68a5c6f22f95b4c6e5e63b1237296de30bda99d5
[libav.git] / libavcodec / adpcm.c
1 /*
2 * ADPCM codecs
3 * Copyright (c) 2001-2003 The ffmpeg Project
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 * Fringe ADPCM codecs (e.g., DK3, DK4, Westwood)
26 * by Mike Melanson (melanson@pcisys.net)
27 *
28 * Features and limitations:
29 *
30 * Reference documents:
31 * http://www.pcisys.net/~melanson/codecs/simpleaudio.html
32 * http://www.geocities.com/SiliconValley/8682/aud3.txt
33 * http://openquicktime.sourceforge.net/plugins.htm
34 * XAnim sources (xa_codec.c) http://www.rasnaimaging.com/people/lapus/download.html
35 * http://www.cs.ucla.edu/~leec/mediabench/applications.html
36 * SoX source code http://home.sprynet.com/~cbagwell/sox.html
37 */
38
39 #define BLKSIZE 1024
40
41 #define CLAMP_TO_SHORT(value) \
42 if (value > 32767) \
43 value = 32767; \
44 else if (value < -32768) \
45 value = -32768; \
46
47 /* step_table[] and index_table[] are from the ADPCM reference source */
48 /* This is the index table: */
49 static const int index_table[16] = {
50 -1, -1, -1, -1, 2, 4, 6, 8,
51 -1, -1, -1, -1, 2, 4, 6, 8,
52 };
53
54 /**
55 * This is the step table. Note that many programs use slight deviations from
56 * this table, but such deviations are negligible:
57 */
58 static const int step_table[89] = {
59 7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
60 19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
61 50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
62 130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
63 337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
64 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
65 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
66 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
67 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
68 };
69
70 /* Those are for MS-ADPCM */
71 /* AdaptationTable[], AdaptCoeff1[], and AdaptCoeff2[] are from libsndfile */
72 static const int AdaptationTable[] = {
73 230, 230, 230, 230, 307, 409, 512, 614,
74 768, 614, 512, 409, 307, 230, 230, 230
75 };
76
77 static const int AdaptCoeff1[] = {
78 256, 512, 0, 192, 240, 460, 392
79 };
80
81 static const int AdaptCoeff2[] = {
82 0, -256, 0, 64, 0, -208, -232
83 };
84
85 /* end of tables */
86
87 typedef struct ADPCMChannelStatus {
88 int predictor;
89 short int step_index;
90 int step;
91 /* for encoding */
92 int prev_sample;
93
94 /* MS version */
95 short sample1;
96 short sample2;
97 int coeff1;
98 int coeff2;
99 int idelta;
100 } ADPCMChannelStatus;
101
102 typedef struct ADPCMContext {
103 int channel; /* for stereo MOVs, decode left, then decode right, then tell it's decoded */
104 ADPCMChannelStatus status[2];
105 short sample_buffer[32]; /* hold left samples while waiting for right samples */
106 } ADPCMContext;
107
108 /* XXX: implement encoding */
109
110 #ifdef CONFIG_ENCODERS
111 static int adpcm_encode_init(AVCodecContext *avctx)
112 {
113 if (avctx->channels > 2)
114 return -1; /* only stereo or mono =) */
115 switch(avctx->codec->id) {
116 case CODEC_ID_ADPCM_IMA_QT:
117 fprintf(stderr, "ADPCM: codec admcp_ima_qt unsupported for encoding !\n");
118 avctx->frame_size = 64; /* XXX: can multiple of avctx->channels * 64 (left and right blocks are interleaved) */
119 return -1;
120 break;
121 case CODEC_ID_ADPCM_IMA_WAV:
122 avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 / (4 * avctx->channels) + 1; /* each 16 bits sample gives one nibble */
123 /* and we have 4 bytes per channel overhead */
124 avctx->block_align = BLKSIZE;
125 /* seems frame_size isn't taken into account... have to buffer the samples :-( */
126 break;
127 case CODEC_ID_ADPCM_MS:
128 fprintf(stderr, "ADPCM: codec admcp_ms unsupported for encoding !\n");
129 return -1;
130 break;
131 default:
132 return -1;
133 break;
134 }
135
136 avctx->coded_frame= avcodec_alloc_frame();
137 avctx->coded_frame->key_frame= 1;
138
139 return 0;
140 }
141
142 static int adpcm_encode_close(AVCodecContext *avctx)
143 {
144 av_freep(&avctx->coded_frame);
145
146 return 0;
147 }
148
149
150 static inline unsigned char adpcm_ima_compress_sample(ADPCMChannelStatus *c, short sample)
151 {
152 int step_index;
153 unsigned char nibble;
154
155 int sign = 0; /* sign bit of the nibble (MSB) */
156 int delta, predicted_delta;
157
158 delta = sample - c->prev_sample;
159
160 if (delta < 0) {
161 sign = 1;
162 delta = -delta;
163 }
164
165 step_index = c->step_index;
166
167 /* nibble = 4 * delta / step_table[step_index]; */
168 nibble = (delta << 2) / step_table[step_index];
169
170 if (nibble > 7)
171 nibble = 7;
172
173 step_index += index_table[nibble];
174 if (step_index < 0)
175 step_index = 0;
176 if (step_index > 88)
177 step_index = 88;
178
179 /* what the decoder will find */
180 predicted_delta = ((step_table[step_index] * nibble) / 4) + (step_table[step_index] / 8);
181
182 if (sign)
183 c->prev_sample -= predicted_delta;
184 else
185 c->prev_sample += predicted_delta;
186
187 CLAMP_TO_SHORT(c->prev_sample);
188
189
190 nibble += sign << 3; /* sign * 8 */
191
192 /* save back */
193 c->step_index = step_index;
194
195 return nibble;
196 }
197
198 static int adpcm_encode_frame(AVCodecContext *avctx,
199 unsigned char *frame, int buf_size, void *data)
200 {
201 int n;
202 short *samples;
203 unsigned char *dst;
204 ADPCMContext *c = avctx->priv_data;
205
206 dst = frame;
207 samples = (short *)data;
208 /* n = (BLKSIZE - 4 * avctx->channels) / (2 * 8 * avctx->channels); */
209
210 switch(avctx->codec->id) {
211 case CODEC_ID_ADPCM_IMA_QT: /* XXX: can't test until we get .mov writer */
212 break;
213 case CODEC_ID_ADPCM_IMA_WAV:
214 n = avctx->frame_size / 8;
215 c->status[0].prev_sample = (signed short)samples[0]; /* XXX */
216 /* c->status[0].step_index = 0; *//* XXX: not sure how to init the state machine */
217 *dst++ = (c->status[0].prev_sample) & 0xFF; /* little endian */
218 *dst++ = (c->status[0].prev_sample >> 8) & 0xFF;
219 *dst++ = (unsigned char)c->status[0].step_index;
220 *dst++ = 0; /* unknown */
221 samples++;
222 if (avctx->channels == 2) {
223 c->status[1].prev_sample = (signed short)samples[0];
224 /* c->status[1].step_index = 0; */
225 *dst++ = (c->status[1].prev_sample) & 0xFF;
226 *dst++ = (c->status[1].prev_sample >> 8) & 0xFF;
227 *dst++ = (unsigned char)c->status[1].step_index;
228 *dst++ = 0;
229 samples++;
230 }
231
232 /* stereo: 4 bytes (8 samples) for left, 4 bytes for right, 4 bytes left, ... */
233 for (; n>0; n--) {
234 *dst = adpcm_ima_compress_sample(&c->status[0], samples[0]) & 0x0F;
235 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels]) << 4) & 0xF0;
236 dst++;
237 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 2]) & 0x0F;
238 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 3]) << 4) & 0xF0;
239 dst++;
240 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 4]) & 0x0F;
241 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 5]) << 4) & 0xF0;
242 dst++;
243 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 6]) & 0x0F;
244 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 7]) << 4) & 0xF0;
245 dst++;
246 /* right channel */
247 if (avctx->channels == 2) {
248 *dst = adpcm_ima_compress_sample(&c->status[1], samples[1]);
249 *dst |= adpcm_ima_compress_sample(&c->status[1], samples[3]) << 4;
250 dst++;
251 *dst = adpcm_ima_compress_sample(&c->status[1], samples[5]);
252 *dst |= adpcm_ima_compress_sample(&c->status[1], samples[7]) << 4;
253 dst++;
254 *dst = adpcm_ima_compress_sample(&c->status[1], samples[9]);
255 *dst |= adpcm_ima_compress_sample(&c->status[1], samples[11]) << 4;
256 dst++;
257 *dst = adpcm_ima_compress_sample(&c->status[1], samples[13]);
258 *dst |= adpcm_ima_compress_sample(&c->status[1], samples[15]) << 4;
259 dst++;
260 }
261 samples += 8 * avctx->channels;
262 }
263 break;
264 default:
265 return -1;
266 }
267 return dst - frame;
268 }
269 #endif //CONFIG_ENCODERS
270
271 static int adpcm_decode_init(AVCodecContext * avctx)
272 {
273 ADPCMContext *c = avctx->priv_data;
274
275 c->channel = 0;
276 c->status[0].predictor = c->status[1].predictor = 0;
277 c->status[0].step_index = c->status[1].step_index = 0;
278 c->status[0].step = c->status[1].step = 0;
279
280 switch(avctx->codec->id) {
281 default:
282 break;
283 }
284 return 0;
285 }
286
287 static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble)
288 {
289 int step_index;
290 int predictor;
291 int sign, delta, diff, step;
292
293 step = step_table[c->step_index];
294 step_index = c->step_index + index_table[(unsigned)nibble];
295 if (step_index < 0) step_index = 0;
296 else if (step_index > 88) step_index = 88;
297
298 sign = nibble & 8;
299 delta = nibble & 7;
300 /* perform direct multiplication instead of series of jumps proposed by
301 * the reference ADPCM implementation since modern CPUs can do the mults
302 * quickly enough */
303 diff = ((2 * delta + 1) * step) >> 3;
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_4xa_expand_nibble(ADPCMChannelStatus *c, char nibble)
316 {
317 int step_index;
318 int predictor;
319 int sign, delta, diff, step;
320
321 step = step_table[c->step_index];
322 step_index = c->step_index + index_table[(unsigned)nibble];
323 if (step_index < 0) step_index = 0;
324 else if (step_index > 88) step_index = 88;
325
326 sign = nibble & 8;
327 delta = nibble & 7;
328
329 diff = (delta*step + (step>>1))>>3; // difference to code above
330
331 predictor = c->predictor;
332 if (sign) predictor -= diff;
333 else predictor += diff;
334
335 CLAMP_TO_SHORT(predictor);
336 c->predictor = predictor;
337 c->step_index = step_index;
338
339 return (short)predictor;
340 }
341
342 static inline short adpcm_ms_expand_nibble(ADPCMChannelStatus *c, char nibble)
343 {
344 int predictor;
345
346 predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256;
347 predictor += (signed)((nibble & 0x08)?(nibble - 0x10):(nibble)) * c->idelta;
348 CLAMP_TO_SHORT(predictor);
349
350 c->sample2 = c->sample1;
351 c->sample1 = predictor;
352 c->idelta = (AdaptationTable[(int)nibble] * c->idelta) / 256;
353 if (c->idelta < 16) c->idelta = 16;
354
355 return (short)predictor;
356 }
357
358 /* DK3 ADPCM support macro */
359 #define DK3_GET_NEXT_NIBBLE() \
360 if (decode_top_nibble_next) \
361 { \
362 nibble = (last_byte >> 4) & 0x0F; \
363 decode_top_nibble_next = 0; \
364 } \
365 else \
366 { \
367 last_byte = *src++; \
368 if (src >= buf + buf_size) break; \
369 nibble = last_byte & 0x0F; \
370 decode_top_nibble_next = 1; \
371 }
372
373 static int adpcm_decode_frame(AVCodecContext *avctx,
374 void *data, int *data_size,
375 uint8_t *buf, int buf_size)
376 {
377 ADPCMContext *c = avctx->priv_data;
378 ADPCMChannelStatus *cs;
379 int n, m, channel, i;
380 int block_predictor[2];
381 short *samples;
382 uint8_t *src;
383 int st; /* stereo */
384
385 /* DK3 ADPCM accounting variables */
386 unsigned char last_byte = 0;
387 unsigned char nibble;
388 int decode_top_nibble_next = 0;
389 int diff_channel;
390
391 samples = data;
392 src = buf;
393
394 st = avctx->channels == 2;
395
396 switch(avctx->codec->id) {
397 case CODEC_ID_ADPCM_IMA_QT:
398 n = (buf_size - 2);/* >> 2*avctx->channels;*/
399 channel = c->channel;
400 cs = &(c->status[channel]);
401 /* (pppppp) (piiiiiii) */
402
403 /* Bits 15-7 are the _top_ 9 bits of the 16-bit initial predictor value */
404 cs->predictor = (*src++) << 8;
405 cs->predictor |= (*src & 0x80);
406 cs->predictor &= 0xFF80;
407
408 /* sign extension */
409 if(cs->predictor & 0x8000)
410 cs->predictor -= 0x10000;
411
412 CLAMP_TO_SHORT(cs->predictor);
413
414 cs->step_index = (*src++) & 0x7F;
415
416 if (cs->step_index > 88) fprintf(stderr, "ERROR: step_index = %i\n", cs->step_index);
417 if (cs->step_index > 88) cs->step_index = 88;
418
419 cs->step = step_table[cs->step_index];
420
421 if (st && channel)
422 samples++;
423
424 *samples++ = cs->predictor;
425 samples += st;
426
427 for(m=32; n>0 && m>0; n--, m--) { /* in QuickTime, IMA is encoded by chuncks of 34 bytes (=64 samples) */
428 *samples = adpcm_ima_expand_nibble(cs, src[0] & 0x0F);
429 samples += avctx->channels;
430 *samples = adpcm_ima_expand_nibble(cs, (src[0] >> 4) & 0x0F);
431 samples += avctx->channels;
432 src ++;
433 }
434
435 if(st) { /* handle stereo interlacing */
436 c->channel = (channel + 1) % 2; /* we get one packet for left, then one for right data */
437 if(channel == 0) { /* wait for the other packet before outputing anything */
438 *data_size = 0;
439 return src - buf;
440 }
441 }
442 break;
443 case CODEC_ID_ADPCM_IMA_WAV:
444 if (buf_size > BLKSIZE) {
445 if (avctx->block_align != 0)
446 buf_size = avctx->block_align;
447 else
448 buf_size = BLKSIZE;
449 }
450 // XXX: do as per-channel loop
451 cs = &(c->status[0]);
452 cs->predictor = (*src++) & 0x0FF;
453 cs->predictor |= ((*src++) << 8) & 0x0FF00;
454 if(cs->predictor & 0x8000)
455 cs->predictor -= 0x10000;
456 CLAMP_TO_SHORT(cs->predictor);
457
458 // XXX: is this correct ??: *samples++ = cs->predictor;
459
460 cs->step_index = *src++;
461 if (cs->step_index < 0) cs->step_index = 0;
462 if (cs->step_index > 88) cs->step_index = 88;
463 if (*src++) fprintf(stderr, "unused byte should be null !!\n"); /* unused */
464
465 if (st) {
466 cs = &(c->status[1]);
467 cs->predictor = (*src++) & 0x0FF;
468 cs->predictor |= ((*src++) << 8) & 0x0FF00;
469 if(cs->predictor & 0x8000)
470 cs->predictor -= 0x10000;
471 CLAMP_TO_SHORT(cs->predictor);
472
473 // XXX: is this correct ??: *samples++ = cs->predictor;
474
475 cs->step_index = *src++;
476 if (cs->step_index < 0) cs->step_index = 0;
477 if (cs->step_index > 88) cs->step_index = 88;
478 src++; /* if != 0 -> out-of-sync */
479 }
480
481 for(m=4; src < (buf + buf_size);) {
482 *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] & 0x0F);
483 if (st)
484 *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[4] & 0x0F);
485 *samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
486 if (st) {
487 *samples++ = adpcm_ima_expand_nibble(&c->status[1], (src[4] >> 4) & 0x0F);
488 if (!--m) {
489 m=4;
490 src+=4;
491 }
492 }
493 src++;
494 }
495 break;
496 case CODEC_ID_ADPCM_4XM:
497 cs = &(c->status[0]);
498 c->status[0].predictor= (int16_t)(src[0] + (src[1]<<8)); src+=2;
499 if(st){
500 c->status[1].predictor= (int16_t)(src[0] + (src[1]<<8)); src+=2;
501 }
502 c->status[0].step_index= (int16_t)(src[0] + (src[1]<<8)); src+=2;
503 if(st){
504 c->status[1].step_index= (int16_t)(src[0] + (src[1]<<8)); src+=2;
505 }
506 // if (cs->step_index < 0) cs->step_index = 0;
507 // if (cs->step_index > 88) cs->step_index = 88;
508
509 m= (buf_size - (src - buf))>>st;
510 //printf("%d %d %d %d\n", st, m, c->status[0].predictor, c->status[0].step_index);
511 //FIXME / XXX decode chanels individual & interleave samples
512 for(i=0; i<m; i++) {
513 *samples++ = adpcm_4xa_expand_nibble(&c->status[0], src[i] & 0x0F);
514 if (st)
515 *samples++ = adpcm_4xa_expand_nibble(&c->status[1], src[i+m] & 0x0F);
516 *samples++ = adpcm_4xa_expand_nibble(&c->status[0], src[i] >> 4);
517 if (st)
518 *samples++ = adpcm_4xa_expand_nibble(&c->status[1], src[i+m] >> 4);
519 }
520
521 src += m<<st;
522
523 break;
524 case CODEC_ID_ADPCM_MS:
525
526 if (buf_size > BLKSIZE) {
527 if (avctx->block_align != 0)
528 buf_size = avctx->block_align;
529 else
530 buf_size = BLKSIZE;
531 }
532 n = buf_size - 7 * avctx->channels;
533 if (n < 0)
534 return -1;
535 block_predictor[0] = (*src++); /* should be bound */
536 block_predictor[0] = (block_predictor[0] < 0)?(0):((block_predictor[0] > 7)?(7):(block_predictor[0]));
537 block_predictor[1] = 0;
538 if (st)
539 block_predictor[1] = (*src++);
540 block_predictor[1] = (block_predictor[1] < 0)?(0):((block_predictor[1] > 7)?(7):(block_predictor[1]));
541 c->status[0].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
542 if (c->status[0].idelta & 0x08000)
543 c->status[0].idelta -= 0x10000;
544 src+=2;
545 if (st)
546 c->status[1].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
547 if (st && c->status[1].idelta & 0x08000)
548 c->status[1].idelta |= 0xFFFF0000;
549 if (st)
550 src+=2;
551 c->status[0].coeff1 = AdaptCoeff1[block_predictor[0]];
552 c->status[0].coeff2 = AdaptCoeff2[block_predictor[0]];
553 c->status[1].coeff1 = AdaptCoeff1[block_predictor[1]];
554 c->status[1].coeff2 = AdaptCoeff2[block_predictor[1]];
555
556 c->status[0].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
557 src+=2;
558 if (st) c->status[1].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
559 if (st) src+=2;
560 c->status[0].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
561 src+=2;
562 if (st) c->status[1].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
563 if (st) src+=2;
564
565 *samples++ = c->status[0].sample1;
566 if (st) *samples++ = c->status[1].sample1;
567 *samples++ = c->status[0].sample2;
568 if (st) *samples++ = c->status[1].sample2;
569 for(;n>0;n--) {
570 *samples++ = adpcm_ms_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
571 *samples++ = adpcm_ms_expand_nibble(&c->status[st], src[0] & 0x0F);
572 src ++;
573 }
574 break;
575 case CODEC_ID_ADPCM_IMA_DK4:
576 if (buf_size > BLKSIZE) {
577 if (avctx->block_align != 0)
578 buf_size = avctx->block_align;
579 else
580 buf_size = BLKSIZE;
581 }
582 c->status[0].predictor = (src[0] | (src[1] << 8));
583 c->status[0].step_index = src[2];
584 src += 4;
585 if(c->status[0].predictor & 0x8000)
586 c->status[0].predictor -= 0x10000;
587 *samples++ = c->status[0].predictor;
588 if (st) {
589 c->status[1].predictor = (src[0] | (src[1] << 8));
590 c->status[1].step_index = src[2];
591 src += 4;
592 if(c->status[1].predictor & 0x8000)
593 c->status[1].predictor -= 0x10000;
594 *samples++ = c->status[1].predictor;
595 }
596 while (src < buf + buf_size) {
597
598 /* take care of the top nibble (always left or mono channel) */
599 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
600 (src[0] >> 4) & 0x0F);
601
602 /* take care of the bottom nibble, which is right sample for
603 * stereo, or another mono sample */
604 if (st)
605 *samples++ = adpcm_ima_expand_nibble(&c->status[1],
606 src[0] & 0x0F);
607 else
608 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
609 src[0] & 0x0F);
610
611 src++;
612 }
613 break;
614 case CODEC_ID_ADPCM_IMA_DK3:
615 if (buf_size > BLKSIZE) {
616 if (avctx->block_align != 0)
617 buf_size = avctx->block_align;
618 else
619 buf_size = BLKSIZE;
620 }
621 c->status[0].predictor = (src[10] | (src[11] << 8));
622 c->status[1].predictor = (src[12] | (src[13] << 8));
623 c->status[0].step_index = src[14];
624 c->status[1].step_index = src[15];
625 /* sign extend the predictors */
626 if(c->status[0].predictor & 0x8000)
627 c->status[0].predictor -= 0x10000;
628 if(c->status[1].predictor & 0x8000)
629 c->status[1].predictor -= 0x10000;
630 src += 16;
631 diff_channel = c->status[1].predictor;
632
633 /* the DK3_GET_NEXT_NIBBLE macro issues the break statement when
634 * the buffer is consumed */
635 while (1) {
636
637 /* for this algorithm, c->status[0] is the sum channel and
638 * c->status[1] is the diff channel */
639
640 /* process the first predictor of the sum channel */
641 DK3_GET_NEXT_NIBBLE();
642 adpcm_ima_expand_nibble(&c->status[0], nibble);
643
644 /* process the diff channel predictor */
645 DK3_GET_NEXT_NIBBLE();
646 adpcm_ima_expand_nibble(&c->status[1], nibble);
647
648 /* process the first pair of stereo PCM samples */
649 diff_channel = (diff_channel + c->status[1].predictor) / 2;
650 *samples++ = c->status[0].predictor + c->status[1].predictor;
651 *samples++ = c->status[0].predictor - c->status[1].predictor;
652
653 /* process the second predictor of the sum channel */
654 DK3_GET_NEXT_NIBBLE();
655 adpcm_ima_expand_nibble(&c->status[0], nibble);
656
657 /* process the second pair of stereo PCM samples */
658 diff_channel = (diff_channel + c->status[1].predictor) / 2;
659 *samples++ = c->status[0].predictor + c->status[1].predictor;
660 *samples++ = c->status[0].predictor - c->status[1].predictor;
661 }
662 break;
663 case CODEC_ID_ADPCM_IMA_WS:
664 /* no per-block initialization; just start decoding the data */
665 while (src < buf + buf_size) {
666
667 if (st) {
668 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
669 (src[0] >> 4) & 0x0F);
670 *samples++ = adpcm_ima_expand_nibble(&c->status[1],
671 src[0] & 0x0F);
672 } else {
673 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
674 (src[0] >> 4) & 0x0F);
675 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
676 src[0] & 0x0F);
677 }
678
679 src++;
680 }
681 break;
682 default:
683 *data_size = 0;
684 return -1;
685 }
686 *data_size = (uint8_t *)samples - (uint8_t *)data;
687 return src - buf;
688 }
689
690
691
692 #ifdef CONFIG_ENCODERS
693 #define ADPCM_ENCODER(id,name) \
694 AVCodec name ## _encoder = { \
695 #name, \
696 CODEC_TYPE_AUDIO, \
697 id, \
698 sizeof(ADPCMContext), \
699 adpcm_encode_init, \
700 adpcm_encode_frame, \
701 adpcm_encode_close, \
702 NULL, \
703 };
704 #else
705 #define ADPCM_ENCODER(id,name)
706 #endif
707
708 #ifdef CONFIG_DECODERS
709 #define ADPCM_DECODER(id,name) \
710 AVCodec name ## _decoder = { \
711 #name, \
712 CODEC_TYPE_AUDIO, \
713 id, \
714 sizeof(ADPCMContext), \
715 adpcm_decode_init, \
716 NULL, \
717 NULL, \
718 adpcm_decode_frame, \
719 };
720 #else
721 #define ADPCM_DECODER(id,name)
722 #endif
723
724 #define ADPCM_CODEC(id, name) \
725 ADPCM_ENCODER(id,name) ADPCM_DECODER(id,name)
726
727 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);
728 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);
729 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);
730 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);
731 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WS, adpcm_ima_ws);
732 ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);
733 ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);
734
735 #undef ADPCM_CODEC