adpcmenc.c
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1 /*
2  * Copyright (c) 2001-2003 The ffmpeg Project
3  *
4  * This file is part of Libav.
5  *
6  * Libav is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * Libav is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "avcodec.h"
22 #include "get_bits.h"
23 #include "put_bits.h"
24 #include "bytestream.h"
25 #include "adpcm.h"
26 #include "adpcm_data.h"
27 
38 typedef struct TrellisPath {
39  int nibble;
40  int prev;
41 } TrellisPath;
42 
43 typedef struct TrellisNode {
44  uint32_t ssd;
45  int path;
46  int sample1;
47  int sample2;
48  int step;
49 } TrellisNode;
50 
51 typedef struct ADPCMEncodeContext {
56  uint8_t *trellis_hash;
58 
59 #define FREEZE_INTERVAL 128
60 
62 {
63  ADPCMEncodeContext *s = avctx->priv_data;
64  uint8_t *extradata;
65  int i;
66  if (avctx->channels > 2)
67  return -1; /* only stereo or mono =) */
68 
69  if (avctx->trellis && (unsigned)avctx->trellis > 16U) {
70  av_log(avctx, AV_LOG_ERROR, "invalid trellis size\n");
71  return -1;
72  }
73 
74  if (avctx->trellis) {
75  int frontier = 1 << avctx->trellis;
76  int max_paths = frontier * FREEZE_INTERVAL;
77  FF_ALLOC_OR_GOTO(avctx, s->paths,
78  max_paths * sizeof(*s->paths), error);
79  FF_ALLOC_OR_GOTO(avctx, s->node_buf,
80  2 * frontier * sizeof(*s->node_buf), error);
81  FF_ALLOC_OR_GOTO(avctx, s->nodep_buf,
82  2 * frontier * sizeof(*s->nodep_buf), error);
84  65536 * sizeof(*s->trellis_hash), error);
85  }
86 
88 
89  switch (avctx->codec->id) {
91  /* each 16 bits sample gives one nibble
92  and we have 4 bytes per channel overhead */
93  avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 /
94  (4 * avctx->channels) + 1;
95  /* seems frame_size isn't taken into account...
96  have to buffer the samples :-( */
97  avctx->block_align = BLKSIZE;
98  break;
100  avctx->frame_size = 64;
101  avctx->block_align = 34 * avctx->channels;
102  break;
103  case CODEC_ID_ADPCM_MS:
104  /* each 16 bits sample gives one nibble
105  and we have 7 bytes per channel overhead */
106  avctx->frame_size = (BLKSIZE - 7 * avctx->channels) * 2 /
107  avctx->channels + 2;
108  avctx->block_align = BLKSIZE;
109  avctx->extradata_size = 32;
110  extradata = avctx->extradata = av_malloc(avctx->extradata_size);
111  if (!extradata)
112  return AVERROR(ENOMEM);
113  bytestream_put_le16(&extradata, avctx->frame_size);
114  bytestream_put_le16(&extradata, 7); /* wNumCoef */
115  for (i = 0; i < 7; i++) {
116  bytestream_put_le16(&extradata, ff_adpcm_AdaptCoeff1[i] * 4);
117  bytestream_put_le16(&extradata, ff_adpcm_AdaptCoeff2[i] * 4);
118  }
119  break;
121  avctx->frame_size = BLKSIZE * avctx->channels;
122  avctx->block_align = BLKSIZE;
123  break;
124  case CODEC_ID_ADPCM_SWF:
125  if (avctx->sample_rate != 11025 &&
126  avctx->sample_rate != 22050 &&
127  avctx->sample_rate != 44100) {
128  av_log(avctx, AV_LOG_ERROR, "Sample rate must be 11025, "
129  "22050 or 44100\n");
130  goto error;
131  }
132  avctx->frame_size = 512 * (avctx->sample_rate / 11025);
133  break;
134  default:
135  goto error;
136  }
137 
138  avctx->coded_frame = avcodec_alloc_frame();
139  avctx->coded_frame->key_frame= 1;
140 
141  return 0;
142 error:
143  av_freep(&s->paths);
144  av_freep(&s->node_buf);
145  av_freep(&s->nodep_buf);
146  av_freep(&s->trellis_hash);
147  return -1;
148 }
149 
151 {
152  ADPCMEncodeContext *s = avctx->priv_data;
153  av_freep(&avctx->coded_frame);
154  av_freep(&s->paths);
155  av_freep(&s->node_buf);
156  av_freep(&s->nodep_buf);
157  av_freep(&s->trellis_hash);
158 
159  return 0;
160 }
161 
162 
163 static inline unsigned char adpcm_ima_compress_sample(ADPCMChannelStatus *c,
164  short sample)
165 {
166  int delta = sample - c->prev_sample;
167  int nibble = FFMIN(7, abs(delta) * 4 /
168  ff_adpcm_step_table[c->step_index]) + (delta < 0) * 8;
170  ff_adpcm_yamaha_difflookup[nibble]) / 8);
171  c->prev_sample = av_clip_int16(c->prev_sample);
172  c->step_index = av_clip(c->step_index + ff_adpcm_index_table[nibble], 0, 88);
173  return nibble;
174 }
175 
176 static inline unsigned char adpcm_ima_qt_compress_sample(ADPCMChannelStatus *c,
177  short sample)
178 {
179  int delta = sample - c->prev_sample;
181  int diff = step >> 3;
182  int nibble = 0;
183 
184  if (delta < 0) {
185  nibble = 8;
186  delta = -delta;
187  }
188 
189  for (mask = 4; mask;) {
190  if (delta >= step) {
191  nibble |= mask;
192  delta -= step;
193  diff += step;
194  }
195  step >>= 1;
196  mask >>= 1;
197  }
198 
199  if (nibble & 8)
200  c->prev_sample -= diff;
201  else
202  c->prev_sample += diff;
203 
204  c->prev_sample = av_clip_int16(c->prev_sample);
205  c->step_index = av_clip(c->step_index + ff_adpcm_index_table[nibble], 0, 88);
206 
207  return nibble;
208 }
209 
210 static inline unsigned char adpcm_ms_compress_sample(ADPCMChannelStatus *c,
211  short sample)
212 {
213  int predictor, nibble, bias;
214 
215  predictor = (((c->sample1) * (c->coeff1)) +
216  (( c->sample2) * (c->coeff2))) / 64;
217 
218  nibble = sample - predictor;
219  if (nibble >= 0)
220  bias = c->idelta / 2;
221  else
222  bias = -c->idelta / 2;
223 
224  nibble = (nibble + bias) / c->idelta;
225  nibble = av_clip(nibble, -8, 7) & 0x0F;
226 
227  predictor += (signed)((nibble & 0x08) ? (nibble - 0x10) : nibble) * c->idelta;
228 
229  c->sample2 = c->sample1;
230  c->sample1 = av_clip_int16(predictor);
231 
232  c->idelta = (ff_adpcm_AdaptationTable[(int)nibble] * c->idelta) >> 8;
233  if (c->idelta < 16)
234  c->idelta = 16;
235 
236  return nibble;
237 }
238 
239 static inline unsigned char adpcm_yamaha_compress_sample(ADPCMChannelStatus *c,
240  short sample)
241 {
242  int nibble, delta;
243 
244  if (!c->step) {
245  c->predictor = 0;
246  c->step = 127;
247  }
248 
249  delta = sample - c->predictor;
250 
251  nibble = FFMIN(7, abs(delta) * 4 / c->step) + (delta < 0) * 8;
252 
253  c->predictor += ((c->step * ff_adpcm_yamaha_difflookup[nibble]) / 8);
254  c->predictor = av_clip_int16(c->predictor);
255  c->step = (c->step * ff_adpcm_yamaha_indexscale[nibble]) >> 8;
256  c->step = av_clip(c->step, 127, 24567);
257 
258  return nibble;
259 }
260 
261 static void adpcm_compress_trellis(AVCodecContext *avctx, const short *samples,
262  uint8_t *dst, ADPCMChannelStatus *c, int n)
263 {
264  //FIXME 6% faster if frontier is a compile-time constant
265  ADPCMEncodeContext *s = avctx->priv_data;
266  const int frontier = 1 << avctx->trellis;
267  const int stride = avctx->channels;
268  const int version = avctx->codec->id;
269  TrellisPath *paths = s->paths, *p;
270  TrellisNode *node_buf = s->node_buf;
271  TrellisNode **nodep_buf = s->nodep_buf;
272  TrellisNode **nodes = nodep_buf; // nodes[] is always sorted by .ssd
273  TrellisNode **nodes_next = nodep_buf + frontier;
274  int pathn = 0, froze = -1, i, j, k, generation = 0;
275  uint8_t *hash = s->trellis_hash;
276  memset(hash, 0xff, 65536 * sizeof(*hash));
277 
278  memset(nodep_buf, 0, 2 * frontier * sizeof(*nodep_buf));
279  nodes[0] = node_buf + frontier;
280  nodes[0]->ssd = 0;
281  nodes[0]->path = 0;
282  nodes[0]->step = c->step_index;
283  nodes[0]->sample1 = c->sample1;
284  nodes[0]->sample2 = c->sample2;
285  if (version == CODEC_ID_ADPCM_IMA_WAV ||
286  version == CODEC_ID_ADPCM_IMA_QT ||
287  version == CODEC_ID_ADPCM_SWF)
288  nodes[0]->sample1 = c->prev_sample;
289  if (version == CODEC_ID_ADPCM_MS)
290  nodes[0]->step = c->idelta;
291  if (version == CODEC_ID_ADPCM_YAMAHA) {
292  if (c->step == 0) {
293  nodes[0]->step = 127;
294  nodes[0]->sample1 = 0;
295  } else {
296  nodes[0]->step = c->step;
297  nodes[0]->sample1 = c->predictor;
298  }
299  }
300 
301  for (i = 0; i < n; i++) {
302  TrellisNode *t = node_buf + frontier*(i&1);
303  TrellisNode **u;
304  int sample = samples[i * stride];
305  int heap_pos = 0;
306  memset(nodes_next, 0, frontier * sizeof(TrellisNode*));
307  for (j = 0; j < frontier && nodes[j]; j++) {
308  // higher j have higher ssd already, so they're likely
309  // to yield a suboptimal next sample too
310  const int range = (j < frontier / 2) ? 1 : 0;
311  const int step = nodes[j]->step;
312  int nidx;
313  if (version == CODEC_ID_ADPCM_MS) {
314  const int predictor = ((nodes[j]->sample1 * c->coeff1) +
315  (nodes[j]->sample2 * c->coeff2)) / 64;
316  const int div = (sample - predictor) / step;
317  const int nmin = av_clip(div-range, -8, 6);
318  const int nmax = av_clip(div+range, -7, 7);
319  for (nidx = nmin; nidx <= nmax; nidx++) {
320  const int nibble = nidx & 0xf;
321  int dec_sample = predictor + nidx * step;
322 #define STORE_NODE(NAME, STEP_INDEX)\
323  int d;\
324  uint32_t ssd;\
325  int pos;\
326  TrellisNode *u;\
327  uint8_t *h;\
328  dec_sample = av_clip_int16(dec_sample);\
329  d = sample - dec_sample;\
330  ssd = nodes[j]->ssd + d*d;\
331  /* Check for wraparound, skip such samples completely. \
332  * Note, changing ssd to a 64 bit variable would be \
333  * simpler, avoiding this check, but it's slower on \
334  * x86 32 bit at the moment. */\
335  if (ssd < nodes[j]->ssd)\
336  goto next_##NAME;\
337  /* Collapse any two states with the same previous sample value. \
338  * One could also distinguish states by step and by 2nd to last
339  * sample, but the effects of that are negligible.
340  * Since nodes in the previous generation are iterated
341  * through a heap, they're roughly ordered from better to
342  * worse, but not strictly ordered. Therefore, an earlier
343  * node with the same sample value is better in most cases
344  * (and thus the current is skipped), but not strictly
345  * in all cases. Only skipping samples where ssd >=
346  * ssd of the earlier node with the same sample gives
347  * slightly worse quality, though, for some reason. */ \
348  h = &hash[(uint16_t) dec_sample];\
349  if (*h == generation)\
350  goto next_##NAME;\
351  if (heap_pos < frontier) {\
352  pos = heap_pos++;\
353  } else {\
354  /* Try to replace one of the leaf nodes with the new \
355  * one, but try a different slot each time. */\
356  pos = (frontier >> 1) +\
357  (heap_pos & ((frontier >> 1) - 1));\
358  if (ssd > nodes_next[pos]->ssd)\
359  goto next_##NAME;\
360  heap_pos++;\
361  }\
362  *h = generation;\
363  u = nodes_next[pos];\
364  if (!u) {\
365  assert(pathn < FREEZE_INTERVAL << avctx->trellis);\
366  u = t++;\
367  nodes_next[pos] = u;\
368  u->path = pathn++;\
369  }\
370  u->ssd = ssd;\
371  u->step = STEP_INDEX;\
372  u->sample2 = nodes[j]->sample1;\
373  u->sample1 = dec_sample;\
374  paths[u->path].nibble = nibble;\
375  paths[u->path].prev = nodes[j]->path;\
376  /* Sift the newly inserted node up in the heap to \
377  * restore the heap property. */\
378  while (pos > 0) {\
379  int parent = (pos - 1) >> 1;\
380  if (nodes_next[parent]->ssd <= ssd)\
381  break;\
382  FFSWAP(TrellisNode*, nodes_next[parent], nodes_next[pos]);\
383  pos = parent;\
384  }\
385  next_##NAME:;
386  STORE_NODE(ms, FFMAX(16,
387  (ff_adpcm_AdaptationTable[nibble] * step) >> 8));
388  }
389  } else if (version == CODEC_ID_ADPCM_IMA_WAV ||
390  version == CODEC_ID_ADPCM_IMA_QT ||
391  version == CODEC_ID_ADPCM_SWF) {
392 #define LOOP_NODES(NAME, STEP_TABLE, STEP_INDEX)\
393  const int predictor = nodes[j]->sample1;\
394  const int div = (sample - predictor) * 4 / STEP_TABLE;\
395  int nmin = av_clip(div - range, -7, 6);\
396  int nmax = av_clip(div + range, -6, 7);\
397  if (nmin <= 0)\
398  nmin--; /* distinguish -0 from +0 */\
399  if (nmax < 0)\
400  nmax--;\
401  for (nidx = nmin; nidx <= nmax; nidx++) {\
402  const int nibble = nidx < 0 ? 7 - nidx : nidx;\
403  int dec_sample = predictor +\
404  (STEP_TABLE *\
405  ff_adpcm_yamaha_difflookup[nibble]) / 8;\
406  STORE_NODE(NAME, STEP_INDEX);\
407  }
408  LOOP_NODES(ima, ff_adpcm_step_table[step],
409  av_clip(step + ff_adpcm_index_table[nibble], 0, 88));
410  } else { //CODEC_ID_ADPCM_YAMAHA
411  LOOP_NODES(yamaha, step,
412  av_clip((step * ff_adpcm_yamaha_indexscale[nibble]) >> 8,
413  127, 24567));
414 #undef LOOP_NODES
415 #undef STORE_NODE
416  }
417  }
418 
419  u = nodes;
420  nodes = nodes_next;
421  nodes_next = u;
422 
423  generation++;
424  if (generation == 255) {
425  memset(hash, 0xff, 65536 * sizeof(*hash));
426  generation = 0;
427  }
428 
429  // prevent overflow
430  if (nodes[0]->ssd > (1 << 28)) {
431  for (j = 1; j < frontier && nodes[j]; j++)
432  nodes[j]->ssd -= nodes[0]->ssd;
433  nodes[0]->ssd = 0;
434  }
435 
436  // merge old paths to save memory
437  if (i == froze + FREEZE_INTERVAL) {
438  p = &paths[nodes[0]->path];
439  for (k = i; k > froze; k--) {
440  dst[k] = p->nibble;
441  p = &paths[p->prev];
442  }
443  froze = i;
444  pathn = 0;
445  // other nodes might use paths that don't coincide with the frozen one.
446  // checking which nodes do so is too slow, so just kill them all.
447  // this also slightly improves quality, but I don't know why.
448  memset(nodes + 1, 0, (frontier - 1) * sizeof(TrellisNode*));
449  }
450  }
452  p = &paths[nodes[0]->path];
453  for (i = n - 1; i > froze; i--) {
454  dst[i] = p->nibble;
455  p = &paths[p->prev];
456  }
457 
458  c->predictor = nodes[0]->sample1;
459  c->sample1 = nodes[0]->sample1;
460  c->sample2 = nodes[0]->sample2;
461  c->step_index = nodes[0]->step;
462  c->step = nodes[0]->step;
463  c->idelta = nodes[0]->step;
464 }
465 
466 static int adpcm_encode_frame(AVCodecContext *avctx,
467  unsigned char *frame, int buf_size, void *data)
468 {
469  int n, i, st;
470  short *samples;
471  unsigned char *dst;
472  ADPCMEncodeContext *c = avctx->priv_data;
473  uint8_t *buf;
474 
475  dst = frame;
476  samples = (short *)data;
477  st = avctx->channels == 2;
478  /* n = (BLKSIZE - 4 * avctx->channels) / (2 * 8 * avctx->channels); */
479 
480  switch(avctx->codec->id) {
482  n = avctx->frame_size / 8;
483  c->status[0].prev_sample = (signed short)samples[0]; /* XXX */
484  /* c->status[0].step_index = 0;
485  XXX: not sure how to init the state machine */
486  bytestream_put_le16(&dst, c->status[0].prev_sample);
487  *dst++ = (unsigned char)c->status[0].step_index;
488  *dst++ = 0; /* unknown */
489  samples++;
490  if (avctx->channels == 2) {
491  c->status[1].prev_sample = (signed short)samples[0];
492  /* c->status[1].step_index = 0; */
493  bytestream_put_le16(&dst, c->status[1].prev_sample);
494  *dst++ = (unsigned char)c->status[1].step_index;
495  *dst++ = 0;
496  samples++;
497  }
498 
499  /* stereo: 4 bytes (8 samples) for left,
500  4 bytes for right, 4 bytes left, ... */
501  if (avctx->trellis > 0) {
502  FF_ALLOC_OR_GOTO(avctx, buf, 2 * n * 8, error);
503  adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n * 8);
504  if (avctx->channels == 2)
505  adpcm_compress_trellis(avctx, samples + 1, buf + n * 8,
506  &c->status[1], n * 8);
507  for (i = 0; i < n; i++) {
508  *dst++ = buf[8 * i + 0] | (buf[8 * i + 1] << 4);
509  *dst++ = buf[8 * i + 2] | (buf[8 * i + 3] << 4);
510  *dst++ = buf[8 * i + 4] | (buf[8 * i + 5] << 4);
511  *dst++ = buf[8 * i + 6] | (buf[8 * i + 7] << 4);
512  if (avctx->channels == 2) {
513  uint8_t *buf1 = buf + n * 8;
514  *dst++ = buf1[8 * i + 0] | (buf1[8 * i + 1] << 4);
515  *dst++ = buf1[8 * i + 2] | (buf1[8 * i + 3] << 4);
516  *dst++ = buf1[8 * i + 4] | (buf1[8 * i + 5] << 4);
517  *dst++ = buf1[8 * i + 6] | (buf1[8 * i + 7] << 4);
518  }
519  }
520  av_free(buf);
521  } else {
522  for (; n > 0; n--) {
523  *dst = adpcm_ima_compress_sample(&c->status[0], samples[0]);
524  *dst++ |= adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels ]) << 4;
525  *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 2]);
526  *dst++ |= adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 3]) << 4;
527  *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 4]);
528  *dst++ |= adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 5]) << 4;
529  *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 6]);
530  *dst++ |= adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 7]) << 4;
531  /* right channel */
532  if (avctx->channels == 2) {
533  *dst = adpcm_ima_compress_sample(&c->status[1], samples[1 ]);
534  *dst++ |= adpcm_ima_compress_sample(&c->status[1], samples[3 ]) << 4;
535  *dst = adpcm_ima_compress_sample(&c->status[1], samples[5 ]);
536  *dst++ |= adpcm_ima_compress_sample(&c->status[1], samples[7 ]) << 4;
537  *dst = adpcm_ima_compress_sample(&c->status[1], samples[9 ]);
538  *dst++ |= adpcm_ima_compress_sample(&c->status[1], samples[11]) << 4;
539  *dst = adpcm_ima_compress_sample(&c->status[1], samples[13]);
540  *dst++ |= adpcm_ima_compress_sample(&c->status[1], samples[15]) << 4;
541  }
542  samples += 8 * avctx->channels;
543  }
544  }
545  break;
547  {
548  int ch, i;
549  PutBitContext pb;
550  init_put_bits(&pb, dst, buf_size * 8);
551 
552  for (ch = 0; ch < avctx->channels; ch++) {
553  put_bits(&pb, 9, (c->status[ch].prev_sample & 0xFFFF) >> 7);
554  put_bits(&pb, 7, c->status[ch].step_index);
555  if (avctx->trellis > 0) {
556  uint8_t buf[64];
557  adpcm_compress_trellis(avctx, samples+ch, buf, &c->status[ch], 64);
558  for (i = 0; i < 64; i++)
559  put_bits(&pb, 4, buf[i ^ 1]);
560  } else {
561  for (i = 0; i < 64; i += 2) {
562  int t1, t2;
564  samples[avctx->channels * (i + 0) + ch]);
566  samples[avctx->channels * (i + 1) + ch]);
567  put_bits(&pb, 4, t2);
568  put_bits(&pb, 4, t1);
569  }
570  }
571  }
572 
573  flush_put_bits(&pb);
574  dst += put_bits_count(&pb) >> 3;
575  break;
576  }
577  case CODEC_ID_ADPCM_SWF:
578  {
579  int i;
580  PutBitContext pb;
581  init_put_bits(&pb, dst, buf_size * 8);
582 
583  n = avctx->frame_size - 1;
584 
585  // store AdpcmCodeSize
586  put_bits(&pb, 2, 2); // set 4-bit flash adpcm format
587 
588  // init the encoder state
589  for (i = 0; i < avctx->channels; i++) {
590  // clip step so it fits 6 bits
591  c->status[i].step_index = av_clip(c->status[i].step_index, 0, 63);
592  put_sbits(&pb, 16, samples[i]);
593  put_bits(&pb, 6, c->status[i].step_index);
594  c->status[i].prev_sample = (signed short)samples[i];
595  }
596 
597  if (avctx->trellis > 0) {
598  FF_ALLOC_OR_GOTO(avctx, buf, 2 * n, error);
599  adpcm_compress_trellis(avctx, samples + 2, buf, &c->status[0], n);
600  if (avctx->channels == 2)
601  adpcm_compress_trellis(avctx, samples + 3, buf + n,
602  &c->status[1], n);
603  for (i = 0; i < n; i++) {
604  put_bits(&pb, 4, buf[i]);
605  if (avctx->channels == 2)
606  put_bits(&pb, 4, buf[n + i]);
607  }
608  av_free(buf);
609  } else {
610  for (i = 1; i < avctx->frame_size; i++) {
612  samples[avctx->channels * i]));
613  if (avctx->channels == 2)
615  samples[2 * i + 1]));
616  }
617  }
618  flush_put_bits(&pb);
619  dst += put_bits_count(&pb) >> 3;
620  break;
621  }
622  case CODEC_ID_ADPCM_MS:
623  for (i = 0; i < avctx->channels; i++) {
624  int predictor = 0;
625  *dst++ = predictor;
626  c->status[i].coeff1 = ff_adpcm_AdaptCoeff1[predictor];
627  c->status[i].coeff2 = ff_adpcm_AdaptCoeff2[predictor];
628  }
629  for (i = 0; i < avctx->channels; i++) {
630  if (c->status[i].idelta < 16)
631  c->status[i].idelta = 16;
632  bytestream_put_le16(&dst, c->status[i].idelta);
633  }
634  for (i = 0; i < avctx->channels; i++)
635  c->status[i].sample2= *samples++;
636  for (i = 0; i < avctx->channels; i++) {
637  c->status[i].sample1 = *samples++;
638  bytestream_put_le16(&dst, c->status[i].sample1);
639  }
640  for (i = 0; i < avctx->channels; i++)
641  bytestream_put_le16(&dst, c->status[i].sample2);
642 
643  if (avctx->trellis > 0) {
644  int n = avctx->block_align - 7 * avctx->channels;
645  FF_ALLOC_OR_GOTO(avctx, buf, 2 * n, error);
646  if (avctx->channels == 1) {
647  adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n);
648  for (i = 0; i < n; i += 2)
649  *dst++ = (buf[i] << 4) | buf[i + 1];
650  } else {
651  adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n);
652  adpcm_compress_trellis(avctx, samples + 1, buf + n, &c->status[1], n);
653  for (i = 0; i < n; i++)
654  *dst++ = (buf[i] << 4) | buf[n + i];
655  }
656  av_free(buf);
657  } else {
658  for (i = 7 * avctx->channels; i < avctx->block_align; i++) {
659  int nibble;
660  nibble = adpcm_ms_compress_sample(&c->status[ 0], *samples++) << 4;
661  nibble |= adpcm_ms_compress_sample(&c->status[st], *samples++);
662  *dst++ = nibble;
663  }
664  }
665  break;
667  n = avctx->frame_size / 2;
668  if (avctx->trellis > 0) {
669  FF_ALLOC_OR_GOTO(avctx, buf, 2 * n * 2, error);
670  n *= 2;
671  if (avctx->channels == 1) {
672  adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n);
673  for (i = 0; i < n; i += 2)
674  *dst++ = buf[i] | (buf[i + 1] << 4);
675  } else {
676  adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n);
677  adpcm_compress_trellis(avctx, samples + 1, buf + n, &c->status[1], n);
678  for (i = 0; i < n; i++)
679  *dst++ = buf[i] | (buf[n + i] << 4);
680  }
681  av_free(buf);
682  } else
683  for (n *= avctx->channels; n > 0; n--) {
684  int nibble;
685  nibble = adpcm_yamaha_compress_sample(&c->status[ 0], *samples++);
686  nibble |= adpcm_yamaha_compress_sample(&c->status[st], *samples++) << 4;
687  *dst++ = nibble;
688  }
689  break;
690  default:
691  error:
692  return -1;
693  }
694  return dst - frame;
695 }
696 
697 
698 #define ADPCM_ENCODER(id_, name_, long_name_) \
699 AVCodec ff_ ## name_ ## _encoder = { \
700  .name = #name_, \
701  .type = AVMEDIA_TYPE_AUDIO, \
702  .id = id_, \
703  .priv_data_size = sizeof(ADPCMEncodeContext), \
704  .init = adpcm_encode_init, \
705  .encode = adpcm_encode_frame, \
706  .close = adpcm_encode_close, \
707  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, \
708  AV_SAMPLE_FMT_NONE}, \
709  .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
710 }
711 
712 ADPCM_ENCODER(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt, "ADPCM IMA QuickTime");
713 ADPCM_ENCODER(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav, "ADPCM IMA WAV");
714 ADPCM_ENCODER(CODEC_ID_ADPCM_MS, adpcm_ms, "ADPCM Microsoft");
715 ADPCM_ENCODER(CODEC_ID_ADPCM_SWF, adpcm_swf, "ADPCM Shockwave Flash");
716 ADPCM_ENCODER(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha, "ADPCM Yamaha");