libavcodec/adpcmenc.c

   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 #include "internal.h"
  28
  29 /**
  30  * @file
  31  * ADPCM encoders
  32  * First version by Francois Revol (revol@free.fr)
  33  * Fringe ADPCM codecs (e.g., DK3, DK4, Westwood)
  34  *   by Mike Melanson (melanson@pcisys.net)
  35  *
  36  * See ADPCM decoder reference documents for codec information.
  37  */
  38
  39 typedef struct TrellisPath {
  40     int nibble;
  41     int prev;
  42 } TrellisPath;
  43
  44 typedef struct TrellisNode {
  45     uint32_t ssd;
  46     int path;
  47     int sample1;
  48     int sample2;
  49     int step;
  50 } TrellisNode;
  51
  52 typedef struct ADPCMEncodeContext {
  53     ADPCMChannelStatus status[6];
  54     TrellisPath *paths;
  55     TrellisNode *node_buf;
  56     TrellisNode **nodep_buf;
  57     uint8_t *trellis_hash;
  58 } ADPCMEncodeContext;
  59
  60 #define FREEZE_INTERVAL 128
  61
  62 static av_cold int adpcm_encode_init(AVCodecContext *avctx)
  63 {
  64     ADPCMEncodeContext *s = avctx->priv_data;
  65     uint8_t *extradata;
  66     int i;
  67     int ret = AVERROR(ENOMEM);
  68
  69     if (avctx->channels > 2) {
  70         av_log(avctx, AV_LOG_ERROR, "only stereo or mono is supported\n");
  71         return AVERROR(EINVAL);
  72     }
  73
  74     if (avctx->trellis && (unsigned)avctx->trellis > 16U) {
  75         av_log(avctx, AV_LOG_ERROR, "invalid trellis size\n");
  76         return AVERROR(EINVAL);
  77     }
  78
  79     if (avctx->trellis) {
  80         int frontier  = 1 << avctx->trellis;
  81         int max_paths =  frontier * FREEZE_INTERVAL;
  82         FF_ALLOC_OR_GOTO(avctx, s->paths,
  83                          max_paths * sizeof(*s->paths), error);
  84         FF_ALLOC_OR_GOTO(avctx, s->node_buf,
  85                          2 * frontier * sizeof(*s->node_buf),  error);
  86         FF_ALLOC_OR_GOTO(avctx, s->nodep_buf,
  87                          2 * frontier * sizeof(*s->nodep_buf), error);
  88         FF_ALLOC_OR_GOTO(avctx, s->trellis_hash,
  89                          65536 * sizeof(*s->trellis_hash), error);
  90     }
  91
  92     avctx->bits_per_coded_sample = av_get_bits_per_sample(avctx->codec->id);
  93
  94     switch (avctx->codec->id) {
  95     case AV_CODEC_ID_ADPCM_IMA_WAV:
  96         /* each 16 bits sample gives one nibble
  97            and we have 4 bytes per channel overhead */
  98         avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 /
  99                             (4 * avctx->channels) + 1;
 100         /* seems frame_size isn't taken into account...
 101            have to buffer the samples :-( */
 102         avctx->block_align = BLKSIZE;
 103         break;
 104     case AV_CODEC_ID_ADPCM_IMA_QT:
 105         avctx->frame_size  = 64;
 106         avctx->block_align = 34 * avctx->channels;
 107         break;
 108     case AV_CODEC_ID_ADPCM_MS:
 109         /* each 16 bits sample gives one nibble
 110            and we have 7 bytes per channel overhead */
 111         avctx->frame_size = (BLKSIZE - 7 * avctx->channels) * 2 /
 112                              avctx->channels + 2;
 113         avctx->block_align    = BLKSIZE;
 114         if (!(avctx->extradata = av_malloc(32 + FF_INPUT_BUFFER_PADDING_SIZE)))
 115             goto error;
 116         avctx->extradata_size = 32;
 117         extradata = avctx->extradata;
 118         bytestream_put_le16(&extradata, avctx->frame_size);
 119         bytestream_put_le16(&extradata, 7); /* wNumCoef */
 120         for (i = 0; i < 7; i++) {
 121             bytestream_put_le16(&extradata, ff_adpcm_AdaptCoeff1[i] * 4);
 122             bytestream_put_le16(&extradata, ff_adpcm_AdaptCoeff2[i] * 4);
 123         }
 124         break;
 125     case AV_CODEC_ID_ADPCM_YAMAHA:
 126         avctx->frame_size  = BLKSIZE * 2 / avctx->channels;
 127         avctx->block_align = BLKSIZE;
 128         break;
 129     case AV_CODEC_ID_ADPCM_SWF:
 130         if (avctx->sample_rate != 11025 &&
 131             avctx->sample_rate != 22050 &&
 132             avctx->sample_rate != 44100) {
 133             av_log(avctx, AV_LOG_ERROR, "Sample rate must be 11025, "
 134                    "22050 or 44100\n");
 135             ret = AVERROR(EINVAL);
 136             goto error;
 137         }
 138         avctx->frame_size = 512 * (avctx->sample_rate / 11025);
 139         break;
 140     default:
 141         ret = AVERROR(EINVAL);
 142         goto error;
 143     }
 144
 145 #if FF_API_OLD_ENCODE_AUDIO
 146     if (!(avctx->coded_frame = avcodec_alloc_frame()))
 147         goto error;
 148 #endif
 149
 150     return 0;
 151 error:
 152     av_freep(&s->paths);
 153     av_freep(&s->node_buf);
 154     av_freep(&s->nodep_buf);
 155     av_freep(&s->trellis_hash);
 156     return ret;
 157 }
 158
 159 static av_cold int adpcm_encode_close(AVCodecContext *avctx)
 160 {
 161     ADPCMEncodeContext *s = avctx->priv_data;
 162 #if FF_API_OLD_ENCODE_AUDIO
 163     av_freep(&avctx->coded_frame);
 164 #endif
 165     av_freep(&s->paths);
 166     av_freep(&s->node_buf);
 167     av_freep(&s->nodep_buf);
 168     av_freep(&s->trellis_hash);
 169
 170     return 0;
 171 }
 172
 173
 174 static inline uint8_t adpcm_ima_compress_sample(ADPCMChannelStatus *c,
 175                                                 int16_t sample)
 176 {
 177     int delta  = sample - c->prev_sample;
 178     int nibble = FFMIN(7, abs(delta) * 4 /
 179                        ff_adpcm_step_table[c->step_index]) + (delta < 0) * 8;
 180     c->prev_sample += ((ff_adpcm_step_table[c->step_index] *
 181                         ff_adpcm_yamaha_difflookup[nibble]) / 8);
 182     c->prev_sample = av_clip_int16(c->prev_sample);
 183     c->step_index  = av_clip(c->step_index + ff_adpcm_index_table[nibble], 0, 88);
 184     return nibble;
 185 }
 186
 187 static inline uint8_t adpcm_ima_qt_compress_sample(ADPCMChannelStatus *c,
 188                                                    int16_t sample)
 189 {
 190     int delta  = sample - c->prev_sample;
 191     int mask, step = ff_adpcm_step_table[c->step_index];
 192     int diff   = step >> 3;
 193     int nibble = 0;
 194
 195     if (delta < 0) {
 196         nibble = 8;
 197         delta  = -delta;
 198     }
 199
 200     for (mask = 4; mask;) {
 201         if (delta >= step) {
 202             nibble |= mask;
 203             delta  -= step;
 204             diff   += step;
 205         }
 206         step >>= 1;
 207         mask >>= 1;
 208     }
 209
 210     if (nibble & 8)
 211         c->prev_sample -= diff;
 212     else
 213         c->prev_sample += diff;
 214
 215     c->prev_sample = av_clip_int16(c->prev_sample);
 216     c->step_index  = av_clip(c->step_index + ff_adpcm_index_table[nibble], 0, 88);
 217
 218     return nibble;
 219 }
 220
 221 static inline uint8_t adpcm_ms_compress_sample(ADPCMChannelStatus *c,
 222                                                int16_t sample)
 223 {
 224     int predictor, nibble, bias;
 225
 226     predictor = (((c->sample1) * (c->coeff1)) +
 227                 (( c->sample2) * (c->coeff2))) / 64;
 228
 229     nibble = sample - predictor;
 230     if (nibble >= 0)
 231         bias =  c->idelta / 2;
 232     else
 233         bias = -c->idelta / 2;
 234
 235     nibble = (nibble + bias) / c->idelta;
 236     nibble = av_clip(nibble, -8, 7) & 0x0F;
 237
 238     predictor += ((nibble & 0x08) ? (nibble - 0x10) : nibble) * c->idelta;
 239
 240     c->sample2 = c->sample1;
 241     c->sample1 = av_clip_int16(predictor);
 242
 243     c->idelta = (ff_adpcm_AdaptationTable[nibble] * c->idelta) >> 8;
 244     if (c->idelta < 16)
 245         c->idelta = 16;
 246
 247     return nibble;
 248 }
 249
 250 static inline uint8_t adpcm_yamaha_compress_sample(ADPCMChannelStatus *c,
 251                                                    int16_t sample)
 252 {
 253     int nibble, delta;
 254
 255     if (!c->step) {
 256         c->predictor = 0;
 257         c->step      = 127;
 258     }
 259
 260     delta = sample - c->predictor;
 261
 262     nibble = FFMIN(7, abs(delta) * 4 / c->step) + (delta < 0) * 8;
 263
 264     c->predictor += ((c->step * ff_adpcm_yamaha_difflookup[nibble]) / 8);
 265     c->predictor = av_clip_int16(c->predictor);
 266     c->step = (c->step * ff_adpcm_yamaha_indexscale[nibble]) >> 8;
 267     c->step = av_clip(c->step, 127, 24567);
 268
 269     return nibble;
 270 }
 271
 272 static void adpcm_compress_trellis(AVCodecContext *avctx,
 273                                    const int16_t *samples, uint8_t *dst,
 274                                    ADPCMChannelStatus *c, int n, int stride)
 275 {
 276     //FIXME 6% faster if frontier is a compile-time constant
 277     ADPCMEncodeContext *s = avctx->priv_data;
 278     const int frontier = 1 << avctx->trellis;
 279     const int version  = avctx->codec->id;
 280     TrellisPath *paths       = s->paths, *p;
 281     TrellisNode *node_buf    = s->node_buf;
 282     TrellisNode **nodep_buf  = s->nodep_buf;
 283     TrellisNode **nodes      = nodep_buf; // nodes[] is always sorted by .ssd
 284     TrellisNode **nodes_next = nodep_buf + frontier;
 285     int pathn = 0, froze = -1, i, j, k, generation = 0;
 286     uint8_t *hash = s->trellis_hash;
 287     memset(hash, 0xff, 65536 * sizeof(*hash));
 288
 289     memset(nodep_buf, 0, 2 * frontier * sizeof(*nodep_buf));
 290     nodes[0]          = node_buf + frontier;
 291     nodes[0]->ssd     = 0;
 292     nodes[0]->path    = 0;
 293     nodes[0]->step    = c->step_index;
 294     nodes[0]->sample1 = c->sample1;
 295     nodes[0]->sample2 = c->sample2;
 296     if (version == AV_CODEC_ID_ADPCM_IMA_WAV ||
 297         version == AV_CODEC_ID_ADPCM_IMA_QT  ||
 298         version == AV_CODEC_ID_ADPCM_SWF)
 299         nodes[0]->sample1 = c->prev_sample;
 300     if (version == AV_CODEC_ID_ADPCM_MS)
 301         nodes[0]->step = c->idelta;
 302     if (version == AV_CODEC_ID_ADPCM_YAMAHA) {
 303         if (c->step == 0) {
 304             nodes[0]->step    = 127;
 305             nodes[0]->sample1 = 0;
 306         } else {
 307             nodes[0]->step    = c->step;
 308             nodes[0]->sample1 = c->predictor;
 309         }
 310     }
 311
 312     for (i = 0; i < n; i++) {
 313         TrellisNode *t = node_buf + frontier*(i&1);
 314         TrellisNode **u;
 315         int sample   = samples[i * stride];
 316         int heap_pos = 0;
 317         memset(nodes_next, 0, frontier * sizeof(TrellisNode*));
 318         for (j = 0; j < frontier && nodes[j]; j++) {
 319             // higher j have higher ssd already, so they're likely
 320             // to yield a suboptimal next sample too
 321             const int range = (j < frontier / 2) ? 1 : 0;
 322             const int step  = nodes[j]->step;
 323             int nidx;
 324             if (version == AV_CODEC_ID_ADPCM_MS) {
 325                 const int predictor = ((nodes[j]->sample1 * c->coeff1) +
 326                                        (nodes[j]->sample2 * c->coeff2)) / 64;
 327                 const int div  = (sample - predictor) / step;
 328                 const int nmin = av_clip(div-range, -8, 6);
 329                 const int nmax = av_clip(div+range, -7, 7);
 330                 for (nidx = nmin; nidx <= nmax; nidx++) {
 331                     const int nibble = nidx & 0xf;
 332                     int dec_sample   = predictor + nidx * step;
 333 #define STORE_NODE(NAME, STEP_INDEX)\
 334                     int d;\
 335                     uint32_t ssd;\
 336                     int pos;\
 337                     TrellisNode *u;\
 338                     uint8_t *h;\
 339                     dec_sample = av_clip_int16(dec_sample);\
 340                     d = sample - dec_sample;\
 341                     ssd = nodes[j]->ssd + d*d;\
 342                     /* Check for wraparound, skip such samples completely. \
 343                      * Note, changing ssd to a 64 bit variable would be \
 344                      * simpler, avoiding this check, but it's slower on \
 345                      * x86 32 bit at the moment. */\
 346                     if (ssd < nodes[j]->ssd)\
 347                         goto next_##NAME;\
 348                     /* Collapse any two states with the same previous sample value. \
 349                      * One could also distinguish states by step and by 2nd to last
 350                      * sample, but the effects of that are negligible.
 351                      * Since nodes in the previous generation are iterated
 352                      * through a heap, they're roughly ordered from better to
 353                      * worse, but not strictly ordered. Therefore, an earlier
 354                      * node with the same sample value is better in most cases
 355                      * (and thus the current is skipped), but not strictly
 356                      * in all cases. Only skipping samples where ssd >=
 357                      * ssd of the earlier node with the same sample gives
 358                      * slightly worse quality, though, for some reason. */ \
 359                     h = &hash[(uint16_t) dec_sample];\
 360                     if (*h == generation)\
 361                         goto next_##NAME;\
 362                     if (heap_pos < frontier) {\
 363                         pos = heap_pos++;\
 364                     } else {\
 365                         /* Try to replace one of the leaf nodes with the new \
 366                          * one, but try a different slot each time. */\
 367                         pos = (frontier >> 1) +\
 368                               (heap_pos & ((frontier >> 1) - 1));\
 369                         if (ssd > nodes_next[pos]->ssd)\
 370                             goto next_##NAME;\
 371                         heap_pos++;\
 372                     }\
 373                     *h = generation;\
 374                     u  = nodes_next[pos];\
 375                     if (!u) {\
 376                         assert(pathn < FREEZE_INTERVAL << avctx->trellis);\
 377                         u = t++;\
 378                         nodes_next[pos] = u;\
 379                         u->path = pathn++;\
 380                     }\
 381                     u->ssd  = ssd;\
 382                     u->step = STEP_INDEX;\
 383                     u->sample2 = nodes[j]->sample1;\
 384                     u->sample1 = dec_sample;\
 385                     paths[u->path].nibble = nibble;\
 386                     paths[u->path].prev   = nodes[j]->path;\
 387                     /* Sift the newly inserted node up in the heap to \
 388                      * restore the heap property. */\
 389                     while (pos > 0) {\
 390                         int parent = (pos - 1) >> 1;\
 391                         if (nodes_next[parent]->ssd <= ssd)\
 392                             break;\
 393                         FFSWAP(TrellisNode*, nodes_next[parent], nodes_next[pos]);\
 394                         pos = parent;\
 395                     }\
 396                     next_##NAME:;
 397                     STORE_NODE(ms, FFMAX(16,
 398                                (ff_adpcm_AdaptationTable[nibble] * step) >> 8));
 399                 }
 400             } else if (version == AV_CODEC_ID_ADPCM_IMA_WAV ||
 401                        version == AV_CODEC_ID_ADPCM_IMA_QT  ||
 402                        version == AV_CODEC_ID_ADPCM_SWF) {
 403 #define LOOP_NODES(NAME, STEP_TABLE, STEP_INDEX)\
 404                 const int predictor = nodes[j]->sample1;\
 405                 const int div = (sample - predictor) * 4 / STEP_TABLE;\
 406                 int nmin = av_clip(div - range, -7, 6);\
 407                 int nmax = av_clip(div + range, -6, 7);\
 408                 if (nmin <= 0)\
 409                     nmin--; /* distinguish -0 from +0 */\
 410                 if (nmax < 0)\
 411                     nmax--;\
 412                 for (nidx = nmin; nidx <= nmax; nidx++) {\
 413                     const int nibble = nidx < 0 ? 7 - nidx : nidx;\
 414                     int dec_sample = predictor +\
 415                                     (STEP_TABLE *\
 416                                      ff_adpcm_yamaha_difflookup[nibble]) / 8;\
 417                     STORE_NODE(NAME, STEP_INDEX);\
 418                 }
 419                 LOOP_NODES(ima, ff_adpcm_step_table[step],
 420                            av_clip(step + ff_adpcm_index_table[nibble], 0, 88));
 421             } else { //AV_CODEC_ID_ADPCM_YAMAHA
 422                 LOOP_NODES(yamaha, step,
 423                            av_clip((step * ff_adpcm_yamaha_indexscale[nibble]) >> 8,
 424                                    127, 24567));
 425 #undef LOOP_NODES
 426 #undef STORE_NODE
 427             }
 428         }
 429
 430         u = nodes;
 431         nodes = nodes_next;
 432         nodes_next = u;
 433
 434         generation++;
 435         if (generation == 255) {
 436             memset(hash, 0xff, 65536 * sizeof(*hash));
 437             generation = 0;
 438         }
 439
 440         // prevent overflow
 441         if (nodes[0]->ssd > (1 << 28)) {
 442             for (j = 1; j < frontier && nodes[j]; j++)
 443                 nodes[j]->ssd -= nodes[0]->ssd;
 444             nodes[0]->ssd = 0;
 445         }
 446
 447         // merge old paths to save memory
 448         if (i == froze + FREEZE_INTERVAL) {
 449             p = &paths[nodes[0]->path];
 450             for (k = i; k > froze; k--) {
 451                 dst[k] = p->nibble;
 452                 p = &paths[p->prev];
 453             }
 454             froze = i;
 455             pathn = 0;
 456             // other nodes might use paths that don't coincide with the frozen one.
 457             // checking which nodes do so is too slow, so just kill them all.
 458             // this also slightly improves quality, but I don't know why.
 459             memset(nodes + 1, 0, (frontier - 1) * sizeof(TrellisNode*));
 460         }
 461     }
 462
 463     p = &paths[nodes[0]->path];
 464     for (i = n - 1; i > froze; i--) {
 465         dst[i] = p->nibble;
 466         p = &paths[p->prev];
 467     }
 468
 469     c->predictor  = nodes[0]->sample1;
 470     c->sample1    = nodes[0]->sample1;
 471     c->sample2    = nodes[0]->sample2;
 472     c->step_index = nodes[0]->step;
 473     c->step       = nodes[0]->step;
 474     c->idelta     = nodes[0]->step;
 475 }
 476
 477 static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 478                               const AVFrame *frame, int *got_packet_ptr)
 479 {
 480     int n, i, ch, st, pkt_size, ret;
 481     const int16_t *samples;
 482     int16_t **samples_p;
 483     uint8_t *dst;
 484     ADPCMEncodeContext *c = avctx->priv_data;
 485     uint8_t *buf;
 486
 487     samples = (const int16_t *)frame->data[0];
 488     samples_p = (int16_t **)frame->extended_data;
 489     st = avctx->channels == 2;
 490
 491     if (avctx->codec_id == AV_CODEC_ID_ADPCM_SWF)
 492         pkt_size = (2 + avctx->channels * (22 + 4 * (frame->nb_samples - 1)) + 7) / 8;
 493     else
 494         pkt_size = avctx->block_align;
 495     if ((ret = ff_alloc_packet(avpkt, pkt_size))) {
 496         av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
 497         return ret;
 498     }
 499     dst = avpkt->data;
 500
 501     switch(avctx->codec->id) {
 502     case AV_CODEC_ID_ADPCM_IMA_WAV:
 503     {
 504         int blocks, j;
 505
 506         blocks = (frame->nb_samples - 1) / 8;
 507
 508         for (ch = 0; ch < avctx->channels; ch++) {
 509             ADPCMChannelStatus *status = &c->status[ch];
 510             status->prev_sample = samples_p[ch][0];
 511             /* status->step_index = 0;
 512                XXX: not sure how to init the state machine */
 513             bytestream_put_le16(&dst, status->prev_sample);
 514             *dst++ = status->step_index;
 515             *dst++ = 0; /* unknown */
 516         }
 517
 518         /* stereo: 4 bytes (8 samples) for left, 4 bytes for right */
 519         if (avctx->trellis > 0) {
 520             FF_ALLOC_OR_GOTO(avctx, buf, avctx->channels * blocks * 8, error);
 521             for (ch = 0; ch < avctx->channels; ch++) {
 522                 adpcm_compress_trellis(avctx, &samples_p[ch][1],
 523                                        buf + ch * blocks * 8, &c->status[ch],
 524                                        blocks * 8, 1);
 525             }
 526             for (i = 0; i < blocks; i++) {
 527                 for (ch = 0; ch < avctx->channels; ch++) {
 528                     uint8_t *buf1 = buf + ch * blocks * 8 + i * 8;
 529                     for (j = 0; j < 8; j += 2)
 530                         *dst++ = buf1[j] | (buf1[j + 1] << 4);
 531                 }
 532             }
 533             av_free(buf);
 534         } else {
 535             for (i = 0; i < blocks; i++) {
 536                 for (ch = 0; ch < avctx->channels; ch++) {
 537                     ADPCMChannelStatus *status = &c->status[ch];
 538                     const int16_t *smp = &samples_p[ch][1 + i * 8];
 539                     for (j = 0; j < 8; j += 2) {
 540                         uint8_t v = adpcm_ima_compress_sample(status, smp[j    ]);
 541                         v        |= adpcm_ima_compress_sample(status, smp[j + 1]) << 4;
 542                         *dst++ = v;
 543                     }
 544                 }
 545             }
 546         }
 547         break;
 548     }
 549     case AV_CODEC_ID_ADPCM_IMA_QT:
 550     {
 551         PutBitContext pb;
 552         init_put_bits(&pb, dst, pkt_size * 8);
 553
 554         for (ch = 0; ch < avctx->channels; ch++) {
 555             ADPCMChannelStatus *status = &c->status[ch];
 556             put_bits(&pb, 9, (status->prev_sample & 0xFFFF) >> 7);
 557             put_bits(&pb, 7,  status->step_index);
 558             if (avctx->trellis > 0) {
 559                 uint8_t buf[64];
 560                 adpcm_compress_trellis(avctx, &samples_p[ch][1], buf, status,
 561                                        64, 1);
 562                 for (i = 0; i < 64; i++)
 563                     put_bits(&pb, 4, buf[i ^ 1]);
 564             } else {
 565                 for (i = 0; i < 64; i += 2) {
 566                     int t1, t2;
 567                     t1 = adpcm_ima_qt_compress_sample(status, samples_p[ch][i    ]);
 568                     t2 = adpcm_ima_qt_compress_sample(status, samples_p[ch][i + 1]);
 569                     put_bits(&pb, 4, t2);
 570                     put_bits(&pb, 4, t1);
 571                 }
 572             }
 573         }
 574
 575         flush_put_bits(&pb);
 576         break;
 577     }
 578     case AV_CODEC_ID_ADPCM_SWF:
 579     {
 580         PutBitContext pb;
 581         init_put_bits(&pb, dst, pkt_size * 8);
 582
 583         n = frame->nb_samples - 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 = 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 + avctx->channels, buf,
 600                                    &c->status[0], n, avctx->channels);
 601             if (avctx->channels == 2)
 602                 adpcm_compress_trellis(avctx, samples + avctx->channels + 1,
 603                                        buf + n, &c->status[1], n,
 604                                        avctx->channels);
 605             for (i = 0; i < n; i++) {
 606                 put_bits(&pb, 4, buf[i]);
 607                 if (avctx->channels == 2)
 608                     put_bits(&pb, 4, buf[n + i]);
 609             }
 610             av_free(buf);
 611         } else {
 612             for (i = 1; i < frame->nb_samples; i++) {
 613                 put_bits(&pb, 4, adpcm_ima_compress_sample(&c->status[0],
 614                          samples[avctx->channels * i]));
 615                 if (avctx->channels == 2)
 616                     put_bits(&pb, 4, adpcm_ima_compress_sample(&c->status[1],
 617                              samples[2 * i + 1]));
 618             }
 619         }
 620         flush_put_bits(&pb);
 621         break;
 622     }
 623     case AV_CODEC_ID_ADPCM_MS:
 624         for (i = 0; i < avctx->channels; i++) {
 625             int predictor = 0;
 626             *dst++ = predictor;
 627             c->status[i].coeff1 = ff_adpcm_AdaptCoeff1[predictor];
 628             c->status[i].coeff2 = ff_adpcm_AdaptCoeff2[predictor];
 629         }
 630         for (i = 0; i < avctx->channels; i++) {
 631             if (c->status[i].idelta < 16)
 632                 c->status[i].idelta = 16;
 633             bytestream_put_le16(&dst, c->status[i].idelta);
 634         }
 635         for (i = 0; i < avctx->channels; i++)
 636             c->status[i].sample2= *samples++;
 637         for (i = 0; i < avctx->channels; i++) {
 638             c->status[i].sample1 = *samples++;
 639             bytestream_put_le16(&dst, c->status[i].sample1);
 640         }
 641         for (i = 0; i < avctx->channels; i++)
 642             bytestream_put_le16(&dst, c->status[i].sample2);
 643
 644         if (avctx->trellis > 0) {
 645             n = avctx->block_align - 7 * avctx->channels;
 646             FF_ALLOC_OR_GOTO(avctx, buf, 2 * n, error);
 647             if (avctx->channels == 1) {
 648                 adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n,
 649                                        avctx->channels);
 650                 for (i = 0; i < n; i += 2)
 651                     *dst++ = (buf[i] << 4) | buf[i + 1];
 652             } else {
 653                 adpcm_compress_trellis(avctx, samples,     buf,
 654                                        &c->status[0], n, avctx->channels);
 655                 adpcm_compress_trellis(avctx, samples + 1, buf + n,
 656                                        &c->status[1], n, avctx->channels);
 657                 for (i = 0; i < n; i++)
 658                     *dst++ = (buf[i] << 4) | buf[n + i];
 659             }
 660             av_free(buf);
 661         } else {
 662             for (i = 7 * avctx->channels; i < avctx->block_align; i++) {
 663                 int nibble;
 664                 nibble  = adpcm_ms_compress_sample(&c->status[ 0], *samples++) << 4;
 665                 nibble |= adpcm_ms_compress_sample(&c->status[st], *samples++);
 666                 *dst++  = nibble;
 667             }
 668         }
 669         break;
 670     case AV_CODEC_ID_ADPCM_YAMAHA:
 671         n = frame->nb_samples / 2;
 672         if (avctx->trellis > 0) {
 673             FF_ALLOC_OR_GOTO(avctx, buf, 2 * n * 2, error);
 674             n *= 2;
 675             if (avctx->channels == 1) {
 676                 adpcm_compress_trellis(avctx, samples, buf, &c->status[0], n,
 677                                        avctx->channels);
 678                 for (i = 0; i < n; i += 2)
 679                     *dst++ = buf[i] | (buf[i + 1] << 4);
 680             } else {
 681                 adpcm_compress_trellis(avctx, samples,     buf,
 682                                        &c->status[0], n, avctx->channels);
 683                 adpcm_compress_trellis(avctx, samples + 1, buf + n,
 684                                        &c->status[1], n, avctx->channels);
 685                 for (i = 0; i < n; i++)
 686                     *dst++ = buf[i] | (buf[n + i] << 4);
 687             }
 688             av_free(buf);
 689         } else
 690             for (n *= avctx->channels; n > 0; n--) {
 691                 int nibble;
 692                 nibble  = adpcm_yamaha_compress_sample(&c->status[ 0], *samples++);
 693                 nibble |= adpcm_yamaha_compress_sample(&c->status[st], *samples++) << 4;
 694                 *dst++  = nibble;
 695             }
 696         break;
 697     default:
 698         return AVERROR(EINVAL);
 699     }
 700
 701     avpkt->size = pkt_size;
 702     *got_packet_ptr = 1;
 703     return 0;
 704 error:
 705     return AVERROR(ENOMEM);
 706 }
 707
 708 static const enum AVSampleFormat sample_fmts[] = {
 709     AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
 710 };
 711
 712 static const enum AVSampleFormat sample_fmts_p[] = {
 713     AV_SAMPLE_FMT_S16P, AV_SAMPLE_FMT_NONE
 714 };
 715
 716 #define ADPCM_ENCODER(id_, name_, sample_fmts_, long_name_) \
 717 AVCodec ff_ ## name_ ## _encoder = {                        \
 718     .name           = #name_,                               \
 719     .type           = AVMEDIA_TYPE_AUDIO,                   \
 720     .id             = id_,                                  \
 721     .priv_data_size = sizeof(ADPCMEncodeContext),           \
 722     .init           = adpcm_encode_init,                    \
 723     .encode2        = adpcm_encode_frame,                   \
 724     .close          = adpcm_encode_close,                   \
 725     .sample_fmts    = sample_fmts_,                         \
 726     .long_name      = NULL_IF_CONFIG_SMALL(long_name_),     \
 727 }
 728
 729 ADPCM_ENCODER(AV_CODEC_ID_ADPCM_IMA_QT,  adpcm_ima_qt,  sample_fmts_p, "ADPCM IMA QuickTime");
 730 ADPCM_ENCODER(AV_CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav, sample_fmts_p, "ADPCM IMA WAV");
 731 ADPCM_ENCODER(AV_CODEC_ID_ADPCM_MS,      adpcm_ms,      sample_fmts,   "ADPCM Microsoft");
 732 ADPCM_ENCODER(AV_CODEC_ID_ADPCM_SWF,     adpcm_swf,     sample_fmts,   "ADPCM Shockwave Flash");
 733 ADPCM_ENCODER(AV_CODEC_ID_ADPCM_YAMAHA,  adpcm_yamaha,  sample_fmts,   "ADPCM Yamaha");