            }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
769
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
770
            state->rsi_len = 4;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
771
            if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
772
773
                state->get_sample = aec_get_msb_32;
                state->get_rsi = aec_get_rsi_msb_32;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
774
            } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
775
776
                state->get_sample = aec_get_lsb_32;
                state->get_rsi = aec_get_rsi_lsb_32;
777
778
            }
        }
779
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
780
    else if (strm->bits_per_sample > 8) {
781
782
        /* 16 bit settings */
        state->id_len = 4;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
783
        state->rsi_len = 2;
784

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
785
        if (strm->flags & AEC_DATA_MSB) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
786
787
            state->get_sample = aec_get_msb_16;
            state->get_rsi = aec_get_rsi_msb_16;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
788
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
789
790
            state->get_sample = aec_get_lsb_16;
            state->get_rsi = aec_get_rsi_lsb_16;
791
        }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
792
    } else {
793
794
        /* 8 bit settings */
        state->id_len = 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
795
        state->rsi_len = 1;
796

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
797
798
        state->get_sample = aec_get_8;
        state->get_rsi = aec_get_rsi_8;
799
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
800
    state->rsi_len *= strm->rsi * strm->block_size;
801

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
802
    if (strm->flags & AEC_DATA_SIGNED) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
803
804
        state->xmin = -(1ULL << (strm->bits_per_sample - 1));
        state->xmax = (1ULL << (strm->bits_per_sample - 1)) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
805
        state->preprocess = preprocess_signed;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
806
    } else {
807
        state->xmin = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
808
        state->xmax = (1ULL << strm->bits_per_sample) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
809
        state->preprocess = preprocess_unsigned;
810
811
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
812
813
    state->kmax = (1U << state->id_len) - 3;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
814
815
816
    state->data_pp = malloc(strm->rsi
                            * strm->block_size
                            * sizeof(uint32_t));
817
    if (state->data_pp == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
818
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
819

820
    if (strm->flags & AEC_DATA_PREPROCESS) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
821
822
823
        state->data_raw = malloc(strm->rsi
                                 * strm->block_size
                                 * sizeof(uint32_t));
824
825
826
827
828
829
        if (state->data_raw == NULL)
            return AEC_MEM_ERROR;
    } else {
        state->data_raw = state->data_pp;
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
830
    state->block = state->data_pp;
831

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
832
    /* Largest possible CDS according to specs */
833
    state->cds_len = (5 + 64 * 32) / 8 + 3;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
834
    state->cds_buf = malloc(state->cds_len);
835
    if (state->cds_buf == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
836
        return AEC_MEM_ERROR;
837

838
839
840
    strm->total_in = 0;
    strm->total_out = 0;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
841
842
843
    state->cds = state->cds_buf;
    *state->cds = 0;
    state->bits = 8;
844
845
    state->mode = m_get_block;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
846
    return AEC_OK;
847
848
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
849
int aec_encode(struct aec_stream *strm, int flush)
850
851
852
853
854
{
    /**
       Finite-state machine implementation of the adaptive entropy
       encoder.
    */
855
    int n;
856
857
    struct internal_state *state = strm->state;

858
    state->flush = flush;
859
860
    strm->total_in += strm->avail_in;
    strm->total_out += strm->avail_out;
861
862
863

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

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
864
    if (state->direct_out) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
865
        n = state->cds - strm->next_out;
866
867
868
        strm->next_out += n;
        strm->avail_out -= n;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
869
870
        *state->cds_buf = *state->cds;
        state->cds = state->cds_buf;
871
        state->direct_out = 0;
872
    }
873
874
    strm->total_in -= strm->avail_in;
    strm->total_out -= strm->avail_out;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
875
    return AEC_OK;
876
877
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
878
int aec_encode_end(struct aec_stream *strm)
879
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
880
    struct internal_state *state = strm->state;
881

882
883
884
    if (strm->flags & AEC_DATA_PREPROCESS)
        free(state->data_raw);
    free(state->data_pp);
885
    free(state->cds_buf);
886
    free(state);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
887
    return AEC_OK;
888
}
889

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
890
int aec_buffer_encode(struct aec_stream *strm)
891
892
893
894
895
896
897
{
    int status;

    status = aec_encode_init(strm);
    if (status != AEC_OK)
        return status;
    status = aec_encode(strm, AEC_FLUSH);
898
    if (strm->avail_in > 0)
899
900
901
902
903
        status = AEC_DATA_ERROR;

    aec_encode_end(strm);
    return status;
}