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 <libavutil/intreadwrite.h>
  36
  37 #include "config.h"
  38 #include "ad_internal.h"
  39
  40 static const ad_info_t info =
  41 {
  42         "Duck Corp. DK3 ADPCM decoder",
  43         "dk3adpcm",
  44         "Nick Kurshev",
  45         "Mike Melanson",
  46         ""
  47 };
  48
  49 LIBAD_EXTERN(dk3adpcm)
  50
  51 #define DK3_ADPCM_PREAMBLE_SIZE 16
  52
  53 // useful macros
  54 // clamp a number between 0 and 88
  55 #define CLAMP_0_TO_88(x)  if (x < 0) x = 0; else if (x > 88) x = 88;
  56 // clamp a number within a signed 16-bit range
  57 #define CLAMP_S16(x)  if (x < -32768) x = -32768; \
  58   else if (x > 32767) x = 32767;
  59 // clamp a number above 16
  60 #define CLAMP_ABOVE_16(x)  if (x < 16) x = 16;
  61 // sign extend a 16-bit value
  62 #define SE_16BIT(x)  if (x & 0x8000) x -= 0x10000;
  63 // sign extend a 4-bit value
  64 #define SE_4BIT(x)  if (x & 0x8) x -= 0x10;
  65
  66 // pertinent tables
  67 static int adpcm_step[89] =
  68 {
  69   7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
  70   19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
  71   50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
  72   130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
  73   337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
  74   876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
  75   2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
  76   5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
  77   15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
  78 };
  79
  80 static int adpcm_index[16] =
  81 {
  82   -1, -1, -1, -1, 2, 4, 6, 8,
  83   -1, -1, -1, -1, 2, 4, 6, 8
  84 };
  85
  86 static int preinit(sh_audio_t *sh_audio)
  87 {
  88   sh_audio->audio_out_minsize = sh_audio->wf->nBlockAlign * 6;
  89   sh_audio->ds->ss_div =
  90     (sh_audio->wf->nBlockAlign - DK3_ADPCM_PREAMBLE_SIZE) * 8 / 3;
  91   sh_audio->audio_in_minsize=
  92   sh_audio->ds->ss_mul = sh_audio->wf->nBlockAlign;
  93   return 1;
  94 }
  95
  96 static int init(sh_audio_t *sh_audio)
  97 {
  98   sh_audio->channels = sh_audio->wf->nChannels;
  99   sh_audio->samplerate = sh_audio->wf->nSamplesPerSec;
 100   sh_audio->i_bps =
 101     (sh_audio->ds->ss_mul * sh_audio->samplerate) / sh_audio->ds->ss_div;
 102   sh_audio->samplesize=2;
 103   return 1;
 104 }
 105
 106 static void uninit(sh_audio_t *sh_audio)
 107 {
 108 }
 109
 110 static int control(sh_audio_t *sh_audio,int cmd,void* arg, ...)
 111 {
 112   if(cmd==ADCTRL_SKIP_FRAME){
 113     demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,sh_audio->ds->ss_mul);
 114     return CONTROL_TRUE;
 115   }
 116   return CONTROL_UNKNOWN;
 117 }
 118
 119 #define DK3_GET_NEXT_NIBBLE() \
 120     if (decode_top_nibble_next) \
 121     { \
 122       nibble = (last_byte >> 4) & 0x0F; \
 123       decode_top_nibble_next = 0; \
 124     } \
 125     else \
 126     { \
 127       last_byte = input[in_ptr++]; \
 128       nibble = last_byte & 0x0F; \
 129       decode_top_nibble_next = 1; \
 130     }
 131
 132 // note: This decoder assumes the format 0x62 data always comes in
 133 // stereo flavor
 134 static int dk3_adpcm_decode_block(unsigned short *output, unsigned char *input,
 135   int block_size)
 136 {
 137   int sum_pred;
 138   int diff_pred;
 139   int sum_index;
 140   int diff_index;
 141   int diff_channel;
 142   int in_ptr = 0x10;
 143   int out_ptr = 0;
 144
 145   unsigned char last_byte = 0;
 146   unsigned char nibble;
 147   int decode_top_nibble_next = 0;
 148
 149   // ADPCM work variables
 150   int sign;
 151   int delta;
 152   int step;
 153   int diff;
 154
 155   sum_pred = AV_RL16(&input[10]);
 156   diff_pred = AV_RL16(&input[12]);
 157   SE_16BIT(sum_pred);
 158   SE_16BIT(diff_pred);
 159   diff_channel = diff_pred;
 160   sum_index = input[14];
 161   diff_index = input[15];
 162
 163   while (in_ptr < block_size - !decode_top_nibble_next)
 164 //  while (in_ptr < 2048)
 165   {
 166     // process the first predictor of the sum channel
 167     DK3_GET_NEXT_NIBBLE();
 168
 169     step = adpcm_step[sum_index];
 170
 171     sign = nibble & 8;
 172     delta = nibble & 7;
 173
 174     diff = step >> 3;
 175     if (delta & 4) diff += step;
 176     if (delta & 2) diff += step >> 1;
 177     if (delta & 1) diff += step >> 2;
 178
 179     if (sign)
 180       sum_pred -= diff;
 181     else
 182       sum_pred += diff;
 183
 184     CLAMP_S16(sum_pred);
 185
 186     sum_index += adpcm_index[nibble];
 187     CLAMP_0_TO_88(sum_index);
 188
 189     // process the diff channel predictor
 190     DK3_GET_NEXT_NIBBLE();
 191
 192     step = adpcm_step[diff_index];
 193
 194     sign = nibble & 8;
 195     delta = nibble & 7;
 196
 197     diff = step >> 3;
 198     if (delta & 4) diff += step;
 199     if (delta & 2) diff += step >> 1;
 200     if (delta & 1) diff += step >> 2;
 201
 202     if (sign)
 203       diff_pred -= diff;
 204     else
 205       diff_pred += diff;
 206
 207     CLAMP_S16(diff_pred);
 208
 209     diff_index += adpcm_index[nibble];
 210     CLAMP_0_TO_88(diff_index);
 211
 212     // output the first pair of stereo PCM samples
 213     diff_channel = (diff_channel + diff_pred) / 2;
 214     output[out_ptr++] = sum_pred + diff_channel;
 215     output[out_ptr++] = sum_pred - diff_channel;
 216
 217     // process the second predictor of the sum channel
 218     DK3_GET_NEXT_NIBBLE();
 219
 220     step = adpcm_step[sum_index];
 221
 222     sign = nibble & 8;
 223     delta = nibble & 7;
 224
 225     diff = step >> 3;
 226     if (delta & 4) diff += step;
 227     if (delta & 2) diff += step >> 1;
 228     if (delta & 1) diff += step >> 2;
 229
 230     if (sign)
 231       sum_pred -= diff;
 232     else
 233       sum_pred += diff;
 234
 235     CLAMP_S16(sum_pred);
 236
 237     sum_index += adpcm_index[nibble];
 238     CLAMP_0_TO_88(sum_index);
 239
 240     // output the second pair of stereo PCM samples
 241     output[out_ptr++] = sum_pred + diff_channel;
 242     output[out_ptr++] = sum_pred - diff_channel;
 243   }
 244
 245   return out_ptr;
 246 }
 247
 248 static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
 249 {
 250   if (demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,
 251     sh_audio->ds->ss_mul) !=
 252     sh_audio->ds->ss_mul)
 253       return -1; /* EOF */
 254
 255   if (maxlen < 2 * 4 * sh_audio->wf->nBlockAlign * 2 / 3) {
 256     mp_msg(MSGT_DECAUDIO, MSGL_V, "dk3adpcm: maxlen too small in decode_audio\n");
 257     return -1;
 258   }
 259   return 2 * dk3_adpcm_decode_block(
 260     (unsigned short*)buf, sh_audio->a_in_buffer,
 261     sh_audio->ds->ss_mul);
 262 }