libavcodec/dpcm.c

   1 /*
   2  * Assorted DPCM codecs
   3  * Copyright (c) 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
  22 /**
  23  * @file: dpcm.c
  24  * Assorted DPCM (differential pulse code modulation) audio codecs
  25  * by Mike Melanson (melanson@pcisys.net)
  26  * Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt)
  27  * for more information on the specific data formats, visit:
  28  *   http://www.pcisys.net/~melanson/codecs/simpleaudio.html
  29  * SOL DPCMs implemented by Konstantin Shishkov
  30  *
  31  * Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files
  32  * found in the Wing Commander IV computer game. These AVI files contain
  33  * WAVEFORMAT headers which report the audio format as 0x01: raw PCM.
  34  * Clearly incorrect. To detect Xan DPCM, you will probably have to
  35  * special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan'
  36  * (Xan video) for its video codec. Alternately, such AVI files also contain
  37  * the fourcc 'Axan' in the 'auds' chunk of the AVI header.
  38  */
  39
  40 #include "avcodec.h"
  41
  42 typedef struct DPCMContext {
  43     int channels;
  44     short roq_square_array[256];
  45     long sample[2];//for SOL_DPCM
  46     const int *sol_table;//for SOL_DPCM
  47 } DPCMContext;
  48
  49 #define SE_16BIT(x)  if (x & 0x8000) x -= 0x10000;
  50
  51 static int interplay_delta_table[] = {
  52          0,      1,      2,      3,      4,      5,      6,      7,
  53          8,      9,     10,     11,     12,     13,     14,     15,
  54         16,     17,     18,     19,     20,     21,     22,     23,
  55         24,     25,     26,     27,     28,     29,     30,     31,
  56         32,     33,     34,     35,     36,     37,     38,     39,
  57         40,     41,     42,     43,     47,     51,     56,     61,
  58         66,     72,     79,     86,     94,    102,    112,    122,
  59        133,    145,    158,    173,    189,    206,    225,    245,
  60        267,    292,    318,    348,    379,    414,    452,    493,
  61        538,    587,    640,    699,    763,    832,    908,    991,
  62       1081,   1180,   1288,   1405,   1534,   1673,   1826,   1993,
  63       2175,   2373,   2590,   2826,   3084,   3365,   3672,   4008,
  64       4373,   4772,   5208,   5683,   6202,   6767,   7385,   8059,
  65       8794,   9597,  10472,  11428,  12471,  13609,  14851,  16206,
  66      17685,  19298,  21060,  22981,  25078,  27367,  29864,  32589,
  67     -29973, -26728, -23186, -19322, -15105, -10503,  -5481,     -1,
  68          1,      1,   5481,  10503,  15105,  19322,  23186,  26728,
  69      29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
  70     -17685, -16206, -14851, -13609, -12471, -11428, -10472,  -9597,
  71      -8794,  -8059,  -7385,  -6767,  -6202,  -5683,  -5208,  -4772,
  72      -4373,  -4008,  -3672,  -3365,  -3084,  -2826,  -2590,  -2373,
  73      -2175,  -1993,  -1826,  -1673,  -1534,  -1405,  -1288,  -1180,
  74      -1081,   -991,   -908,   -832,   -763,   -699,   -640,   -587,
  75       -538,   -493,   -452,   -414,   -379,   -348,   -318,   -292,
  76       -267,   -245,   -225,   -206,   -189,   -173,   -158,   -145,
  77       -133,   -122,   -112,   -102,    -94,    -86,    -79,    -72,
  78        -66,    -61,    -56,    -51,    -47,    -43,    -42,    -41,
  79        -40,    -39,    -38,    -37,    -36,    -35,    -34,    -33,
  80        -32,    -31,    -30,    -29,    -28,    -27,    -26,    -25,
  81        -24,    -23,    -22,    -21,    -20,    -19,    -18,    -17,
  82        -16,    -15,    -14,    -13,    -12,    -11,    -10,     -9,
  83         -8,     -7,     -6,     -5,     -4,     -3,     -2,     -1
  84
  85 };
  86
  87 static const int sol_table_old[16] =
  88     { 0x0,  0x1,  0x2 , 0x3,  0x6,  0xA,  0xF, 0x15,
  89     -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0};
  90
  91 static const int sol_table_new[16] =
  92     { 0x0,  0x1,  0x2,  0x3,  0x6,  0xA,  0xF,  0x15,
  93       0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15};
  94
  95 static const int sol_table_16[128] = {
  96     0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
  97     0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
  98     0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
  99     0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
 100     0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
 101     0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
 102     0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
 103     0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
 104     0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
 105     0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
 106     0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
 107     0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
 108     0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
 109 };
 110
 111
 112
 113 static av_cold int dpcm_decode_init(AVCodecContext *avctx)
 114 {
 115     DPCMContext *s = avctx->priv_data;
 116     int i;
 117     short square;
 118
 119     s->channels = avctx->channels;
 120     s->sample[0] = s->sample[1] = 0;
 121
 122     switch(avctx->codec->id) {
 123
 124     case CODEC_ID_ROQ_DPCM:
 125         /* initialize square table */
 126         for (i = 0; i < 128; i++) {
 127             square = i * i;
 128             s->roq_square_array[i] = square;
 129             s->roq_square_array[i + 128] = -square;
 130         }
 131         break;
 132
 133
 134     case CODEC_ID_SOL_DPCM:
 135         switch(avctx->codec_tag){
 136         case 1:
 137             s->sol_table=sol_table_old;
 138             s->sample[0] = s->sample[1] = 0x80;
 139             break;
 140         case 2:
 141             s->sol_table=sol_table_new;
 142             s->sample[0] = s->sample[1] = 0x80;
 143             break;
 144         case 3:
 145             s->sol_table=sol_table_16;
 146             break;
 147         default:
 148             av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
 149             return -1;
 150         }
 151         break;
 152
 153     default:
 154         break;
 155     }
 156
 157     return 0;
 158 }
 159
 160 static int dpcm_decode_frame(AVCodecContext *avctx,
 161                              void *data, int *data_size,
 162                              const uint8_t *buf, int buf_size)
 163 {
 164     DPCMContext *s = avctx->priv_data;
 165     int in, out = 0;
 166     int predictor[2];
 167     int channel_number = 0;
 168     short *output_samples = data;
 169     int shift[2];
 170     unsigned char byte;
 171     short diff;
 172
 173     if (!buf_size)
 174         return 0;
 175
 176     // almost every DPCM variant expands one byte of data into two
 177     if(*data_size/2 < buf_size)
 178         return -1;
 179
 180     switch(avctx->codec->id) {
 181
 182     case CODEC_ID_ROQ_DPCM:
 183         if (s->channels == 1)
 184             predictor[0] = AV_RL16(&buf[6]);
 185         else {
 186             predictor[0] = buf[7] << 8;
 187             predictor[1] = buf[6] << 8;
 188         }
 189         SE_16BIT(predictor[0]);
 190         SE_16BIT(predictor[1]);
 191
 192         /* decode the samples */
 193         for (in = 8, out = 0; in < buf_size; in++, out++) {
 194             predictor[channel_number] += s->roq_square_array[buf[in]];
 195             predictor[channel_number] = av_clip_int16(predictor[channel_number]);
 196             output_samples[out] = predictor[channel_number];
 197
 198             /* toggle channel */
 199             channel_number ^= s->channels - 1;
 200         }
 201         break;
 202
 203     case CODEC_ID_INTERPLAY_DPCM:
 204         in = 6;  /* skip over the stream mask and stream length */
 205         predictor[0] = AV_RL16(&buf[in]);
 206         in += 2;
 207         SE_16BIT(predictor[0])
 208         output_samples[out++] = predictor[0];
 209         if (s->channels == 2) {
 210             predictor[1] = AV_RL16(&buf[in]);
 211             in += 2;
 212             SE_16BIT(predictor[1])
 213             output_samples[out++] = predictor[1];
 214         }
 215
 216         while (in < buf_size) {
 217             predictor[channel_number] += interplay_delta_table[buf[in++]];
 218             predictor[channel_number] = av_clip_int16(predictor[channel_number]);
 219             output_samples[out++] = predictor[channel_number];
 220
 221             /* toggle channel */
 222             channel_number ^= s->channels - 1;
 223         }
 224
 225         break;
 226
 227     case CODEC_ID_XAN_DPCM:
 228         in = 0;
 229         shift[0] = shift[1] = 4;
 230         predictor[0] = AV_RL16(&buf[in]);
 231         in += 2;
 232         SE_16BIT(predictor[0]);
 233         if (s->channels == 2) {
 234             predictor[1] = AV_RL16(&buf[in]);
 235             in += 2;
 236             SE_16BIT(predictor[1]);
 237         }
 238
 239         while (in < buf_size) {
 240             byte = buf[in++];
 241             diff = (byte & 0xFC) << 8;
 242             if ((byte & 0x03) == 3)
 243                 shift[channel_number]++;
 244             else
 245                 shift[channel_number] -= (2 * (byte & 3));
 246             /* saturate the shifter to a lower limit of 0 */
 247             if (shift[channel_number] < 0)
 248                 shift[channel_number] = 0;
 249
 250             diff >>= shift[channel_number];
 251             predictor[channel_number] += diff;
 252
 253             predictor[channel_number] = av_clip_int16(predictor[channel_number]);
 254             output_samples[out++] = predictor[channel_number];
 255
 256             /* toggle channel */
 257             channel_number ^= s->channels - 1;
 258         }
 259         break;
 260     case CODEC_ID_SOL_DPCM:
 261         in = 0;
 262         if (avctx->codec_tag != 3) {
 263             if(*data_size/4 < buf_size)
 264                 return -1;
 265             while (in < buf_size) {
 266                 int n1, n2;
 267                 n1 = (buf[in] >> 4) & 0xF;
 268                 n2 = buf[in++] & 0xF;
 269                 s->sample[0] += s->sol_table[n1];
 270                  if (s->sample[0] < 0) s->sample[0] = 0;
 271                 if (s->sample[0] > 255) s->sample[0] = 255;
 272                 output_samples[out++] = (s->sample[0] - 128) << 8;
 273                 s->sample[s->channels - 1] += s->sol_table[n2];
 274                 if (s->sample[s->channels - 1] < 0) s->sample[s->channels - 1] = 0;
 275                 if (s->sample[s->channels - 1] > 255) s->sample[s->channels - 1] = 255;
 276                 output_samples[out++] = (s->sample[s->channels - 1] - 128) << 8;
 277             }
 278         } else {
 279             while (in < buf_size) {
 280                 int n;
 281                 n = buf[in++];
 282                 if (n & 0x80) s->sample[channel_number] -= s->sol_table[n & 0x7F];
 283                 else s->sample[channel_number] += s->sol_table[n & 0x7F];
 284                 s->sample[channel_number] = av_clip_int16(s->sample[channel_number]);
 285                 output_samples[out++] = s->sample[channel_number];
 286                 /* toggle channel */
 287                 channel_number ^= s->channels - 1;
 288             }
 289         }
 290         break;
 291     }
 292
 293     *data_size = out * sizeof(short);
 294     return buf_size;
 295 }
 296
 297 #define DPCM_DECODER(id, name, long_name_)      \
 298 AVCodec name ## _decoder = {                    \
 299     #name,                                      \
 300     CODEC_TYPE_AUDIO,                           \
 301     id,                                         \
 302     sizeof(DPCMContext),                        \
 303     dpcm_decode_init,                           \
 304     NULL,                                       \
 305     NULL,                                       \
 306     dpcm_decode_frame,                          \
 307     .long_name = long_name_,                    \
 308 };
 309
 310 DPCM_DECODER(CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "Interplay DPCM");
 311 DPCM_DECODER(CODEC_ID_ROQ_DPCM, roq_dpcm, "id RoQ DPCM");
 312 DPCM_DECODER(CODEC_ID_SOL_DPCM, sol_dpcm, "Sol DPCM");
 313 DPCM_DECODER(CODEC_ID_XAN_DPCM, xan_dpcm, "Xan DPCM");