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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 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. #include "bitstream.h"

  21. 

  22. /**

  23.  * @file adpcm.c

  24.  * ADPCM codecs.

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

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

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

  28.  * CD-ROM XA ADPCM codec by BERO

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

  30.  *

  31.  * Features and limitations:

  32.  *

  33.  * Reference documents:

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

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

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

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

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

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

  40.  *

  41.  * CD-ROM XA:

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

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

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

  45.  */

  46. 

  47. #define BLKSIZE 1024

  48. 

  49. #define CLAMP_TO_SHORT(value) \

  50. if (value > 32767) \

  51.     value = 32767; \

  52. else if (value < -32768) \

  53.     value = -32768; \

  54. 

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

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

  57. static const int index_table[16] = {

  58.     -1, -1, -1, -1, 2, 4, 6, 8,

  59.     -1, -1, -1, -1, 2, 4, 6, 8,

  60. };

  61. 

  62. /** 

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

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

  65.  */

  66. static const int step_table[89] = {

  67.     7, 8, 9, 10, 11, 12, 13, 14, 16, 17,

  68.     19, 21, 23, 25, 28, 31, 34, 37, 41, 45,

  69.     50, 55, 60, 66, 73, 80, 88, 97, 107, 118,

  70.     130, 143, 157, 173, 190, 209, 230, 253, 279, 307,

  71.     337, 371, 408, 449, 494, 544, 598, 658, 724, 796,

  72.     876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,

  73.     2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,

  74.     5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,

  75.     15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767

  76. };

  77. 

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

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

  80. static const int AdaptationTable[] = {

  81.         230, 230, 230, 230, 307, 409, 512, 614,

  82.         768, 614, 512, 409, 307, 230, 230, 230

  83. };

  84. 

  85. static const int AdaptCoeff1[] = {

  86.         256, 512, 0, 192, 240, 460, 392

  87. };

  88. 

  89. static const int AdaptCoeff2[] = {

  90.         0, -256, 0, 64, 0, -208, -232

  91. };

  92. 

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

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

  95.    {   0,   0 },

  96.    {  60,   0 },

  97.    { 115, -52 },

  98.    {  98, -55 },

  99.    { 122, -60 }

  100. };

  101. 

  102. static const int ea_adpcm_table[] = {

  103.     0, 240, 460, 392, 0, 0, -208, -220, 0, 1,

  104.     3, 4, 7, 8, 10, 11, 0, -1, -3, -4

  105. };

  106. 

  107. static const int ct_adpcm_table[8] = {

  108.     0x00E6, 0x00E6, 0x00E6, 0x00E6,

  109.     0x0133, 0x0199, 0x0200, 0x0266

  110. };

  111. 

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

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

  114.     /*2*/ { -1, 2 },

  115.     /*3*/ { -1, -1, 2, 4 },

  116.     /*4*/ { -1, -1, -1, -1, 2, 4, 6, 8 },

  117.     /*5*/ { -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 4, 6, 8, 10, 13, 16 }

  118. };

  119. 

  120. /* end of tables */

  121. 

  122. typedef struct ADPCMChannelStatus {

  123.     int predictor;

  124.     short int step_index;

  125.     int step;

  126.     /* for encoding */

  127.     int prev_sample;

  128. 

  129.     /* MS version */

  130.     short sample1;

  131.     short sample2;

  132.     int coeff1;

  133.     int coeff2;

  134.     int idelta;

  135. } ADPCMChannelStatus;

  136. 

  137. typedef struct ADPCMContext {

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

  139.     ADPCMChannelStatus status[2];

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

  141. 

  142.     /* SWF only */

  143.     int nb_bits;

  144.     int nb_samples;

  145. } ADPCMContext;

  146. 

  147. /* XXX: implement encoding */

  148. 

  149. #ifdef CONFIG_ENCODERS

  150. static int adpcm_encode_init(AVCodecContext *avctx)

  151. {

  152.     if (avctx->channels > 2)

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

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

  155.     case CODEC_ID_ADPCM_IMA_QT:

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

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

  158.         return -1;

  159.         break;

  160.     case CODEC_ID_ADPCM_IMA_WAV:

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

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

  163.         avctx->block_align = BLKSIZE;

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

  165.         break;

  166.     case CODEC_ID_ADPCM_MS:

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

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

  169.         avctx->block_align = BLKSIZE;

  170.         break;

  171.     default:

  172.         return -1;

  173.         break;

  174.     }

  175. 

  176.     avctx->coded_frame= avcodec_alloc_frame();

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

  178. 

  179.     return 0;

  180. }

  181. 

  182. static int adpcm_encode_close(AVCodecContext *avctx)

  183. {

  184.     av_freep(&avctx->coded_frame);

  185. 

  186.     return 0;

  187. }

  188. 

  189. 

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

  191. {

  192.     int step_index;

  193.     unsigned char nibble;

  194.     

  195.     int sign = 0; /* sign bit of the nibble (MSB) */

  196.     int delta, predicted_delta;

  197. 

  198.     delta = sample - c->prev_sample;

  199. 

  200.     if (delta < 0) {

  201.         sign = 1;

  202.         delta = -delta;

  203.     }

  204. 

  205.     step_index = c->step_index;

  206. 

  207.     /* nibble = 4 * delta / step_table[step_index]; */

  208.     nibble = (delta << 2) / step_table[step_index];

  209. 

  210.     if (nibble > 7)

  211.         nibble = 7;

  212. 

  213.     step_index += index_table[nibble];

  214.     if (step_index < 0)

  215.         step_index = 0;

  216.     if (step_index > 88)

  217.         step_index = 88;

  218. 

  219.     /* what the decoder will find */

  220.     predicted_delta = ((step_table[step_index] * nibble) / 4) + (step_table[step_index] / 8);

  221. 

  222.     if (sign)

  223.         c->prev_sample -= predicted_delta;

  224.     else

  225.         c->prev_sample += predicted_delta;

  226. 

  227.     CLAMP_TO_SHORT(c->prev_sample);

  228. 

  229. 

  230.     nibble += sign << 3; /* sign * 8 */   

  231. 

  232.     /* save back */

  233.     c->step_index = step_index;

  234. 

  235.     return nibble;

  236. }

  237. 

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

  239. {

  240.     int predictor, nibble, bias;

  241. 

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

  243.     

  244.     nibble= sample - predictor;

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

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

  247.         

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

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

  250.     

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

  252.     CLAMP_TO_SHORT(predictor);

  253. 

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

  255.     c->sample1 = predictor;

  256. 

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

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

  259. 

  260.     return nibble;

  261. }

  262. 

  263. static int adpcm_encode_frame(AVCodecContext *avctx,

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

  265. {

  266.     int n, i, st;

  267.     short *samples;

  268.     unsigned char *dst;

  269.     ADPCMContext *c = avctx->priv_data;

  270. 

  271.     dst = frame;

  272.     samples = (short *)data;

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

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

  275. 

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

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

  278.         break;

  279.     case CODEC_ID_ADPCM_IMA_WAV:

  280.         n = avctx->frame_size / 8;

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

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

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

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

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

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

  287.             samples++;

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

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

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

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

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

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

  294.                 *dst++ = 0;

  295.                 samples++;

  296.             }

  297.         

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

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

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

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

  302.                 dst++;

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

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

  305.                 dst++;

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

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

  308.                 dst++;

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

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

  311.                 dst++;

  312.                 /* right channel */

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

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

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

  316.                     dst++;

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

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

  319.                     dst++;

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

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

  322.                     dst++;

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

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

  325.                     dst++;

  326.                 }

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

  328.             }

  329.         break;

  330.     case CODEC_ID_ADPCM_MS:

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

  332.             int predictor=0;

  333. 

  334.             *dst++ = predictor;

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

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

  337.         }

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

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

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

  341.             

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

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

  344.         }

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

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

  347. 

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

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

  350.         }

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

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

  353. 

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

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

  356.         }

  357. 

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

  359.             int nibble;

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

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

  362.             *dst++ = nibble;

  363.         }

  364.         break;

  365.     default:

  366.         return -1;

  367.     }

  368.     return dst - frame;

  369. }

  370. #endif //CONFIG_ENCODERS

  371. 

  372. static int adpcm_decode_init(AVCodecContext * avctx)

  373. {

  374.     ADPCMContext *c = avctx->priv_data;

  375. 

  376.     c->channel = 0;

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

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

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

  380. 

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

  382.     case CODEC_ID_ADPCM_CT:

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

  384. 	break;

  385.     default:

  386.         break;

  387.     }

  388.     return 0;

  389. }

  390. 

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

  392. {

  393.     int step_index;

  394.     int predictor;

  395.     int sign, delta, diff, step;

  396. 

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

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

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

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

  401. 

  402.     sign = nibble & 8;

  403.     delta = nibble & 7;

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

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

  406.      * quickly enough */

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

  408.     predictor = c->predictor;

  409.     if (sign) predictor -= diff;

  410.     else predictor += diff;

  411. 

  412.     CLAMP_TO_SHORT(predictor);

  413.     c->predictor = predictor;

  414.     c->step_index = step_index;

  415. 

  416.     return (short)predictor;

  417. }

  418. 

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

  420. {

  421.     int predictor;

  422. 

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

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

  425.     CLAMP_TO_SHORT(predictor);

  426. 

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

  428.     c->sample1 = predictor;

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

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

  431. 

  432.     return (short)predictor;

  433. }

  434. 

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

  436. {

  437.     int predictor;

  438.     int sign, delta, diff;

  439.     int new_step;

  440. 

  441.     sign = nibble & 8;

  442.     delta = nibble & 7;

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

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

  445.      * quickly enough */

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

  447.     predictor = c->predictor;

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

  449.     if(sign)

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

  451.     else

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

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

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

  455.     c->step = new_step;

  456.     if(c->step < 511)

  457. 	c->step = 511;

  458.     if(c->step > 32767)

  459. 	c->step = 32767;

  460. 

  461.     CLAMP_TO_SHORT(predictor);

  462.     c->predictor = predictor;

  463.     return (short)predictor;

  464. }

  465. 

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

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

  468. {

  469.     int i, j;

  470.     int shift,filter,f0,f1;

  471.     int s_1,s_2;

  472.     int d,s,t;

  473. 

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

  475. 

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

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

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

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

  480. 

  481.         s_1 = left->sample1;

  482.         s_2 = left->sample2;

  483. 

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

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

  486. 

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

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

  489.             CLAMP_TO_SHORT(s);

  490.             *out = s;

  491.             out += inc;

  492.             s_2 = s_1;

  493.             s_1 = s;

  494.         }

  495. 

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

  497.             left->sample1 = s_1;

  498.             left->sample2 = s_2;

  499.             s_1 = right->sample1;

  500.             s_2 = right->sample2;

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

  502.         }

  503. 

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

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

  506. 

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

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

  509. 

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

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

  512. 

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

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

  515.             CLAMP_TO_SHORT(s);

  516.             *out = s;

  517.             out += inc;

  518.             s_2 = s_1;

  519.             s_1 = s;

  520.         }

  521. 

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

  523.             right->sample1 = s_1;

  524.             right->sample2 = s_2;

  525.             out -= 1;

  526.         } else {

  527.             left->sample1 = s_1;

  528.             left->sample2 = s_2;

  529.         }

  530.     }

  531. }

  532. 

  533. 

  534. /* DK3 ADPCM support macro */

  535. #define DK3_GET_NEXT_NIBBLE() \

  536.     if (decode_top_nibble_next) \

  537.     { \

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

  539.         decode_top_nibble_next = 0; \

  540.     } \

  541.     else \

  542.     { \

  543.         last_byte = *src++; \

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

  545.         nibble = last_byte & 0x0F; \

  546.         decode_top_nibble_next = 1; \

  547.     }

  548. 

  549. static int adpcm_decode_frame(AVCodecContext *avctx,

  550. 			    void *data, int *data_size,

  551. 			    uint8_t *buf, int buf_size)

  552. {

  553.     ADPCMContext *c = avctx->priv_data;

  554.     ADPCMChannelStatus *cs;

  555.     int n, m, channel, i;

  556.     int block_predictor[2];

  557.     short *samples;

  558.     uint8_t *src;

  559.     int st; /* stereo */

  560. 

  561.     /* DK3 ADPCM accounting variables */

  562.     unsigned char last_byte = 0;

  563.     unsigned char nibble;

  564.     int decode_top_nibble_next = 0;

  565.     int diff_channel;

  566. 

  567.     /* EA ADPCM state variables */

  568.     uint32_t samples_in_chunk;

  569.     int32_t previous_left_sample, previous_right_sample;

  570.     int32_t current_left_sample, current_right_sample;

  571.     int32_t next_left_sample, next_right_sample;

  572.     int32_t coeff1l, coeff2l, coeff1r, coeff2r;

  573.     uint8_t shift_left, shift_right;

  574.     int count1, count2;

  575. 

  576.     if (!buf_size)

  577.         return 0;

  578. 

  579.     samples = data;

  580.     src = buf;

  581. 

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

  583. 

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

  585.     case CODEC_ID_ADPCM_IMA_QT:

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

  587.         channel = c->channel;

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

  589.         /* (pppppp) (piiiiiii) */

  590. 

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

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

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

  594.         cs->predictor &= 0xFF80;

  595. 

  596.         /* sign extension */

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

  598.             cs->predictor -= 0x10000;

  599. 

  600.         CLAMP_TO_SHORT(cs->predictor);

  601. 

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

  603. 

  604.         if (cs->step_index > 88) av_log(avctx, AV_LOG_ERROR, "ERROR: step_index = %i\n", cs->step_index);

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

  606. 

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

  608. 

  609.         if (st && channel)

  610.             samples++;

  611. 

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

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

  614.             samples += avctx->channels;

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

  616.             samples += avctx->channels;

  617.             src ++;

  618.         }

  619. 

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

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

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

  623.                 return src - buf;

  624.             }

  625.         }

  626.         break;

  627.     case CODEC_ID_ADPCM_IMA_WAV:

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

  629.             buf_size = avctx->block_align;

  630. 

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

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

  633.             cs->predictor = *src++;

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

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

  636.                 cs->predictor -= 0x10000;

  637.             CLAMP_TO_SHORT(cs->predictor);

  638. 

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

  640. 

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

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

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

  644.             if (*src++) av_log(avctx, AV_LOG_ERROR, "unused byte should be null !!\n"); /* unused */

  645.         }

  646. 

  647.         for(m=4; src < (buf + buf_size);) {

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

  649.             if (st)

  650.                 *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[4] & 0x0F, 3);

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

  652. 	    if (st) {

  653.                 *samples++ = adpcm_ima_expand_nibble(&c->status[1], (src[4] >> 4) & 0x0F, 3);

  654. 		if (!--m) {

  655. 		    m=4;

  656. 		    src+=4;

  657. 		}

  658. 	    }

  659. 	    src++;

  660. 	}

  661.         break;

  662.     case CODEC_ID_ADPCM_4XM:

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

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

  665.         if(st){

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

  667.         }

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

  669.         if(st){

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

  671.         }

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

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

  674. 

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

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

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

  678.             if (st)

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

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

  681. 	    if (st)

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

  683. 	}

  684. 

  685.         src += m<<st;

  686. 

  687.         break;

  688.     case CODEC_ID_ADPCM_MS:

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

  690.             buf_size = avctx->block_align;

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

  692.         if (n < 0)

  693.             return -1;

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

  695.         block_predictor[1] = 0;

  696.         if (st)

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

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

  699.         src+=2;

  700.         if (st){

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

  702.             src+=2;

  703.         }

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

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

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

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

  708.         

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

  710.         src+=2;

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

  712.         if (st) src+=2;

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

  714.         src+=2;

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

  716.         if (st) src+=2;

  717. 

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

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

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

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

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

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

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

  725.             src ++;

  726.         }

  727.         break;

  728.     case CODEC_ID_ADPCM_IMA_DK4:

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

  730.             buf_size = avctx->block_align;

  731. 

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

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

  734.         src += 4;

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

  736.         if (st) {

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

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

  739.             src += 4;

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

  741.         }

  742.         while (src < buf + buf_size) {

  743. 

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

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

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

  747. 

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

  749.              * stereo, or another mono sample */

  750.             if (st)

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

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

  753.             else

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

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

  756. 

  757.             src++;

  758.         }

  759.         break;

  760.     case CODEC_ID_ADPCM_IMA_DK3:

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

  762.             buf_size = avctx->block_align;

  763. 

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

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

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

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

  768.         /* sign extend the predictors */

  769.         src += 16;

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

  771. 

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

  773.          * the buffer is consumed */

  774.         while (1) {

  775. 

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

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

  778. 

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

  780.             DK3_GET_NEXT_NIBBLE();

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

  782. 

  783.             /* process the diff channel predictor */

  784.             DK3_GET_NEXT_NIBBLE();

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

  786. 

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

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

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

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

  791. 

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

  793.             DK3_GET_NEXT_NIBBLE();

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

  795. 

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

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

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

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

  800.         }

  801.         break;

  802.     case CODEC_ID_ADPCM_IMA_WS:

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

  804.         while (src < buf + buf_size) {

  805. 

  806.             if (st) {

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

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

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

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

  811.             } else {

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

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

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

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

  816.             }

  817. 

  818.             src++;

  819.         }

  820.         break;

  821.     case CODEC_ID_ADPCM_XA:

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

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

  824.         while (buf_size >= 128) {

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

  826.                 avctx->channels);

  827.             src += 128;

  828.             samples += 28 * 8;

  829.             buf_size -= 128;

  830.         }

  831.         break;

  832.     case CODEC_ID_ADPCM_EA:

  833.         samples_in_chunk = LE_32(src);

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

  835.             src += buf_size;

  836.             break;

  837.         }

  838.         src += 4;

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

  840.         src += 2;

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

  842.         src += 2;

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

  844.         src += 2;

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

  846.         src += 2;

  847. 

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

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

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

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

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

  853.             src++;

  854. 

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

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

  857.             src++;

  858. 

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

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

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

  862.                 src++;

  863. 

  864.                 next_left_sample = (next_left_sample + 

  865.                     (current_left_sample * coeff1l) + 

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

  867.                 next_right_sample = (next_right_sample + 

  868.                     (current_right_sample * coeff1r) + 

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

  870.                 CLAMP_TO_SHORT(next_left_sample);

  871.                 CLAMP_TO_SHORT(next_right_sample);

  872. 

  873.                 previous_left_sample = current_left_sample;

  874.                 current_left_sample = next_left_sample;

  875.                 previous_right_sample = current_right_sample;

  876.                 current_right_sample = next_right_sample;

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

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

  879.             }

  880.         }

  881.         break;

  882.     case CODEC_ID_ADPCM_IMA_SMJPEG:

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

  884.         src += 2;

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

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

  887.         while (src < buf + buf_size) {

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

  889.                 *src & 0x0F, 3);

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

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

  892.             src++;

  893.         }

  894.         break;

  895.     case CODEC_ID_ADPCM_CT:

  896. 	while (src < buf + buf_size) {

  897.             if (st) {

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

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

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

  901.                     src[0] & 0x0F);

  902.             } else {

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

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

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

  906.                     src[0] & 0x0F);

  907.             }

  908. 	    src++;

  909.         }

  910.         break;

  911.     case CODEC_ID_ADPCM_SWF:

  912.     {

  913. 	GetBitContext gb;

  914. 	const int *table;

  915. 	int k0, signmask;

  916. 	int size = buf_size*8;

  917. 	

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

  919. 

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

  921. 	if (!c->nb_bits)

  922. 	{

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

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

  925. 	}

  926. 	

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

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

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

  930. 	

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

  932. 	{

  933. 	    int i;

  934. 

  935. 	    c->nb_samples++;

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

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

  938. 	    {

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

  940. 		{

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

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

  943. 		}

  944. 	    }

  945. 

  946. 	    // similar to IMA adpcm

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

  948. 	    {

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

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

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

  952. 		int k = k0;

  953. 		

  954. 		do {

  955. 		    if (delta & k)

  956. 			vpdiff += step;

  957. 		    step >>= 1;

  958. 		    k >>= 1;

  959. 		} while(k);

  960. 		vpdiff += step;

  961. 		

  962. 		if (delta & signmask)

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

  964. 		else

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

  966. 		

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

  968. 		

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

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

  971. 		

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

  973. 	    }

  974. 	}

  975. 	

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

  977. 	src += size;

  978. 	

  979. 	break;

  980.     }

  981.     default:

  982.         return -1;

  983.     }

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

  985.     return src - buf;

  986. }

  987. 

  988. 

  989. 

  990. #ifdef CONFIG_ENCODERS

  991. #define ADPCM_ENCODER(id,name)                  \

  992. AVCodec name ## _encoder = {                    \

  993.     #name,                                      \

  994.     CODEC_TYPE_AUDIO,                           \

  995.     id,                                         \

  996.     sizeof(ADPCMContext),                       \

  997.     adpcm_encode_init,                          \

  998.     adpcm_encode_frame,                         \

  999.     adpcm_encode_close,                         \

  1000.     NULL,                                       \

  1001. };

  1002. #else

  1003. #define ADPCM_ENCODER(id,name)

  1004. #endif

  1005. 

  1006. #ifdef CONFIG_DECODERS

  1007. #define ADPCM_DECODER(id,name)                  \

  1008. AVCodec name ## _decoder = {                    \

  1009.     #name,                                      \

  1010.     CODEC_TYPE_AUDIO,                           \

  1011.     id,                                         \

  1012.     sizeof(ADPCMContext),                       \

  1013.     adpcm_decode_init,                          \

  1014.     NULL,                                       \

  1015.     NULL,                                       \

  1016.     adpcm_decode_frame,                         \

  1017. };

  1018. #else

  1019. #define ADPCM_DECODER(id,name)

  1020. #endif

  1021. 

  1022. #define ADPCM_CODEC(id, name)                   \

  1023. ADPCM_ENCODER(id,name) ADPCM_DECODER(id,name)

  1024. 

  1025. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);

  1026. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);

  1027. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);

  1028. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);

  1029. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WS, adpcm_ima_ws);

  1030. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_SMJPEG, adpcm_ima_smjpeg);

  1031. ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);

  1032. ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);

  1033. ADPCM_CODEC(CODEC_ID_ADPCM_XA, adpcm_xa);

  1034. ADPCM_CODEC(CODEC_ID_ADPCM_ADX, adpcm_adx);

  1035. ADPCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea);

  1036. ADPCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct);

  1037. ADPCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);

  1038. 

  1039. #undef ADPCM_CODEC