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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. 

  21. /**

  22.  * @file adpcm.c

  23.  * ADPCM codecs.

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

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

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

  27.  * CD-ROM XA ADPCM codec by BERO

  28.  *

  29.  * Features and limitations:

  30.  *

  31.  * Reference documents:

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

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

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

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

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

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

  38.  *

  39.  * CD-ROM XA:

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

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

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

  43.  */

  44. 

  45. #define BLKSIZE 1024

  46. 

  47. #define CLAMP_TO_SHORT(value) \

  48. if (value > 32767) \

  49.     value = 32767; \

  50. else if (value < -32768) \

  51.     value = -32768; \

  52. 

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

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

  55. static const int index_table[16] = {

  56.     -1, -1, -1, -1, 2, 4, 6, 8,

  57.     -1, -1, -1, -1, 2, 4, 6, 8,

  58. };

  59. 

  60. /** 

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

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

  63.  */

  64. static const int step_table[89] = {

  65.     7, 8, 9, 10, 11, 12, 13, 14, 16, 17,

  66.     19, 21, 23, 25, 28, 31, 34, 37, 41, 45,

  67.     50, 55, 60, 66, 73, 80, 88, 97, 107, 118,

  68.     130, 143, 157, 173, 190, 209, 230, 253, 279, 307,

  69.     337, 371, 408, 449, 494, 544, 598, 658, 724, 796,

  70.     876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,

  71.     2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,

  72.     5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,

  73.     15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767

  74. };

  75. 

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

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

  78. static const int AdaptationTable[] = {

  79.         230, 230, 230, 230, 307, 409, 512, 614,

  80.         768, 614, 512, 409, 307, 230, 230, 230

  81. };

  82. 

  83. static const int AdaptCoeff1[] = {

  84.         256, 512, 0, 192, 240, 460, 392

  85. };

  86. 

  87. static const int AdaptCoeff2[] = {

  88.         0, -256, 0, 64, 0, -208, -232

  89. };

  90. 

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

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

  93.    {   0,   0 },

  94.    {  60,   0 },

  95.    { 115, -52 },

  96.    {  98, -55 },

  97.    { 122, -60 }

  98. };

  99. 

  100. /* end of tables */

  101. 

  102. typedef struct ADPCMChannelStatus {

  103.     int predictor;

  104.     short int step_index;

  105.     int step;

  106.     /* for encoding */

  107.     int prev_sample;

  108. 

  109.     /* MS version */

  110.     short sample1;

  111.     short sample2;

  112.     int coeff1;

  113.     int coeff2;

  114.     int idelta;

  115. } ADPCMChannelStatus;

  116. 

  117. typedef struct ADPCMContext {

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

  119.     ADPCMChannelStatus status[2];

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

  121. } ADPCMContext;

  122. 

  123. /* XXX: implement encoding */

  124. 

  125. #ifdef CONFIG_ENCODERS

  126. static int adpcm_encode_init(AVCodecContext *avctx)

  127. {

  128.     if (avctx->channels > 2)

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

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

  131.     case CODEC_ID_ADPCM_IMA_QT:

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

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

  134.         return -1;

  135.         break;

  136.     case CODEC_ID_ADPCM_IMA_WAV:

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

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

  139.         avctx->block_align = BLKSIZE;

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

  141.         break;

  142.     case CODEC_ID_ADPCM_MS:

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

  144.         return -1;

  145.         break;

  146.     default:

  147.         return -1;

  148.         break;

  149.     }

  150. 

  151.     avctx->coded_frame= avcodec_alloc_frame();

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

  153. 

  154.     return 0;

  155. }

  156. 

  157. static int adpcm_encode_close(AVCodecContext *avctx)

  158. {

  159.     av_freep(&avctx->coded_frame);

  160. 

  161.     return 0;

  162. }

  163. 

  164. 

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

  166. {

  167.     int step_index;

  168.     unsigned char nibble;

  169.     

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

  171.     int delta, predicted_delta;

  172. 

  173.     delta = sample - c->prev_sample;

  174. 

  175.     if (delta < 0) {

  176.         sign = 1;

  177.         delta = -delta;

  178.     }

  179. 

  180.     step_index = c->step_index;

  181. 

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

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

  184. 

  185.     if (nibble > 7)

  186.         nibble = 7;

  187. 

  188.     step_index += index_table[nibble];

  189.     if (step_index < 0)

  190.         step_index = 0;

  191.     if (step_index > 88)

  192.         step_index = 88;

  193. 

  194.     /* what the decoder will find */

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

  196. 

  197.     if (sign)

  198.         c->prev_sample -= predicted_delta;

  199.     else

  200.         c->prev_sample += predicted_delta;

  201. 

  202.     CLAMP_TO_SHORT(c->prev_sample);

  203. 

  204. 

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

  206. 

  207.     /* save back */

  208.     c->step_index = step_index;

  209. 

  210.     return nibble;

  211. }

  212. 

  213. static int adpcm_encode_frame(AVCodecContext *avctx,

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

  215. {

  216.     int n;

  217.     short *samples;

  218.     unsigned char *dst;

  219.     ADPCMContext *c = avctx->priv_data;

  220. 

  221.     dst = frame;

  222.     samples = (short *)data;

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

  224. 

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

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

  227.         break;

  228.     case CODEC_ID_ADPCM_IMA_WAV:

  229.         n = avctx->frame_size / 8;

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

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

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

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

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

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

  236.             samples++;

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

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

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

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

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

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

  243.                 *dst++ = 0;

  244.                 samples++;

  245.             }

  246.         

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

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

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

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

  251.                 dst++;

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

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

  254.                 dst++;

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

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

  257.                 dst++;

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

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

  260.                 dst++;

  261.                 /* right channel */

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

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

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

  265.                     dst++;

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

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

  268.                     dst++;

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

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

  271.                     dst++;

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

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

  274.                     dst++;

  275.                 }

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

  277.             }

  278.         break;

  279.     default:

  280.         return -1;

  281.     }

  282.     return dst - frame;

  283. }

  284. #endif //CONFIG_ENCODERS

  285. 

  286. static int adpcm_decode_init(AVCodecContext * avctx)

  287. {

  288.     ADPCMContext *c = avctx->priv_data;

  289. 

  290.     c->channel = 0;

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

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

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

  294. 

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

  296.     default:

  297.         break;

  298.     }

  299.     return 0;

  300. }

  301. 

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

  303. {

  304.     int step_index;

  305.     int predictor;

  306.     int sign, delta, diff, step;

  307. 

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

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

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

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

  312. 

  313.     sign = nibble & 8;

  314.     delta = nibble & 7;

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

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

  317.      * quickly enough */

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

  319.     predictor = c->predictor;

  320.     if (sign) predictor -= diff;

  321.     else predictor += diff;

  322. 

  323.     CLAMP_TO_SHORT(predictor);

  324.     c->predictor = predictor;

  325.     c->step_index = step_index;

  326. 

  327.     return (short)predictor;

  328. }

  329. 

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

  331. {

  332.     int predictor;

  333. 

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

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

  336.     CLAMP_TO_SHORT(predictor);

  337. 

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

  339.     c->sample1 = predictor;

  340.     c->idelta = (AdaptationTable[(int)nibble] * c->idelta) / 256;

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

  342. 

  343.     return (short)predictor;

  344. }

  345. 

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

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

  348. {

  349.     int i, j;

  350.     int shift,filter,f0,f1;

  351.     int s_1,s_2;

  352.     int d,s,t;

  353. 

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

  355. 

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

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

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

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

  360. 

  361.         s_1 = left->sample1;

  362.         s_2 = left->sample2;

  363. 

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

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

  366. 

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

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

  369.             CLAMP_TO_SHORT(s);

  370.             *out = s;

  371.             out += inc;

  372.             s_2 = s_1;

  373.             s_1 = s;

  374.         }

  375. 

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

  377.             left->sample1 = s_1;

  378.             left->sample2 = s_2;

  379.             s_1 = right->sample1;

  380.             s_2 = right->sample2;

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

  382.         }

  383. 

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

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

  386. 

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

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

  389. 

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

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

  392. 

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

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

  395.             CLAMP_TO_SHORT(s);

  396.             *out = s;

  397.             out += inc;

  398.             s_2 = s_1;

  399.             s_1 = s;

  400.         }

  401. 

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

  403.             right->sample1 = s_1;

  404.             right->sample2 = s_2;

  405.             out -= 1;

  406.         } else {

  407.             left->sample1 = s_1;

  408.             left->sample2 = s_2;

  409.         }

  410.     }

  411. }

  412. 

  413. 

  414. /* DK3 ADPCM support macro */

  415. #define DK3_GET_NEXT_NIBBLE() \

  416.     if (decode_top_nibble_next) \

  417.     { \

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

  419.         decode_top_nibble_next = 0; \

  420.     } \

  421.     else \

  422.     { \

  423.         last_byte = *src++; \

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

  425.         nibble = last_byte & 0x0F; \

  426.         decode_top_nibble_next = 1; \

  427.     }

  428. 

  429. static int adpcm_decode_frame(AVCodecContext *avctx,

  430. 			    void *data, int *data_size,

  431. 			    uint8_t *buf, int buf_size)

  432. {

  433.     ADPCMContext *c = avctx->priv_data;

  434.     ADPCMChannelStatus *cs;

  435.     int n, m, channel, i;

  436.     int block_predictor[2];

  437.     short *samples;

  438.     uint8_t *src;

  439.     int st; /* stereo */

  440. 

  441.     /* DK3 ADPCM accounting variables */

  442.     unsigned char last_byte = 0;

  443.     unsigned char nibble;

  444.     int decode_top_nibble_next = 0;

  445.     int diff_channel;

  446. 

  447.     if (!buf_size)

  448.         return 0;

  449. 

  450.     samples = data;

  451.     src = buf;

  452. 

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

  454. 

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

  456.     case CODEC_ID_ADPCM_IMA_QT:

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

  458.         channel = c->channel;

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

  460.         /* (pppppp) (piiiiiii) */

  461. 

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

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

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

  465.         cs->predictor &= 0xFF80;

  466. 

  467.         /* sign extension */

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

  469.             cs->predictor -= 0x10000;

  470. 

  471.         CLAMP_TO_SHORT(cs->predictor);

  472. 

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

  474. 

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

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

  477. 

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

  479. 

  480.         if (st && channel)

  481.             samples++;

  482. 

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

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

  485.             samples += avctx->channels;

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

  487.             samples += avctx->channels;

  488.             src ++;

  489.         }

  490. 

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

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

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

  494.                 *data_size = 0;

  495.                 return src - buf;

  496.             }

  497.         }

  498.         break;

  499.     case CODEC_ID_ADPCM_IMA_WAV:

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

  501.             buf_size = avctx->block_align;

  502. 

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

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

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

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

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

  508.                 cs->predictor -= 0x10000;

  509.             CLAMP_TO_SHORT(cs->predictor);

  510. 

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

  512. 

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

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

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

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

  517.         }

  518. 

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

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

  521.             if (st)

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

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

  524. 	    if (st) {

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

  526. 		if (!--m) {

  527. 		    m=4;

  528. 		    src+=4;

  529. 		}

  530. 	    }

  531. 	    src++;

  532. 	}

  533.         break;

  534.     case CODEC_ID_ADPCM_4XM:

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

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

  537.         if(st){

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

  539.         }

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

  541.         if(st){

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

  543.         }

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

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

  546. 

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

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

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

  550.             if (st)

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

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

  553. 	    if (st)

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

  555. 	}

  556. 

  557.         src += m<<st;

  558. 

  559.         break;

  560.     case CODEC_ID_ADPCM_MS:

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

  562.             buf_size = avctx->block_align;

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

  564.         if (n < 0)

  565.             return -1;

  566.         block_predictor[0] = (*src++); /* should be bound */

  567.         block_predictor[0] = (block_predictor[0] < 0)?(0):((block_predictor[0] > 7)?(7):(block_predictor[0]));

  568.         block_predictor[1] = 0;

  569.         if (st)

  570.             block_predictor[1] = (*src++);

  571.         block_predictor[1] = (block_predictor[1] < 0)?(0):((block_predictor[1] > 7)?(7):(block_predictor[1]));

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

  573.         if (c->status[0].idelta & 0x08000)

  574.             c->status[0].idelta -= 0x10000;

  575.         src+=2;

  576.         if (st)

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

  578.         if (st && c->status[1].idelta & 0x08000)

  579.             c->status[1].idelta |= 0xFFFF0000;

  580.         if (st)

  581.             src+=2;

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

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

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

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

  586.         

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

  588.         src+=2;

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

  590.         if (st) src+=2;

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

  592.         src+=2;

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

  594.         if (st) src+=2;

  595. 

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

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

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

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

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

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

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

  603.             src ++;

  604.         }

  605.         break;

  606.     case CODEC_ID_ADPCM_IMA_DK4:

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

  608.             buf_size = avctx->block_align;

  609. 

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

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

  612.         src += 4;

  613.         if(c->status[0].predictor & 0x8000)

  614.             c->status[0].predictor -= 0x10000;

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

  616.         if (st) {

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

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

  619.             src += 4;

  620.             if(c->status[1].predictor & 0x8000)

  621.                 c->status[1].predictor -= 0x10000;

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

  623.         }

  624.         while (src < buf + buf_size) {

  625. 

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

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

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

  629. 

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

  631.              * stereo, or another mono sample */

  632.             if (st)

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

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

  635.             else

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

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

  638. 

  639.             src++;

  640.         }

  641.         break;

  642.     case CODEC_ID_ADPCM_IMA_DK3:

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

  644.             buf_size = avctx->block_align;

  645. 

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

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

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

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

  650.         /* sign extend the predictors */

  651.         if(c->status[0].predictor & 0x8000)

  652.             c->status[0].predictor -= 0x10000;

  653.         if(c->status[1].predictor & 0x8000)

  654.             c->status[1].predictor -= 0x10000;

  655.         src += 16;

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

  657. 

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

  659.          * the buffer is consumed */

  660.         while (1) {

  661. 

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

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

  664. 

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

  666.             DK3_GET_NEXT_NIBBLE();

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

  668. 

  669.             /* process the diff channel predictor */

  670.             DK3_GET_NEXT_NIBBLE();

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

  672. 

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

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

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

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

  677. 

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

  679.             DK3_GET_NEXT_NIBBLE();

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

  681. 

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

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

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

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

  686.         }

  687.         break;

  688.     case CODEC_ID_ADPCM_IMA_WS:

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

  690.         while (src < buf + buf_size) {

  691. 

  692.             if (st) {

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

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

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

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

  697.             } else {

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

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

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

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

  702.             }

  703. 

  704.             src++;

  705.         }

  706.         break;

  707.     case CODEC_ID_ADPCM_XA:

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

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

  710.         while (buf_size >= 128) {

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

  712.                 avctx->channels);

  713.             src += 128;

  714.             samples += 28 * 8;

  715.             buf_size -= 128;

  716.         }

  717.         break;

  718.     default:

  719.         *data_size = 0;

  720.         return -1;

  721.     }

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

  723.     return src - buf;

  724. }

  725. 

  726. 

  727. 

  728. #ifdef CONFIG_ENCODERS

  729. #define ADPCM_ENCODER(id,name)                  \

  730. AVCodec name ## _encoder = {                    \

  731.     #name,                                      \

  732.     CODEC_TYPE_AUDIO,                           \

  733.     id,                                         \

  734.     sizeof(ADPCMContext),                       \

  735.     adpcm_encode_init,                          \

  736.     adpcm_encode_frame,                         \

  737.     adpcm_encode_close,                         \

  738.     NULL,                                       \

  739. };

  740. #else

  741. #define ADPCM_ENCODER(id,name)

  742. #endif

  743. 

  744. #ifdef CONFIG_DECODERS

  745. #define ADPCM_DECODER(id,name)                  \

  746. AVCodec name ## _decoder = {                    \

  747.     #name,                                      \

  748.     CODEC_TYPE_AUDIO,                           \

  749.     id,                                         \

  750.     sizeof(ADPCMContext),                       \

  751.     adpcm_decode_init,                          \

  752.     NULL,                                       \

  753.     NULL,                                       \

  754.     adpcm_decode_frame,                         \

  755. };

  756. #else

  757. #define ADPCM_DECODER(id,name)

  758. #endif

  759. 

  760. #define ADPCM_CODEC(id, name)                   \

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

  762. 

  763. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);

  764. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);

  765. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);

  766. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);

  767. ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WS, adpcm_ima_ws);

  768. ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);

  769. ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);

  770. ADPCM_CODEC(CODEC_ID_ADPCM_XA, adpcm_xa);

  771. ADPCM_CODEC(CODEC_ID_ADPCM_ADX, adpcm_adx);

  772. 

  773. #undef ADPCM_CODEC