Statistics
| Branch: | Revision:

ffmpeg / libavcodec / adpcm.c @ 983e3246

History | View | Annotate | Download (17.6 KB)

1
/*
2
 * ADPCM codecs
3
 * Copyright (c) 2001 Fabrice Bellard.
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
10
 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
16
 * License along with this library; if not, write to the Free Software
17
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 */
19
#include "avcodec.h"
20

    
21
/**
22
 * @file adpcm.c
23
 * ADPCM codecs.
24
 * First version by Francois Revol revol@free.fr
25
 *
26
 * Features and limitations:
27
 *
28
 * Reference documents:
29
 * http://www.pcisys.net/~melanson/codecs/adpcm.txt
30
 * http://www.geocities.com/SiliconValley/8682/aud3.txt
31
 * http://openquicktime.sourceforge.net/plugins.htm
32
 * XAnim sources (xa_codec.c) http://www.rasnaimaging.com/people/lapus/download.html
33
 * http://www.cs.ucla.edu/~leec/mediabench/applications.html
34
 * SoX source code http://home.sprynet.com/~cbagwell/sox.html
35
 */
36

    
37
#define BLKSIZE 1024
38

    
39
#define CLAMP_TO_SHORT(value) \
40
if (value > 32767) \
41
    value = 32767; \
42
else if (value < -32768) \
43
    value = -32768; \
44

    
45
/* step_table[] and index_table[] are from the ADPCM reference source */
46
/* This is the index table: */
47
static const int index_table[16] = {
48
    -1, -1, -1, -1, 2, 4, 6, 8,
49
    -1, -1, -1, -1, 2, 4, 6, 8,
50
};
51

    
52
/** 
53
 * This is the step table. Note that many programs use slight deviations from
54
 * this table, but such deviations are negligible:
55
 */
56
static const int step_table[89] = {
57
    7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
58
    19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
59
    50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
60
    130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
61
    337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
62
    876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
63
    2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
64
    5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
65
    15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
66
};
67

    
68
/* Those are for MS-ADPCM */
69
/* AdaptationTable[], AdaptCoeff1[], and AdaptCoeff2[] are from libsndfile */
70
static const int AdaptationTable[] = {
71
        230, 230, 230, 230, 307, 409, 512, 614,
72
        768, 614, 512, 409, 307, 230, 230, 230
73
};
74

    
75
static const int AdaptCoeff1[] = {
76
        256, 512, 0, 192, 240, 460, 392
77
};
78

    
79
static const int AdaptCoeff2[] = {
80
        0, -256, 0, 64, 0, -208, -232
81
};
82

    
83
/* end of tables */
84

    
85
typedef struct ADPCMChannelStatus {
86
    int predictor;
87
    short int step_index;
88
    int step;
89
    /* for encoding */
90
    int prev_sample;
91

    
92
    /* MS version */
93
    short sample1;
94
    short sample2;
95
    int coeff1;
96
    int coeff2;
97
    int idelta;
98
} ADPCMChannelStatus;
99

    
100
typedef struct ADPCMContext {
101
    int channel; /* for stereo MOVs, decode left, then decode right, then tell it's decoded */
102
    ADPCMChannelStatus status[2];
103
    short sample_buffer[32]; /* hold left samples while waiting for right samples */
104
} ADPCMContext;
105

    
106
/* XXX: implement encoding */
107

    
108
static int adpcm_encode_init(AVCodecContext *avctx)
109
{
110
    if (avctx->channels > 2)
111
        return -1; /* only stereo or mono =) */
112
    switch(avctx->codec->id) {
113
    case CODEC_ID_ADPCM_IMA_QT:
114
        fprintf(stderr, "ADPCM: codec admcp_ima_qt unsupported for encoding !\n");
115
        avctx->frame_size = 64; /* XXX: can multiple of avctx->channels * 64 (left and right blocks are interleaved) */
116
        return -1;
117
        break;
118
    case CODEC_ID_ADPCM_IMA_WAV:
119
        avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 / (4 * avctx->channels) + 1; /* each 16 bits sample gives one nibble */
120
                                                             /* and we have 4 bytes per channel overhead */
121
        avctx->block_align = BLKSIZE;
122
        /* seems frame_size isn't taken into account... have to buffer the samples :-( */
123
        break;
124
    case CODEC_ID_ADPCM_MS:
125
        fprintf(stderr, "ADPCM: codec admcp_ms unsupported for encoding !\n");
126
        return -1;
127
        break;
128
    default:
129
        return -1;
130
        break;
131
    }
132

    
133
    avctx->coded_frame= avcodec_alloc_frame();
134
    avctx->coded_frame->key_frame= 1;
135

    
136
    return 0;
137
}
138

    
139
static int adpcm_encode_close(AVCodecContext *avctx)
140
{
141
    av_freep(&avctx->coded_frame);
142

    
143
    return 0;
144
}
145

    
146

    
147
static inline unsigned char adpcm_ima_compress_sample(ADPCMChannelStatus *c, short sample)
148
{
149
    int step_index;
150
    unsigned char nibble;
151
    
152
    int sign = 0; /* sign bit of the nibble (MSB) */
153
    int delta, predicted_delta;
154

    
155
    delta = sample - c->prev_sample;
156

    
157
    if (delta < 0) {
158
        sign = 1;
159
        delta = -delta;
160
    }
161

    
162
    step_index = c->step_index;
163

    
164
    /* nibble = 4 * delta / step_table[step_index]; */
165
    nibble = (delta << 2) / step_table[step_index];
166

    
167
    if (nibble > 7)
168
        nibble = 7;
169

    
170
    step_index += index_table[nibble];
171
    if (step_index < 0)
172
        step_index = 0;
173
    if (step_index > 88)
174
        step_index = 88;
175

    
176
    /* what the decoder will find */
177
    predicted_delta = ((step_table[step_index] * nibble) / 4) + (step_table[step_index] / 8);
178

    
179
    if (sign)
180
        c->prev_sample -= predicted_delta;
181
    else
182
        c->prev_sample += predicted_delta;
183

    
184
    CLAMP_TO_SHORT(c->prev_sample);
185

    
186

    
187
    nibble += sign << 3; /* sign * 8 */   
188

    
189
    /* save back */
190
    c->step_index = step_index;
191

    
192
    return nibble;
193
}
194

    
195
static int adpcm_encode_frame(AVCodecContext *avctx,
196
                            unsigned char *frame, int buf_size, void *data)
197
{
198
    int n;
199
    short *samples;
200
    unsigned char *dst;
201
    ADPCMContext *c = avctx->priv_data;
202

    
203
    dst = frame;
204
    samples = (short *)data;
205
/*    n = (BLKSIZE - 4 * avctx->channels) / (2 * 8 * avctx->channels); */
206

    
207
    switch(avctx->codec->id) {
208
    case CODEC_ID_ADPCM_IMA_QT: /* XXX: can't test until we get .mov writer */
209
        break;
210
    case CODEC_ID_ADPCM_IMA_WAV:
211
        n = avctx->frame_size / 8;
212
            c->status[0].prev_sample = (signed short)samples[0]; /* XXX */
213
/*            c->status[0].step_index = 0; *//* XXX: not sure how to init the state machine */
214
            *dst++ = (c->status[0].prev_sample) & 0xFF; /* little endian */
215
            *dst++ = (c->status[0].prev_sample >> 8) & 0xFF;
216
            *dst++ = (unsigned char)c->status[0].step_index;
217
            *dst++ = 0; /* unknown */
218
            samples++;
219
            if (avctx->channels == 2) {
220
                c->status[1].prev_sample = (signed short)samples[0];
221
/*                c->status[1].step_index = 0; */
222
                *dst++ = (c->status[1].prev_sample) & 0xFF;
223
                *dst++ = (c->status[1].prev_sample >> 8) & 0xFF;
224
                *dst++ = (unsigned char)c->status[1].step_index;
225
                *dst++ = 0;
226
                samples++;
227
            }
228
        
229
            /* stereo: 4 bytes (8 samples) for left, 4 bytes for right, 4 bytes left, ... */
230
            for (; n>0; n--) {
231
                *dst = adpcm_ima_compress_sample(&c->status[0], samples[0]) & 0x0F;
232
                *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels]) << 4) & 0xF0;
233
                dst++;
234
                *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 2]) & 0x0F;
235
                *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 3]) << 4) & 0xF0;
236
                dst++;
237
                *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 4]) & 0x0F;
238
                *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 5]) << 4) & 0xF0;
239
                dst++;
240
                *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 6]) & 0x0F;
241
                *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 7]) << 4) & 0xF0;
242
                dst++;
243
                /* right channel */
244
                if (avctx->channels == 2) {
245
                    *dst = adpcm_ima_compress_sample(&c->status[1], samples[1]);
246
                    *dst |= adpcm_ima_compress_sample(&c->status[1], samples[3]) << 4;
247
                    dst++;
248
                    *dst = adpcm_ima_compress_sample(&c->status[1], samples[5]);
249
                    *dst |= adpcm_ima_compress_sample(&c->status[1], samples[7]) << 4;
250
                    dst++;
251
                    *dst = adpcm_ima_compress_sample(&c->status[1], samples[9]);
252
                    *dst |= adpcm_ima_compress_sample(&c->status[1], samples[11]) << 4;
253
                    dst++;
254
                    *dst = adpcm_ima_compress_sample(&c->status[1], samples[13]);
255
                    *dst |= adpcm_ima_compress_sample(&c->status[1], samples[15]) << 4;
256
                    dst++;
257
                }
258
                samples += 8 * avctx->channels;
259
            }
260
        break;
261
    default:
262
        return -1;
263
    }
264
    return dst - frame;
265
}
266

    
267
static int adpcm_decode_init(AVCodecContext * avctx)
268
{
269
    ADPCMContext *c = avctx->priv_data;
270

    
271
    c->channel = 0;
272
    c->status[0].predictor = c->status[1].predictor = 0;
273
    c->status[0].step_index = c->status[1].step_index = 0;
274
    c->status[0].step = c->status[1].step = 0;
275

    
276
    switch(avctx->codec->id) {
277
    default:
278
        break;
279
    }
280
    return 0;
281
}
282

    
283
static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble)
284
{
285
    int step_index;
286
    int predictor;
287
    int sign, delta, diff, step;
288

    
289
    step = step_table[c->step_index];
290
    step_index = c->step_index + index_table[(unsigned)nibble];
291
    if (step_index < 0) step_index = 0;
292
    else if (step_index > 88) step_index = 88;
293

    
294
    sign = nibble & 8;
295
    delta = nibble & 7;
296
#if 0
297
    diff = step >> 3;
298
    if (delta & 4) diff += step;
299
    if (delta & 2) diff += step >> 1;
300
    if (delta & 1) diff += step >> 2;
301
#else
302
    diff = ((2 * delta + 1) * step) >> 3; // no jumps
303
#endif
304
    predictor = c->predictor;
305
    if (sign) predictor -= diff;
306
    else predictor += diff;
307

    
308
    CLAMP_TO_SHORT(predictor);
309
    c->predictor = predictor;
310
    c->step_index = step_index;
311

    
312
    return (short)predictor;
313
}
314

    
315
static inline short adpcm_ms_expand_nibble(ADPCMChannelStatus *c, char nibble)
316
{
317
    int predictor;
318

    
319
    predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256;
320
    predictor += (signed)((nibble & 0x08)?(nibble - 0x10):(nibble)) * c->idelta;
321
    CLAMP_TO_SHORT(predictor);
322

    
323
    c->sample2 = c->sample1;
324
    c->sample1 = predictor;
325
    c->idelta = (AdaptationTable[(int)nibble] * c->idelta) / 256;
326
    if (c->idelta < 16) c->idelta = 16;
327

    
328
    return (short)predictor;
329
}
330

    
331
static int adpcm_decode_frame(AVCodecContext *avctx,
332
                            void *data, int *data_size,
333
                            uint8_t *buf, int buf_size)
334
{
335
    ADPCMContext *c = avctx->priv_data;
336
    ADPCMChannelStatus *cs;
337
    int n, m, channel;
338
    int block_predictor[2];
339
    short *samples;
340
    uint8_t *src;
341
    int st; /* stereo */
342

    
343
    samples = data;
344
    src = buf;
345

    
346
    st = avctx->channels == 2;
347

    
348
    switch(avctx->codec->id) {
349
    case CODEC_ID_ADPCM_IMA_QT:
350
        n = (buf_size - 2);/* >> 2*avctx->channels;*/
351
        channel = c->channel;
352
        cs = &(c->status[channel]);
353
        /* (pppppp) (piiiiiii) */
354

    
355
        /* Bits 15-7 are the _top_ 9 bits of the 16-bit initial predictor value */
356
        cs->predictor = (*src++) << 8;
357
        cs->predictor |= (*src & 0x80);
358
        cs->predictor &= 0xFF80;
359

    
360
        /* sign extension */
361
        if(cs->predictor & 0x8000)
362
            cs->predictor -= 0x10000;
363

    
364
        CLAMP_TO_SHORT(cs->predictor);
365

    
366
        cs->step_index = (*src++) & 0x7F;
367

    
368
        if (cs->step_index > 88) fprintf(stderr, "ERROR: step_index = %i\n", cs->step_index);
369
        if (cs->step_index > 88) cs->step_index = 88;
370

    
371
        cs->step = step_table[cs->step_index];
372

    
373
        if (st && channel)
374
            samples++;
375

    
376
        *samples++ = cs->predictor;
377
        samples += st;
378

    
379
        for(m=32; n>0 && m>0; n--, m--) { /* in QuickTime, IMA is encoded by chuncks of 34 bytes (=64 samples) */
380
            *samples = adpcm_ima_expand_nibble(cs, src[0] & 0x0F);
381
            samples += avctx->channels;
382
            *samples = adpcm_ima_expand_nibble(cs, (src[0] >> 4) & 0x0F);
383
            samples += avctx->channels;
384
            src ++;
385
        }
386

    
387
        if(st) { /* handle stereo interlacing */
388
            c->channel = (channel + 1) % 2; /* we get one packet for left, then one for right data */
389
            if(channel == 0) { /* wait for the other packet before outputing anything */
390
                *data_size = 0;
391
                return src - buf;
392
            }
393
        }
394
        break;
395
    case CODEC_ID_ADPCM_IMA_WAV:
396
        if (buf_size > BLKSIZE) {
397
            if (avctx->block_align != 0)
398
                buf_size = avctx->block_align;
399
            else
400
                buf_size = BLKSIZE;
401
        }
402
        // XXX: do as per-channel loop
403
        cs = &(c->status[0]);
404
        cs->predictor = (*src++) & 0x0FF;
405
        cs->predictor |= ((*src++) << 8) & 0x0FF00;
406
        if(cs->predictor & 0x8000)
407
            cs->predictor -= 0x10000;
408
        CLAMP_TO_SHORT(cs->predictor);
409

    
410
        // XXX: is this correct ??: *samples++ = cs->predictor;
411

    
412
        cs->step_index = *src++;
413
        if (cs->step_index < 0) cs->step_index = 0;
414
        if (cs->step_index > 88) cs->step_index = 88;
415
        if (*src++) fprintf(stderr, "unused byte should be null !!\n"); /* unused */
416

    
417
        if (st) {
418
            cs = &(c->status[1]);
419
            cs->predictor = (*src++) & 0x0FF;
420
            cs->predictor |= ((*src++) << 8) & 0x0FF00;
421
            if(cs->predictor & 0x8000)
422
                cs->predictor -= 0x10000;
423
            CLAMP_TO_SHORT(cs->predictor);
424

    
425
            // XXX: is this correct ??: *samples++ = cs->predictor;
426

    
427
            cs->step_index = *src++;
428
            if (cs->step_index < 0) cs->step_index = 0;
429
            if (cs->step_index > 88) cs->step_index = 88;
430
            src++; /* if != 0  -> out-of-sync */
431
        }
432

    
433
        for(m=4; src < (buf + buf_size);) {
434
            *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] & 0x0F);
435
            if (st)
436
                *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[4] & 0x0F);
437
            *samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
438
            if (st) {
439
                *samples++ = adpcm_ima_expand_nibble(&c->status[1], (src[4] >> 4) & 0x0F);
440
                if (!--m) {
441
                    m=4;
442
                    src+=4;
443
                }
444
            }
445
            src++;
446
        }
447
        break;
448
    case CODEC_ID_ADPCM_MS:
449

    
450
        if (buf_size > BLKSIZE) {
451
            if (avctx->block_align != 0)
452
                buf_size = avctx->block_align;
453
            else
454
                buf_size = BLKSIZE;
455
        }
456
        n = buf_size - 7 * avctx->channels;
457
        if (n < 0)
458
            return -1;
459
        block_predictor[0] = (*src++); /* should be bound */
460
        block_predictor[0] = (block_predictor[0] < 0)?(0):((block_predictor[0] > 7)?(7):(block_predictor[0]));
461
        block_predictor[1] = 0;
462
        if (st)
463
            block_predictor[1] = (*src++);
464
        block_predictor[1] = (block_predictor[1] < 0)?(0):((block_predictor[1] > 7)?(7):(block_predictor[1]));
465
        c->status[0].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
466
        if (c->status[0].idelta & 0x08000)
467
            c->status[0].idelta -= 0x10000;
468
        src+=2;
469
        if (st)
470
            c->status[1].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
471
        if (st && c->status[1].idelta & 0x08000)
472
            c->status[1].idelta |= 0xFFFF0000;
473
        if (st)
474
            src+=2;
475
        c->status[0].coeff1 = AdaptCoeff1[block_predictor[0]];
476
        c->status[0].coeff2 = AdaptCoeff2[block_predictor[0]];
477
        c->status[1].coeff1 = AdaptCoeff1[block_predictor[1]];
478
        c->status[1].coeff2 = AdaptCoeff2[block_predictor[1]];
479
        
480
        c->status[0].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
481
        src+=2;
482
        if (st) c->status[1].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
483
        if (st) src+=2;
484
        c->status[0].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
485
        src+=2;
486
        if (st) c->status[1].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
487
        if (st) src+=2;
488

    
489
        *samples++ = c->status[0].sample1;
490
        if (st) *samples++ = c->status[1].sample1;
491
        *samples++ = c->status[0].sample2;
492
        if (st) *samples++ = c->status[1].sample2;
493
        for(;n>0;n--) {
494
            *samples++ = adpcm_ms_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
495
            *samples++ = adpcm_ms_expand_nibble(&c->status[st], src[0] & 0x0F);
496
            src ++;
497
        }
498
        break;
499
    default:
500
        *data_size = 0;
501
        return -1;
502
    }
503
    *data_size = (uint8_t *)samples - (uint8_t *)data;
504
    return src - buf;
505
}
506

    
507
#define ADPCM_CODEC(id, name)                   \
508
AVCodec name ## _encoder = {                    \
509
    #name,                                      \
510
    CODEC_TYPE_AUDIO,                           \
511
    id,                                         \
512
    sizeof(ADPCMContext),                       \
513
    adpcm_encode_init,                          \
514
    adpcm_encode_frame,                         \
515
    adpcm_encode_close,                         \
516
    NULL,                                       \
517
};                                              \
518
AVCodec name ## _decoder = {                    \
519
    #name,                                      \
520
    CODEC_TYPE_AUDIO,                           \
521
    id,                                         \
522
    sizeof(ADPCMContext),                       \
523
    adpcm_decode_init,                          \
524
    NULL,                                       \
525
    NULL,                                       \
526
    adpcm_decode_frame,                         \
527
};
528

    
529
ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);
530
ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);
531
ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);
532

    
533
#undef ADPCM_CODEC
534