extern/ffmpeg/libavcodec/dtsdec.c

   1 /*
   2  * dtsdec.c : free DTS Coherent Acoustics stream decoder.
   3  * Copyright (C) 2004 Benjamin Zores <ben@geexbox.org>
   4  *
   5  * This file is part of libavcodec.
   6  *
   7  * This library is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #ifdef HAVE_AV_CONFIG_H
  23 #undef HAVE_AV_CONFIG_H
  24 #endif
  25
  26 #include "avcodec.h"
  27 #include <dts.h>
  28
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #ifdef HAVE_MALLOC_H
  33 #include <malloc.h>
  34 #endif
  35
  36 #define BUFFER_SIZE 18726
  37 #define HEADER_SIZE 14
  38
  39 #ifdef LIBDTS_FIXED
  40 #define CONVERT_LEVEL (1 << 26)
  41 #define CONVERT_BIAS 0
  42 #else
  43 #define CONVERT_LEVEL 1
  44 #define CONVERT_BIAS 384
  45 #endif
  46
  47 static inline
  48 int16_t convert (int32_t i)
  49 {
  50 #ifdef LIBDTS_FIXED
  51     i >>= 15;
  52 #else
  53     i -= 0x43c00000;
  54 #endif
  55     return (i > 32767) ? 32767 : ((i < -32768) ? -32768 : i);
  56 }
  57
  58 void
  59 convert2s16_2 (sample_t * _f, int16_t * s16)
  60 {
  61   int i;
  62   int32_t * f = (int32_t *) _f;
  63
  64   for (i = 0; i < 256; i++)
  65     {
  66       s16[2*i] = convert (f[i]);
  67       s16[2*i+1] = convert (f[i+256]);
  68     }
  69 }
  70
  71 void
  72 convert2s16_4 (sample_t * _f, int16_t * s16)
  73 {
  74   int i;
  75   int32_t * f = (int32_t *) _f;
  76
  77   for (i = 0; i < 256; i++)
  78     {
  79       s16[4*i] = convert (f[i]);
  80       s16[4*i+1] = convert (f[i+256]);
  81       s16[4*i+2] = convert (f[i+512]);
  82       s16[4*i+3] = convert (f[i+768]);
  83     }
  84 }
  85
  86 void
  87 convert2s16_5 (sample_t * _f, int16_t * s16)
  88 {
  89   int i;
  90   int32_t * f = (int32_t *) _f;
  91
  92   for (i = 0; i < 256; i++)
  93     {
  94       s16[5*i] = convert (f[i]);
  95       s16[5*i+1] = convert (f[i+256]);
  96       s16[5*i+2] = convert (f[i+512]);
  97       s16[5*i+3] = convert (f[i+768]);
  98       s16[5*i+4] = convert (f[i+1024]);
  99     }
 100 }
 101
 102 static void
 103 convert2s16_multi (sample_t * _f, int16_t * s16, int flags)
 104 {
 105   int i;
 106   int32_t * f = (int32_t *) _f;
 107
 108   switch (flags)
 109     {
 110     case DTS_MONO:
 111       for (i = 0; i < 256; i++)
 112         {
 113           s16[5*i] = s16[5*i+1] = s16[5*i+2] = s16[5*i+3] = 0;
 114           s16[5*i+4] = convert (f[i]);
 115         }
 116       break;
 117     case DTS_CHANNEL:
 118     case DTS_STEREO:
 119     case DTS_DOLBY:
 120       convert2s16_2 (_f, s16);
 121       break;
 122     case DTS_3F:
 123       for (i = 0; i < 256; i++)
 124         {
 125           s16[5*i] = convert (f[i]);
 126           s16[5*i+1] = convert (f[i+512]);
 127           s16[5*i+2] = s16[5*i+3] = 0;
 128           s16[5*i+4] = convert (f[i+256]);
 129         }
 130       break;
 131     case DTS_2F2R:
 132       convert2s16_4 (_f, s16);
 133       break;
 134     case DTS_3F2R:
 135       convert2s16_5 (_f, s16);
 136       break;
 137     case DTS_MONO | DTS_LFE:
 138       for (i = 0; i < 256; i++)
 139         {
 140           s16[6*i] = s16[6*i+1] = s16[6*i+2] = s16[6*i+3] = 0;
 141           s16[6*i+4] = convert (f[i+256]);
 142           s16[6*i+5] = convert (f[i]);
 143         }
 144       break;
 145     case DTS_CHANNEL | DTS_LFE:
 146     case DTS_STEREO | DTS_LFE:
 147     case DTS_DOLBY | DTS_LFE:
 148       for (i = 0; i < 256; i++)
 149         {
 150           s16[6*i] = convert (f[i+256]);
 151           s16[6*i+1] = convert (f[i+512]);
 152           s16[6*i+2] = s16[6*i+3] = s16[6*i+4] = 0;
 153           s16[6*i+5] = convert (f[i]);
 154         }
 155       break;
 156     case DTS_3F | DTS_LFE:
 157       for (i = 0; i < 256; i++)
 158         {
 159           s16[6*i] = convert (f[i+256]);
 160           s16[6*i+1] = convert (f[i+768]);
 161           s16[6*i+2] = s16[6*i+3] = 0;
 162           s16[6*i+4] = convert (f[i+512]);
 163           s16[6*i+5] = convert (f[i]);
 164         }
 165       break;
 166     case DTS_2F2R | DTS_LFE:
 167       for (i = 0; i < 256; i++)
 168         {
 169           s16[6*i] = convert (f[i+256]);
 170           s16[6*i+1] = convert (f[i+512]);
 171           s16[6*i+2] = convert (f[i+768]);
 172           s16[6*i+3] = convert (f[i+1024]);
 173           s16[6*i+4] = 0;
 174           s16[6*i+5] = convert (f[i]);
 175         }
 176       break;
 177     case DTS_3F2R | DTS_LFE:
 178       for (i = 0; i < 256; i++)
 179         {
 180           s16[6*i] = convert (f[i+256]);
 181           s16[6*i+1] = convert (f[i+768]);
 182           s16[6*i+2] = convert (f[i+1024]);
 183           s16[6*i+3] = convert (f[i+1280]);
 184           s16[6*i+4] = convert (f[i+512]);
 185           s16[6*i+5] = convert (f[i]);
 186         }
 187       break;
 188     }
 189 }
 190
 191 static int
 192 channels_multi (int flags)
 193 {
 194   if (flags & DTS_LFE)
 195     return 6;
 196   else if (flags & 1)   /* center channel */
 197     return 5;
 198   else if ((flags & DTS_CHANNEL_MASK) == DTS_2F2R)
 199     return 4;
 200   else
 201     return 2;
 202 }
 203
 204 static int
 205 dts_decode_frame (AVCodecContext *avctx, void *data, int *data_size,
 206                   uint8_t *buff, int buff_size)
 207 {
 208   uint8_t * start = buff;
 209   uint8_t * end = buff + buff_size;
 210   static uint8_t buf[BUFFER_SIZE];
 211   static uint8_t * bufptr = buf;
 212   static uint8_t * bufpos = buf + HEADER_SIZE;
 213
 214   static int sample_rate;
 215   static int frame_length;
 216   static int flags;
 217   int bit_rate;
 218   int len;
 219   dts_state_t *state = avctx->priv_data;
 220
 221   *data_size = 0;
 222
 223   while (1)
 224     {
 225       len = end - start;
 226       if (!len)
 227         break;
 228       if (len > bufpos - bufptr)
 229         len = bufpos - bufptr;
 230       memcpy (bufptr, start, len);
 231       bufptr += len;
 232       start += len;
 233       if (bufptr != bufpos)
 234           return start - buff;
 235       if (bufpos != buf + HEADER_SIZE)
 236           break;
 237
 238             {
 239               int length;
 240
 241               length = dts_syncinfo (state, buf, &flags, &sample_rate,
 242                                      &bit_rate, &frame_length);
 243               if (!length)
 244                 {
 245                   av_log (NULL, AV_LOG_INFO, "skip\n");
 246                   for (bufptr = buf; bufptr < buf + HEADER_SIZE-1; bufptr++)
 247                     bufptr[0] = bufptr[1];
 248                   continue;
 249                 }
 250               bufpos = buf + length;
 251             }
 252     }
 253
 254             {
 255               level_t level;
 256               sample_t bias;
 257               int i;
 258
 259               flags = 2; /* ???????????? */
 260               level = CONVERT_LEVEL;
 261               bias = CONVERT_BIAS;
 262
 263               flags |= DTS_ADJUST_LEVEL;
 264               if (dts_frame (state, buf, &flags, &level, bias))
 265                 goto error;
 266               avctx->sample_rate = sample_rate;
 267               avctx->channels = channels_multi (flags);
 268               avctx->bit_rate = bit_rate;
 269               for (i = 0; i < dts_blocks_num (state); i++)
 270                 {
 271                   if (dts_block (state))
 272                     goto error;
 273                   {
 274                     int chans;
 275                     chans = channels_multi (flags);
 276                     convert2s16_multi (dts_samples (state), data,
 277                                        flags & (DTS_CHANNEL_MASK | DTS_LFE));
 278
 279                     data += 256 * sizeof (int16_t) * chans;
 280                     *data_size += 256 * sizeof (int16_t) * chans;
 281                   }
 282                 }
 283               bufptr = buf;
 284               bufpos = buf + HEADER_SIZE;
 285               return start-buff;
 286             error:
 287               av_log (NULL, AV_LOG_ERROR, "error\n");
 288               bufptr = buf;
 289               bufpos = buf + HEADER_SIZE;
 290             }
 291
 292   return start-buff;
 293 }
 294
 295 static int
 296 dts_decode_init (AVCodecContext *avctx)
 297 {
 298   avctx->priv_data = dts_init (0);
 299   if (avctx->priv_data == NULL)
 300     return -1;
 301
 302   return 0;
 303 }
 304
 305 static int
 306 dts_decode_end (AVCodecContext *s)
 307 {
 308   return 0;
 309 }
 310
 311 AVCodec dts_decoder = {
 312   "dts",
 313   CODEC_TYPE_AUDIO,
 314   CODEC_ID_DTS,
 315   sizeof (dts_state_t *),
 316   dts_decode_init,
 317   NULL,
 318   dts_decode_end,
 319   dts_decode_frame,
 320 };