libfaad2/mp4.c

   1 /*
   2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
   3 ** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
   4 **
   5 ** This program is free software; you can redistribute it and/or modify
   6 ** it under the terms of the GNU General Public License as published by
   7 ** the Free Software Foundation; either version 2 of the License, or
   8 ** (at your option) any later version.
   9 **
  10 ** This program is distributed in the hope that it will be useful,
  11 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 ** GNU General Public License for more details.
  14 **
  15 ** You should have received a copy of the GNU General Public License
  16 ** along with this program; if not, write to the Free Software
  17 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18 **
  19 ** Any non-GPL usage of this software or parts of this software is strictly
  20 ** forbidden.
  21 **
  22 ** Commercial non-GPL licensing of this software is possible.
  23 ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
  24 **
  25 ** $Id: mp4.c,v 1.32 2004/09/04 14:56:28 menno Exp $
  26 **/
  27
  28 #include "common.h"
  29 #include "structs.h"
  30
  31 #include <stdlib.h>
  32
  33 #include "bits.h"
  34 #include "mp4.h"
  35 #include "syntax.h"
  36
  37 /* defines if an object type can be decoded by this library or not */
  38 static uint8_t ObjectTypesTable[32] = {
  39     0, /*  0 NULL */
  40 #ifdef MAIN_DEC
  41     1, /*  1 AAC Main */
  42 #else
  43     0, /*  1 AAC Main */
  44 #endif
  45     1, /*  2 AAC LC */
  46 #ifdef SSR_DEC
  47     1, /*  3 AAC SSR */
  48 #else
  49     0, /*  3 AAC SSR */
  50 #endif
  51 #ifdef LTP_DEC
  52     1, /*  4 AAC LTP */
  53 #else
  54     0, /*  4 AAC LTP */
  55 #endif
  56 #ifdef SBR_DEC
  57     1, /*  5 SBR */
  58 #else
  59     0, /*  5 SBR */
  60 #endif
  61 #ifdef SCALABLE_DEC
  62     1, /*  6 AAC Scalable */
  63 #else
  64     0, /*  6 AAC Scalable */
  65 #endif
  66     0, /*  7 TwinVQ */
  67     0, /*  8 CELP */
  68     0, /*  9 HVXC */
  69     0, /* 10 Reserved */
  70     0, /* 11 Reserved */
  71     0, /* 12 TTSI */
  72     0, /* 13 Main synthetic */
  73     0, /* 14 Wavetable synthesis */
  74     0, /* 15 General MIDI */
  75     0, /* 16 Algorithmic Synthesis and Audio FX */
  76
  77     /* MPEG-4 Version 2 */
  78 #ifdef ERROR_RESILIENCE
  79     1, /* 17 ER AAC LC */
  80     0, /* 18 (Reserved) */
  81 #ifdef LTP_DEC
  82     1, /* 19 ER AAC LTP */
  83 #else
  84     0, /* 19 ER AAC LTP */
  85 #endif
  86 #ifdef SCALABLE_DEC
  87     1, /* 20 ER AAC scalable */
  88 #else
  89     0, /* 20 ER AAC scalable */
  90 #endif
  91     0, /* 21 ER TwinVQ */
  92     0, /* 22 ER BSAC */
  93 #ifdef LD_DEC
  94     1, /* 23 ER AAC LD */
  95 #else
  96     0, /* 23 ER AAC LD */
  97 #endif
  98     0, /* 24 ER CELP */
  99     0, /* 25 ER HVXC */
 100     0, /* 26 ER HILN */
 101     0, /* 27 ER Parametric */
 102 #else /* No ER defined */
 103     0, /* 17 ER AAC LC */
 104     0, /* 18 (Reserved) */
 105     0, /* 19 ER AAC LTP */
 106     0, /* 20 ER AAC scalable */
 107     0, /* 21 ER TwinVQ */
 108     0, /* 22 ER BSAC */
 109     0, /* 23 ER AAC LD */
 110     0, /* 24 ER CELP */
 111     0, /* 25 ER HVXC */
 112     0, /* 26 ER HILN */
 113     0, /* 27 ER Parametric */
 114 #endif
 115     0, /* 28 (Reserved) */
 116     0, /* 29 (Reserved) */
 117     0, /* 30 (Reserved) */
 118     0  /* 31 (Reserved) */
 119 };
 120
 121 /* Table 1.6.1 */
 122 int8_t NEAACDECAPI NeAACDecAudioSpecificConfig(uint8_t *pBuffer,
 123                                                uint32_t buffer_size,
 124                                                mp4AudioSpecificConfig *mp4ASC)
 125 {
 126     return AudioSpecificConfig2(pBuffer, buffer_size, mp4ASC, NULL);
 127 }
 128
 129 int8_t AudioSpecificConfig2(uint8_t *pBuffer,
 130                             uint32_t buffer_size,
 131                             mp4AudioSpecificConfig *mp4ASC,
 132                             program_config *pce)
 133 {
 134     bitfile ld;
 135     int8_t result = 0;
 136 #ifdef SBR_DEC
 137     int8_t bits_to_decode = 0;
 138 #endif
 139
 140     if (pBuffer == NULL)
 141         return -7;
 142     if (mp4ASC == NULL)
 143         return -8;
 144
 145     memset(mp4ASC, 0, sizeof(mp4AudioSpecificConfig));
 146
 147     faad_initbits(&ld, pBuffer, buffer_size);
 148     faad_byte_align(&ld);
 149
 150     mp4ASC->objectTypeIndex = (uint8_t)faad_getbits(&ld, 5
 151         DEBUGVAR(1,1,"parse_audio_decoder_specific_info(): ObjectTypeIndex"));
 152
 153     mp4ASC->samplingFrequencyIndex = (uint8_t)faad_getbits(&ld, 4
 154         DEBUGVAR(1,2,"parse_audio_decoder_specific_info(): SamplingFrequencyIndex"));
 155
 156     mp4ASC->channelsConfiguration = (uint8_t)faad_getbits(&ld, 4
 157         DEBUGVAR(1,3,"parse_audio_decoder_specific_info(): ChannelsConfiguration"));
 158
 159     mp4ASC->samplingFrequency = get_sample_rate(mp4ASC->samplingFrequencyIndex);
 160
 161     if (ObjectTypesTable[mp4ASC->objectTypeIndex] != 1)
 162     {
 163         faad_endbits(&ld);
 164         return -1;
 165     }
 166
 167     if (mp4ASC->samplingFrequency == 0)
 168     {
 169         faad_endbits(&ld);
 170         return -2;
 171     }
 172
 173     if (mp4ASC->channelsConfiguration > 7)
 174     {
 175         faad_endbits(&ld);
 176         return -3;
 177     }
 178
 179 #if (defined(PS_DEC) || defined(DRM_PS))
 180     /* check if we have a mono file */
 181     if (mp4ASC->channelsConfiguration == 1)
 182     {
 183         /* upMatrix to 2 channels for implicit signalling of PS */
 184         mp4ASC->channelsConfiguration = 2;
 185     }
 186 #endif
 187
 188 #ifdef SBR_DEC
 189     mp4ASC->sbr_present_flag = -1;
 190     if (mp4ASC->objectTypeIndex == 5)
 191     {
 192         uint8_t tmp;
 193
 194         mp4ASC->sbr_present_flag = 1;
 195         tmp = (uint8_t)faad_getbits(&ld, 4
 196             DEBUGVAR(1,5,"parse_audio_decoder_specific_info(): extensionSamplingFrequencyIndex"));
 197         /* check for downsampled SBR */
 198         if (tmp == mp4ASC->samplingFrequencyIndex)
 199             mp4ASC->downSampledSBR = 1;
 200         mp4ASC->samplingFrequencyIndex = tmp;
 201         if (mp4ASC->samplingFrequencyIndex == 15)
 202         {
 203             mp4ASC->samplingFrequency = (uint32_t)faad_getbits(&ld, 24
 204                 DEBUGVAR(1,6,"parse_audio_decoder_specific_info(): extensionSamplingFrequencyIndex"));
 205         } else {
 206             mp4ASC->samplingFrequency = get_sample_rate(mp4ASC->samplingFrequencyIndex);
 207         }
 208         mp4ASC->objectTypeIndex = (uint8_t)faad_getbits(&ld, 5
 209             DEBUGVAR(1,7,"parse_audio_decoder_specific_info(): ObjectTypeIndex"));
 210     }
 211 #endif
 212
 213     /* get GASpecificConfig */
 214     if (mp4ASC->objectTypeIndex == 1 || mp4ASC->objectTypeIndex == 2 ||
 215         mp4ASC->objectTypeIndex == 3 || mp4ASC->objectTypeIndex == 4 ||
 216         mp4ASC->objectTypeIndex == 6 || mp4ASC->objectTypeIndex == 7)
 217     {
 218         result = GASpecificConfig(&ld, mp4ASC, pce);
 219
 220 #ifdef ERROR_RESILIENCE
 221     } else if (mp4ASC->objectTypeIndex >= ER_OBJECT_START) { /* ER */
 222         result = GASpecificConfig(&ld, mp4ASC, pce);
 223         mp4ASC->epConfig = (uint8_t)faad_getbits(&ld, 2
 224             DEBUGVAR(1,143,"parse_audio_decoder_specific_info(): epConfig"));
 225
 226         if (mp4ASC->epConfig != 0)
 227             result = -5;
 228 #endif
 229
 230     } else {
 231         result = -4;
 232     }
 233
 234 #ifdef SSR_DEC
 235     /* shorter frames not allowed for SSR */
 236     if ((mp4ASC->objectTypeIndex == 4) && mp4ASC->frameLengthFlag)
 237         return -6;
 238 #endif
 239
 240
 241 #ifdef SBR_DEC
 242     bits_to_decode = (int8_t)(buffer_size*8 - faad_get_processed_bits(&ld));
 243
 244     if ((mp4ASC->objectTypeIndex != 5) && (bits_to_decode >= 16))
 245     {
 246         int16_t syncExtensionType = (int16_t)faad_getbits(&ld, 11
 247             DEBUGVAR(1,9,"parse_audio_decoder_specific_info(): syncExtensionType"));
 248
 249         if (syncExtensionType == 0x2b7)
 250         {
 251             mp4ASC->objectTypeIndex = (uint8_t)faad_getbits(&ld, 5
 252                 DEBUGVAR(1,10,"parse_audio_decoder_specific_info(): extensionAudioObjectType"));
 253
 254             if (mp4ASC->objectTypeIndex == 5)
 255             {
 256                 mp4ASC->sbr_present_flag = (uint8_t)faad_get1bit(&ld
 257                     DEBUGVAR(1,11,"parse_audio_decoder_specific_info(): sbr_present_flag"));
 258
 259                 if (mp4ASC->sbr_present_flag)
 260                 {
 261                     uint8_t tmp;
 262                     tmp = (uint8_t)faad_getbits(&ld, 4
 263                         DEBUGVAR(1,12,"parse_audio_decoder_specific_info(): extensionSamplingFrequencyIndex"));
 264
 265                     /* check for downsampled SBR */
 266                     if (tmp == mp4ASC->samplingFrequencyIndex)
 267                         mp4ASC->downSampledSBR = 1;
 268                     mp4ASC->samplingFrequencyIndex = tmp;
 269
 270                     if (mp4ASC->samplingFrequencyIndex == 15)
 271                     {
 272                         mp4ASC->samplingFrequency = (uint32_t)faad_getbits(&ld, 24
 273                             DEBUGVAR(1,13,"parse_audio_decoder_specific_info(): extensionSamplingFrequencyIndex"));
 274                     } else {
 275                         mp4ASC->samplingFrequency = get_sample_rate(mp4ASC->samplingFrequencyIndex);
 276                     }
 277                 }
 278             }
 279         }
 280     }
 281
 282     /* no SBR signalled, this could mean either implicit signalling or no SBR in this file */
 283     /* MPEG specification states: assume SBR on files with samplerate <= 24000 Hz */
 284     if (mp4ASC->sbr_present_flag == -1)
 285     {
 286         if (mp4ASC->samplingFrequency <= 24000)
 287         {
 288             mp4ASC->samplingFrequency *= 2;
 289             mp4ASC->forceUpSampling = 1;
 290         } else /* > 24000*/ {
 291             mp4ASC->downSampledSBR = 1;
 292         }
 293     }
 294 #endif
 295
 296     faad_endbits(&ld);
 297
 298     return result;
 299 }