libmpcodecs/ad_dk3adpcm.c

   1 /*
   2     DK3 ADPCM Decoder for MPlayer
   3       by Mike Melanson
   4
   5     "This format number was used by Duck Corp. but not officially
   6     registered with Microsoft"
   7
   8     This file is responsible for decoding audio data encoded with
   9     Duck Corp's DK3 ADPCM algorithm. Details about the data format
  10     can be found here:
  11       http://www.pcisys.net/~melanson/codecs/
  12 */
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17
  18 #include "config.h"
  19 #include "mpbswap.h"
  20 #include "ad_internal.h"
  21
  22 static ad_info_t info =
  23 {
  24         "Duck Corp. DK3 ADPCM decoder",
  25         "dk3adpcm",
  26         "Nick Kurshev",
  27         "Mike Melanson",
  28         ""
  29 };
  30
  31 LIBAD_EXTERN(dk3adpcm)
  32
  33 #define DK3_ADPCM_PREAMBLE_SIZE 16
  34
  35 #define LE_16(x) (le2me_16(*(unsigned short *)(x)))
  36 #define LE_32(x) (le2me_32(*(unsigned int *)(x)))
  37
  38 // useful macros
  39 // clamp a number between 0 and 88
  40 #define CLAMP_0_TO_88(x)  if (x < 0) x = 0; else if (x > 88) x = 88;
  41 // clamp a number within a signed 16-bit range
  42 #define CLAMP_S16(x)  if (x < -32768) x = -32768; \
  43   else if (x > 32767) x = 32767;
  44 // clamp a number above 16
  45 #define CLAMP_ABOVE_16(x)  if (x < 16) x = 16;
  46 // sign extend a 16-bit value
  47 #define SE_16BIT(x)  if (x & 0x8000) x -= 0x10000;
  48 // sign extend a 4-bit value
  49 #define SE_4BIT(x)  if (x & 0x8) x -= 0x10;
  50
  51 // pertinent tables
  52 static int adpcm_step[89] =
  53 {
  54   7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
  55   19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
  56   50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
  57   130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
  58   337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
  59   876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
  60   2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
  61   5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
  62   15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
  63 };
  64
  65 static int adpcm_index[16] =
  66 {
  67   -1, -1, -1, -1, 2, 4, 6, 8,
  68   -1, -1, -1, -1, 2, 4, 6, 8
  69 };
  70
  71 static int preinit(sh_audio_t *sh_audio)
  72 {
  73   sh_audio->audio_out_minsize = sh_audio->wf->nBlockAlign * 6;
  74   sh_audio->ds->ss_div =
  75     (sh_audio->wf->nBlockAlign - DK3_ADPCM_PREAMBLE_SIZE) * 8 / 3;
  76   sh_audio->audio_in_minsize=
  77   sh_audio->ds->ss_mul = sh_audio->wf->nBlockAlign;
  78   return 1;
  79 }
  80
  81 static int init(sh_audio_t *sh_audio)
  82 {
  83   sh_audio->channels = sh_audio->wf->nChannels;
  84   sh_audio->samplerate = sh_audio->wf->nSamplesPerSec;
  85   sh_audio->i_bps =
  86     (sh_audio->ds->ss_mul * sh_audio->samplerate) / sh_audio->ds->ss_div;
  87   sh_audio->samplesize=2;
  88   return 1;
  89 }
  90
  91 static void uninit(sh_audio_t *sh_audio)
  92 {
  93 }
  94
  95 static int control(sh_audio_t *sh_audio,int cmd,void* arg, ...)
  96 {
  97   if(cmd==ADCTRL_SKIP_FRAME){
  98     demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,sh_audio->ds->ss_mul);
  99     return CONTROL_TRUE;
 100   }
 101   return CONTROL_UNKNOWN;
 102 }
 103
 104 #define DK3_GET_NEXT_NIBBLE() \
 105     if (decode_top_nibble_next) \
 106     { \
 107       nibble = (last_byte >> 4) & 0x0F; \
 108       decode_top_nibble_next = 0; \
 109     } \
 110     else \
 111     { \
 112       last_byte = input[in_ptr++]; \
 113       nibble = last_byte & 0x0F; \
 114       decode_top_nibble_next = 1; \
 115     }
 116
 117 // note: This decoder assumes the format 0x62 data always comes in
 118 // stereo flavor
 119 static int dk3_adpcm_decode_block(unsigned short *output, unsigned char *input,
 120   int block_size)
 121 {
 122   int sum_pred;
 123   int diff_pred;
 124   int sum_index;
 125   int diff_index;
 126   int diff_channel;
 127   int in_ptr = 0x10;
 128   int out_ptr = 0;
 129
 130   unsigned char last_byte = 0;
 131   unsigned char nibble;
 132   int decode_top_nibble_next = 0;
 133
 134   // ADPCM work variables
 135   int sign;
 136   int delta;
 137   int step;
 138   int diff;
 139
 140   sum_pred = LE_16(&input[10]);
 141   diff_pred = LE_16(&input[12]);
 142   SE_16BIT(sum_pred);
 143   SE_16BIT(diff_pred);
 144   diff_channel = diff_pred;
 145   sum_index = input[14];
 146   diff_index = input[15];
 147
 148   while (in_ptr < block_size - !decode_top_nibble_next)
 149 //  while (in_ptr < 2048)
 150   {
 151     // process the first predictor of the sum channel
 152     DK3_GET_NEXT_NIBBLE();
 153
 154     step = adpcm_step[sum_index];
 155
 156     sign = nibble & 8;
 157     delta = nibble & 7;
 158
 159     diff = step >> 3;
 160     if (delta & 4) diff += step;
 161     if (delta & 2) diff += step >> 1;
 162     if (delta & 1) diff += step >> 2;
 163
 164     if (sign)
 165       sum_pred -= diff;
 166     else
 167       sum_pred += diff;
 168
 169     CLAMP_S16(sum_pred);
 170
 171     sum_index += adpcm_index[nibble];
 172     CLAMP_0_TO_88(sum_index);
 173
 174     // process the diff channel predictor
 175     DK3_GET_NEXT_NIBBLE();
 176
 177     step = adpcm_step[diff_index];
 178
 179     sign = nibble & 8;
 180     delta = nibble & 7;
 181
 182     diff = step >> 3;
 183     if (delta & 4) diff += step;
 184     if (delta & 2) diff += step >> 1;
 185     if (delta & 1) diff += step >> 2;
 186
 187     if (sign)
 188       diff_pred -= diff;
 189     else
 190       diff_pred += diff;
 191
 192     CLAMP_S16(diff_pred);
 193
 194     diff_index += adpcm_index[nibble];
 195     CLAMP_0_TO_88(diff_index);
 196
 197     // output the first pair of stereo PCM samples
 198     diff_channel = (diff_channel + diff_pred) / 2;
 199     output[out_ptr++] = sum_pred + diff_channel;
 200     output[out_ptr++] = sum_pred - diff_channel;
 201
 202     // process the second predictor of the sum channel
 203     DK3_GET_NEXT_NIBBLE();
 204
 205     step = adpcm_step[sum_index];
 206
 207     sign = nibble & 8;
 208     delta = nibble & 7;
 209
 210     diff = step >> 3;
 211     if (delta & 4) diff += step;
 212     if (delta & 2) diff += step >> 1;
 213     if (delta & 1) diff += step >> 2;
 214
 215     if (sign)
 216       sum_pred -= diff;
 217     else
 218       sum_pred += diff;
 219
 220     CLAMP_S16(sum_pred);
 221
 222     sum_index += adpcm_index[nibble];
 223     CLAMP_0_TO_88(sum_index);
 224
 225     // output the second pair of stereo PCM samples
 226     output[out_ptr++] = sum_pred + diff_channel;
 227     output[out_ptr++] = sum_pred - diff_channel;
 228   }
 229
 230   return out_ptr;
 231 }
 232
 233 static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
 234 {
 235   if (demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,
 236     sh_audio->ds->ss_mul) !=
 237     sh_audio->ds->ss_mul)
 238       return -1; /* EOF */
 239
 240   if (maxlen < 2 * 4 * sh_audio->wf->nBlockAlign * 2 / 3) {
 241     mp_msg(MSGT_DECAUDIO, MSGL_V, "dk3adpcm: maxlen too small in decode_audio\n");
 242     return -1;
 243   }
 244   return 2 * dk3_adpcm_decode_block(
 245     (unsigned short*)buf, sh_audio->a_in_buffer,
 246     sh_audio->ds->ss_mul);
 247 }