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 const 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     avctx->sample_fmt = SAMPLE_FMT_S16;
 158     return 0;
 159 }
 160
 161 static int dpcm_decode_frame(AVCodecContext *avctx,
 162                              void *data, int *data_size,
 163                              const uint8_t *buf, int buf_size)
 164 {
 165     DPCMContext *s = avctx->priv_data;
 166     int in, out = 0;
 167     int predictor[2];
 168     int channel_number = 0;
 169     short *output_samples = data;
 170     int shift[2];
 171     unsigned char byte;
 172     short diff;
 173
 174     if (!buf_size)
 175         return 0;
 176
 177     // almost every DPCM variant expands one byte of data into two
 178     if(*data_size/2 < buf_size)
 179         return -1;
 180
 181     switch(avctx->codec->id) {
 182
 183     case CODEC_ID_ROQ_DPCM:
 184         if (s->channels == 1)
 185             predictor[0] = AV_RL16(&buf[6]);
 186         else {
 187             predictor[0] = buf[7] << 8;
 188             predictor[1] = buf[6] << 8;
 189         }
 190         SE_16BIT(predictor[0]);
 191         SE_16BIT(predictor[1]);
 192
 193         /* decode the samples */
 194         for (in = 8, out = 0; in < buf_size; in++, out++) {
 195             predictor[channel_number] += s->roq_square_array[buf[in]];
 196             predictor[channel_number] = av_clip_int16(predictor[channel_number]);
 197             output_samples[out] = predictor[channel_number];
 198
 199             /* toggle channel */
 200             channel_number ^= s->channels - 1;
 201         }
 202         break;
 203
 204     case CODEC_ID_INTERPLAY_DPCM:
 205         in = 6;  /* skip over the stream mask and stream length */
 206         predictor[0] = AV_RL16(&buf[in]);
 207         in += 2;
 208         SE_16BIT(predictor[0])
 209         output_samples[out++] = predictor[0];
 210         if (s->channels == 2) {
 211             predictor[1] = AV_RL16(&buf[in]);
 212             in += 2;
 213             SE_16BIT(predictor[1])
 214             output_samples[out++] = predictor[1];
 215         }
 216
 217         while (in < buf_size) {
 218             predictor[channel_number] += interplay_delta_table[buf[in++]];
 219             predictor[channel_number] = av_clip_int16(predictor[channel_number]);
 220             output_samples[out++] = predictor[channel_number];
 221
 222             /* toggle channel */
 223             channel_number ^= s->channels - 1;
 224         }
 225
 226         break;
 227
 228     case CODEC_ID_XAN_DPCM:
 229         in = 0;
 230         shift[0] = shift[1] = 4;
 231         predictor[0] = AV_RL16(&buf[in]);
 232         in += 2;
 233         SE_16BIT(predictor[0]);
 234         if (s->channels == 2) {
 235             predictor[1] = AV_RL16(&buf[in]);
 236             in += 2;
 237             SE_16BIT(predictor[1]);
 238         }
 239
 240         while (in < buf_size) {
 241             byte = buf[in++];
 242             diff = (byte & 0xFC) << 8;
 243             if ((byte & 0x03) == 3)
 244                 shift[channel_number]++;
 245             else
 246                 shift[channel_number] -= (2 * (byte & 3));
 247             /* saturate the shifter to a lower limit of 0 */
 248             if (shift[channel_number] < 0)
 249                 shift[channel_number] = 0;
 250
 251             diff >>= shift[channel_number];
 252             predictor[channel_number] += diff;
 253
 254             predictor[channel_number] = av_clip_int16(predictor[channel_number]);
 255             output_samples[out++] = predictor[channel_number];
 256
 257             /* toggle channel */
 258             channel_number ^= s->channels - 1;
 259         }
 260         break;
 261     case CODEC_ID_SOL_DPCM:
 262         in = 0;
 263         if (avctx->codec_tag != 3) {
 264             if(*data_size/4 < buf_size)
 265                 return -1;
 266             while (in < buf_size) {
 267                 int n1, n2;
 268                 n1 = (buf[in] >> 4) & 0xF;
 269                 n2 = buf[in++] & 0xF;
 270                 s->sample[0] += s->sol_table[n1];
 271                  if (s->sample[0] < 0) s->sample[0] = 0;
 272                 if (s->sample[0] > 255) s->sample[0] = 255;
 273                 output_samples[out++] = (s->sample[0] - 128) << 8;
 274                 s->sample[s->channels - 1] += s->sol_table[n2];
 275                 if (s->sample[s->channels - 1] < 0) s->sample[s->channels - 1] = 0;
 276                 if (s->sample[s->channels - 1] > 255) s->sample[s->channels - 1] = 255;
 277                 output_samples[out++] = (s->sample[s->channels - 1] - 128) << 8;
 278             }
 279         } else {
 280             while (in < buf_size) {
 281                 int n;
 282                 n = buf[in++];
 283                 if (n & 0x80) s->sample[channel_number] -= s->sol_table[n & 0x7F];
 284                 else s->sample[channel_number] += s->sol_table[n & 0x7F];
 285                 s->sample[channel_number] = av_clip_int16(s->sample[channel_number]);
 286                 output_samples[out++] = s->sample[channel_number];
 287                 /* toggle channel */
 288                 channel_number ^= s->channels - 1;
 289             }
 290         }
 291         break;
 292     }
 293
 294     *data_size = out * sizeof(short);
 295     return buf_size;
 296 }
 297
 298 #define DPCM_DECODER(id, name, long_name_)      \
 299 AVCodec name ## _decoder = {                    \
 300     #name,                                      \
 301     CODEC_TYPE_AUDIO,                           \
 302     id,                                         \
 303     sizeof(DPCMContext),                        \
 304     dpcm_decode_init,                           \
 305     NULL,                                       \
 306     NULL,                                       \
 307     dpcm_decode_frame,                          \
 308     .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
 309 };
 310
 311 DPCM_DECODER(CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "Interplay DPCM");
 312 DPCM_DECODER(CODEC_ID_ROQ_DPCM, roq_dpcm, "id RoQ DPCM");
 313 DPCM_DECODER(CODEC_ID_SOL_DPCM, sol_dpcm, "Sol DPCM");
 314 DPCM_DECODER(CODEC_ID_XAN_DPCM, xan_dpcm, "Xan DPCM");