libmpcodecs/ad_dk3adpcm.c

   1 /*
   2  * DK3 ADPCM decoder
   3  *
   4  * "This format number was used by Duck Corp. but not officially
   5  * registered with Microsoft"
   6  *
   7  * This file is responsible for decoding audio data encoded with
   8  * Duck Corp's DK3 ADPCM algorithm. Details about the data format
   9  * can be found here:
  10  *   http://www.pcisys.net/~melanson/codecs/
  11  *
  12  * Copyright (c) 2002 Mike Melanson
  13  *
  14  * This file is part of MPlayer.
  15  *
  16  * MPlayer is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License as published by
  18  * the Free Software Foundation; either version 2 of the License, or
  19  * (at your option) any later version.
  20  *
  21  * MPlayer is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License along
  27  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  28  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  29  */
  30
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <unistd.h>
  34
  35 #include "config.h"
  36 #include "ffmpeg_files/intreadwrite.h"
  37 #include "ad_internal.h"
  38
  39 static const ad_info_t info =
  40 {
  41         "Duck Corp. DK3 ADPCM decoder",
  42         "dk3adpcm",
  43         "Nick Kurshev",
  44         "Mike Melanson",
  45         ""
  46 };
  47
  48 LIBAD_EXTERN(dk3adpcm)
  49
  50 #define DK3_ADPCM_PREAMBLE_SIZE 16
  51
  52 // useful macros
  53 // clamp a number between 0 and 88
  54 #define CLAMP_0_TO_88(x)  if (x < 0) x = 0; else if (x > 88) x = 88;
  55 // clamp a number within a signed 16-bit range
  56 #define CLAMP_S16(x)  if (x < -32768) x = -32768; \
  57   else if (x > 32767) x = 32767;
  58 // clamp a number above 16
  59 #define CLAMP_ABOVE_16(x)  if (x < 16) x = 16;
  60 // sign extend a 16-bit value
  61 #define SE_16BIT(x)  if (x & 0x8000) x -= 0x10000;
  62 // sign extend a 4-bit value
  63 #define SE_4BIT(x)  if (x & 0x8) x -= 0x10;
  64
  65 // pertinent tables
  66 static int adpcm_step[89] =
  67 {
  68   7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
  69   19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
  70   50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
  71   130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
  72   337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
  73   876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
  74   2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
  75   5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
  76   15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
  77 };
  78
  79 static int adpcm_index[16] =
  80 {
  81   -1, -1, -1, -1, 2, 4, 6, 8,
  82   -1, -1, -1, -1, 2, 4, 6, 8
  83 };
  84
  85 static int preinit(sh_audio_t *sh_audio)
  86 {
  87   sh_audio->audio_out_minsize = sh_audio->wf->nBlockAlign * 6;
  88   sh_audio->ds->ss_div =
  89     (sh_audio->wf->nBlockAlign - DK3_ADPCM_PREAMBLE_SIZE) * 8 / 3;
  90   sh_audio->audio_in_minsize=
  91   sh_audio->ds->ss_mul = sh_audio->wf->nBlockAlign;
  92   return 1;
  93 }
  94
  95 static int init(sh_audio_t *sh_audio)
  96 {
  97   sh_audio->channels = sh_audio->wf->nChannels;
  98   sh_audio->samplerate = sh_audio->wf->nSamplesPerSec;
  99   sh_audio->i_bps =
 100     (sh_audio->ds->ss_mul * sh_audio->samplerate) / sh_audio->ds->ss_div;
 101   sh_audio->samplesize=2;
 102   return 1;
 103 }
 104
 105 static void uninit(sh_audio_t *sh_audio)
 106 {
 107 }
 108
 109 static int control(sh_audio_t *sh_audio,int cmd,void* arg, ...)
 110 {
 111   if(cmd==ADCTRL_SKIP_FRAME){
 112     demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,sh_audio->ds->ss_mul);
 113     return CONTROL_TRUE;
 114   }
 115   return CONTROL_UNKNOWN;
 116 }
 117
 118 #define DK3_GET_NEXT_NIBBLE() \
 119     if (decode_top_nibble_next) \
 120     { \
 121       nibble = (last_byte >> 4) & 0x0F; \
 122       decode_top_nibble_next = 0; \
 123     } \
 124     else \
 125     { \
 126       last_byte = input[in_ptr++]; \
 127       nibble = last_byte & 0x0F; \
 128       decode_top_nibble_next = 1; \
 129     }
 130
 131 // note: This decoder assumes the format 0x62 data always comes in
 132 // stereo flavor
 133 static int dk3_adpcm_decode_block(unsigned short *output, unsigned char *input,
 134   int block_size)
 135 {
 136   int sum_pred;
 137   int diff_pred;
 138   int sum_index;
 139   int diff_index;
 140   int diff_channel;
 141   int in_ptr = 0x10;
 142   int out_ptr = 0;
 143
 144   unsigned char last_byte = 0;
 145   unsigned char nibble;
 146   int decode_top_nibble_next = 0;
 147
 148   // ADPCM work variables
 149   int sign;
 150   int delta;
 151   int step;
 152   int diff;
 153
 154   sum_pred = AV_RL16(&input[10]);
 155   diff_pred = AV_RL16(&input[12]);
 156   SE_16BIT(sum_pred);
 157   SE_16BIT(diff_pred);
 158   diff_channel = diff_pred;
 159   sum_index = input[14];
 160   diff_index = input[15];
 161
 162   while (in_ptr < block_size - !decode_top_nibble_next)
 163 //  while (in_ptr < 2048)
 164   {
 165     // process the first predictor of the sum channel
 166     DK3_GET_NEXT_NIBBLE();
 167
 168     step = adpcm_step[sum_index];
 169
 170     sign = nibble & 8;
 171     delta = nibble & 7;
 172
 173     diff = step >> 3;
 174     if (delta & 4) diff += step;
 175     if (delta & 2) diff += step >> 1;
 176     if (delta & 1) diff += step >> 2;
 177
 178     if (sign)
 179       sum_pred -= diff;
 180     else
 181       sum_pred += diff;
 182
 183     CLAMP_S16(sum_pred);
 184
 185     sum_index += adpcm_index[nibble];
 186     CLAMP_0_TO_88(sum_index);
 187
 188     // process the diff channel predictor
 189     DK3_GET_NEXT_NIBBLE();
 190
 191     step = adpcm_step[diff_index];
 192
 193     sign = nibble & 8;
 194     delta = nibble & 7;
 195
 196     diff = step >> 3;
 197     if (delta & 4) diff += step;
 198     if (delta & 2) diff += step >> 1;
 199     if (delta & 1) diff += step >> 2;
 200
 201     if (sign)
 202       diff_pred -= diff;
 203     else
 204       diff_pred += diff;
 205
 206     CLAMP_S16(diff_pred);
 207
 208     diff_index += adpcm_index[nibble];
 209     CLAMP_0_TO_88(diff_index);
 210
 211     // output the first pair of stereo PCM samples
 212     diff_channel = (diff_channel + diff_pred) / 2;
 213     output[out_ptr++] = sum_pred + diff_channel;
 214     output[out_ptr++] = sum_pred - diff_channel;
 215
 216     // process the second predictor of the sum channel
 217     DK3_GET_NEXT_NIBBLE();
 218
 219     step = adpcm_step[sum_index];
 220
 221     sign = nibble & 8;
 222     delta = nibble & 7;
 223
 224     diff = step >> 3;
 225     if (delta & 4) diff += step;
 226     if (delta & 2) diff += step >> 1;
 227     if (delta & 1) diff += step >> 2;
 228
 229     if (sign)
 230       sum_pred -= diff;
 231     else
 232       sum_pred += diff;
 233
 234     CLAMP_S16(sum_pred);
 235
 236     sum_index += adpcm_index[nibble];
 237     CLAMP_0_TO_88(sum_index);
 238
 239     // output the second pair of stereo PCM samples
 240     output[out_ptr++] = sum_pred + diff_channel;
 241     output[out_ptr++] = sum_pred - diff_channel;
 242   }
 243
 244   return out_ptr;
 245 }
 246
 247 static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
 248 {
 249   if (demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,
 250     sh_audio->ds->ss_mul) !=
 251     sh_audio->ds->ss_mul)
 252       return -1; /* EOF */
 253
 254   if (maxlen < 2 * 4 * sh_audio->wf->nBlockAlign * 2 / 3) {
 255     mp_msg(MSGT_DECAUDIO, MSGL_V, "dk3adpcm: maxlen too small in decode_audio\n");
 256     return -1;
 257   }
 258   return 2 * dk3_adpcm_decode_block(
 259     (unsigned short*)buf, sh_audio->a_in_buffer,
 260     sh_audio->ds->ss_mul);
 261 }