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FFmpeg/libavcodec/adpcm.c

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  1. /*

  2.  * ADPCM codecs

  3.  * Copyright (c) 2001-2003 The ffmpeg Project

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

  8.  * modify it under the terms of the GNU Lesser General Public

  9.  * License as published by the Free Software Foundation; either

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  15.  * Lesser General Public License for more details.

  16.  *

  17.  * You should have received a copy of the GNU Lesser General Public

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. #include "avcodec.h"

  22. #include "bitstream.h"

  23. 

  24. /**

  25.  * @file adpcm.c

  26.  * ADPCM codecs.

  27.  * First version by Francois Revol (revol@free.fr)

  28.  * Fringe ADPCM codecs (e.g., DK3, DK4, Westwood)

  29.  *   by Mike Melanson (melanson@pcisys.net)

  30.  * CD-ROM XA ADPCM codec by BERO

  31.  * EA ADPCM decoder by Robin Kay (komadori@myrealbox.com)

  32.  *

  33.  * Features and limitations:

  34.  *

  35.  * Reference documents:

  36.  * http://www.pcisys.net/~melanson/codecs/simpleaudio.html

  37.  * http://www.geocities.com/SiliconValley/8682/aud3.txt

  38.  * http://openquicktime.sourceforge.net/plugins.htm

  39.  * XAnim sources (xa_codec.c) http://www.rasnaimaging.com/people/lapus/download.html

  40.  * http://www.cs.ucla.edu/~leec/mediabench/applications.html

  41.  * SoX source code http://home.sprynet.com/~cbagwell/sox.html

  42.  *

  43.  * CD-ROM XA:

  44.  * http://ku-www.ss.titech.ac.jp/~yatsushi/xaadpcm.html

  45.  * vagpack & depack http://homepages.compuserve.de/bITmASTER32/psx-index.html

  46.  * readstr http://www.geocities.co.jp/Playtown/2004/

  47.  */

  48. 

  49. #define BLKSIZE 1024

  50. 

  51. #define CLAMP_TO_SHORT(value) \

  52. if (value > 32767) \

  53.     value = 32767; \

  54. else if (value < -32768) \

  55.     value = -32768; \

  56. 

  57. /* step_table[] and index_table[] are from the ADPCM reference source */

  58. /* This is the index table: */

  59. static const int index_table[16] = {

  60.     -1, -1, -1, -1, 2, 4, 6, 8,

  61.     -1, -1, -1, -1, 2, 4, 6, 8,

  62. };

  63. 

  64. /**

  65.  * This is the step table. Note that many programs use slight deviations from

  66.  * this table, but such deviations are negligible:

  67.  */

  68. static const int step_table[89] = {

  69.     7, 8, 9, 10, 11, 12, 13, 14, 16, 17,

  70.     19, 21, 23, 25, 28, 31, 34, 37, 41, 45,

  71.     50, 55, 60, 66, 73, 80, 88, 97, 107, 118,

  72.     130, 143, 157, 173, 190, 209, 230, 253, 279, 307,

  73.     337, 371, 408, 449, 494, 544, 598, 658, 724, 796,

  74.     876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,

  75.     2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,

  76.     5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,

  77.     15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767

  78. };

  79. 

  80. /* These are for MS-ADPCM */

  81. /* AdaptationTable[], AdaptCoeff1[], and AdaptCoeff2[] are from libsndfile */

  82. static const int AdaptationTable[] = {

  83.         230, 230, 230, 230, 307, 409, 512, 614,

  84.         768, 614, 512, 409, 307, 230, 230, 230

  85. };

  86. 

  87. static const int AdaptCoeff1[] = {

  88.         256, 512, 0, 192, 240, 460, 392

  89. };

  90. 

  91. static const int AdaptCoeff2[] = {

  92.         0, -256, 0, 64, 0, -208, -232

  93. };

  94. 

  95. /* These are for CD-ROM XA ADPCM */

  96. static const int xa_adpcm_table[5][2] = {

  97.    {   0,   0 },

  98.    {  60,   0 },

  99.    { 115, -52 },

  100.    {  98, -55 },

  101.    { 122, -60 }

  102. };

  103. 

  104. static const int ea_adpcm_table[] = {

  105.     0, 240, 460, 392, 0, 0, -208, -220, 0, 1,

  106.     3, 4, 7, 8, 10, 11, 0, -1, -3, -4

  107. };

  108. 

  109. static const int ct_adpcm_table[8] = {

  110.     0x00E6, 0x00E6, 0x00E6, 0x00E6,

  111.     0x0133, 0x0199, 0x0200, 0x0266

  112. };

  113. 

  114. // padded to zero where table size is less then 16

  115. static const int swf_index_tables[4][16] = {

  116.     /*2*/ { -1, 2 },

  117.     /*3*/ { -1, -1, 2, 4 },

  118.     /*4*/ { -1, -1, -1, -1, 2, 4, 6, 8 },

  119.     /*5*/ { -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 4, 6, 8, 10, 13, 16 }

  120. };

  121. 

  122. static const int yamaha_indexscale[] = {

  123.     230, 230, 230, 230, 307, 409, 512, 614,

  124.     230, 230, 230, 230, 307, 409, 512, 614

  125. };

  126. 

  127. static const int yamaha_difflookup[] = {

  128.     1, 3, 5, 7, 9, 11, 13, 15,

  129.     -1, -3, -5, -7, -9, -11, -13, -15

  130. };

  131. 

  132. /* end of tables */

  133. 

  134. typedef struct ADPCMChannelStatus {

  135.     int predictor;

  136.     short int step_index;

  137.     int step;

  138.     /* for encoding */

  139.     int prev_sample;

  140. 

  141.     /* MS version */

  142.     short sample1;

  143.     short sample2;

  144.     int coeff1;

  145.     int coeff2;

  146.     int idelta;

  147. } ADPCMChannelStatus;

  148. 

  149. typedef struct ADPCMContext {

  150.     int channel; /* for stereo MOVs, decode left, then decode right, then tell it's decoded */

  151.     ADPCMChannelStatus status[2];

  152.     short sample_buffer[32]; /* hold left samples while waiting for right samples */

  153. 

  154.     /* SWF only */

  155.     int nb_bits;

  156.     int nb_samples;

  157. } ADPCMContext;

  158. 

  159. /* XXX: implement encoding */

  160. 

  161. #ifdef CONFIG_ENCODERS

  162. static int adpcm_encode_init(AVCodecContext *avctx)

  163. {

  164.     if (avctx->channels > 2)

  165.         return -1; /* only stereo or mono =) */

  166.     switch(avctx->codec->id) {

  167.     case CODEC_ID_ADPCM_IMA_QT:

  168.         av_log(avctx, AV_LOG_ERROR, "ADPCM: codec adpcm_ima_qt unsupported for encoding !\n");

  169.         avctx->frame_size = 64; /* XXX: can multiple of avctx->channels * 64 (left and right blocks are interleaved) */

  170.         return -1;

  171.         break;

  172.     case CODEC_ID_ADPCM_IMA_WAV:

  173.         avctx->frame_size = (BLKSIZE - 4 * avctx->channels) * 8 / (4 * avctx->channels) + 1; /* each 16 bits sample gives one nibble */

  174.                                                              /* and we have 4 bytes per channel overhead */

  175.         avctx->block_align = BLKSIZE;

  176.         /* seems frame_size isn't taken into account... have to buffer the samples :-( */

  177.         break;

  178.     case CODEC_ID_ADPCM_MS:

  179.         avctx->frame_size = (BLKSIZE - 7 * avctx->channels) * 2 / avctx->channels + 2; /* each 16 bits sample gives one nibble */

  180.                                                              /* and we have 7 bytes per channel overhead */

  181.         avctx->block_align = BLKSIZE;

  182.         break;

  183.     case CODEC_ID_ADPCM_YAMAHA:

  184.         avctx->frame_size = BLKSIZE * avctx->channels;

  185.         avctx->block_align = BLKSIZE;

  186.         break;

  187.     default:

  188.         return -1;

  189.         break;

  190.     }

  191. 

  192.     avctx->coded_frame= avcodec_alloc_frame();

  193.     avctx->coded_frame->key_frame= 1;

  194. 

  195.     return 0;

  196. }

  197. 

  198. static int adpcm_encode_close(AVCodecContext *avctx)

  199. {

  200.     av_freep(&avctx->coded_frame);

  201. 

  202.     return 0;

  203. }

  204. 

  205. 

  206. static inline unsigned char adpcm_ima_compress_sample(ADPCMChannelStatus *c, short sample)

  207. {

  208.     int delta = sample - c->prev_sample;

  209.     int nibble = FFMIN(7, abs(delta)*4/step_table[c->step_index]) + (delta<0)*8;

  210.     c->prev_sample = c->prev_sample + ((step_table[c->step_index] * yamaha_difflookup[nibble]) / 8);

  211.     CLAMP_TO_SHORT(c->prev_sample);

  212.     c->step_index = clip(c->step_index + index_table[nibble], 0, 88);

  213.     return nibble;

  214. }

  215. 

  216. static inline unsigned char adpcm_ms_compress_sample(ADPCMChannelStatus *c, short sample)

  217. {

  218.     int predictor, nibble, bias;

  219. 

  220.     predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256;

  221. 

  222.     nibble= sample - predictor;

  223.     if(nibble>=0) bias= c->idelta/2;

  224.     else          bias=-c->idelta/2;

  225. 

  226.     nibble= (nibble + bias) / c->idelta;

  227.     nibble= clip(nibble, -8, 7)&0x0F;

  228. 

  229.     predictor += (signed)((nibble & 0x08)?(nibble - 0x10):(nibble)) * c->idelta;

  230.     CLAMP_TO_SHORT(predictor);

  231. 

  232.     c->sample2 = c->sample1;

  233.     c->sample1 = predictor;

  234. 

  235.     c->idelta = (AdaptationTable[(int)nibble] * c->idelta) >> 8;

  236.     if (c->idelta < 16) c->idelta = 16;

  237. 

  238.     return nibble;

  239. }

  240. 

  241. static inline unsigned char adpcm_yamaha_compress_sample(ADPCMChannelStatus *c, short sample)

  242. {

  243.     int nibble, delta;

  244. 

  245.     if(!c->step) {

  246.         c->predictor = 0;

  247.         c->step = 127;

  248.     }

  249. 

  250.     delta = sample - c->predictor;

  251. 

  252.     nibble = FFMIN(7, abs(delta)*4/c->step) + (delta<0)*8;

  253. 

  254.     c->predictor = c->predictor + ((c->step * yamaha_difflookup[nibble]) / 8);

  255.     CLAMP_TO_SHORT(c->predictor);

  256.     c->step = (c->step * yamaha_indexscale[nibble]) >> 8;

  257.     c->step = clip(c->step, 127, 24567);

  258. 

  259.     return nibble;

  260. }

  261. 

  262. typedef struct TrellisPath {

  263.     int nibble;

  264.     int prev;

  265. } TrellisPath;

  266. 

  267. typedef struct TrellisNode {

  268.     uint32_t ssd;

  269.     int path;

  270.     int sample1;

  271.     int sample2;

  272.     int step;

  273. } TrellisNode;

  274. 

  275. static void adpcm_compress_trellis(AVCodecContext *avctx, const short *samples,

  276.                                    uint8_t *dst, ADPCMChannelStatus *c, int n)

  277. {

  278. #define FREEZE_INTERVAL 128

  279.     //FIXME 6% faster if frontier is a compile-time constant

  280.     const int frontier = 1 << avctx->trellis;

  281.     const int stride = avctx->channels;

  282.     const int version = avctx->codec->id;

  283.     const int max_paths = frontier*FREEZE_INTERVAL;

  284.     TrellisPath paths[max_paths], *p;

  285.     TrellisNode node_buf[2][frontier];

  286.     TrellisNode *nodep_buf[2][frontier];

  287.     TrellisNode **nodes = nodep_buf[0]; // nodes[] is always sorted by .ssd

  288.     TrellisNode **nodes_next = nodep_buf[1];

  289.     int pathn = 0, froze = -1, i, j, k;

  290. 

  291.     assert(!(max_paths&(max_paths-1)));

  292. 

  293.     memset(nodep_buf, 0, sizeof(nodep_buf));

  294.     nodes[0] = &node_buf[1][0];

  295.     nodes[0]->ssd = 0;

  296.     nodes[0]->path = 0;

  297.     nodes[0]->step = c->step_index;

  298.     nodes[0]->sample1 = c->sample1;

  299.     nodes[0]->sample2 = c->sample2;

  300.     if(version == CODEC_ID_ADPCM_IMA_WAV)

  301.         nodes[0]->sample1 = c->prev_sample;

  302.     if(version == CODEC_ID_ADPCM_MS)

  303.         nodes[0]->step = c->idelta;

  304.     if(version == CODEC_ID_ADPCM_YAMAHA) {

  305.         if(c->step == 0) {

  306.             nodes[0]->step = 127;

  307.             nodes[0]->sample1 = 0;

  308.         } else {

  309.             nodes[0]->step = c->step;

  310.             nodes[0]->sample1 = c->predictor;

  311.         }

  312.     }

  313. 

  314.     for(i=0; i<n; i++) {

  315.         TrellisNode *t = node_buf[i&1];

  316.         TrellisNode **u;

  317.         int sample = samples[i*stride];

  318.         memset(nodes_next, 0, frontier*sizeof(TrellisNode*));

  319.         for(j=0; j<frontier && nodes[j]; j++) {

  320.             // higher j have higher ssd already, so they're unlikely to use 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 == CODEC_ID_ADPCM_MS) {

  325.                 const int predictor = ((nodes[j]->sample1 * c->coeff1) + (nodes[j]->sample2 * c->coeff2)) / 256;

  326.                 const int div = (sample - predictor) / step;

  327.                 const int nmin = clip(div-range, -8, 6);

  328.                 const int nmax = clip(div+range, -7, 7);

  329.                 for(nidx=nmin; nidx<=nmax; nidx++) {

  330.                     const int nibble = nidx & 0xf;

  331.                     int dec_sample = predictor + nidx * step;

  332. #define STORE_NODE(NAME, STEP_INDEX)\

  333.                     int d;\

  334.                     uint32_t ssd;\

  335.                     CLAMP_TO_SHORT(dec_sample);\

  336.                     d = sample - dec_sample;\

  337.                     ssd = nodes[j]->ssd + d*d;\

  338.                     if(nodes_next[frontier-1] && ssd >= nodes_next[frontier-1]->ssd)\

  339.                         continue;\

  340.                     /* Collapse any two states with the same previous sample value. \

  341.                      * One could also distinguish states by step and by 2nd to last

  342.                      * sample, but the effects of that are negligible. */\

  343.                     for(k=0; k<frontier && nodes_next[k]; k++) {\

  344.                         if(dec_sample == nodes_next[k]->sample1) {\

  345.                             assert(ssd >= nodes_next[k]->ssd);\

  346.                             goto next_##NAME;\

  347.                         }\

  348.                     }\

  349.                     for(k=0; k<frontier; k++) {\

  350.                         if(!nodes_next[k] || ssd < nodes_next[k]->ssd) {\

  351.                             TrellisNode *u = nodes_next[frontier-1];\

  352.                             if(!u) {\

  353.                                 assert(pathn < max_paths);\

  354.                                 u = t++;\

  355.                                 u->path = pathn++;\

  356.                             }\

  357.                             u->ssd = ssd;\

  358.                             u->step = STEP_INDEX;\

  359.                             u->sample2 = nodes[j]->sample1;\

  360.                             u->sample1 = dec_sample;\

  361.                             paths[u->path].nibble = nibble;\

  362.                             paths[u->path].prev = nodes[j]->path;\

  363.                             memmove(&nodes_next[k+1], &nodes_next[k], (frontier-k-1)*sizeof(TrellisNode*));\

  364.                             nodes_next[k] = u;\

  365.                             break;\

  366.                         }\

  367.                     }\

  368.                     next_##NAME:;

  369.                     STORE_NODE(ms, FFMAX(16, (AdaptationTable[nibble] * step) >> 8));

  370.                 }

  371.             } else if(version == CODEC_ID_ADPCM_IMA_WAV) {

  372. #define LOOP_NODES(NAME, STEP_TABLE, STEP_INDEX)\

  373.                 const int predictor = nodes[j]->sample1;\

  374.                 const int div = (sample - predictor) * 4 / STEP_TABLE;\

  375.                 int nmin = clip(div-range, -7, 6);\

  376.                 int nmax = clip(div+range, -6, 7);\

  377.                 if(nmin<=0) nmin--; /* distinguish -0 from +0 */\

  378.                 if(nmax<0) nmax--;\

  379.                 for(nidx=nmin; nidx<=nmax; nidx++) {\

  380.                     const int nibble = nidx<0 ? 7-nidx : nidx;\

  381.                     int dec_sample = predictor + (STEP_TABLE * yamaha_difflookup[nibble]) / 8;\

  382.                     STORE_NODE(NAME, STEP_INDEX);\

  383.                 }

  384.                 LOOP_NODES(ima, step_table[step], clip(step + index_table[nibble], 0, 88));

  385.             } else { //CODEC_ID_ADPCM_YAMAHA

  386.                 LOOP_NODES(yamaha, step, clip((step * yamaha_indexscale[nibble]) >> 8, 127, 24567));

  387. #undef LOOP_NODES

  388. #undef STORE_NODE

  389.             }

  390.         }

  391. 

  392.         u = nodes;

  393.         nodes = nodes_next;

  394.         nodes_next = u;

  395. 

  396.         // prevent overflow

  397.         if(nodes[0]->ssd > (1<<28)) {

  398.             for(j=1; j<frontier && nodes[j]; j++)

  399.                 nodes[j]->ssd -= nodes[0]->ssd;

  400.             nodes[0]->ssd = 0;

  401.         }

  402. 

  403.         // merge old paths to save memory

  404.         if(i == froze + FREEZE_INTERVAL) {

  405.             p = &paths[nodes[0]->path];

  406.             for(k=i; k>froze; k--) {

  407.                 dst[k] = p->nibble;

  408.                 p = &paths[p->prev];

  409.             }

  410.             froze = i;

  411.             pathn = 0;

  412.             // other nodes might use paths that don't coincide with the frozen one.

  413.             // checking which nodes do so is too slow, so just kill them all.

  414.             // this also slightly improves quality, but I don't know why.

  415.             memset(nodes+1, 0, (frontier-1)*sizeof(TrellisNode*));

  416.         }

  417.     }

  418. 

  419.     p = &paths[nodes[0]->path];

  420.     for(i=n-1; i>froze; i--) {

  421.         dst[i] = p->nibble;

  422.         p = &paths[p->prev];

  423.     }

  424. 

  425.     c->predictor = nodes[0]->sample1;

  426.     c->sample1 = nodes[0]->sample1;

  427.     c->sample2 = nodes[0]->sample2;

  428.     c->step_index = nodes[0]->step;

  429.     c->step = nodes[0]->step;

  430.     c->idelta = nodes[0]->step;

  431. }

  432. 

  433. static int adpcm_encode_frame(AVCodecContext *avctx,

  434.                             unsigned char *frame, int buf_size, void *data)

  435. {

  436.     int n, i, st;

  437.     short *samples;

  438.     unsigned char *dst;

  439.     ADPCMContext *c = avctx->priv_data;

  440. 

  441.     dst = frame;

  442.     samples = (short *)data;

  443.     st= avctx->channels == 2;

  444. /*    n = (BLKSIZE - 4 * avctx->channels) / (2 * 8 * avctx->channels); */

  445. 

  446.     switch(avctx->codec->id) {

  447.     case CODEC_ID_ADPCM_IMA_QT: /* XXX: can't test until we get .mov writer */

  448.         break;

  449.     case CODEC_ID_ADPCM_IMA_WAV:

  450.         n = avctx->frame_size / 8;

  451.             c->status[0].prev_sample = (signed short)samples[0]; /* XXX */

  452. /*            c->status[0].step_index = 0; *//* XXX: not sure how to init the state machine */

  453.             *dst++ = (c->status[0].prev_sample) & 0xFF; /* little endian */

  454.             *dst++ = (c->status[0].prev_sample >> 8) & 0xFF;

  455.             *dst++ = (unsigned char)c->status[0].step_index;

  456.             *dst++ = 0; /* unknown */

  457.             samples++;

  458.             if (avctx->channels == 2) {

  459.                 c->status[1].prev_sample = (signed short)samples[1];

  460. /*                c->status[1].step_index = 0; */

  461.                 *dst++ = (c->status[1].prev_sample) & 0xFF;

  462.                 *dst++ = (c->status[1].prev_sample >> 8) & 0xFF;

  463.                 *dst++ = (unsigned char)c->status[1].step_index;

  464.                 *dst++ = 0;

  465.                 samples++;

  466.             }

  467. 

  468.             /* stereo: 4 bytes (8 samples) for left, 4 bytes for right, 4 bytes left, ... */

  469.             if(avctx->trellis > 0) {

  470.                 uint8_t buf[2][n*8];

  471.                 adpcm_compress_trellis(avctx, samples, buf[0], &c->status[0], n*8);

  472.                 if(avctx->channels == 2)

  473.                     adpcm_compress_trellis(avctx, samples+1, buf[1], &c->status[1], n*8);

  474.                 for(i=0; i<n; i++) {

  475.                     *dst++ = buf[0][8*i+0] | (buf[0][8*i+1] << 4);

  476.                     *dst++ = buf[0][8*i+2] | (buf[0][8*i+3] << 4);

  477.                     *dst++ = buf[0][8*i+4] | (buf[0][8*i+5] << 4);

  478.                     *dst++ = buf[0][8*i+6] | (buf[0][8*i+7] << 4);

  479.                     if (avctx->channels == 2) {

  480.                         *dst++ = buf[1][8*i+0] | (buf[1][8*i+1] << 4);

  481.                         *dst++ = buf[1][8*i+2] | (buf[1][8*i+3] << 4);

  482.                         *dst++ = buf[1][8*i+4] | (buf[1][8*i+5] << 4);

  483.                         *dst++ = buf[1][8*i+6] | (buf[1][8*i+7] << 4);

  484.                     }

  485.                 }

  486.             } else

  487.             for (; n>0; n--) {

  488.                 *dst = adpcm_ima_compress_sample(&c->status[0], samples[0]) & 0x0F;

  489.                 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels]) << 4) & 0xF0;

  490.                 dst++;

  491.                 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 2]) & 0x0F;

  492.                 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 3]) << 4) & 0xF0;

  493.                 dst++;

  494.                 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 4]) & 0x0F;

  495.                 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 5]) << 4) & 0xF0;

  496.                 dst++;

  497.                 *dst = adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 6]) & 0x0F;

  498.                 *dst |= (adpcm_ima_compress_sample(&c->status[0], samples[avctx->channels * 7]) << 4) & 0xF0;

  499.                 dst++;

  500.                 /* right channel */

  501.                 if (avctx->channels == 2) {

  502.                     *dst = adpcm_ima_compress_sample(&c->status[1], samples[1]);

  503.                     *dst |= adpcm_ima_compress_sample(&c->status[1], samples[3]) << 4;

  504.                     dst++;

  505.                     *dst = adpcm_ima_compress_sample(&c->status[1], samples[5]);

  506.                     *dst |= adpcm_ima_compress_sample(&c->status[1], samples[7]) << 4;

  507.                     dst++;

  508.                     *dst = adpcm_ima_compress_sample(&c->status[1], samples[9]);

  509.                     *dst |= adpcm_ima_compress_sample(&c->status[1], samples[11]) << 4;

  510.                     dst++;

  511.                     *dst = adpcm_ima_compress_sample(&c->status[1], samples[13]);

  512.                     *dst |= adpcm_ima_compress_sample(&c->status[1], samples[15]) << 4;

  513.                     dst++;

  514.                 }

  515.                 samples += 8 * avctx->channels;

  516.             }

  517.         break;

  518.     case CODEC_ID_ADPCM_MS:

  519.         for(i=0; i<avctx->channels; i++){

  520.             int predictor=0;

  521. 

  522.             *dst++ = predictor;

  523.             c->status[i].coeff1 = AdaptCoeff1[predictor];

  524.             c->status[i].coeff2 = AdaptCoeff2[predictor];

  525.         }

  526.         for(i=0; i<avctx->channels; i++){

  527.             if (c->status[i].idelta < 16)

  528.                 c->status[i].idelta = 16;

  529. 

  530.             *dst++ = c->status[i].idelta & 0xFF;

  531.             *dst++ = c->status[i].idelta >> 8;

  532.         }

  533.         for(i=0; i<avctx->channels; i++){

  534.             c->status[i].sample1= *samples++;

  535. 

  536.             *dst++ = c->status[i].sample1 & 0xFF;

  537.             *dst++ = c->status[i].sample1 >> 8;

  538.         }

  539.         for(i=0; i<avctx->channels; i++){

  540.             c->status[i].sample2= *samples++;

  541. 

  542.             *dst++ = c->status[i].sample2 & 0xFF;

  543.             *dst++ = c->status[i].sample2 >> 8;

  544.         }

  545. 

  546.         if(avctx->trellis > 0) {

  547.             int n = avctx->block_align - 7*avctx->channels;

  548.             uint8_t buf[2][n];

  549.             if(avctx->channels == 1) {

  550.                 n *= 2;

  551.                 adpcm_compress_trellis(avctx, samples, buf[0], &c->status[0], n);

  552.                 for(i=0; i<n; i+=2)

  553.                     *dst++ = (buf[0][i] << 4) | buf[0][i+1];

  554.             } else {

  555.                 adpcm_compress_trellis(avctx, samples, buf[0], &c->status[0], n);

  556.                 adpcm_compress_trellis(avctx, samples+1, buf[1], &c->status[1], n);

  557.                 for(i=0; i<n; i++)

  558.                     *dst++ = (buf[0][i] << 4) | buf[1][i];

  559.             }

  560.         } else

  561.         for(i=7*avctx->channels; i<avctx->block_align; i++) {

  562.             int nibble;

  563.             nibble = adpcm_ms_compress_sample(&c->status[ 0], *samples++)<<4;

  564.             nibble|= adpcm_ms_compress_sample(&c->status[st], *samples++);

  565.             *dst++ = nibble;

  566.         }

  567.         break;

  568.     case CODEC_ID_ADPCM_YAMAHA:

  569.         n = avctx->frame_size / 2;

  570.         if(avctx->trellis > 0) {

  571.             uint8_t buf[2][n*2];

  572.             n *= 2;

  573.             if(avctx->channels == 1) {

  574.                 adpcm_compress_trellis(avctx, samples, buf[0], &c->status[0], n);

  575.                 for(i=0; i<n; i+=2)

  576.                     *dst++ = buf[0][i] | (buf[0][i+1] << 4);

  577.             } else {

  578.                 adpcm_compress_trellis(avctx, samples, buf[0], &c->status[0], n);

  579.                 adpcm_compress_trellis(avctx, samples+1, buf[1], &c->status[1], n);

  580.                 for(i=0; i<n; i++)

  581.                     *dst++ = buf[0][i] | (buf[1][i] << 4);

  582.             }

  583.         } else

  584.         for (; n>0; n--) {

  585.             for(i = 0; i < avctx->channels; i++) {

  586.                 int nibble;

  587.                 nibble  = adpcm_yamaha_compress_sample(&c->status[i], samples[i]);

  588.                 nibble |= adpcm_yamaha_compress_sample(&c->status[i], samples[i+avctx->channels]) << 4;

  589.                 *dst++ = nibble;

  590.             }

  591.             samples += 2 * avctx->channels;

  592.         }

  593.         break;

  594.     default:

  595.         return -1;

  596.     }

  597.     return dst - frame;

  598. }

  599. #endif //CONFIG_ENCODERS

  600. 

  601. static int adpcm_decode_init(AVCodecContext * avctx)

  602. {

  603.     ADPCMContext *c = avctx->priv_data;

  604. 

  605.     c->channel = 0;

  606.     c->status[0].predictor = c->status[1].predictor = 0;

  607.     c->status[0].step_index = c->status[1].step_index = 0;

  608.     c->status[0].step = c->status[1].step = 0;

  609. 

  610.     switch(avctx->codec->id) {

  611.     case CODEC_ID_ADPCM_CT:

  612.         c->status[0].step = c->status[1].step = 511;

  613.         break;

  614.     default:

  615.         break;

  616.     }

  617.     return 0;

  618. }

  619. 

  620. static inline short adpcm_ima_expand_nibble(ADPCMChannelStatus *c, char nibble, int shift)

  621. {

  622.     int step_index;

  623.     int predictor;

  624.     int sign, delta, diff, step;

  625. 

  626.     step = step_table[c->step_index];

  627.     step_index = c->step_index + index_table[(unsigned)nibble];

  628.     if (step_index < 0) step_index = 0;

  629.     else if (step_index > 88) step_index = 88;

  630. 

  631.     sign = nibble & 8;

  632.     delta = nibble & 7;

  633.     /* perform direct multiplication instead of series of jumps proposed by

  634.      * the reference ADPCM implementation since modern CPUs can do the mults

  635.      * quickly enough */

  636.     diff = ((2 * delta + 1) * step) >> shift;

  637.     predictor = c->predictor;

  638.     if (sign) predictor -= diff;

  639.     else predictor += diff;

  640. 

  641.     CLAMP_TO_SHORT(predictor);

  642.     c->predictor = predictor;

  643.     c->step_index = step_index;

  644. 

  645.     return (short)predictor;

  646. }

  647. 

  648. static inline short adpcm_ms_expand_nibble(ADPCMChannelStatus *c, char nibble)

  649. {

  650.     int predictor;

  651. 

  652.     predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256;

  653.     predictor += (signed)((nibble & 0x08)?(nibble - 0x10):(nibble)) * c->idelta;

  654.     CLAMP_TO_SHORT(predictor);

  655. 

  656.     c->sample2 = c->sample1;

  657.     c->sample1 = predictor;

  658.     c->idelta = (AdaptationTable[(int)nibble] * c->idelta) >> 8;

  659.     if (c->idelta < 16) c->idelta = 16;

  660. 

  661.     return (short)predictor;

  662. }

  663. 

  664. static inline short adpcm_ct_expand_nibble(ADPCMChannelStatus *c, char nibble)

  665. {

  666.     int predictor;

  667.     int sign, delta, diff;

  668.     int new_step;

  669. 

  670.     sign = nibble & 8;

  671.     delta = nibble & 7;

  672.     /* perform direct multiplication instead of series of jumps proposed by

  673.      * the reference ADPCM implementation since modern CPUs can do the mults

  674.      * quickly enough */

  675.     diff = ((2 * delta + 1) * c->step) >> 3;

  676.     predictor = c->predictor;

  677.     /* predictor update is not so trivial: predictor is multiplied on 254/256 before updating */

  678.     if(sign)

  679.         predictor = ((predictor * 254) >> 8) - diff;

  680.     else

  681.             predictor = ((predictor * 254) >> 8) + diff;

  682.     /* calculate new step and clamp it to range 511..32767 */

  683.     new_step = (ct_adpcm_table[nibble & 7] * c->step) >> 8;

  684.     c->step = new_step;

  685.     if(c->step < 511)

  686.         c->step = 511;

  687.     if(c->step > 32767)

  688.         c->step = 32767;

  689. 

  690.     CLAMP_TO_SHORT(predictor);

  691.     c->predictor = predictor;

  692.     return (short)predictor;

  693. }

  694. 

  695. static inline short adpcm_sbpro_expand_nibble(ADPCMChannelStatus *c, char nibble, int size, int shift)

  696. {

  697.     int sign, delta, diff;

  698. 

  699.     sign = nibble & (1<<(size-1));

  700.     delta = nibble & ((1<<(size-1))-1);

  701.     diff = delta << (7 + c->step + shift);

  702. 

  703.     if (sign)

  704.         c->predictor -= diff;

  705.     else

  706.         c->predictor += diff;

  707. 

  708.     /* clamp result */

  709.     if (c->predictor > 16256)

  710.         c->predictor = 16256;

  711.     else if (c->predictor < -16384)

  712.         c->predictor = -16384;

  713. 

  714.     /* calculate new step */

  715.     if (delta >= (2*size - 3) && c->step < 3)

  716.         c->step++;

  717.     else if (delta == 0 && c->step > 0)

  718.         c->step--;

  719. 

  720.     return (short) c->predictor;

  721. }

  722. 

  723. static inline short adpcm_yamaha_expand_nibble(ADPCMChannelStatus *c, unsigned char nibble)

  724. {

  725.     if(!c->step) {

  726.         c->predictor = 0;

  727.         c->step = 127;

  728.     }

  729. 

  730.     c->predictor += (c->step * yamaha_difflookup[nibble]) / 8;

  731.     CLAMP_TO_SHORT(c->predictor);

  732.     c->step = (c->step * yamaha_indexscale[nibble]) >> 8;

  733.     c->step = clip(c->step, 127, 24567);

  734.     return c->predictor;

  735. }

  736. 

  737. static void xa_decode(short *out, const unsigned char *in,

  738.     ADPCMChannelStatus *left, ADPCMChannelStatus *right, int inc)

  739. {

  740.     int i, j;

  741.     int shift,filter,f0,f1;

  742.     int s_1,s_2;

  743.     int d,s,t;

  744. 

  745.     for(i=0;i<4;i++) {

  746. 

  747.         shift  = 12 - (in[4+i*2] & 15);

  748.         filter = in[4+i*2] >> 4;

  749.         f0 = xa_adpcm_table[filter][0];

  750.         f1 = xa_adpcm_table[filter][1];

  751. 

  752.         s_1 = left->sample1;

  753.         s_2 = left->sample2;

  754. 

  755.         for(j=0;j<28;j++) {

  756.             d = in[16+i+j*4];

  757. 

  758.             t = (signed char)(d<<4)>>4;

  759.             s = ( t<<shift ) + ((s_1*f0 + s_2*f1+32)>>6);

  760.             CLAMP_TO_SHORT(s);

  761.             *out = s;

  762.             out += inc;

  763.             s_2 = s_1;

  764.             s_1 = s;

  765.         }

  766. 

  767.         if (inc==2) { /* stereo */

  768.             left->sample1 = s_1;

  769.             left->sample2 = s_2;

  770.             s_1 = right->sample1;

  771.             s_2 = right->sample2;

  772.             out = out + 1 - 28*2;

  773.         }

  774. 

  775.         shift  = 12 - (in[5+i*2] & 15);

  776.         filter = in[5+i*2] >> 4;

  777. 

  778.         f0 = xa_adpcm_table[filter][0];

  779.         f1 = xa_adpcm_table[filter][1];

  780. 

  781.         for(j=0;j<28;j++) {

  782.             d = in[16+i+j*4];

  783. 

  784.             t = (signed char)d >> 4;

  785.             s = ( t<<shift ) + ((s_1*f0 + s_2*f1+32)>>6);

  786.             CLAMP_TO_SHORT(s);

  787.             *out = s;

  788.             out += inc;

  789.             s_2 = s_1;

  790.             s_1 = s;

  791.         }

  792. 

  793.         if (inc==2) { /* stereo */

  794.             right->sample1 = s_1;

  795.             right->sample2 = s_2;

  796.             out -= 1;

  797.         } else {

  798.             left->sample1 = s_1;

  799.             left->sample2 = s_2;

  800.         }

  801.     }

  802. }

  803. 

  804. 

  805. /* DK3 ADPCM support macro */

  806. #define DK3_GET_NEXT_NIBBLE() \

  807.     if (decode_top_nibble_next) \

  808.     { \

  809.         nibble = (last_byte >> 4) & 0x0F; \

  810.         decode_top_nibble_next = 0; \

  811.     } \

  812.     else \

  813.     { \

  814.         last_byte = *src++; \

  815.         if (src >= buf + buf_size) break; \

  816.         nibble = last_byte & 0x0F; \

  817.         decode_top_nibble_next = 1; \

  818.     }

  819. 

  820. static int adpcm_decode_frame(AVCodecContext *avctx,

  821.                             void *data, int *data_size,

  822.                             uint8_t *buf, int buf_size)

  823. {

  824.     ADPCMContext *c = avctx->priv_data;

  825.     ADPCMChannelStatus *cs;

  826.     int n, m, channel, i;

  827.     int block_predictor[2];

  828.     short *samples;

  829.     uint8_t *src;

  830.     int st; /* stereo */

  831. 

  832.     /* DK3 ADPCM accounting variables */

  833.     unsigned char last_byte = 0;

  834.     unsigned char nibble;

  835.     int decode_top_nibble_next = 0;

  836.     int diff_channel;

  837. 

  838.     /* EA ADPCM state variables */

  839.     uint32_t samples_in_chunk;

  840.     int32_t previous_left_sample, previous_right_sample;

  841.     int32_t current_left_sample, current_right_sample;

  842.     int32_t next_left_sample, next_right_sample;

  843.     int32_t coeff1l, coeff2l, coeff1r, coeff2r;

  844.     uint8_t shift_left, shift_right;

  845.     int count1, count2;

  846. 

  847.     if (!buf_size)

  848.         return 0;

  849. 

  850.     samples = data;

  851.     src = buf;

  852. 

  853.     st = avctx->channels == 2 ? 1 : 0;

  854. 

  855.     switch(avctx->codec->id) {

  856.     case CODEC_ID_ADPCM_IMA_QT:

  857.         n = (buf_size - 2);/* >> 2*avctx->channels;*/

  858.         channel = c->channel;

  859.         cs = &(c->status[channel]);

  860.         /* (pppppp) (piiiiiii) */

  861. 

  862.         /* Bits 15-7 are the _top_ 9 bits of the 16-bit initial predictor value */

  863.         cs->predictor = (*src++) << 8;

  864.         cs->predictor |= (*src & 0x80);

  865.         cs->predictor &= 0xFF80;

  866. 

  867.         /* sign extension */

  868.         if(cs->predictor & 0x8000)

  869.             cs->predictor -= 0x10000;

  870. 

  871.         CLAMP_TO_SHORT(cs->predictor);

  872. 

  873.         cs->step_index = (*src++) & 0x7F;

  874. 

  875.         if (cs->step_index > 88){

  876.             av_log(avctx, AV_LOG_ERROR, "ERROR: step_index = %i\n", cs->step_index);

  877.             cs->step_index = 88;

  878.         }

  879. 

  880.         cs->step = step_table[cs->step_index];

  881. 

  882.         if (st && channel)

  883.             samples++;

  884. 

  885.         for(m=32; n>0 && m>0; n--, m--) { /* in QuickTime, IMA is encoded by chuncks of 34 bytes (=64 samples) */

  886.             *samples = adpcm_ima_expand_nibble(cs, src[0] & 0x0F, 3);

  887.             samples += avctx->channels;

  888.             *samples = adpcm_ima_expand_nibble(cs, (src[0] >> 4) & 0x0F, 3);

  889.             samples += avctx->channels;

  890.             src ++;

  891.         }

  892. 

  893.         if(st) { /* handle stereo interlacing */

  894.             c->channel = (channel + 1) % 2; /* we get one packet for left, then one for right data */

  895.             if(channel == 1) { /* wait for the other packet before outputing anything */

  896.                 return src - buf;

  897.             }

  898.         }

  899.         break;

  900.     case CODEC_ID_ADPCM_IMA_WAV:

  901.         if (avctx->block_align != 0 && buf_size > avctx->block_align)

  902.             buf_size = avctx->block_align;

  903. 

  904. //        samples_per_block= (block_align-4*chanels)*8 / (bits_per_sample * chanels) + 1;

  905. 

  906.         for(i=0; i<avctx->channels; i++){

  907.             cs = &(c->status[i]);

  908.             cs->predictor = (int16_t)(src[0] + (src[1]<<8));

  909.             src+=2;

  910. 

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

  912. 

  913.             cs->step_index = *src++;

  914.             if (cs->step_index > 88){

  915.                 av_log(avctx, AV_LOG_ERROR, "ERROR: step_index = %i\n", cs->step_index);

  916.                 cs->step_index = 88;

  917.             }

  918.             if (*src++) av_log(avctx, AV_LOG_ERROR, "unused byte should be null but is %d!!\n", src[-1]); /* unused */

  919.         }

  920. 

  921.         while(src < buf + buf_size){

  922.             for(m=0; m<4; m++){

  923.                 for(i=0; i<=st; i++)

  924.                     *samples++ = adpcm_ima_expand_nibble(&c->status[i], src[4*i] & 0x0F, 3);

  925.                 for(i=0; i<=st; i++)

  926.                     *samples++ = adpcm_ima_expand_nibble(&c->status[i], src[4*i] >> 4  , 3);

  927.                 src++;

  928.             }

  929.             src += 4*st;

  930.         }

  931.         break;

  932.     case CODEC_ID_ADPCM_4XM:

  933.         cs = &(c->status[0]);

  934.         c->status[0].predictor= (int16_t)(src[0] + (src[1]<<8)); src+=2;

  935.         if(st){

  936.             c->status[1].predictor= (int16_t)(src[0] + (src[1]<<8)); src+=2;

  937.         }

  938.         c->status[0].step_index= (int16_t)(src[0] + (src[1]<<8)); src+=2;

  939.         if(st){

  940.             c->status[1].step_index= (int16_t)(src[0] + (src[1]<<8)); src+=2;

  941.         }

  942.         if (cs->step_index < 0) cs->step_index = 0;

  943.         if (cs->step_index > 88) cs->step_index = 88;

  944. 

  945.         m= (buf_size - (src - buf))>>st;

  946.         for(i=0; i<m; i++) {

  947.             *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[i] & 0x0F, 4);

  948.             if (st)

  949.                 *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[i+m] & 0x0F, 4);

  950.             *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[i] >> 4, 4);

  951.             if (st)

  952.                 *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[i+m] >> 4, 4);

  953.         }

  954. 

  955.         src += m<<st;

  956. 

  957.         break;

  958.     case CODEC_ID_ADPCM_MS:

  959.         if (avctx->block_align != 0 && buf_size > avctx->block_align)

  960.             buf_size = avctx->block_align;

  961.         n = buf_size - 7 * avctx->channels;

  962.         if (n < 0)

  963.             return -1;

  964.         block_predictor[0] = clip(*src++, 0, 7);

  965.         block_predictor[1] = 0;

  966.         if (st)

  967.             block_predictor[1] = clip(*src++, 0, 7);

  968.         c->status[0].idelta = (int16_t)((*src & 0xFF) | ((src[1] << 8) & 0xFF00));

  969.         src+=2;

  970.         if (st){

  971.             c->status[1].idelta = (int16_t)((*src & 0xFF) | ((src[1] << 8) & 0xFF00));

  972.             src+=2;

  973.         }

  974.         c->status[0].coeff1 = AdaptCoeff1[block_predictor[0]];

  975.         c->status[0].coeff2 = AdaptCoeff2[block_predictor[0]];

  976.         c->status[1].coeff1 = AdaptCoeff1[block_predictor[1]];

  977.         c->status[1].coeff2 = AdaptCoeff2[block_predictor[1]];

  978. 

  979.         c->status[0].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));

  980.         src+=2;

  981.         if (st) c->status[1].sample1 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));

  982.         if (st) src+=2;

  983.         c->status[0].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));

  984.         src+=2;

  985.         if (st) c->status[1].sample2 = ((*src & 0xFF) | ((src[1] << 8) & 0xFF00));

  986.         if (st) src+=2;

  987. 

  988.         *samples++ = c->status[0].sample1;

  989.         if (st) *samples++ = c->status[1].sample1;

  990.         *samples++ = c->status[0].sample2;

  991.         if (st) *samples++ = c->status[1].sample2;

  992.         for(;n>0;n--) {

  993.             *samples++ = adpcm_ms_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F);

  994.             *samples++ = adpcm_ms_expand_nibble(&c->status[st], src[0] & 0x0F);

  995.             src ++;

  996.         }

  997.         break;

  998.     case CODEC_ID_ADPCM_IMA_DK4:

  999.         if (avctx->block_align != 0 && buf_size > avctx->block_align)

  1000.             buf_size = avctx->block_align;

  1001. 

  1002.         c->status[0].predictor = (int16_t)(src[0] | (src[1] << 8));

  1003.         c->status[0].step_index = src[2];

  1004.         src += 4;

  1005.         *samples++ = c->status[0].predictor;

  1006.         if (st) {

  1007.             c->status[1].predictor = (int16_t)(src[0] | (src[1] << 8));

  1008.             c->status[1].step_index = src[2];

  1009.             src += 4;

  1010.             *samples++ = c->status[1].predictor;

  1011.         }

  1012.         while (src < buf + buf_size) {

  1013. 

  1014.             /* take care of the top nibble (always left or mono channel) */

  1015.             *samples++ = adpcm_ima_expand_nibble(&c->status[0],

  1016.                 (src[0] >> 4) & 0x0F, 3);

  1017. 

  1018.             /* take care of the bottom nibble, which is right sample for

  1019.              * stereo, or another mono sample */

  1020.             if (st)

  1021.                 *samples++ = adpcm_ima_expand_nibble(&c->status[1],

  1022.                     src[0] & 0x0F, 3);

  1023.             else

  1024.                 *samples++ = adpcm_ima_expand_nibble(&c->status[0],

  1025.                     src[0] & 0x0F, 3);

  1026. 

  1027.             src++;

  1028.         }

  1029.         break;

  1030.     case CODEC_ID_ADPCM_IMA_DK3:

  1031.         if (avctx->block_align != 0 && buf_size > avctx->block_align)

  1032.             buf_size = avctx->block_align;

  1033. 

  1034.         c->status[0].predictor = (int16_t)(src[10] | (src[11] << 8));

  1035.         c->status[1].predictor = (int16_t)(src[12] | (src[13] << 8));

  1036.         c->status[0].step_index = src[14];

  1037.         c->status[1].step_index = src[15];

  1038.         /* sign extend the predictors */

  1039.         src += 16;

  1040.         diff_channel = c->status[1].predictor;

  1041. 

  1042.         /* the DK3_GET_NEXT_NIBBLE macro issues the break statement when

  1043.          * the buffer is consumed */

  1044.         while (1) {

  1045. 

  1046.             /* for this algorithm, c->status[0] is the sum channel and

  1047.              * c->status[1] is the diff channel */

  1048. 

  1049.             /* process the first predictor of the sum channel */

  1050.             DK3_GET_NEXT_NIBBLE();

  1051.             adpcm_ima_expand_nibble(&c->status[0], nibble, 3);

  1052. 

  1053.             /* process the diff channel predictor */

  1054.             DK3_GET_NEXT_NIBBLE();

  1055.             adpcm_ima_expand_nibble(&c->status[1], nibble, 3);

  1056. 

  1057.             /* process the first pair of stereo PCM samples */

  1058.             diff_channel = (diff_channel + c->status[1].predictor) / 2;

  1059.             *samples++ = c->status[0].predictor + c->status[1].predictor;

  1060.             *samples++ = c->status[0].predictor - c->status[1].predictor;

  1061. 

  1062.             /* process the second predictor of the sum channel */

  1063.             DK3_GET_NEXT_NIBBLE();

  1064.             adpcm_ima_expand_nibble(&c->status[0], nibble, 3);

  1065. 

  1066.             /* process the second pair of stereo PCM samples */

  1067.             diff_channel = (diff_channel + c->status[1].predictor) / 2;

  1068.             *samples++ = c->status[0].predictor + c->status[1].predictor;

  1069.             *samples++ = c->status[0].predictor - c->status[1].predictor;

  1070.         }

  1071.         break;

  1072.     case CODEC_ID_ADPCM_IMA_WS:

  1073.         /* no per-block initialization; just start decoding the data */

  1074.         while (src < buf + buf_size) {

  1075. 

  1076.             if (st) {

  1077.                 *samples++ = adpcm_ima_expand_nibble(&c->status[0],

  1078.                     (src[0] >> 4) & 0x0F, 3);

  1079.                 *samples++ = adpcm_ima_expand_nibble(&c->status[1],

  1080.                     src[0] & 0x0F, 3);

  1081.             } else {

  1082.                 *samples++ = adpcm_ima_expand_nibble(&c->status[0],

  1083.                     (src[0] >> 4) & 0x0F, 3);

  1084.                 *samples++ = adpcm_ima_expand_nibble(&c->status[0],

  1085.                     src[0] & 0x0F, 3);

  1086.             }

  1087. 

  1088.             src++;

  1089.         }

  1090.         break;

  1091.     case CODEC_ID_ADPCM_XA:

  1092.         c->status[0].sample1 = c->status[0].sample2 =

  1093.         c->status[1].sample1 = c->status[1].sample2 = 0;

  1094.         while (buf_size >= 128) {

  1095.             xa_decode(samples, src, &c->status[0], &c->status[1],

  1096.                 avctx->channels);

  1097.             src += 128;

  1098.             samples += 28 * 8;

  1099.             buf_size -= 128;

  1100.         }

  1101.         break;

  1102.     case CODEC_ID_ADPCM_EA:

  1103.         samples_in_chunk = LE_32(src);

  1104.         if (samples_in_chunk >= ((buf_size - 12) * 2)) {

  1105.             src += buf_size;

  1106.             break;

  1107.         }

  1108.         src += 4;

  1109.         current_left_sample = (int16_t)LE_16(src);

  1110.         src += 2;

  1111.         previous_left_sample = (int16_t)LE_16(src);

  1112.         src += 2;

  1113.         current_right_sample = (int16_t)LE_16(src);

  1114.         src += 2;

  1115.         previous_right_sample = (int16_t)LE_16(src);

  1116.         src += 2;

  1117. 

  1118.         for (count1 = 0; count1 < samples_in_chunk/28;count1++) {

  1119.             coeff1l = ea_adpcm_table[(*src >> 4) & 0x0F];

  1120.             coeff2l = ea_adpcm_table[((*src >> 4) & 0x0F) + 4];

  1121.             coeff1r = ea_adpcm_table[*src & 0x0F];

  1122.             coeff2r = ea_adpcm_table[(*src & 0x0F) + 4];

  1123.             src++;

  1124. 

  1125.             shift_left = ((*src >> 4) & 0x0F) + 8;

  1126.             shift_right = (*src & 0x0F) + 8;

  1127.             src++;

  1128. 

  1129.             for (count2 = 0; count2 < 28; count2++) {

  1130.                 next_left_sample = (((*src & 0xF0) << 24) >> shift_left);

  1131.                 next_right_sample = (((*src & 0x0F) << 28) >> shift_right);

  1132.                 src++;

  1133. 

  1134.                 next_left_sample = (next_left_sample +

  1135.                     (current_left_sample * coeff1l) +

  1136.                     (previous_left_sample * coeff2l) + 0x80) >> 8;

  1137.                 next_right_sample = (next_right_sample +

  1138.                     (current_right_sample * coeff1r) +

  1139.                     (previous_right_sample * coeff2r) + 0x80) >> 8;

  1140.                 CLAMP_TO_SHORT(next_left_sample);

  1141.                 CLAMP_TO_SHORT(next_right_sample);

  1142. 

  1143.                 previous_left_sample = current_left_sample;

  1144.                 current_left_sample = next_left_sample;

  1145.                 previous_right_sample = current_right_sample;

  1146.                 current_right_sample = next_right_sample;

  1147.                 *samples++ = (unsigned short)current_left_sample;

  1148.                 *samples++ = (unsigned short)current_right_sample;

  1149.             }

  1150.         }

  1151.         break;

  1152.     case CODEC_ID_ADPCM_IMA_SMJPEG:

  1153.         c->status[0].predictor = *src;

  1154.         src += 2;

  1155.         c->status[0].step_index = *src++;

  1156.         src++;  /* skip another byte before getting to the meat */

  1157.         while (src < buf + buf_size) {

  1158.             *samples++ = adpcm_ima_expand_nibble(&c->status[0],

  1159.                 *src & 0x0F, 3);

  1160.             *samples++ = adpcm_ima_expand_nibble(&c->status[0],

  1161.                 (*src >> 4) & 0x0F, 3);

  1162.             src++;

  1163.         }

  1164.         break;

  1165.     case CODEC_ID_ADPCM_CT:

  1166.         while (src < buf + buf_size) {

  1167.             if (st) {

  1168.                 *samples++ = adpcm_ct_expand_nibble(&c->status[0],

  1169.                     (src[0] >> 4) & 0x0F);

  1170.                 *samples++ = adpcm_ct_expand_nibble(&c->status[1],

  1171.                     src[0] & 0x0F);

  1172.             } else {

  1173.                 *samples++ = adpcm_ct_expand_nibble(&c->status[0],

  1174.                     (src[0] >> 4) & 0x0F);

  1175.                 *samples++ = adpcm_ct_expand_nibble(&c->status[0],

  1176.                     src[0] & 0x0F);

  1177.             }

  1178.             src++;

  1179.         }

  1180.         break;

  1181.     case CODEC_ID_ADPCM_SBPRO_4:

  1182.     case CODEC_ID_ADPCM_SBPRO_3:

  1183.     case CODEC_ID_ADPCM_SBPRO_2:

  1184.         if (!c->status[0].step_index) {

  1185.             /* the first byte is a raw sample */

  1186.             *samples++ = 128 * (*src++ - 0x80);

  1187.             if (st)

  1188.               *samples++ = 128 * (*src++ - 0x80);

  1189.             c->status[0].step_index = 1;

  1190.         }

  1191.         if (avctx->codec->id == CODEC_ID_ADPCM_SBPRO_4) {

  1192.             while (src < buf + buf_size) {

  1193.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[0],

  1194.                     (src[0] >> 4) & 0x0F, 4, 0);

  1195.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[st],

  1196.                     src[0] & 0x0F, 4, 0);

  1197.                 src++;

  1198.             }

  1199.         } else if (avctx->codec->id == CODEC_ID_ADPCM_SBPRO_3) {

  1200.             while (src < buf + buf_size) {

  1201.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[0],

  1202.                     (src[0] >> 5) & 0x07, 3, 0);

  1203.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[0],

  1204.                     (src[0] >> 2) & 0x07, 3, 0);

  1205.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[0],

  1206.                     src[0] & 0x03, 2, 0);

  1207.                 src++;

  1208.             }

  1209.         } else {

  1210.             while (src < buf + buf_size) {

  1211.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[0],

  1212.                     (src[0] >> 6) & 0x03, 2, 2);

  1213.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[st],

  1214.                     (src[0] >> 4) & 0x03, 2, 2);

  1215.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[0],

  1216.                     (src[0] >> 2) & 0x03, 2, 2);

  1217.                 *samples++ = adpcm_sbpro_expand_nibble(&c->status[st],

  1218.                     src[0] & 0x03, 2, 2);

  1219.                 src++;

  1220.             }

  1221.         }

  1222.         break;

  1223.     case CODEC_ID_ADPCM_SWF:

  1224.     {

  1225.         GetBitContext gb;

  1226.         const int *table;

  1227.         int k0, signmask;

  1228.         int size = buf_size*8;

  1229. 

  1230.         init_get_bits(&gb, buf, size);

  1231. 

  1232.         // first frame, read bits & inital values

  1233.         if (!c->nb_bits)

  1234.         {

  1235.             c->nb_bits = get_bits(&gb, 2)+2;

  1236. //            av_log(NULL,AV_LOG_INFO,"nb_bits: %d\n", c->nb_bits);

  1237.         }

  1238. 

  1239.         table = swf_index_tables[c->nb_bits-2];

  1240.         k0 = 1 << (c->nb_bits-2);

  1241.         signmask = 1 << (c->nb_bits-1);

  1242. 

  1243.         while (get_bits_count(&gb) <= size)

  1244.         {

  1245.             int i;

  1246. 

  1247.             c->nb_samples++;

  1248.             // wrap around at every 4096 samples...

  1249.             if ((c->nb_samples & 0xfff) == 1)

  1250.             {

  1251.                 for (i = 0; i <= st; i++)

  1252.                 {

  1253.                     *samples++ = c->status[i].predictor = get_sbits(&gb, 16);

  1254.                     c->status[i].step_index = get_bits(&gb, 6);

  1255.                 }

  1256.             }

  1257. 

  1258.             // similar to IMA adpcm

  1259.             for (i = 0; i <= st; i++)

  1260.             {

  1261.                 int delta = get_bits(&gb, c->nb_bits);

  1262.                 int step = step_table[c->status[i].step_index];

  1263.                 long vpdiff = 0; // vpdiff = (delta+0.5)*step/4

  1264.                 int k = k0;

  1265. 

  1266.                 do {

  1267.                     if (delta & k)

  1268.                         vpdiff += step;

  1269.                     step >>= 1;

  1270.                     k >>= 1;

  1271.                 } while(k);

  1272.                 vpdiff += step;

  1273. 

  1274.                 if (delta & signmask)

  1275.                     c->status[i].predictor -= vpdiff;

  1276.                 else

  1277.                     c->status[i].predictor += vpdiff;

  1278. 

  1279.                 c->status[i].step_index += table[delta & (~signmask)];

  1280. 

  1281.                 c->status[i].step_index = clip(c->status[i].step_index, 0, 88);

  1282.                 c->status[i].predictor = clip(c->status[i].predictor, -32768, 32767);

  1283. 

  1284.                 *samples++ = c->status[i].predictor;

  1285.             }

  1286.         }

  1287. 

  1288. //        src += get_bits_count(&gb)*8;

  1289.         src += size;

  1290. 

  1291.         break;

  1292.     }

  1293.     case CODEC_ID_ADPCM_YAMAHA:

  1294.         while (src < buf + buf_size) {

  1295.             if (st) {

  1296.                 *samples++ = adpcm_yamaha_expand_nibble(&c->status[0],

  1297.                         src[0] & 0x0F);

  1298.                 *samples++ = adpcm_yamaha_expand_nibble(&c->status[1],

  1299.                         (src[0] >> 4) & 0x0F);

  1300.             } else {

  1301.                 *samples++ = adpcm_yamaha_expand_nibble(&c->status[0],

  1302.                         src[0] & 0x0F);

  1303.                 *samples++ = adpcm_yamaha_expand_nibble(&c->status[0],

  1304.                         (src[0] >> 4) & 0x0F);

  1305.             }

  1306.             src++;

  1307.         }

  1308.         break;

  1309.     default:

  1310.         return -1;

  1311.     }

  1312.     *data_size = (uint8_t *)samples - (uint8_t *)data;

  1313.     return src - buf;

  1314. }

  1315. 

  1316. 

  1317. 

  1318. #ifdef CONFIG_ENCODERS

  1319. #define ADPCM_ENCODER(id,name)                  \

  1320. AVCodec name ## _encoder = {                    \

  1321.     #name,                                      \

  1322.     CODEC_TYPE_AUDIO,                           \

  1323.     id,                                         \

  1324.     sizeof(ADPCMContext),                       \

  1325.     adpcm_encode_init,                          \

  1326.     adpcm_encode_frame,                         \

  1327.     adpcm_encode_close,                         \

  1328.     NULL,                                       \

  1329. };

  1330. #else

  1331. #define ADPCM_ENCODER(id,name)

  1332. #endif

  1333. 

  1334. #ifdef CONFIG_DECODERS

  1335. #define ADPCM_DECODER(id,name)                  \

  1336. AVCodec name ## _decoder = {                    \

  1337.     #name,                                      \

  1338.     CODEC_TYPE_AUDIO,                           \

  1339.     id,                                         \

  1340.     sizeof(ADPCMContext),                       \

  1341.     adpcm_decode_init,                          \

  1342.     NULL,                                       \

  1343.     NULL,                                       \

  1344.     adpcm_decode_frame,                         \

  1345. };

  1346. #else

  1347. #define ADPCM_DECODER(id,name)

  1348. #endif

  1349. 

  1350. #define ADPCM_CODEC(id, name)                   \

  1351. ADPCM_ENCODER(id,name) ADPCM_DECODER(id,name)

  1352. 

  1353. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);

  1354. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);

  1355. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);

  1356. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);

  1357. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WS, adpcm_ima_ws);

  1358. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_SMJPEG, adpcm_ima_smjpeg);

  1359. ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);

  1360. ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);

  1361. ADPCM_CODEC(CODEC_ID_ADPCM_XA, adpcm_xa);

  1362. ADPCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea);

  1363. ADPCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct);

  1364. ADPCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);

  1365. ADPCM_CODEC(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha);

  1366. ADPCM_CODEC(CODEC_ID_ADPCM_SBPRO_4, adpcm_sbpro_4);

  1367. ADPCM_CODEC(CODEC_ID_ADPCM_SBPRO_3, adpcm_sbpro_3);

  1368. ADPCM_CODEC(CODEC_ID_ADPCM_SBPRO_2, adpcm_sbpro_2);

  1369. 

  1370. #undef ADPCM_CODEC