encode.c 24.5 KB
Newer Older
1
/**
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
2
 * @file encode.c
3
4
5
6
 * @author Mathis Rosenhauer, Deutsches Klimarechenzentrum
 * @section DESCRIPTION
 *
 * Adaptive Entropy Encoder
7
 * Based on CCSDS documents 121.0-B-2 and 120.0-G-2
8
9
 *
 */
10

11
12
13
14
15
16
#include <config.h>

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

17
18
#include <stdio.h>
#include <stdlib.h>
19
#include <unistd.h>
20
21
#include <string.h>

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
22
23
24
#include "libaec.h"
#include "encode.h"
#include "encode_accessors.h"
25

26
/* Marker for Remainder Of Segment condition in zero block encoding */
27
#define ROS -1
28

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
29
30
31
32
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
33
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
34
35
36
37
    /**
       Emit sequence of bits.
     */

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
38
39
40
    if (bits <= state->bits) {
        state->bits -= bits;
        *state->cds += data << state->bits;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
41
    } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
42
43
        bits -= state->bits;
        *state->cds++ += (uint64_t)data >> bits;
44

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
45
        while (bits & ~7) {
46
            bits -= 8;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
47
            *state->cds++ = data >> bits;
48
        }
49

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
50
51
        state->bits = 8 - bits;
        *state->cds = data << state->bits;
52
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
53
54
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
55
static inline void emitfs(struct internal_state *state, int fs)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
56
{
57
58
    /**
       Emits a fundamental sequence.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
59

60
61
       fs zero bits followed by one 1 bit.
     */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
62

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
63
    for(;;) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
64
65
66
        if (fs < state->bits) {
            state->bits -= fs + 1;
            *state->cds += 1U << state->bits;
67
            break;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
68
        } else {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
69
70
71
            fs -= state->bits;
            *++state->cds = 0;
            state->bits = 8;
72
73
        }
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
74
}
75

76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
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
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
155
156
157
158
159
    }

EMITBLOCK(0);
EMITBLOCK(1);

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
160
static void preprocess_unsigned(struct aec_stream *strm)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
161
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
162
163
164
165
    /**
       Preprocess RSI of unsigned samples.
    */

166
    int64_t D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
167
    struct internal_state *state = strm->state;
168
169
    const uint32_t *x = state->data_raw;
    uint32_t *d = state->data_pp;
170
171
    uint32_t xmax = state->xmax;
    uint32_t rsi = strm->rsi * strm->block_size - 1;
172

173
    *d++ = x[0];
174
    while (rsi--) {
175
176
177
178
        if (x[1] >= x[0]) {
            D = x[1] - x[0];
            if (D <= x[0]) {
                *d = 2 * D;
179
            } else {
180
                *d = x[1];
181
            }
182
        } else {
183
184
185
            D = x[0] - x[1];
            if (D <= xmax - x[0]) {
                *d = 2 * D - 1;
186
            } else {
187
                *d = xmax - x[1];
188
            }
189
        }
190
        d++;
191
        x++;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
192
193
194
    }
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
195
static void preprocess_signed(struct aec_stream *strm)
196
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
197
198
199
200
    /**
       Preprocess RSI of signed samples.
    */

201
    int64_t D;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
202
    struct internal_state *state = strm->state;
203
204
    uint32_t *d = state->data_pp;
    int32_t *x = (int32_t *)state->data_raw;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
205
    uint64_t m = 1ULL << (strm->bits_per_sample - 1);
206
207
208
    int64_t xmax = state->xmax;
    int64_t xmin = state->xmin;
    uint32_t rsi = strm->rsi * strm->block_size - 1;
209

210
211
212
    *d++ = (uint32_t)x[0];
    x[0] = (x[0] ^ m) - m;

213
    while (rsi--) {
214
215
216
217
218
        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;
219
            else
220
                *d = xmax - x[1];
221
        } else {
222
223
224
            D = (int64_t)x[1] - x[0];
            if (D <= x[0] - xmin)
                *d = 2 * D;
225
            else
226
                *d = x[1] - xmin;
227
        }
228
229
        x++;
        d++;
230
    }
231
}
232

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
static uint64_t block_fs(struct aec_stream *strm, int k)
{
    /**
       Sum FS of all samples in block for given splitting position.
    */

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

    fs = (uint64_t)(state->block[1] >> k)
        + (uint64_t)(state->block[2] >> k)
        + (uint64_t)(state->block[3] >> k)
        + (uint64_t)(state->block[4] >> k)
        + (uint64_t)(state->block[5] >> k)
        + (uint64_t)(state->block[6] >> k)
        + (uint64_t)(state->block[7] >> k);

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

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

    return fs;
}

static int assess_splitting_option(struct aec_stream *strm)
{
    /**
       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
275
       the same position into k LSB and bits_per_sample - k MSB. The
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
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
349
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
       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;
    no_turn = (k == 0) ? 1 : 0;
    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;
}

static int assess_se_option(uint64_t limit, struct aec_stream *strm)
{
    /**
       Length of CDS encoded with Second Extension option.

       If length is above limit just return UINT64_MAX.
    */

    int i;
    uint64_t d;
    uint64_t len;
    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 */
        if (d > limit) {
            len = UINT64_MAX;
            break;
        } else {
            len += d * (d + 1) / 2
                + (uint64_t)state->block[i + 1];
        }
    }
    return len;
}

382
383
384
385
386
387
/*
 *
 * FSM functions
 *
 */

388
static int m_flush_block_resumable(struct aec_stream *strm)
389
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
390
    /**
391
       Slow and restartable flushing
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
392
    */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
393
    struct internal_state *state = strm->state;
394

395
396
397
    while(state->cds_buf + state->i < state->cds) {
        if (strm->avail_out == 0)
            return M_EXIT;
398

399
400
401
402
        *strm->next_out++ = state->cds_buf[state->i];
        strm->avail_out--;
        strm->total_out++;
        state->i++;
403
    }
404
    state->mode = m_get_block;
405
    return M_CONTINUE;
406
407
}

408
static int m_flush_block(struct aec_stream *strm)
409
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
410
    /**
411
       Flush block in direct_out mode by updating counters.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
412

413
       Fall back to slow flushing if in buffered mode.
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
414
    */
415
    int n;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
416
    struct internal_state *state = strm->state;
417

418
419
420
421
422
    if (state->direct_out) {
        n = state->cds - strm->next_out;
        strm->next_out += n;
        strm->avail_out -= n;
        strm->total_out += n;
423
424
        state->mode = m_get_block;
        return M_CONTINUE;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
425
    }
426

427
428
429
    state->i = 0;
    state->mode = m_flush_block_resumable;
    return M_CONTINUE;
430
}
431

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
432
static int m_encode_splitting(struct aec_stream *strm)
433
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
434
    struct internal_state *state = strm->state;
435
    int k = state->k;
436

437
    emit(state, k + 1, state->id_len);
438

439
    if (state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
440
    {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
441
        emit(state, state->block[0], strm->bits_per_sample);
442
        emitblock_fs_1(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
443
444
        if (k)
            emitblock_1(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
445
446
447
    }
    else
    {
448
        emitblock_fs_0(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
449
450
        if (k)
            emitblock_0(strm, k);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
451
    }
452

453
454
    return m_flush_block(strm);
}
455

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
456
static int m_encode_uncomp(struct aec_stream *strm)
457
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
458
    struct internal_state *state = strm->state;
459

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
460
    emit(state, (1U << state->id_len) - 1, state->id_len);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
461
    emitblock_0(strm, strm->bits_per_sample);
462

463
464
    return m_flush_block(strm);
}
465

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
466
static int m_encode_se(struct aec_stream *strm)
467
468
{
    int i;
469
    uint32_t d;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
470
    struct internal_state *state = strm->state;
471

472
473
    emit(state, 1, state->id_len + 1);
    if (state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
474
        emit(state, state->block[0], strm->bits_per_sample);
475

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
476
    for (i = 0; i < strm->block_size; i+= 2) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
477
478
        d = state->block[i] + state->block[i + 1];
        emitfs(state, d * (d + 1) / 2 + state->block[i + 1]);
479
    }
480

481
482
    return m_flush_block(strm);
}
483

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
484
static int m_encode_zero(struct aec_stream *strm)
485
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
486
    struct internal_state *state = strm->state;
487

488
    emit(state, 0, state->id_len + 1);
489

490
    if (state->zero_ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
491
        emit(state, state->zero_ref_sample, strm->bits_per_sample);
492

493
494
495
496
497
498
    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);
499

500
501
502
    state->zero_blocks = 0;
    return m_flush_block(strm);
}
503

504
static int m_select_code_option(struct aec_stream *strm)
505
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
506
    /**
507
508
       Decide which code option to use.
    */
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
509

510
511
512
513
514
515
    uint64_t uncomp_len;
    uint64_t split_len;
    uint64_t se_len;
    struct internal_state *state = strm->state;

    uncomp_len = (strm->block_size - state->ref)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
516
        * strm->bits_per_sample;
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
    split_len = assess_splitting_option(strm);
    se_len = assess_se_option(split_len, strm);

    if (split_len < uncomp_len) {
        if (split_len < se_len)
            return m_encode_splitting(strm);
        else
            return m_encode_se(strm);
    } else {
        if (uncomp_len <= se_len)
            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
540
    */
541

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
542
    struct internal_state *state = strm->state;
543
544
    uint32_t *p = state->block + state->ref;
    uint32_t *end = state->block + strm->block_size;
545

546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
    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
             * handled later.
             */
            state->block -= strm->block_size;
            state->blocks_avail++;
            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;
        }
575
576
577
        state->mode = m_get_block;
        return M_CONTINUE;
    }
578
}
579

580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
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.
    */

    int j;
    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) {
                    for (j = state->i; j < strm->rsi * strm->block_size; j++)
                        state->data_raw[j] = state->data_raw[state->i - 1];
                    state->i = strm->rsi * strm->block_size;
                } else {
                    if (state->zero_blocks) {
                        state->mode = m_encode_zero;
                        return M_CONTINUE;
                    }

                    emit(state, 0, state->bits);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
608
609
610
611
612
613
                    if (strm->avail_out > 0) {
                        if (state->direct_out == 0)
                            *strm->next_out++ = *state->cds;
                        strm->avail_out--;
                        strm->total_out++;
                    }
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
                    return M_EXIT;
                }
            } else {
                return M_EXIT;
            }
        }
    } while (++state->i < strm->rsi * strm->block_size);

    state->blocks_avail = strm->rsi - 1;
    if (strm->flags & AEC_DATA_PREPROCESS) {
        state->preprocess(strm);
        state->ref = 1;
    }

    return m_check_zero_block(strm);
629
630
}

631
static int m_get_block(struct aec_stream *strm)
632
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
633
    /**
634
635
636
637
       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
638
    */
639

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
640
    struct internal_state *state = strm->state;
641

642
643
644
645
646
647
648
649
650
651
652
653
654
655
    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;
    }
656

657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
    if (state->blocks_avail == 0) {
        state->block = state->data_pp;

        if (strm->avail_in >= state->block_len * strm->rsi) {
            state->get_rsi(strm);
            state->blocks_avail = strm->rsi - 1;

            if (strm->flags & AEC_DATA_PREPROCESS) {
                state->preprocess(strm);
                state->ref = 1;
            }
            return m_check_zero_block(strm);
        } else {
            state->i = 0;
            state->mode = m_get_rsi_resumable;
        }
    } else {
        state->ref = 0;
        state->block += strm->block_size;
        state->blocks_avail--;
        return m_check_zero_block(strm);
678
679
680
681
682
683
684
685
686
    }
    return M_CONTINUE;
}

/*
 *
 * API functions
 *
 */
687

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
688
int aec_encode_init(struct aec_stream *strm)
689
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
690
    struct internal_state *state;
691

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
692
    if (strm->bits_per_sample > 32 || strm->bits_per_sample == 0)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
693
        return AEC_CONF_ERROR;
694
695
696
697
698

    if (strm->block_size != 8
        && strm->block_size != 16
        && strm->block_size != 32
        && strm->block_size != 64)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
699
        return AEC_CONF_ERROR;
700
701

    if (strm->rsi > 4096)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
702
        return AEC_CONF_ERROR;
703

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
704
    state = (struct internal_state *)malloc(sizeof(struct internal_state));
705
    if (state == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
706
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
707
708

    memset(state, 0, sizeof(struct internal_state));
709
710
    strm->state = state;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
711
    if (strm->bits_per_sample > 16) {
712
        /* 24/32 input bit settings */
713
714
        state->id_len = 5;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
715
        if (strm->bits_per_sample <= 24
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
716
            && strm->flags & AEC_DATA_3BYTE) {
717
            state->block_len = 3 * strm->block_size;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
718
            if (strm->flags & AEC_DATA_MSB) {
719
                state->get_sample = get_msb_24;
720
                state->get_rsi = get_rsi_msb_24;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
721
            } else {
722
                state->get_sample = get_lsb_24;
723
                state->get_rsi = get_rsi_lsb_24;
724
            }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
725
        } else {
726
            state->block_len = 4 * strm->block_size;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
727
            if (strm->flags & AEC_DATA_MSB) {
728
                state->get_sample = get_msb_32;
729
                state->get_rsi = get_rsi_msb_32;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
730
            } else {
731
                state->get_sample = get_lsb_32;
732
                state->get_rsi = get_rsi_lsb_32;
733
734
            }
        }
735
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
736
    else if (strm->bits_per_sample > 8) {
737
738
        /* 16 bit settings */
        state->id_len = 4;
739
        state->block_len = 2 * strm->block_size;
740

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
741
        if (strm->flags & AEC_DATA_MSB) {
742
            state->get_sample = get_msb_16;
743
            state->get_rsi = get_rsi_msb_16;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
744
        } else {
745
            state->get_sample = get_lsb_16;
746
            state->get_rsi = get_rsi_lsb_16;
747
        }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
748
    } else {
749
750
        /* 8 bit settings */
        state->id_len = 3;
751
        state->block_len = strm->block_size;
752
753

        state->get_sample = get_8;
754
        state->get_rsi = get_rsi_8;
755
756
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
757
    if (strm->flags & AEC_DATA_SIGNED) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
758
759
        state->xmin = -(1ULL << (strm->bits_per_sample - 1));
        state->xmax = (1ULL << (strm->bits_per_sample - 1)) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
760
        state->preprocess = preprocess_signed;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
761
    } else {
762
        state->xmin = 0;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
763
        state->xmax = (1ULL << strm->bits_per_sample) - 1;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
764
        state->preprocess = preprocess_unsigned;
765
766
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
767
768
    state->kmax = (1U << state->id_len) - 3;

769
    state->data_pp = (uint32_t *)malloc(strm->rsi
770
771
                                         * strm->block_size
                                         * sizeof(uint32_t));
772
    if (state->data_pp == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
773
        return AEC_MEM_ERROR;
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
774

775
776
777
778
779
780
781
782
783
784
    if (strm->flags & AEC_DATA_PREPROCESS) {
        state->data_raw = (uint32_t *)malloc(strm->rsi
                                             * strm->block_size
                                             * sizeof(uint32_t));
        if (state->data_raw == NULL)
            return AEC_MEM_ERROR;
    } else {
        state->data_raw = state->data_pp;
    }

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
785
    state->block = state->data_pp;
786

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
787
    /* Largest possible CDS according to specs */
788
789
790
    state->cds_len = (5 + 64 * 32) / 8 + 3;
    state->cds_buf = (uint8_t *)malloc(state->cds_len);
    if (state->cds_buf == NULL)
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
791
        return AEC_MEM_ERROR;
792

793
794
795
    strm->total_in = 0;
    strm->total_out = 0;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
796
797
798
    state->cds = state->cds_buf;
    *state->cds = 0;
    state->bits = 8;
799
800
    state->mode = m_get_block;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
801
    return AEC_OK;
802
803
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
804
int aec_encode(struct aec_stream *strm, int flush)
805
806
807
808
809
{
    /**
       Finite-state machine implementation of the adaptive entropy
       encoder.
    */
810
    int n;
811
812
    struct internal_state *state = strm->state;

813
814
815
816
    state->flush = flush;

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

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
817
    if (state->direct_out) {
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
818
        n = state->cds - strm->next_out;
819
820
821
822
        strm->next_out += n;
        strm->avail_out -= n;
        strm->total_out += n;

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
823
824
        *state->cds_buf = *state->cds;
        state->cds = state->cds_buf;
825
        state->direct_out = 0;
826
    }
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
827
    return AEC_OK;
828
829
}

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
830
int aec_encode_end(struct aec_stream *strm)
831
{
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
832
    struct internal_state *state = strm->state;
833

834
835
836
    if (strm->flags & AEC_DATA_PREPROCESS)
        free(state->data_raw);
    free(state->data_pp);
837
    free(state->cds_buf);
838
    free(state);
Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
839
    return AEC_OK;
840
}
841

Mathis Rosenhauer's avatar
Mathis Rosenhauer committed
842
int aec_buffer_encode(struct aec_stream *strm)
843
844
845
846
847
848
849
850
851
852
853
854
855
{
    int status;

    status = aec_encode_init(strm);
    if (status != AEC_OK)
        return status;
    status = aec_encode(strm, AEC_FLUSH);
    if (strm->avail_in > 0 || strm->avail_out == 0)
        status = AEC_DATA_ERROR;

    aec_encode_end(strm);
    return status;
}