libmpcodecs/ad_imaadpcm.c

   1 /*
   2  * IMA ADPCM decoder
   3  *
   4  * This file is in charge of decoding all of the various IMA ADPCM data
   5  * formats that various entities have created. Details about the data
   6  * formats can be found here:
   7  *   http://www.pcisys.net/~melanson/codecs/
   8  *
   9  * So far, this file handles these formats:
  10  *   'ima4': IMA ADPCM found in QT files
  11  *     0x11: IMA ADPCM found in MS AVI/ASF/WAV files
  12  *     0x61: DK4 ADPCM found in certain AVI files on Sega Saturn CD-ROMs;
  13  *           note that this is a 'rogue' format number in that it was
  14  *           never officially registered with Microsoft
  15  * 0x1100736d: IMA ADPCM coded like in MS AVI/ASF/WAV found in QT files
  16  *
  17  * Copyright (c) 2002 Mike Melanson
  18  *
  19  * This file is part of MPlayer.
  20  *
  21  * MPlayer is free software; you can redistribute it and/or modify
  22  * it under the terms of the GNU General Public License as published by
  23  * the Free Software Foundation; either version 2 of the License, or
  24  * (at your option) any later version.
  25  *
  26  * MPlayer is distributed in the hope that it will be useful,
  27  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29  * GNU General Public License for more details.
  30  *
  31  * You should have received a copy of the GNU General Public License along
  32  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  33  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  34  */
  35
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <unistd.h>
  39 #include <inttypes.h>
  40
  41 #include "config.h"
  42 #include "ffmpeg_files/intreadwrite.h"
  43 #include "mpbswap.h"
  44 #include "ad_internal.h"
  45
  46 #define MS_IMA_ADPCM_PREAMBLE_SIZE 4
  47
  48 #define QT_IMA_ADPCM_PREAMBLE_SIZE 2
  49 #define QT_IMA_ADPCM_BLOCK_SIZE 0x22
  50 #define QT_IMA_ADPCM_SAMPLES_PER_BLOCK 64
  51
  52 // pertinent tables for IMA ADPCM
  53 static const int16_t adpcm_step[89] =
  54 {
  55   7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
  56   19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
  57   50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
  58   130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
  59   337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
  60   876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
  61   2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
  62   5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
  63   15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
  64 };
  65
  66 static const int8_t adpcm_index[8] =
  67 {
  68   -1, -1, -1, -1, 2, 4, 6, 8,
  69 };
  70
  71 // useful macros
  72 // clamp a number between 0 and 88
  73 #define CLAMP_0_TO_88(x) x = av_clip(x, 0, 88);
  74 // clamp a number within a signed 16-bit range
  75 #define CLAMP_S16(x) x = av_clip_int16(x);
  76 // clamp a number above 16
  77 #define CLAMP_ABOVE_16(x)  if (x < 16) x = 16;
  78
  79 static const ad_info_t info =
  80 {
  81         "IMA ADPCM audio decoder",
  82         "imaadpcm",
  83         "Nick Kurshev",
  84         "Mike Melanson",
  85         ""
  86 };
  87
  88 LIBAD_EXTERN(imaadpcm)
  89
  90 static int preinit(sh_audio_t *sh_audio)
  91 {
  92   // not exactly sure what this field is for
  93   sh_audio->audio_out_minsize = 8192;
  94
  95   // if format is "ima4", assume the audio is coming from a QT file which
  96   // indicates constant block size, whereas an AVI/ASF/WAV file will fill
  97   // in this field with 0x11
  98   if ((sh_audio->format == 0x11) || (sh_audio->format == 0x61) ||
  99       (sh_audio->format == 0x1100736d))
 100   {
 101     sh_audio->ds->ss_div = (sh_audio->wf->nBlockAlign -
 102       (MS_IMA_ADPCM_PREAMBLE_SIZE * sh_audio->wf->nChannels)) * 2;
 103     sh_audio->ds->ss_mul = sh_audio->wf->nBlockAlign;
 104   }
 105   else
 106   {
 107     sh_audio->ds->ss_div = QT_IMA_ADPCM_SAMPLES_PER_BLOCK;
 108     sh_audio->ds->ss_mul = QT_IMA_ADPCM_BLOCK_SIZE * sh_audio->wf->nChannels;
 109   }
 110   sh_audio->audio_in_minsize=sh_audio->ds->ss_mul;
 111   return 1;
 112 }
 113
 114 static int init(sh_audio_t *sh_audio)
 115 {
 116   /* IMA-ADPCM 4:1 audio codec:*/
 117   sh_audio->channels=sh_audio->wf->nChannels;
 118   sh_audio->samplerate=sh_audio->wf->nSamplesPerSec;
 119   /* decodes 34 byte -> 64 short*/
 120   sh_audio->i_bps =
 121     (sh_audio->ds->ss_mul * sh_audio->samplerate) / sh_audio->ds->ss_div;
 122   sh_audio->samplesize=2;
 123
 124   return 1;
 125 }
 126
 127 static void uninit(sh_audio_t *sh_audio)
 128 {
 129 }
 130
 131 static int control(sh_audio_t *sh_audio,int cmd,void* arg, ...)
 132 {
 133   if(cmd==ADCTRL_SKIP_FRAME){
 134     demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,sh_audio->ds->ss_mul);
 135     return CONTROL_TRUE;
 136   }
 137   return CONTROL_UNKNOWN;
 138 }
 139
 140 static void decode_nibbles(unsigned short *output,
 141   int output_size, int channels,
 142   int predictor[2], int index[2])
 143 {
 144   int step[2];
 145   int i;
 146   int sign;
 147   int delta;
 148   int channel_number = 0;
 149
 150   step[0] = adpcm_step[index[0]];
 151   step[1] = adpcm_step[index[1]];
 152
 153   for (i = 0; i < output_size; i++)
 154   {
 155     delta = output[i];
 156     sign = delta & 8;
 157     delta = delta & 7;
 158
 159     index[channel_number] += adpcm_index[delta];
 160     CLAMP_0_TO_88(index[channel_number]);
 161
 162     delta = 2 * delta + 1;
 163     if (sign) delta = -delta;
 164
 165     predictor[channel_number] += (delta * step[channel_number]) >> 3;
 166
 167     CLAMP_S16(predictor[channel_number]);
 168     output[i] = predictor[channel_number];
 169     step[channel_number] = adpcm_step[index[channel_number]];
 170
 171     // toggle channel
 172     channel_number ^= channels - 1;
 173
 174   }
 175 }
 176
 177 static int qt_ima_adpcm_decode_block(unsigned short *output,
 178   unsigned char *input, int channels, int block_size)
 179 {
 180   int initial_predictor[2] = {0};
 181   int initial_index[2] = {0};
 182   int i;
 183
 184   if (channels != 1) channels = 2;
 185   if (block_size < channels * QT_IMA_ADPCM_BLOCK_SIZE)
 186     return -1;
 187
 188   for (i = 0; i < channels; i++) {
 189     initial_index[i] = initial_predictor[i] = (int16_t)AV_RB16(&input[i * QT_IMA_ADPCM_BLOCK_SIZE]);
 190
 191     // mask, sign-extend, and clamp the predictor portion
 192     initial_predictor[i] &= ~0x7F;
 193     CLAMP_S16(initial_predictor[i]);
 194
 195     // mask and clamp the index portion
 196     initial_index[i] &= 0x7F;
 197     CLAMP_0_TO_88(initial_index[i]);
 198   }
 199
 200   // break apart all of the nibbles in the block
 201   if (channels == 1)
 202     for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
 203     {
 204       output[i * 2 + 0] = input[2 + i] & 0x0F;
 205       output[i * 2 + 1] = input[2 + i] >> 4;
 206     }
 207   else
 208     for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
 209     {
 210       output[i * 4 + 0] = input[2 + i] & 0x0F;
 211       output[i * 4 + 1] = input[2 + QT_IMA_ADPCM_BLOCK_SIZE + i] & 0x0F;
 212       output[i * 4 + 2] = input[2 + i] >> 4;
 213       output[i * 4 + 3] = input[2 + QT_IMA_ADPCM_BLOCK_SIZE + i] >> 4;
 214     }
 215
 216   decode_nibbles(output,
 217     QT_IMA_ADPCM_SAMPLES_PER_BLOCK * channels, channels,
 218     initial_predictor, initial_index);
 219
 220   return QT_IMA_ADPCM_SAMPLES_PER_BLOCK * channels;
 221 }
 222
 223 static int ms_ima_adpcm_decode_block(unsigned short *output,
 224   unsigned char *input, int channels, int block_size)
 225 {
 226   int predictor[2];
 227   int index[2];
 228   int i;
 229   int channel_counter;
 230   int channel_index;
 231   int channel_index_l;
 232   int channel_index_r;
 233
 234   if (channels != 1) channels = 2;
 235   if (block_size < MS_IMA_ADPCM_PREAMBLE_SIZE * channels)
 236     return -1;
 237
 238   for (i = 0; i < channels; i++) {
 239     predictor[i] = (int16_t)AV_RL16(&input[i * 4]);
 240     index[i] = input[i * 4 + 2];
 241   }
 242
 243   if (channels == 1)
 244     for (i = 0;
 245       i < (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels); i++)
 246     {
 247       output[i * 2 + 0] = input[MS_IMA_ADPCM_PREAMBLE_SIZE + i] & 0x0F;
 248       output[i * 2 + 1] = input[MS_IMA_ADPCM_PREAMBLE_SIZE + i] >> 4;
 249     }
 250   else
 251   {
 252     // encoded as 8 nibbles (4 bytes) per channel; switch channel every
 253     // 4th byte
 254     channel_counter = 0;
 255     channel_index_l = 0;
 256     channel_index_r = 1;
 257     channel_index = channel_index_l;
 258     for (i = 0;
 259       i < (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels); i++)
 260     {
 261       output[channel_index + 0] =
 262         input[MS_IMA_ADPCM_PREAMBLE_SIZE * 2 + i] & 0x0F;
 263       output[channel_index + 2] =
 264         input[MS_IMA_ADPCM_PREAMBLE_SIZE * 2 + i] >> 4;
 265       channel_index += 4;
 266       channel_counter++;
 267       if (channel_counter == 4)
 268       {
 269         channel_index_l = channel_index;
 270         channel_index = channel_index_r;
 271       }
 272       else if (channel_counter == 8)
 273       {
 274         channel_index_r = channel_index;
 275         channel_index = channel_index_l;
 276         channel_counter = 0;
 277       }
 278     }
 279   }
 280
 281   decode_nibbles(output,
 282     (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2,
 283     channels,
 284     predictor, index);
 285
 286   return (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2;
 287 }
 288
 289 static int dk4_ima_adpcm_decode_block(unsigned short *output,
 290   unsigned char *input, int channels, int block_size)
 291 {
 292   int i;
 293   int output_ptr;
 294   int predictor[2];
 295   int index[2];
 296
 297   if (channels != 1) channels = 2;
 298   if (block_size < MS_IMA_ADPCM_PREAMBLE_SIZE * channels)
 299     return -1;
 300
 301   for (i = 0; i < channels; i++) {
 302     // the first predictor value goes straight to the output
 303     predictor[i] = output[i] = (int16_t)AV_RL16(&input[i * 4]);
 304     index[i] = input[i * 4 + 2];
 305   }
 306
 307   output_ptr = channels;
 308   for (i = MS_IMA_ADPCM_PREAMBLE_SIZE * channels; i < block_size; i++)
 309   {
 310     output[output_ptr++] = input[i] >> 4;
 311     output[output_ptr++] = input[i] & 0x0F;
 312   }
 313
 314   decode_nibbles(&output[channels],
 315     (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2 - channels,
 316     channels,
 317     predictor, index);
 318
 319   return (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2 - channels;
 320 }
 321
 322 static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
 323 {
 324   int res = -1;
 325   int (*decode_func)(unsigned short *output, unsigned char *input, int channels, int block_size) = qt_ima_adpcm_decode_block;
 326   if (demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,
 327     sh_audio->ds->ss_mul) !=
 328     sh_audio->ds->ss_mul)
 329     return -1;
 330
 331   if ((sh_audio->format == 0x11) || (sh_audio->format == 0x1100736d))
 332     decode_func = ms_ima_adpcm_decode_block;
 333   else if (sh_audio->format == 0x61)
 334     decode_func = dk4_ima_adpcm_decode_block;
 335
 336   res = decode_func((unsigned short*)buf, sh_audio->a_in_buffer,
 337                     sh_audio->wf->nChannels, sh_audio->ds->ss_mul);
 338   return res < 0 ? res : 2 * res;
 339 }