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  * CD-ROM XA ADPCM codec by BERO
  28  *
  29  * Features and limitations:
  30  *
  31  * Reference documents:
  32  * http://www.pcisys.net/~melanson/codecs/simpleaudio.html
  33  * http://www.geocities.com/SiliconValley/8682/aud3.txt
  34  * http://openquicktime.sourceforge.net/plugins.htm
  35  * XAnim sources (xa_codec.c) http://www.rasnaimaging.com/people/lapus/download.html
  36  * http://www.cs.ucla.edu/~leec/mediabench/applications.html
  37  * SoX source code http://home.sprynet.com/~cbagwell/sox.html
  38  *
  39  * CD-ROM XA:
  40  * http://ku-www.ss.titech.ac.jp/~yatsushi/xaadpcm.html
  41  * vagpack & depack http://homepages.compuserve.de/bITmASTER32/psx-index.html
  42  * readstr http://www.geocities.co.jp/Playtown/2004/
  43  */
  44
  45 #define BLKSIZE 1024
  46
  47 #define CLAMP_TO_SHORT(value) \
  48 if (value > 32767) \
  49     value = 32767; \
  50 else if (value < -32768) \
  51     value = -32768; \
  52
  53 /* step_table[] and index_table[] are from the ADPCM reference source */
  54 /* This is the index table: */
  55 static const int index_table[16] = {
  56     -1, -1, -1, -1, 2, 4, 6, 8,
  57     -1, -1, -1, -1, 2, 4, 6, 8,
  58 };
  59
  60 /**
  61  * This is the step table. Note that many programs use slight deviations from
  62  * this table, but such deviations are negligible:
  63  */
  64 static const int step_table[89] = {
  65     7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
  66     19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
  67     50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
  68     130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
  69     337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
  70     876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
  71     2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
  72     5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
  73     15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
  74 };
  75
  76 /* These are for MS-ADPCM */
  77 /* AdaptationTable[], AdaptCoeff1[], and AdaptCoeff2[] are from libsndfile */
  78 static const int AdaptationTable[] = {
  79         230, 230, 230, 230, 307, 409, 512, 614,
  80         768, 614, 512, 409, 307, 230, 230, 230
  81 };
  82
  83 static const int AdaptCoeff1[] = {
  84         256, 512, 0, 192, 240, 460, 392
  85 };
  86
  87 static const int AdaptCoeff2[] = {
  88         0, -256, 0, 64, 0, -208, -232
  89 };
  90
  91 /* These are for CD-ROM XA ADPCM */
  92 static const int xa_adpcm_table[5][2] = {
  93    {   0,   0 },
  94    {  60,   0 },
  95    { 115, -52 },
  96    {  98, -55 },
  97    { 122, -60 }
  98 };
  99
 100 /* end of tables */
 101
 102 typedef struct ADPCMChannelStatus {
 103     int predictor;
 104     short int step_index;
 105     int step;
 106     /* for encoding */
 107     int prev_sample;
 108
 109     /* MS version */
 110     short sample1;
 111     short sample2;
 112     int coeff1;
 113     int coeff2;
 114     int idelta;
 115 } ADPCMChannelStatus;
 116
 117 typedef struct ADPCMContext {
 118     int channel; /* for stereo MOVs, decode left, then decode right, then tell it's decoded */
 119     ADPCMChannelStatus status[2];
 120     short sample_buffer[32]; /* hold left samples while waiting for right samples */
 121 } ADPCMContext;
 122
 123 /* XXX: implement encoding */
 124
 125 #ifdef CONFIG_ENCODERS
 126 static int adpcm_encode_init(AVCodecContext *avctx)
 127 {
 128     if (avctx->channels > 2)
 129         return -1; /* only stereo or mono =) */
 130     switch(avctx->codec->id) {
 131     case CODEC_ID_ADPCM_IMA_QT:
 132         av_log(avctx, AV_LOG_ERROR, "ADPCM: codec adpcm_ima_qt unsupported for encoding !\n");
 133         avctx->frame_size = 64; /* XXX: can multiple of avctx->channels * 64 (left and right blocks are interleaved) */
 134         return -1;
 135         break;
 136     case CODEC_ID_ADPCM_IMA_WAV:
 137         avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 / (4 * avctx->channels) + 1; /* each 16 bits sample gives one nibble */
 138                                                              /* and we have 4 bytes per channel overhead */
 139         avctx->block_align = BLKSIZE;
 140         /* seems frame_size isn't taken into account... have to buffer the samples :-( */
 141         break;
 142     case CODEC_ID_ADPCM_MS:
 143         av_log(avctx, AV_LOG_ERROR, "ADPCM: codec adpcm_ms unsupported for encoding !\n");
 144         return -1;
 145         break;
 146     default:
 147         return -1;
 148         break;
 149     }
 150
 151     avctx->coded_frame= avcodec_alloc_frame();
 152     avctx->coded_frame->key_frame= 1;
 153
 154     return 0;
 155 }
 156
 157 static int adpcm_encode_close(AVCodecContext *avctx)
 158 {
 159     av_freep(&avctx->coded_frame);
 160
 161     return 0;
 162 }
 163
 164
 165 static inline unsigned char adpcm_ima_compress_sample(ADPCMChannelStatus *c, short sample)
 166 {
 167     int step_index;
 168     unsigned char nibble;
 169
 170     int sign = 0; /* sign bit of the nibble (MSB) */
 171     int delta, predicted_delta;
 172
 173     delta = sample - c->prev_sample;
 174
 175     if (delta < 0) {
 176         sign = 1;
 177         delta = -delta;
 178     }
 179
 180     step_index = c->step_index;
 181
 182     /* nibble = 4 * delta / step_table[step_index]; */
 183     nibble = (delta << 2) / step_table[step_index];
 184
 185     if (nibble > 7)
 186         nibble = 7;
 187
 188     step_index += index_table[nibble];
 189     if (step_index < 0)
 190         step_index = 0;
 191     if (step_index > 88)
 192         step_index = 88;
 193
 194     /* what the decoder will find */
 195     predicted_delta = ((step_table[step_index] * nibble) / 4) + (step_table[step_index] / 8);
 196
 197     if (sign)
 198         c->prev_sample -= predicted_delta;
 199     else
 200         c->prev_sample += predicted_delta;
 201
 202     CLAMP_TO_SHORT(c->prev_sample);
 203
 204
 205     nibble += sign << 3; /* sign * 8 */
 206
 207     /* save back */
 208     c->step_index = step_index;
 209
 210     return nibble;
 211 }
 212
 213 static int adpcm_encode_frame(AVCodecContext *avctx,
 214                             unsigned char *frame, int buf_size, void *data)
 215 {
 216     int n;
 217     short *samples;
 218     unsigned char *dst;
 219     ADPCMContext *c = avctx->priv_data;
 220
 221     dst = frame;
 222     samples = (short *)data;
 223 /*    n = (BLKSIZE - 4 * avctx->channels) / (2 * 8 * avctx->channels); */
 224
 225     switch(avctx->codec->id) {
 226     case CODEC_ID_ADPCM_IMA_QT: /* XXX: can't test until we get .mov writer */
 227         break;
 228     case CODEC_ID_ADPCM_IMA_WAV:
 229         n = avctx->frame_size / 8;
 230             c->status[0].prev_sample = (signed short)samples[0]; /* XXX */
 231 /*            c->status[0].step_index = 0; *//* XXX: not sure how to init the state machine */
 232             *dst++ = (c->status[0].prev_sample) & 0xFF; /* little endian */
 233             *dst++ = (c->status[0].prev_sample >> 8) & 0xFF;
 234             *dst++ = (unsigned char)c->status[0].step_index;
 235             *dst++ = 0; /* unknown */
 236             samples++;
 237             if (avctx->channels == 2) {
 238                 c->status[1].prev_sample = (signed short)samples[1];
 239 /*                c->status[1].step_index = 0; */
 240                 *dst++ = (c->status[1].prev_sample) & 0xFF;
 241                 *dst++ = (c->status[1].prev_sample >> 8) & 0xFF;
 242                 *dst++ = (unsigned char)c->status[1].step_index;
 243                 *dst++ = 0;
 244                 samples++;
 245             }
 246
 247             /* stereo: 4 bytes (8 samples) for left, 4 bytes for right, 4 bytes left, ... */
 248             for (; n>0; n--) {
 249                 *dst = adpcm_ima_compress_sample(&c->status[0], samples[0]) & 0x0F;
 250                 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels]) << 4) & 0xF0;
 251                 dst++;
 252                 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 2]) & 0x0F;
 253                 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 3]) << 4) & 0xF0;
 254                 dst++;
 255                 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 4]) & 0x0F;
 256                 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 5]) << 4) & 0xF0;
 257                 dst++;
 258                 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 6]) & 0x0F;
 259                 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 7]) << 4) & 0xF0;
 260                 dst++;
 261                 /* right channel */
 262                 if (avctx->channels == 2) {
 263                     *dst = adpcm_ima_compress_sample(&c->status[1], samples[1]);
 264                     *dst |= adpcm_ima_compress_sample(&c->status[1], samples[3]) << 4;
 265                     dst++;
 266                     *dst = adpcm_ima_compress_sample(&c->status[1], samples[5]);
 267                     *dst |= adpcm_ima_compress_sample(&c->status[1], samples[7]) << 4;
 268                     dst++;
 269                     *dst = adpcm_ima_compress_sample(&c->status[1], samples[9]);
 270                     *dst |= adpcm_ima_compress_sample(&c->status[1], samples[11]) << 4;
 271                     dst++;
 272                     *dst = adpcm_ima_compress_sample(&c->status[1], samples[13]);
 273                     *dst |= adpcm_ima_compress_sample(&c->status[1], samples[15]) << 4;
 274                     dst++;
 275                 }
 276                 samples += 8 * avctx->channels;
 277             }
 278         break;
 279     default:
 280         return -1;
 281     }
 282     return dst - frame;
 283 }
 284 #endif //CONFIG_ENCODERS
 285
 286 static int adpcm_decode_init(AVCodecContext * avctx)
 287 {
 288     ADPCMContext *c = avctx->priv_data;
 289
 290     c->channel = 0;
 291     c->status[0].predictor = c->status[1].predictor = 0;
 292     c->status[0].step_index = c->status[1].step_index = 0;
 293     c->status[0].step = c->status[1].step = 0;
 294
 295     switch(avctx->codec->id) {
 296     default:
 297         break;
 298     }
 299     return 0;
 300 }
 301
 302 static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble, int shift)
 303 {
 304     int step_index;
 305     int predictor;
 306     int sign, delta, diff, step;
 307
 308     step = step_table[c->step_index];
 309     step_index = c->step_index + index_table[(unsigned)nibble];
 310     if (step_index < 0) step_index = 0;
 311     else if (step_index > 88) step_index = 88;
 312
 313     sign = nibble & 8;
 314     delta = nibble & 7;
 315     /* perform direct multiplication instead of series of jumps proposed by
 316      * the reference ADPCM implementation since modern CPUs can do the mults
 317      * quickly enough */
 318     diff = ((2 * delta + 1) * step) >> shift;
 319     predictor = c->predictor;
 320     if (sign) predictor -= diff;
 321     else predictor += diff;
 322
 323     CLAMP_TO_SHORT(predictor);
 324     c->predictor = predictor;
 325     c->step_index = step_index;
 326
 327     return (short)predictor;
 328 }
 329
 330 static inline short adpcm_ms_expand_nibble(ADPCMChannelStatus *c, char nibble)
 331 {
 332     int predictor;
 333
 334     predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256;
 335     predictor += (signed)((nibble & 0x08)?(nibble - 0x10):(nibble)) * c->idelta;
 336     CLAMP_TO_SHORT(predictor);
 337
 338     c->sample2 = c->sample1;
 339     c->sample1 = predictor;
 340     c->idelta = (AdaptationTable[(int)nibble] * c->idelta) / 256;
 341     if (c->idelta < 16) c->idelta = 16;
 342
 343     return (short)predictor;
 344 }
 345
 346 static void xa_decode(short *out, const unsigned char *in,
 347     ADPCMChannelStatus *left, ADPCMChannelStatus *right, int inc)
 348 {
 349     int i, j;
 350     int shift,filter,f0,f1;
 351     int s_1,s_2;
 352     int d,s,t;
 353
 354     for(i=0;i<4;i++) {
 355
 356         shift  = 12 - (in[4+i*2] & 15);
 357         filter = in[4+i*2] >> 4;
 358         f0 = xa_adpcm_table[filter][0];
 359         f1 = xa_adpcm_table[filter][1];
 360
 361         s_1 = left->sample1;
 362         s_2 = left->sample2;
 363
 364         for(j=0;j<28;j++) {
 365             d = in[16+i+j*4];
 366
 367             t = (signed char)(d<<4)>>4;
 368             s = ( t<<shift ) + ((s_1*f0 + s_2*f1+32)>>6);
 369             CLAMP_TO_SHORT(s);
 370             *out = s;
 371             out += inc;
 372             s_2 = s_1;
 373             s_1 = s;
 374         }
 375
 376         if (inc==2) { /* stereo */
 377             left->sample1 = s_1;
 378             left->sample2 = s_2;
 379             s_1 = right->sample1;
 380             s_2 = right->sample2;
 381             out = out + 1 - 28*2;
 382         }
 383
 384         shift  = 12 - (in[5+i*2] & 15);
 385         filter = in[5+i*2] >> 4;
 386
 387         f0 = xa_adpcm_table[filter][0];
 388         f1 = xa_adpcm_table[filter][1];
 389
 390         for(j=0;j<28;j++) {
 391             d = in[16+i+j*4];
 392
 393             t = (signed char)d >> 4;
 394             s = ( t<<shift ) + ((s_1*f0 + s_2*f1+32)>>6);
 395             CLAMP_TO_SHORT(s);
 396             *out = s;
 397             out += inc;
 398             s_2 = s_1;
 399             s_1 = s;
 400         }
 401
 402         if (inc==2) { /* stereo */
 403             right->sample1 = s_1;
 404             right->sample2 = s_2;
 405             out -= 1;
 406         } else {
 407             left->sample1 = s_1;
 408             left->sample2 = s_2;
 409         }
 410     }
 411 }
 412
 413
 414 /* DK3 ADPCM support macro */
 415 #define DK3_GET_NEXT_NIBBLE() \
 416     if (decode_top_nibble_next) \
 417     { \
 418         nibble = (last_byte >> 4) & 0x0F; \
 419         decode_top_nibble_next = 0; \
 420     } \
 421     else \
 422     { \
 423         last_byte = *src++; \
 424         if (src >= buf + buf_size) break; \
 425         nibble = last_byte & 0x0F; \
 426         decode_top_nibble_next = 1; \
 427     }
 428
 429 static int adpcm_decode_frame(AVCodecContext *avctx,
 430                             void *data, int *data_size,
 431                             uint8_t *buf, int buf_size)
 432 {
 433     ADPCMContext *c = avctx->priv_data;
 434     ADPCMChannelStatus *cs;
 435     int n, m, channel, i;
 436     int block_predictor[2];
 437     short *samples;
 438     uint8_t *src;
 439     int st; /* stereo */
 440
 441     /* DK3 ADPCM accounting variables */
 442     unsigned char last_byte = 0;
 443     unsigned char nibble;
 444     int decode_top_nibble_next = 0;
 445     int diff_channel;
 446
 447     if (!buf_size)
 448         return 0;
 449
 450     samples = data;
 451     src = buf;
 452
 453     st = avctx->channels == 2;
 454
 455     switch(avctx->codec->id) {
 456     case CODEC_ID_ADPCM_IMA_QT:
 457         n = (buf_size - 2);/* >> 2*avctx->channels;*/
 458         channel = c->channel;
 459         cs = &(c->status[channel]);
 460         /* (pppppp) (piiiiiii) */
 461
 462         /* Bits 15-7 are the _top_ 9 bits of the 16-bit initial predictor value */
 463         cs->predictor = (*src++) << 8;
 464         cs->predictor |= (*src & 0x80);
 465         cs->predictor &= 0xFF80;
 466
 467         /* sign extension */
 468         if(cs->predictor & 0x8000)
 469             cs->predictor -= 0x10000;
 470
 471         CLAMP_TO_SHORT(cs->predictor);
 472
 473         cs->step_index = (*src++) & 0x7F;
 474
 475         if (cs->step_index > 88) av_log(avctx, AV_LOG_ERROR, "ERROR: step_index = %i\n", cs->step_index);
 476         if (cs->step_index > 88) cs->step_index = 88;
 477
 478         cs->step = step_table[cs->step_index];
 479
 480         if (st && channel)
 481             samples++;
 482
 483         for(m=32; n>0 && m>0; n--, m--) { /* in QuickTime, IMA is encoded by chuncks of 34 bytes (=64 samples) */
 484             *samples = adpcm_ima_expand_nibble(cs, src[0] & 0x0F, 3);
 485             samples += avctx->channels;
 486             *samples = adpcm_ima_expand_nibble(cs, (src[0] >> 4) & 0x0F, 3);
 487             samples += avctx->channels;
 488             src ++;
 489         }
 490
 491         if(st) { /* handle stereo interlacing */
 492             c->channel = (channel + 1) % 2; /* we get one packet for left, then one for right data */
 493             if(channel == 1) { /* wait for the other packet before outputing anything */
 494                 *data_size = 0;
 495                 return src - buf;
 496             }
 497         }
 498         break;
 499     case CODEC_ID_ADPCM_IMA_WAV:
 500         if (avctx->block_align != 0 && buf_size > avctx->block_align)
 501             buf_size = avctx->block_align;
 502
 503         for(i=0; i<avctx->channels; i++){
 504             cs = &(c->status[i]);
 505             cs->predictor = *src++;
 506             cs->predictor |= (*src++) << 8;
 507             if(cs->predictor & 0x8000)
 508                 cs->predictor -= 0x10000;
 509             CLAMP_TO_SHORT(cs->predictor);
 510
 511         // XXX: is this correct ??: *samples++ = cs->predictor;
 512
 513             cs->step_index = *src++;
 514             if (cs->step_index < 0) cs->step_index = 0;
 515             if (cs->step_index > 88) cs->step_index = 88;
 516             if (*src++) av_log(avctx, AV_LOG_ERROR, "unused byte should be null !!\n"); /* unused */
 517         }
 518
 519         for(m=4; src < (buf + buf_size);) {
 520             *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] & 0x0F, 3);
 521             if (st)
 522                 *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[4] & 0x0F, 3);
 523             *samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F, 3);
 524             if (st) {
 525                 *samples++ = adpcm_ima_expand_nibble(&c->status[1], (src[4] >> 4) & 0x0F, 3);
 526                 if (!--m) {
 527                     m=4;
 528                     src+=4;
 529                 }
 530             }
 531             src++;
 532         }
 533         break;
 534     case CODEC_ID_ADPCM_4XM:
 535         cs = &(c->status[0]);
 536         c->status[0].predictor= (int16_t)(src[0] + (src[1]<<8)); src+=2;
 537         if(st){
 538             c->status[1].predictor= (int16_t)(src[0] + (src[1]<<8)); src+=2;
 539         }
 540         c->status[0].step_index= (int16_t)(src[0] + (src[1]<<8)); src+=2;
 541         if(st){
 542             c->status[1].step_index= (int16_t)(src[0] + (src[1]<<8)); src+=2;
 543         }
 544         if (cs->step_index < 0) cs->step_index = 0;
 545         if (cs->step_index > 88) cs->step_index = 88;
 546
 547         m= (buf_size - (src - buf))>>st;
 548         for(i=0; i<m; i++) {
 549             *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[i] & 0x0F, 4);
 550             if (st)
 551                 *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[i+m] & 0x0F, 4);
 552             *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[i] >> 4, 4);
 553             if (st)
 554                 *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[i+m] >> 4, 4);
 555         }
 556
 557         src += m<<st;
 558
 559         break;
 560     case CODEC_ID_ADPCM_MS:
 561         if (avctx->block_align != 0 && buf_size > avctx->block_align)
 562             buf_size = avctx->block_align;
 563         n = buf_size - 7 * avctx->channels;
 564         if (n < 0)
 565             return -1;
 566         block_predictor[0] = (*src++); /* should be bound */
 567         block_predictor[0] = (block_predictor[0] < 0)?(0):((block_predictor[0] > 7)?(7):(block_predictor[0]));
 568         block_predictor[1] = 0;
 569         if (st)
 570             block_predictor[1] = (*src++);
 571         block_predictor[1] = (block_predictor[1] < 0)?(0):((block_predictor[1] > 7)?(7):(block_predictor[1]));
 572         c->status[0].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
 573         if (c->status[0].idelta & 0x08000)
 574             c->status[0].idelta -= 0x10000;
 575         src+=2;
 576         if (st)
 577             c->status[1].idelta = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
 578         if (st && c->status[1].idelta & 0x08000)
 579             c->status[1].idelta |= 0xFFFF0000;
 580         if (st)
 581             src+=2;
 582         c->status[0].coeff1 = AdaptCoeff1[block_predictor[0]];
 583         c->status[0].coeff2 = AdaptCoeff2[block_predictor[0]];
 584         c->status[1].coeff1 = AdaptCoeff1[block_predictor[1]];
 585         c->status[1].coeff2 = AdaptCoeff2[block_predictor[1]];
 586
 587         c->status[0].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
 588         src+=2;
 589         if (st) c->status[1].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
 590         if (st) src+=2;
 591         c->status[0].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
 592         src+=2;
 593         if (st) c->status[1].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));
 594         if (st) src+=2;
 595
 596         *samples++ = c->status[0].sample1;
 597         if (st) *samples++ = c->status[1].sample1;
 598         *samples++ = c->status[0].sample2;
 599         if (st) *samples++ = c->status[1].sample2;
 600         for(;n>0;n--) {
 601             *samples++ = adpcm_ms_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);
 602             *samples++ = adpcm_ms_expand_nibble(&c->status[st], src[0] & 0x0F);
 603             src ++;
 604         }
 605         break;
 606     case CODEC_ID_ADPCM_IMA_DK4:
 607         if (avctx->block_align != 0 && buf_size > avctx->block_align)
 608             buf_size = avctx->block_align;
 609
 610         c->status[0].predictor = (src[0] | (src[1] << 8));
 611         c->status[0].step_index = src[2];
 612         src += 4;
 613         if(c->status[0].predictor & 0x8000)
 614             c->status[0].predictor -= 0x10000;
 615         *samples++ = c->status[0].predictor;
 616         if (st) {
 617             c->status[1].predictor = (src[0] | (src[1] << 8));
 618             c->status[1].step_index = src[2];
 619             src += 4;
 620             if(c->status[1].predictor & 0x8000)
 621                 c->status[1].predictor -= 0x10000;
 622             *samples++ = c->status[1].predictor;
 623         }
 624         while (src < buf + buf_size) {
 625
 626             /* take care of the top nibble (always left or mono channel) */
 627             *samples++ = adpcm_ima_expand_nibble(&c->status[0],
 628                 (src[0] >> 4) & 0x0F, 3);
 629
 630             /* take care of the bottom nibble, which is right sample for
 631              * stereo, or another mono sample */
 632             if (st)
 633                 *samples++ = adpcm_ima_expand_nibble(&c->status[1],
 634                     src[0] & 0x0F, 3);
 635             else
 636                 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
 637                     src[0] & 0x0F, 3);
 638
 639             src++;
 640         }
 641         break;
 642     case CODEC_ID_ADPCM_IMA_DK3:
 643         if (avctx->block_align != 0 && buf_size > avctx->block_align)
 644             buf_size = avctx->block_align;
 645
 646         c->status[0].predictor = (src[10] | (src[11] << 8));
 647         c->status[1].predictor = (src[12] | (src[13] << 8));
 648         c->status[0].step_index = src[14];
 649         c->status[1].step_index = src[15];
 650         /* sign extend the predictors */
 651         if(c->status[0].predictor & 0x8000)
 652             c->status[0].predictor -= 0x10000;
 653         if(c->status[1].predictor & 0x8000)
 654             c->status[1].predictor -= 0x10000;
 655         src += 16;
 656         diff_channel = c->status[1].predictor;
 657
 658         /* the DK3_GET_NEXT_NIBBLE macro issues the break statement when
 659          * the buffer is consumed */
 660         while (1) {
 661
 662             /* for this algorithm, c->status[0] is the sum channel and
 663              * c->status[1] is the diff channel */
 664
 665             /* process the first predictor of the sum channel */
 666             DK3_GET_NEXT_NIBBLE();
 667             adpcm_ima_expand_nibble(&c->status[0], nibble, 3);
 668
 669             /* process the diff channel predictor */
 670             DK3_GET_NEXT_NIBBLE();
 671             adpcm_ima_expand_nibble(&c->status[1], nibble, 3);
 672
 673             /* process the first pair of stereo PCM samples */
 674             diff_channel = (diff_channel + c->status[1].predictor) / 2;
 675             *samples++ = c->status[0].predictor + c->status[1].predictor;
 676             *samples++ = c->status[0].predictor - c->status[1].predictor;
 677
 678             /* process the second predictor of the sum channel */
 679             DK3_GET_NEXT_NIBBLE();
 680             adpcm_ima_expand_nibble(&c->status[0], nibble, 3);
 681
 682             /* process the second pair of stereo PCM samples */
 683             diff_channel = (diff_channel + c->status[1].predictor) / 2;
 684             *samples++ = c->status[0].predictor + c->status[1].predictor;
 685             *samples++ = c->status[0].predictor - c->status[1].predictor;
 686         }
 687         break;
 688     case CODEC_ID_ADPCM_IMA_WS:
 689         /* no per-block initialization; just start decoding the data */
 690         while (src < buf + buf_size) {
 691
 692             if (st) {
 693                 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
 694                     (src[0] >> 4) & 0x0F, 3);
 695                 *samples++ = adpcm_ima_expand_nibble(&c->status[1],
 696                     src[0] & 0x0F, 3);
 697             } else {
 698                 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
 699                     (src[0] >> 4) & 0x0F, 3);
 700                 *samples++ = adpcm_ima_expand_nibble(&c->status[0],
 701                     src[0] & 0x0F, 3);
 702             }
 703
 704             src++;
 705         }
 706         break;
 707     case CODEC_ID_ADPCM_XA:
 708         c->status[0].sample1 = c->status[0].sample2 =
 709         c->status[1].sample1 = c->status[1].sample2 = 0;
 710         while (buf_size >= 128) {
 711             xa_decode(samples, src, &c->status[0], &c->status[1],
 712                 avctx->channels);
 713             src += 128;
 714             samples += 28 * 8;
 715             buf_size -= 128;
 716         }
 717         break;
 718     default:
 719         *data_size = 0;
 720         return -1;
 721     }
 722     *data_size = (uint8_t *)samples - (uint8_t *)data;
 723     return src - buf;
 724 }
 725
 726
 727
 728 #ifdef CONFIG_ENCODERS
 729 #define ADPCM_ENCODER(id,name)                  \
 730 AVCodec name ## _encoder = {                    \
 731     #name,                                      \
 732     CODEC_TYPE_AUDIO,                           \
 733     id,                                         \
 734     sizeof(ADPCMContext),                       \
 735     adpcm_encode_init,                          \
 736     adpcm_encode_frame,                         \
 737     adpcm_encode_close,                         \
 738     NULL,                                       \
 739 };
 740 #else
 741 #define ADPCM_ENCODER(id,name)
 742 #endif
 743
 744 #ifdef CONFIG_DECODERS
 745 #define ADPCM_DECODER(id,name)                  \
 746 AVCodec name ## _decoder = {                    \
 747     #name,                                      \
 748     CODEC_TYPE_AUDIO,                           \
 749     id,                                         \
 750     sizeof(ADPCMContext),                       \
 751     adpcm_decode_init,                          \
 752     NULL,                                       \
 753     NULL,                                       \
 754     adpcm_decode_frame,                         \
 755 };
 756 #else
 757 #define ADPCM_DECODER(id,name)
 758 #endif
 759
 760 #define ADPCM_CODEC(id, name)                   \
 761 ADPCM_ENCODER(id,name) ADPCM_DECODER(id,name)
 762
 763 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);
 764 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);
 765 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);
 766 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);
 767 ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WS, adpcm_ima_ws);
 768 ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);
 769 ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);
 770 ADPCM_CODEC(CODEC_ID_ADPCM_XA, adpcm_xa);
 771 ADPCM_CODEC(CODEC_ID_ADPCM_ADX, adpcm_adx);
 772
 773 #undef ADPCM_CODEC