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 <libavutil/intreadwrite.h>
  42
  43 #include "config.h"
  44 #include "mpbswap.h"
  45 #include "ad_internal.h"
  46
  47 #define MS_IMA_ADPCM_PREAMBLE_SIZE 4
  48
  49 #define QT_IMA_ADPCM_PREAMBLE_SIZE 2
  50 #define QT_IMA_ADPCM_BLOCK_SIZE 0x22
  51 #define QT_IMA_ADPCM_SAMPLES_PER_BLOCK 64
  52
  53 // pertinent tables for IMA ADPCM
  54 static const int16_t adpcm_step[89] =
  55 {
  56   7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
  57   19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
  58   50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
  59   130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
  60   337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
  61   876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
  62   2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
  63   5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
  64   15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
  65 };
  66
  67 static const int8_t adpcm_index[8] =
  68 {
  69   -1, -1, -1, -1, 2, 4, 6, 8,
  70 };
  71
  72 // useful macros
  73 // clamp a number between 0 and 88
  74 #define CLAMP_0_TO_88(x) x = av_clip(x, 0, 88);
  75 // clamp a number within a signed 16-bit range
  76 #define CLAMP_S16(x) x = av_clip_int16(x);
  77 // clamp a number above 16
  78 #define CLAMP_ABOVE_16(x)  if (x < 16) x = 16;
  79
  80 static const ad_info_t info =
  81 {
  82         "IMA ADPCM audio decoder",
  83         "imaadpcm",
  84         "Nick Kurshev",
  85         "Mike Melanson",
  86         ""
  87 };
  88
  89 LIBAD_EXTERN(imaadpcm)
  90
  91 static int preinit(sh_audio_t *sh_audio)
  92 {
  93   // not exactly sure what this field is for
  94   sh_audio->audio_out_minsize = 8192;
  95
  96   // if format is "ima4", assume the audio is coming from a QT file which
  97   // indicates constant block size, whereas an AVI/ASF/WAV file will fill
  98   // in this field with 0x11
  99   if ((sh_audio->format == 0x11) || (sh_audio->format == 0x61) ||
 100       (sh_audio->format == 0x1100736d))
 101   {
 102     sh_audio->ds->ss_div = (sh_audio->wf->nBlockAlign -
 103       (MS_IMA_ADPCM_PREAMBLE_SIZE * sh_audio->wf->nChannels)) * 2;
 104     sh_audio->ds->ss_mul = sh_audio->wf->nBlockAlign;
 105   }
 106   else
 107   {
 108     sh_audio->ds->ss_div = QT_IMA_ADPCM_SAMPLES_PER_BLOCK;
 109     sh_audio->ds->ss_mul = QT_IMA_ADPCM_BLOCK_SIZE * sh_audio->wf->nChannels;
 110   }
 111   sh_audio->audio_in_minsize=sh_audio->ds->ss_mul;
 112   return 1;
 113 }
 114
 115 static int init(sh_audio_t *sh_audio)
 116 {
 117   /* IMA-ADPCM 4:1 audio codec:*/
 118   sh_audio->channels=sh_audio->wf->nChannels;
 119   sh_audio->samplerate=sh_audio->wf->nSamplesPerSec;
 120   /* decodes 34 byte -> 64 short*/
 121   sh_audio->i_bps =
 122     (sh_audio->ds->ss_mul * sh_audio->samplerate) / sh_audio->ds->ss_div;
 123   sh_audio->samplesize=2;
 124
 125   return 1;
 126 }
 127
 128 static void uninit(sh_audio_t *sh_audio)
 129 {
 130 }
 131
 132 static int control(sh_audio_t *sh_audio,int cmd,void* arg, ...)
 133 {
 134   if(cmd==ADCTRL_SKIP_FRAME){
 135     demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,sh_audio->ds->ss_mul);
 136     return CONTROL_TRUE;
 137   }
 138   return CONTROL_UNKNOWN;
 139 }
 140
 141 static void decode_nibbles(unsigned short *output,
 142   int output_size, int channels,
 143   int predictor[2], int index[2])
 144 {
 145   int step[2];
 146   int i;
 147   int sign;
 148   int delta;
 149   int channel_number = 0;
 150
 151   step[0] = adpcm_step[index[0]];
 152   step[1] = adpcm_step[index[1]];
 153
 154   for (i = 0; i < output_size; i++)
 155   {
 156     delta = output[i];
 157     sign = delta & 8;
 158     delta = delta & 7;
 159
 160     index[channel_number] += adpcm_index[delta];
 161     CLAMP_0_TO_88(index[channel_number]);
 162
 163     delta = 2 * delta + 1;
 164     if (sign) delta = -delta;
 165
 166     predictor[channel_number] += (delta * step[channel_number]) >> 3;
 167
 168     CLAMP_S16(predictor[channel_number]);
 169     output[i] = predictor[channel_number];
 170     step[channel_number] = adpcm_step[index[channel_number]];
 171
 172     // toggle channel
 173     channel_number ^= channels - 1;
 174
 175   }
 176 }
 177
 178 static int qt_ima_adpcm_decode_block(unsigned short *output,
 179   unsigned char *input, int channels, int block_size)
 180 {
 181   int initial_predictor[2] = {0};
 182   int initial_index[2] = {0};
 183   int i;
 184
 185   if (channels != 1) channels = 2;
 186   if (block_size < channels * QT_IMA_ADPCM_BLOCK_SIZE)
 187     return -1;
 188
 189   for (i = 0; i < channels; i++) {
 190     initial_index[i] = initial_predictor[i] = (int16_t)AV_RB16(&input[i * QT_IMA_ADPCM_BLOCK_SIZE]);
 191
 192     // mask, sign-extend, and clamp the predictor portion
 193     initial_predictor[i] &= ~0x7F;
 194     CLAMP_S16(initial_predictor[i]);
 195
 196     // mask and clamp the index portion
 197     initial_index[i] &= 0x7F;
 198     CLAMP_0_TO_88(initial_index[i]);
 199   }
 200
 201   // break apart all of the nibbles in the block
 202   if (channels == 1)
 203     for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
 204     {
 205       output[i * 2 + 0] = input[2 + i] & 0x0F;
 206       output[i * 2 + 1] = input[2 + i] >> 4;
 207     }
 208   else
 209     for (i = 0; i < QT_IMA_ADPCM_SAMPLES_PER_BLOCK / 2; i++)
 210     {
 211       output[i * 4 + 0] = input[2 + i] & 0x0F;
 212       output[i * 4 + 1] = input[2 + QT_IMA_ADPCM_BLOCK_SIZE + i] & 0x0F;
 213       output[i * 4 + 2] = input[2 + i] >> 4;
 214       output[i * 4 + 3] = input[2 + QT_IMA_ADPCM_BLOCK_SIZE + i] >> 4;
 215     }
 216
 217   decode_nibbles(output,
 218     QT_IMA_ADPCM_SAMPLES_PER_BLOCK * channels, channels,
 219     initial_predictor, initial_index);
 220
 221   return QT_IMA_ADPCM_SAMPLES_PER_BLOCK * channels;
 222 }
 223
 224 static int ms_ima_adpcm_decode_block(unsigned short *output,
 225   unsigned char *input, int channels, int block_size)
 226 {
 227   int predictor[2];
 228   int index[2];
 229   int i;
 230   int channel_counter;
 231   int channel_index;
 232   int channel_index_l;
 233   int channel_index_r;
 234
 235   if (channels != 1) channels = 2;
 236   if (block_size < MS_IMA_ADPCM_PREAMBLE_SIZE * channels)
 237     return -1;
 238
 239   for (i = 0; i < channels; i++) {
 240     predictor[i] = (int16_t)AV_RL16(&input[i * 4]);
 241     index[i] = input[i * 4 + 2];
 242   }
 243
 244   if (channels == 1)
 245     for (i = 0;
 246       i < (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels); i++)
 247     {
 248       output[i * 2 + 0] = input[MS_IMA_ADPCM_PREAMBLE_SIZE + i] & 0x0F;
 249       output[i * 2 + 1] = input[MS_IMA_ADPCM_PREAMBLE_SIZE + i] >> 4;
 250     }
 251   else
 252   {
 253     // encoded as 8 nibbles (4 bytes) per channel; switch channel every
 254     // 4th byte
 255     channel_counter = 0;
 256     channel_index_l = 0;
 257     channel_index_r = 1;
 258     channel_index = channel_index_l;
 259     for (i = 0;
 260       i < (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels); i++)
 261     {
 262       output[channel_index + 0] =
 263         input[MS_IMA_ADPCM_PREAMBLE_SIZE * 2 + i] & 0x0F;
 264       output[channel_index + 2] =
 265         input[MS_IMA_ADPCM_PREAMBLE_SIZE * 2 + i] >> 4;
 266       channel_index += 4;
 267       channel_counter++;
 268       if (channel_counter == 4)
 269       {
 270         channel_index_l = channel_index;
 271         channel_index = channel_index_r;
 272       }
 273       else if (channel_counter == 8)
 274       {
 275         channel_index_r = channel_index;
 276         channel_index = channel_index_l;
 277         channel_counter = 0;
 278       }
 279     }
 280   }
 281
 282   decode_nibbles(output,
 283     (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2,
 284     channels,
 285     predictor, index);
 286
 287   return (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2;
 288 }
 289
 290 static int dk4_ima_adpcm_decode_block(unsigned short *output,
 291   unsigned char *input, int channels, int block_size)
 292 {
 293   int i;
 294   int output_ptr;
 295   int predictor[2];
 296   int index[2];
 297
 298   if (channels != 1) channels = 2;
 299   if (block_size < MS_IMA_ADPCM_PREAMBLE_SIZE * channels)
 300     return -1;
 301
 302   for (i = 0; i < channels; i++) {
 303     // the first predictor value goes straight to the output
 304     predictor[i] = output[i] = (int16_t)AV_RL16(&input[i * 4]);
 305     index[i] = input[i * 4 + 2];
 306   }
 307
 308   output_ptr = channels;
 309   for (i = MS_IMA_ADPCM_PREAMBLE_SIZE * channels; i < block_size; i++)
 310   {
 311     output[output_ptr++] = input[i] >> 4;
 312     output[output_ptr++] = input[i] & 0x0F;
 313   }
 314
 315   decode_nibbles(&output[channels],
 316     (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2 - channels,
 317     channels,
 318     predictor, index);
 319
 320   return (block_size - MS_IMA_ADPCM_PREAMBLE_SIZE * channels) * 2 - channels;
 321 }
 322
 323 static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
 324 {
 325   int res = -1;
 326   int (*decode_func)(unsigned short *output, unsigned char *input, int channels, int block_size) = qt_ima_adpcm_decode_block;
 327   if (demux_read_data(sh_audio->ds, sh_audio->a_in_buffer,
 328     sh_audio->ds->ss_mul) !=
 329     sh_audio->ds->ss_mul)
 330     return -1;
 331
 332   if ((sh_audio->format == 0x11) || (sh_audio->format == 0x1100736d))
 333     decode_func = ms_ima_adpcm_decode_block;
 334   else if (sh_audio->format == 0x61)
 335     decode_func = dk4_ima_adpcm_decode_block;
 336
 337   res = decode_func((unsigned short*)buf, sh_audio->a_in_buffer,
 338                     sh_audio->wf->nChannels, sh_audio->ds->ss_mul);
 339   return res < 0 ? res : 2 * res;
 340 }