wp-includes/ID3/module.audio.ogg.php

   1 <?php
   2 /////////////////////////////////////////////////////////////////
   3 /// getID3() by James Heinrich <info@getid3.org>               //
   4 //  available at http://getid3.sourceforge.net                 //
   5 //            or http://www.getid3.org                         //
   6 //          also https://github.com/JamesHeinrich/getID3       //
   7 /////////////////////////////////////////////////////////////////
   8 // See readme.txt for more details                             //
   9 /////////////////////////////////////////////////////////////////
  10 //                                                             //
  11 // module.audio.ogg.php                                        //
  12 // module for analyzing Ogg Vorbis, OggFLAC and Speex files    //
  13 // dependencies: module.audio.flac.php                         //
  14 //                                                            ///
  15 /////////////////////////////////////////////////////////////////
  16
  17 getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.flac.php', __FILE__, true);
  18
  19 class getid3_ogg extends getid3_handler
  20 {
  21         // http://xiph.org/vorbis/doc/Vorbis_I_spec.html
  22         public function Analyze() {
  23                 $info = &$this->getid3->info;
  24
  25                 $info['fileformat'] = 'ogg';
  26
  27                 // Warn about illegal tags - only vorbiscomments are allowed
  28                 if (isset($info['id3v2'])) {
  29                         $info['warning'][] = 'Illegal ID3v2 tag present.';
  30                 }
  31                 if (isset($info['id3v1'])) {
  32                         $info['warning'][] = 'Illegal ID3v1 tag present.';
  33                 }
  34                 if (isset($info['ape'])) {
  35                         $info['warning'][] = 'Illegal APE tag present.';
  36                 }
  37
  38
  39                 // Page 1 - Stream Header
  40
  41                 $this->fseek($info['avdataoffset']);
  42
  43                 $oggpageinfo = $this->ParseOggPageHeader();
  44                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;
  45
  46                 if ($this->ftell() >= $this->getid3->fread_buffer_size()) {
  47                         $info['error'][] = 'Could not find start of Ogg page in the first '.$this->getid3->fread_buffer_size().' bytes (this might not be an Ogg-Vorbis file?)';
  48                         unset($info['fileformat']);
  49                         unset($info['ogg']);
  50                         return false;
  51                 }
  52
  53                 $filedata = $this->fread($oggpageinfo['page_length']);
  54                 $filedataoffset = 0;
  55
  56                 if (substr($filedata, 0, 4) == 'fLaC') {
  57
  58                         $info['audio']['dataformat']   = 'flac';
  59                         $info['audio']['bitrate_mode'] = 'vbr';
  60                         $info['audio']['lossless']     = true;
  61
  62                 } elseif (substr($filedata, 1, 6) == 'vorbis') {
  63
  64                         $this->ParseVorbisPageHeader($filedata, $filedataoffset, $oggpageinfo);
  65
  66                 } elseif (substr($filedata, 0, 8) == 'OpusHead') {
  67
  68                         if( $this->ParseOpusPageHeader($filedata, $filedataoffset, $oggpageinfo) == false ) {
  69                                 return false;
  70                         }
  71
  72                 } elseif (substr($filedata, 0, 8) == 'Speex   ') {
  73
  74                         // http://www.speex.org/manual/node10.html
  75
  76                         $info['audio']['dataformat']   = 'speex';
  77                         $info['mime_type']             = 'audio/speex';
  78                         $info['audio']['bitrate_mode'] = 'abr';
  79                         $info['audio']['lossless']     = false;
  80
  81                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['speex_string']           =                              substr($filedata, $filedataoffset, 8); // hard-coded to 'Speex   '
  82                         $filedataoffset += 8;
  83                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['speex_version']          =                              substr($filedata, $filedataoffset, 20);
  84                         $filedataoffset += 20;
  85                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['speex_version_id']       = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
  86                         $filedataoffset += 4;
  87                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['header_size']            = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
  88                         $filedataoffset += 4;
  89                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['rate']                   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
  90                         $filedataoffset += 4;
  91                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['mode']                   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
  92                         $filedataoffset += 4;
  93                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['mode_bitstream_version'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
  94                         $filedataoffset += 4;
  95                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['nb_channels']            = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
  96                         $filedataoffset += 4;
  97                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['bitrate']                = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
  98                         $filedataoffset += 4;
  99                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['framesize']              = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 100                         $filedataoffset += 4;
 101                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['vbr']                    = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 102                         $filedataoffset += 4;
 103                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['frames_per_packet']      = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 104                         $filedataoffset += 4;
 105                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['extra_headers']          = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 106                         $filedataoffset += 4;
 107                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['reserved1']              = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 108                         $filedataoffset += 4;
 109                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['reserved2']              = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 110                         $filedataoffset += 4;
 111
 112                         $info['speex']['speex_version'] = trim($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['speex_version']);
 113                         $info['speex']['sample_rate']   = $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['rate'];
 114                         $info['speex']['channels']      = $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['nb_channels'];
 115                         $info['speex']['vbr']           = (bool) $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['vbr'];
 116                         $info['speex']['band_type']     = $this->SpeexBandModeLookup($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['mode']);
 117
 118                         $info['audio']['sample_rate']   = $info['speex']['sample_rate'];
 119                         $info['audio']['channels']      = $info['speex']['channels'];
 120                         if ($info['speex']['vbr']) {
 121                                 $info['audio']['bitrate_mode'] = 'vbr';
 122                         }
 123
 124                 } elseif (substr($filedata, 0, 7) == "\x80".'theora') {
 125
 126                         // http://www.theora.org/doc/Theora.pdf (section 6.2)
 127
 128                         $info['ogg']['pageheader']['theora']['theora_magic']             =                           substr($filedata, $filedataoffset,  7); // hard-coded to "\x80.'theora'
 129                         $filedataoffset += 7;
 130                         $info['ogg']['pageheader']['theora']['version_major']            = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  1));
 131                         $filedataoffset += 1;
 132                         $info['ogg']['pageheader']['theora']['version_minor']            = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  1));
 133                         $filedataoffset += 1;
 134                         $info['ogg']['pageheader']['theora']['version_revision']         = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  1));
 135                         $filedataoffset += 1;
 136                         $info['ogg']['pageheader']['theora']['frame_width_macroblocks']  = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  2));
 137                         $filedataoffset += 2;
 138                         $info['ogg']['pageheader']['theora']['frame_height_macroblocks'] = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  2));
 139                         $filedataoffset += 2;
 140                         $info['ogg']['pageheader']['theora']['resolution_x']             = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  3));
 141                         $filedataoffset += 3;
 142                         $info['ogg']['pageheader']['theora']['resolution_y']             = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  3));
 143                         $filedataoffset += 3;
 144                         $info['ogg']['pageheader']['theora']['picture_offset_x']         = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  1));
 145                         $filedataoffset += 1;
 146                         $info['ogg']['pageheader']['theora']['picture_offset_y']         = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  1));
 147                         $filedataoffset += 1;
 148                         $info['ogg']['pageheader']['theora']['frame_rate_numerator']     = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  4));
 149                         $filedataoffset += 4;
 150                         $info['ogg']['pageheader']['theora']['frame_rate_denominator']   = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  4));
 151                         $filedataoffset += 4;
 152                         $info['ogg']['pageheader']['theora']['pixel_aspect_numerator']   = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  3));
 153                         $filedataoffset += 3;
 154                         $info['ogg']['pageheader']['theora']['pixel_aspect_denominator'] = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  3));
 155                         $filedataoffset += 3;
 156                         $info['ogg']['pageheader']['theora']['color_space_id']           = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  1));
 157                         $filedataoffset += 1;
 158                         $info['ogg']['pageheader']['theora']['nominal_bitrate']          = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  3));
 159                         $filedataoffset += 3;
 160                         $info['ogg']['pageheader']['theora']['flags']                    = getid3_lib::BigEndian2Int(substr($filedata, $filedataoffset,  2));
 161                         $filedataoffset += 2;
 162
 163                         $info['ogg']['pageheader']['theora']['quality']         = ($info['ogg']['pageheader']['theora']['flags'] & 0xFC00) >> 10;
 164                         $info['ogg']['pageheader']['theora']['kfg_shift']       = ($info['ogg']['pageheader']['theora']['flags'] & 0x03E0) >>  5;
 165                         $info['ogg']['pageheader']['theora']['pixel_format_id'] = ($info['ogg']['pageheader']['theora']['flags'] & 0x0018) >>  3;
 166                         $info['ogg']['pageheader']['theora']['reserved']        = ($info['ogg']['pageheader']['theora']['flags'] & 0x0007) >>  0; // should be 0
 167                         $info['ogg']['pageheader']['theora']['color_space']     = self::TheoraColorSpace($info['ogg']['pageheader']['theora']['color_space_id']);
 168                         $info['ogg']['pageheader']['theora']['pixel_format']    = self::TheoraPixelFormat($info['ogg']['pageheader']['theora']['pixel_format_id']);
 169
 170                         $info['video']['dataformat']   = 'theora';
 171                         $info['mime_type']             = 'video/ogg';
 172                         //$info['audio']['bitrate_mode'] = 'abr';
 173                         //$info['audio']['lossless']     = false;
 174                         $info['video']['resolution_x'] = $info['ogg']['pageheader']['theora']['resolution_x'];
 175                         $info['video']['resolution_y'] = $info['ogg']['pageheader']['theora']['resolution_y'];
 176                         if ($info['ogg']['pageheader']['theora']['frame_rate_denominator'] > 0) {
 177                                 $info['video']['frame_rate'] = (float) $info['ogg']['pageheader']['theora']['frame_rate_numerator'] / $info['ogg']['pageheader']['theora']['frame_rate_denominator'];
 178                         }
 179                         if ($info['ogg']['pageheader']['theora']['pixel_aspect_denominator'] > 0) {
 180                                 $info['video']['pixel_aspect_ratio'] = (float) $info['ogg']['pageheader']['theora']['pixel_aspect_numerator'] / $info['ogg']['pageheader']['theora']['pixel_aspect_denominator'];
 181                         }
 182 $info['warning'][] = 'Ogg Theora (v3) not fully supported in this version of getID3 ['.$this->getid3->version().'] -- bitrate, playtime and all audio data are currently unavailable';
 183
 184
 185                 } elseif (substr($filedata, 0, 8) == "fishead\x00") {
 186
 187                         // Ogg Skeleton version 3.0 Format Specification
 188                         // http://xiph.org/ogg/doc/skeleton.html
 189                         $filedataoffset += 8;
 190                         $info['ogg']['skeleton']['fishead']['raw']['version_major']                = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  2));
 191                         $filedataoffset += 2;
 192                         $info['ogg']['skeleton']['fishead']['raw']['version_minor']                = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  2));
 193                         $filedataoffset += 2;
 194                         $info['ogg']['skeleton']['fishead']['raw']['presentationtime_numerator']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
 195                         $filedataoffset += 8;
 196                         $info['ogg']['skeleton']['fishead']['raw']['presentationtime_denominator'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
 197                         $filedataoffset += 8;
 198                         $info['ogg']['skeleton']['fishead']['raw']['basetime_numerator']           = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
 199                         $filedataoffset += 8;
 200                         $info['ogg']['skeleton']['fishead']['raw']['basetime_denominator']         = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
 201                         $filedataoffset += 8;
 202                         $info['ogg']['skeleton']['fishead']['raw']['utc']                          = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 20));
 203                         $filedataoffset += 20;
 204
 205                         $info['ogg']['skeleton']['fishead']['version']          = $info['ogg']['skeleton']['fishead']['raw']['version_major'].'.'.$info['ogg']['skeleton']['fishead']['raw']['version_minor'];
 206                         $info['ogg']['skeleton']['fishead']['presentationtime'] = $info['ogg']['skeleton']['fishead']['raw']['presentationtime_numerator'] / $info['ogg']['skeleton']['fishead']['raw']['presentationtime_denominator'];
 207                         $info['ogg']['skeleton']['fishead']['basetime']         = $info['ogg']['skeleton']['fishead']['raw']['basetime_numerator']         / $info['ogg']['skeleton']['fishead']['raw']['basetime_denominator'];
 208                         $info['ogg']['skeleton']['fishead']['utc']              = $info['ogg']['skeleton']['fishead']['raw']['utc'];
 209
 210
 211                         $counter = 0;
 212                         do {
 213                                 $oggpageinfo = $this->ParseOggPageHeader();
 214                                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno'].'.'.$counter++] = $oggpageinfo;
 215                                 $filedata = $this->fread($oggpageinfo['page_length']);
 216                                 $this->fseek($oggpageinfo['page_end_offset']);
 217
 218                                 if (substr($filedata, 0, 8) == "fisbone\x00") {
 219
 220                                         $filedataoffset = 8;
 221                                         $info['ogg']['skeleton']['fisbone']['raw']['message_header_offset']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
 222                                         $filedataoffset += 4;
 223                                         $info['ogg']['skeleton']['fisbone']['raw']['serial_number']           = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
 224                                         $filedataoffset += 4;
 225                                         $info['ogg']['skeleton']['fisbone']['raw']['number_header_packets']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
 226                                         $filedataoffset += 4;
 227                                         $info['ogg']['skeleton']['fisbone']['raw']['granulerate_numerator']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
 228                                         $filedataoffset += 8;
 229                                         $info['ogg']['skeleton']['fisbone']['raw']['granulerate_denominator'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
 230                                         $filedataoffset += 8;
 231                                         $info['ogg']['skeleton']['fisbone']['raw']['basegranule']             = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  8));
 232                                         $filedataoffset += 8;
 233                                         $info['ogg']['skeleton']['fisbone']['raw']['preroll']                 = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
 234                                         $filedataoffset += 4;
 235                                         $info['ogg']['skeleton']['fisbone']['raw']['granuleshift']            = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  1));
 236                                         $filedataoffset += 1;
 237                                         $info['ogg']['skeleton']['fisbone']['raw']['padding']                 =                              substr($filedata, $filedataoffset,  3);
 238                                         $filedataoffset += 3;
 239
 240                                 } elseif (substr($filedata, 1, 6) == 'theora') {
 241
 242                                         $info['video']['dataformat'] = 'theora1';
 243                                         $info['error'][] = 'Ogg Theora (v1) not correctly handled in this version of getID3 ['.$this->getid3->version().']';
 244                                         //break;
 245
 246                                 } elseif (substr($filedata, 1, 6) == 'vorbis') {
 247
 248                                         $this->ParseVorbisPageHeader($filedata, $filedataoffset, $oggpageinfo);
 249
 250                                 } else {
 251                                         $info['error'][] = 'unexpected';
 252                                         //break;
 253                                 }
 254                         //} while ($oggpageinfo['page_seqno'] == 0);
 255                         } while (($oggpageinfo['page_seqno'] == 0) && (substr($filedata, 0, 8) != "fisbone\x00"));
 256
 257                         $this->fseek($oggpageinfo['page_start_offset']);
 258
 259                         $info['error'][] = 'Ogg Skeleton not correctly handled in this version of getID3 ['.$this->getid3->version().']';
 260                         //return false;
 261
 262                 } else {
 263
 264                         $info['error'][] = 'Expecting either "Speex   ", "OpusHead" or "vorbis" identifier strings, found "'.substr($filedata, 0, 8).'"';
 265                         unset($info['ogg']);
 266                         unset($info['mime_type']);
 267                         return false;
 268
 269                 }
 270
 271                 // Page 2 - Comment Header
 272                 $oggpageinfo = $this->ParseOggPageHeader();
 273                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;
 274
 275                 switch ($info['audio']['dataformat']) {
 276                         case 'vorbis':
 277                                 $filedata = $this->fread($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length']);
 278                                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['packet_type'] = getid3_lib::LittleEndian2Int(substr($filedata, 0, 1));
 279                                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['stream_type'] =                              substr($filedata, 1, 6); // hard-coded to 'vorbis'
 280
 281                                 $this->ParseVorbisComments();
 282                                 break;
 283
 284                         case 'flac':
 285                                 $flac = new getid3_flac($this->getid3);
 286                                 if (!$flac->parseMETAdata()) {
 287                                         $info['error'][] = 'Failed to parse FLAC headers';
 288                                         return false;
 289                                 }
 290                                 unset($flac);
 291                                 break;
 292
 293                         case 'speex':
 294                                 $this->fseek($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length'], SEEK_CUR);
 295                                 $this->ParseVorbisComments();
 296                                 break;
 297
 298                         case 'opus':
 299                                 $filedata = $this->fread($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length']);
 300                                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['stream_type'] = substr($filedata, 0, 8); // hard-coded to 'OpusTags'
 301                                 if(substr($filedata, 0, 8)  != 'OpusTags') {
 302                                         $info['error'][] = 'Expected "OpusTags" as header but got "'.substr($filedata, 0, 8).'"';
 303                                         return false;
 304                                 }
 305
 306                                 $this->ParseVorbisComments();
 307                                 break;
 308
 309                 }
 310
 311                 // Last Page - Number of Samples
 312                 if (!getid3_lib::intValueSupported($info['avdataend'])) {
 313
 314                         $info['warning'][] = 'Unable to parse Ogg end chunk file (PHP does not support file operations beyond '.round(PHP_INT_MAX / 1073741824).'GB)';
 315
 316                 } else {
 317
 318                         $this->fseek(max($info['avdataend'] - $this->getid3->fread_buffer_size(), 0));
 319                         $LastChunkOfOgg = strrev($this->fread($this->getid3->fread_buffer_size()));
 320                         if ($LastOggSpostion = strpos($LastChunkOfOgg, 'SggO')) {
 321                                 $this->fseek($info['avdataend'] - ($LastOggSpostion + strlen('SggO')));
 322                                 $info['avdataend'] = $this->ftell();
 323                                 $info['ogg']['pageheader']['eos'] = $this->ParseOggPageHeader();
 324                                 $info['ogg']['samples']   = $info['ogg']['pageheader']['eos']['pcm_abs_position'];
 325                                 if ($info['ogg']['samples'] == 0) {
 326                                         $info['error'][] = 'Corrupt Ogg file: eos.number of samples == zero';
 327                                         return false;
 328                                 }
 329                                 if (!empty($info['audio']['sample_rate'])) {
 330                                         $info['ogg']['bitrate_average'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / ($info['ogg']['samples'] / $info['audio']['sample_rate']);
 331                                 }
 332                         }
 333
 334                 }
 335
 336                 if (!empty($info['ogg']['bitrate_average'])) {
 337                         $info['audio']['bitrate'] = $info['ogg']['bitrate_average'];
 338                 } elseif (!empty($info['ogg']['bitrate_nominal'])) {
 339                         $info['audio']['bitrate'] = $info['ogg']['bitrate_nominal'];
 340                 } elseif (!empty($info['ogg']['bitrate_min']) && !empty($info['ogg']['bitrate_max'])) {
 341                         $info['audio']['bitrate'] = ($info['ogg']['bitrate_min'] + $info['ogg']['bitrate_max']) / 2;
 342                 }
 343                 if (isset($info['audio']['bitrate']) && !isset($info['playtime_seconds'])) {
 344                         if ($info['audio']['bitrate'] == 0) {
 345                                 $info['error'][] = 'Corrupt Ogg file: bitrate_audio == zero';
 346                                 return false;
 347                         }
 348                         $info['playtime_seconds'] = (float) ((($info['avdataend'] - $info['avdataoffset']) * 8) / $info['audio']['bitrate']);
 349                 }
 350
 351                 if (isset($info['ogg']['vendor'])) {
 352                         $info['audio']['encoder'] = preg_replace('/^Encoded with /', '', $info['ogg']['vendor']);
 353
 354                         // Vorbis only
 355                         if ($info['audio']['dataformat'] == 'vorbis') {
 356
 357                                 // Vorbis 1.0 starts with Xiph.Org
 358                                 if  (preg_match('/^Xiph.Org/', $info['audio']['encoder'])) {
 359
 360                                         if ($info['audio']['bitrate_mode'] == 'abr') {
 361
 362                                                 // Set -b 128 on abr files
 363                                                 $info['audio']['encoder_options'] = '-b '.round($info['ogg']['bitrate_nominal'] / 1000);
 364
 365                                         } elseif (($info['audio']['bitrate_mode'] == 'vbr') && ($info['audio']['channels'] == 2) && ($info['audio']['sample_rate'] >= 44100) && ($info['audio']['sample_rate'] <= 48000)) {
 366                                                 // Set -q N on vbr files
 367                                                 $info['audio']['encoder_options'] = '-q '.$this->get_quality_from_nominal_bitrate($info['ogg']['bitrate_nominal']);
 368
 369                                         }
 370                                 }
 371
 372                                 if (empty($info['audio']['encoder_options']) && !empty($info['ogg']['bitrate_nominal'])) {
 373                                         $info['audio']['encoder_options'] = 'Nominal bitrate: '.intval(round($info['ogg']['bitrate_nominal'] / 1000)).'kbps';
 374                                 }
 375                         }
 376                 }
 377
 378                 return true;
 379         }
 380
 381         public function ParseVorbisPageHeader(&$filedata, &$filedataoffset, &$oggpageinfo) {
 382                 $info = &$this->getid3->info;
 383                 $info['audio']['dataformat'] = 'vorbis';
 384                 $info['audio']['lossless']   = false;
 385
 386                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['packet_type'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
 387                 $filedataoffset += 1;
 388                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['stream_type'] = substr($filedata, $filedataoffset, 6); // hard-coded to 'vorbis'
 389                 $filedataoffset += 6;
 390                 $info['ogg']['bitstreamversion'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 391                 $filedataoffset += 4;
 392                 $info['ogg']['numberofchannels'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
 393                 $filedataoffset += 1;
 394                 $info['audio']['channels']       = $info['ogg']['numberofchannels'];
 395                 $info['ogg']['samplerate']       = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 396                 $filedataoffset += 4;
 397                 if ($info['ogg']['samplerate'] == 0) {
 398                         $info['error'][] = 'Corrupt Ogg file: sample rate == zero';
 399                         return false;
 400                 }
 401                 $info['audio']['sample_rate']    = $info['ogg']['samplerate'];
 402                 $info['ogg']['samples']          = 0; // filled in later
 403                 $info['ogg']['bitrate_average']  = 0; // filled in later
 404                 $info['ogg']['bitrate_max']      = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 405                 $filedataoffset += 4;
 406                 $info['ogg']['bitrate_nominal']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 407                 $filedataoffset += 4;
 408                 $info['ogg']['bitrate_min']      = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 409                 $filedataoffset += 4;
 410                 $info['ogg']['blocksize_small']  = pow(2,  getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1)) & 0x0F);
 411                 $info['ogg']['blocksize_large']  = pow(2, (getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1)) & 0xF0) >> 4);
 412                 $info['ogg']['stop_bit']         = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1)); // must be 1, marks end of packet
 413
 414                 $info['audio']['bitrate_mode'] = 'vbr'; // overridden if actually abr
 415                 if ($info['ogg']['bitrate_max'] == 0xFFFFFFFF) {
 416                         unset($info['ogg']['bitrate_max']);
 417                         $info['audio']['bitrate_mode'] = 'abr';
 418                 }
 419                 if ($info['ogg']['bitrate_nominal'] == 0xFFFFFFFF) {
 420                         unset($info['ogg']['bitrate_nominal']);
 421                 }
 422                 if ($info['ogg']['bitrate_min'] == 0xFFFFFFFF) {
 423                         unset($info['ogg']['bitrate_min']);
 424                         $info['audio']['bitrate_mode'] = 'abr';
 425                 }
 426                 return true;
 427         }
 428
 429         // http://tools.ietf.org/html/draft-ietf-codec-oggopus-03
 430         public function ParseOpusPageHeader(&$filedata, &$filedataoffset, &$oggpageinfo) {
 431                 $info = &$this->getid3->info;
 432                 $info['audio']['dataformat']   = 'opus';
 433                 $info['mime_type']             = 'audio/ogg; codecs=opus';
 434
 435                 /** @todo find a usable way to detect abr (vbr that is padded to be abr) */
 436                 $info['audio']['bitrate_mode'] = 'vbr';
 437
 438                 $info['audio']['lossless']     = false;
 439
 440                 $info['ogg']['pageheader']['opus']['opus_magic'] = substr($filedata, $filedataoffset, 8); // hard-coded to 'OpusHead'
 441                 $filedataoffset += 8;
 442                 $info['ogg']['pageheader']['opus']['version']    = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  1));
 443                 $filedataoffset += 1;
 444
 445                 if ($info['ogg']['pageheader']['opus']['version'] < 1 || $info['ogg']['pageheader']['opus']['version'] > 15) {
 446                         $info['error'][] = 'Unknown opus version number (only accepting 1-15)';
 447                         return false;
 448                 }
 449
 450                 $info['ogg']['pageheader']['opus']['out_channel_count'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  1));
 451                 $filedataoffset += 1;
 452
 453                 if ($info['ogg']['pageheader']['opus']['out_channel_count'] == 0) {
 454                         $info['error'][] = 'Invalid channel count in opus header (must not be zero)';
 455                         return false;
 456                 }
 457
 458                 $info['ogg']['pageheader']['opus']['pre_skip'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  2));
 459                 $filedataoffset += 2;
 460
 461                 $info['ogg']['pageheader']['opus']['sample_rate'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  4));
 462                 $filedataoffset += 4;
 463
 464                 //$info['ogg']['pageheader']['opus']['output_gain'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  2));
 465                 //$filedataoffset += 2;
 466
 467                 //$info['ogg']['pageheader']['opus']['channel_mapping_family'] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset,  1));
 468                 //$filedataoffset += 1;
 469
 470                 $info['opus']['opus_version']      = $info['ogg']['pageheader']['opus']['version'];
 471                 $info['opus']['sample_rate']       = $info['ogg']['pageheader']['opus']['sample_rate'];
 472                 $info['opus']['out_channel_count'] = $info['ogg']['pageheader']['opus']['out_channel_count'];
 473
 474                 $info['audio']['channels']      = $info['opus']['out_channel_count'];
 475                 $info['audio']['sample_rate']   = $info['opus']['sample_rate'];
 476                 return true;
 477         }
 478
 479
 480         public function ParseOggPageHeader() {
 481                 // http://xiph.org/ogg/vorbis/doc/framing.html
 482                 $oggheader['page_start_offset'] = $this->ftell(); // where we started from in the file
 483
 484                 $filedata = $this->fread($this->getid3->fread_buffer_size());
 485                 $filedataoffset = 0;
 486                 while ((substr($filedata, $filedataoffset++, 4) != 'OggS')) {
 487                         if (($this->ftell() - $oggheader['page_start_offset']) >= $this->getid3->fread_buffer_size()) {
 488                                 // should be found before here
 489                                 return false;
 490                         }
 491                         if ((($filedataoffset + 28) > strlen($filedata)) || (strlen($filedata) < 28)) {
 492                                 if ($this->feof() || (($filedata .= $this->fread($this->getid3->fread_buffer_size())) === false)) {
 493                                         // get some more data, unless eof, in which case fail
 494                                         return false;
 495                                 }
 496                         }
 497                 }
 498                 $filedataoffset += strlen('OggS') - 1; // page, delimited by 'OggS'
 499
 500                 $oggheader['stream_structver']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
 501                 $filedataoffset += 1;
 502                 $oggheader['flags_raw']         = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
 503                 $filedataoffset += 1;
 504                 $oggheader['flags']['fresh']    = (bool) ($oggheader['flags_raw'] & 0x01); // fresh packet
 505                 $oggheader['flags']['bos']      = (bool) ($oggheader['flags_raw'] & 0x02); // first page of logical bitstream (bos)
 506                 $oggheader['flags']['eos']      = (bool) ($oggheader['flags_raw'] & 0x04); // last page of logical bitstream (eos)
 507
 508                 $oggheader['pcm_abs_position']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 8));
 509                 $filedataoffset += 8;
 510                 $oggheader['stream_serialno']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 511                 $filedataoffset += 4;
 512                 $oggheader['page_seqno']        = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 513                 $filedataoffset += 4;
 514                 $oggheader['page_checksum']     = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
 515                 $filedataoffset += 4;
 516                 $oggheader['page_segments']     = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
 517                 $filedataoffset += 1;
 518                 $oggheader['page_length'] = 0;
 519                 for ($i = 0; $i < $oggheader['page_segments']; $i++) {
 520                         $oggheader['segment_table'][$i] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
 521                         $filedataoffset += 1;
 522                         $oggheader['page_length'] += $oggheader['segment_table'][$i];
 523                 }
 524                 $oggheader['header_end_offset'] = $oggheader['page_start_offset'] + $filedataoffset;
 525                 $oggheader['page_end_offset']   = $oggheader['header_end_offset'] + $oggheader['page_length'];
 526                 $this->fseek($oggheader['header_end_offset']);
 527
 528                 return $oggheader;
 529         }
 530
 531     // http://xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-810005
 532         public function ParseVorbisComments() {
 533                 $info = &$this->getid3->info;
 534
 535                 $OriginalOffset = $this->ftell();
 536                 $commentdataoffset = 0;
 537                 $VorbisCommentPage = 1;
 538
 539                 switch ($info['audio']['dataformat']) {
 540                         case 'vorbis':
 541                         case 'speex':
 542                         case 'opus':
 543                                 $CommentStartOffset = $info['ogg']['pageheader'][$VorbisCommentPage]['page_start_offset'];  // Second Ogg page, after header block
 544                                 $this->fseek($CommentStartOffset);
 545                                 $commentdataoffset = 27 + $info['ogg']['pageheader'][$VorbisCommentPage]['page_segments'];
 546                                 $commentdata = $this->fread(self::OggPageSegmentLength($info['ogg']['pageheader'][$VorbisCommentPage], 1) + $commentdataoffset);
 547
 548                                 if ($info['audio']['dataformat'] == 'vorbis') {
 549                                         $commentdataoffset += (strlen('vorbis') + 1);
 550                                 }
 551                                 else if ($info['audio']['dataformat'] == 'opus') {
 552                                         $commentdataoffset += strlen('OpusTags');
 553                                 }
 554
 555                                 break;
 556
 557                         case 'flac':
 558                                 $CommentStartOffset = $info['flac']['VORBIS_COMMENT']['raw']['offset'] + 4;
 559                                 $this->fseek($CommentStartOffset);
 560                                 $commentdata = $this->fread($info['flac']['VORBIS_COMMENT']['raw']['block_length']);
 561                                 break;
 562
 563                         default:
 564                                 return false;
 565                 }
 566
 567                 $VendorSize = getid3_lib::LittleEndian2Int(substr($commentdata, $commentdataoffset, 4));
 568                 $commentdataoffset += 4;
 569
 570                 $info['ogg']['vendor'] = substr($commentdata, $commentdataoffset, $VendorSize);
 571                 $commentdataoffset += $VendorSize;
 572
 573                 $CommentsCount = getid3_lib::LittleEndian2Int(substr($commentdata, $commentdataoffset, 4));
 574                 $commentdataoffset += 4;
 575                 $info['avdataoffset'] = $CommentStartOffset + $commentdataoffset;
 576
 577                 $basicfields = array('TITLE', 'ARTIST', 'ALBUM', 'TRACKNUMBER', 'GENRE', 'DATE', 'DESCRIPTION', 'COMMENT');
 578                 $ThisFileInfo_ogg_comments_raw = &$info['ogg']['comments_raw'];
 579                 for ($i = 0; $i < $CommentsCount; $i++) {
 580
 581                         if ($i >= 10000) {
 582                                 // https://github.com/owncloud/music/issues/212#issuecomment-43082336
 583                                 $info['warning'][] = 'Unexpectedly large number ('.$CommentsCount.') of Ogg comments - breaking after reading '.$i.' comments';
 584                                 break;
 585                         }
 586
 587                         $ThisFileInfo_ogg_comments_raw[$i]['dataoffset'] = $CommentStartOffset + $commentdataoffset;
 588
 589                         if ($this->ftell() < ($ThisFileInfo_ogg_comments_raw[$i]['dataoffset'] + 4)) {
 590                                 if ($oggpageinfo = $this->ParseOggPageHeader()) {
 591                                         $info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;
 592
 593                                         $VorbisCommentPage++;
 594
 595                                         // First, save what we haven't read yet
 596                                         $AsYetUnusedData = substr($commentdata, $commentdataoffset);
 597
 598                                         // Then take that data off the end
 599                                         $commentdata     = substr($commentdata, 0, $commentdataoffset);
 600
 601                                         // Add [headerlength] bytes of dummy data for the Ogg Page Header, just to keep absolute offsets correct
 602                                         $commentdata .= str_repeat("\x00", 27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);
 603                                         $commentdataoffset += (27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);
 604
 605                                         // Finally, stick the unused data back on the end
 606                                         $commentdata .= $AsYetUnusedData;
 607
 608                                         //$commentdata .= $this->fread($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length']);
 609                                         $commentdata .= $this->fread($this->OggPageSegmentLength($info['ogg']['pageheader'][$VorbisCommentPage], 1));
 610                                 }
 611
 612                         }
 613                         $ThisFileInfo_ogg_comments_raw[$i]['size'] = getid3_lib::LittleEndian2Int(substr($commentdata, $commentdataoffset, 4));
 614
 615                         // replace avdataoffset with position just after the last vorbiscomment
 616                         $info['avdataoffset'] = $ThisFileInfo_ogg_comments_raw[$i]['dataoffset'] + $ThisFileInfo_ogg_comments_raw[$i]['size'] + 4;
 617
 618                         $commentdataoffset += 4;
 619                         while ((strlen($commentdata) - $commentdataoffset) < $ThisFileInfo_ogg_comments_raw[$i]['size']) {
 620                                 if (($ThisFileInfo_ogg_comments_raw[$i]['size'] > $info['avdataend']) || ($ThisFileInfo_ogg_comments_raw[$i]['size'] < 0)) {
 621                                         $info['warning'][] = 'Invalid Ogg comment size (comment #'.$i.', claims to be '.number_format($ThisFileInfo_ogg_comments_raw[$i]['size']).' bytes) - aborting reading comments';
 622                                         break 2;
 623                                 }
 624
 625                                 $VorbisCommentPage++;
 626
 627                                 $oggpageinfo = $this->ParseOggPageHeader();
 628                                 $info['ogg']['pageheader'][$oggpageinfo['page_seqno']] = $oggpageinfo;
 629
 630                                 // First, save what we haven't read yet
 631                                 $AsYetUnusedData = substr($commentdata, $commentdataoffset);
 632
 633                                 // Then take that data off the end
 634                                 $commentdata     = substr($commentdata, 0, $commentdataoffset);
 635
 636                                 // Add [headerlength] bytes of dummy data for the Ogg Page Header, just to keep absolute offsets correct
 637                                 $commentdata .= str_repeat("\x00", 27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);
 638                                 $commentdataoffset += (27 + $info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_segments']);
 639
 640                                 // Finally, stick the unused data back on the end
 641                                 $commentdata .= $AsYetUnusedData;
 642
 643                                 //$commentdata .= $this->fread($info['ogg']['pageheader'][$oggpageinfo['page_seqno']]['page_length']);
 644                                 if (!isset($info['ogg']['pageheader'][$VorbisCommentPage])) {
 645                                         $info['warning'][] = 'undefined Vorbis Comment page "'.$VorbisCommentPage.'" at offset '.$this->ftell();
 646                                         break;
 647                                 }
 648                                 $readlength = self::OggPageSegmentLength($info['ogg']['pageheader'][$VorbisCommentPage], 1);
 649                                 if ($readlength <= 0) {
 650                                         $info['warning'][] = 'invalid length Vorbis Comment page "'.$VorbisCommentPage.'" at offset '.$this->ftell();
 651                                         break;
 652                                 }
 653                                 $commentdata .= $this->fread($readlength);
 654
 655                                 //$filebaseoffset += $oggpageinfo['header_end_offset'] - $oggpageinfo['page_start_offset'];
 656                         }
 657                         $ThisFileInfo_ogg_comments_raw[$i]['offset'] = $commentdataoffset;
 658                         $commentstring = substr($commentdata, $commentdataoffset, $ThisFileInfo_ogg_comments_raw[$i]['size']);
 659                         $commentdataoffset += $ThisFileInfo_ogg_comments_raw[$i]['size'];
 660
 661                         if (!$commentstring) {
 662
 663                                 // no comment?
 664                                 $info['warning'][] = 'Blank Ogg comment ['.$i.']';
 665
 666                         } elseif (strstr($commentstring, '=')) {
 667
 668                                 $commentexploded = explode('=', $commentstring, 2);
 669                                 $ThisFileInfo_ogg_comments_raw[$i]['key']   = strtoupper($commentexploded[0]);
 670                                 $ThisFileInfo_ogg_comments_raw[$i]['value'] = (isset($commentexploded[1]) ? $commentexploded[1] : '');
 671
 672                                 if ($ThisFileInfo_ogg_comments_raw[$i]['key'] == 'METADATA_BLOCK_PICTURE') {
 673
 674                                         // http://wiki.xiph.org/VorbisComment#METADATA_BLOCK_PICTURE
 675                                         // The unencoded format is that of the FLAC picture block. The fields are stored in big endian order as in FLAC, picture data is stored according to the relevant standard.
 676                                         // http://flac.sourceforge.net/format.html#metadata_block_picture
 677                                         $flac = new getid3_flac($this->getid3);
 678                                         $flac->setStringMode(base64_decode($ThisFileInfo_ogg_comments_raw[$i]['value']));
 679                                         $flac->parsePICTURE();
 680                                         $info['ogg']['comments']['picture'][] = $flac->getid3->info['flac']['PICTURE'][0];
 681                                         unset($flac);
 682
 683                                 } elseif ($ThisFileInfo_ogg_comments_raw[$i]['key'] == 'COVERART') {
 684
 685                                         $data = base64_decode($ThisFileInfo_ogg_comments_raw[$i]['value']);
 686                                         $this->notice('Found deprecated COVERART tag, it should be replaced in honor of METADATA_BLOCK_PICTURE structure');
 687                                         /** @todo use 'coverartmime' where available */
 688                                         $imageinfo = getid3_lib::GetDataImageSize($data);
 689                                         if ($imageinfo === false || !isset($imageinfo['mime'])) {
 690                                                 $this->warning('COVERART vorbiscomment tag contains invalid image');
 691                                                 continue;
 692                                         }
 693
 694                                         $ogg = new self($this->getid3);
 695                                         $ogg->setStringMode($data);
 696                                         $info['ogg']['comments']['picture'][] = array(
 697                                                 'image_mime'   => $imageinfo['mime'],
 698                                                 'datalength'   => strlen($data),
 699                                                 'picturetype'  => 'cover art',
 700                                                 'image_height' => $imageinfo['height'],
 701                                                 'image_width'  => $imageinfo['width'],
 702                                                 'data'         => $ogg->saveAttachment('coverart', 0, strlen($data), $imageinfo['mime']),
 703                                         );
 704                                         unset($ogg);
 705
 706                                 } else {
 707
 708                                         $info['ogg']['comments'][strtolower($ThisFileInfo_ogg_comments_raw[$i]['key'])][] = $ThisFileInfo_ogg_comments_raw[$i]['value'];
 709
 710                                 }
 711
 712                         } else {
 713
 714                                 $info['warning'][] = '[known problem with CDex >= v1.40, < v1.50b7] Invalid Ogg comment name/value pair ['.$i.']: '.$commentstring;
 715
 716                         }
 717                         unset($ThisFileInfo_ogg_comments_raw[$i]);
 718                 }
 719                 unset($ThisFileInfo_ogg_comments_raw);
 720
 721
 722                 // Replay Gain Adjustment
 723                 // http://privatewww.essex.ac.uk/~djmrob/replaygain/
 724                 if (isset($info['ogg']['comments']) && is_array($info['ogg']['comments'])) {
 725                         foreach ($info['ogg']['comments'] as $index => $commentvalue) {
 726                                 switch ($index) {
 727                                         case 'rg_audiophile':
 728                                         case 'replaygain_album_gain':
 729                                                 $info['replay_gain']['album']['adjustment'] = (double) $commentvalue[0];
 730                                                 unset($info['ogg']['comments'][$index]);
 731                                                 break;
 732
 733                                         case 'rg_radio':
 734                                         case 'replaygain_track_gain':
 735                                                 $info['replay_gain']['track']['adjustment'] = (double) $commentvalue[0];
 736                                                 unset($info['ogg']['comments'][$index]);
 737                                                 break;
 738
 739                                         case 'replaygain_album_peak':
 740                                                 $info['replay_gain']['album']['peak'] = (double) $commentvalue[0];
 741                                                 unset($info['ogg']['comments'][$index]);
 742                                                 break;
 743
 744                                         case 'rg_peak':
 745                                         case 'replaygain_track_peak':
 746                                                 $info['replay_gain']['track']['peak'] = (double) $commentvalue[0];
 747                                                 unset($info['ogg']['comments'][$index]);
 748                                                 break;
 749
 750                                         case 'replaygain_reference_loudness':
 751                                                 $info['replay_gain']['reference_volume'] = (double) $commentvalue[0];
 752                                                 unset($info['ogg']['comments'][$index]);
 753                                                 break;
 754
 755                                         default:
 756                                                 // do nothing
 757                                                 break;
 758                                 }
 759                         }
 760                 }
 761
 762                 $this->fseek($OriginalOffset);
 763
 764                 return true;
 765         }
 766
 767         public static function SpeexBandModeLookup($mode) {
 768                 static $SpeexBandModeLookup = array();
 769                 if (empty($SpeexBandModeLookup)) {
 770                         $SpeexBandModeLookup[0] = 'narrow';
 771                         $SpeexBandModeLookup[1] = 'wide';
 772                         $SpeexBandModeLookup[2] = 'ultra-wide';
 773                 }
 774                 return (isset($SpeexBandModeLookup[$mode]) ? $SpeexBandModeLookup[$mode] : null);
 775         }
 776
 777
 778         public static function OggPageSegmentLength($OggInfoArray, $SegmentNumber=1) {
 779                 for ($i = 0; $i < $SegmentNumber; $i++) {
 780                         $segmentlength = 0;
 781                         foreach ($OggInfoArray['segment_table'] as $key => $value) {
 782                                 $segmentlength += $value;
 783                                 if ($value < 255) {
 784                                         break;
 785                                 }
 786                         }
 787                 }
 788                 return $segmentlength;
 789         }
 790
 791
 792         public static function get_quality_from_nominal_bitrate($nominal_bitrate) {
 793
 794                 // decrease precision
 795                 $nominal_bitrate = $nominal_bitrate / 1000;
 796
 797                 if ($nominal_bitrate < 128) {
 798                         // q-1 to q4
 799                         $qval = ($nominal_bitrate - 64) / 16;
 800                 } elseif ($nominal_bitrate < 256) {
 801                         // q4 to q8
 802                         $qval = $nominal_bitrate / 32;
 803                 } elseif ($nominal_bitrate < 320) {
 804                         // q8 to q9
 805                         $qval = ($nominal_bitrate + 256) / 64;
 806                 } else {
 807                         // q9 to q10
 808                         $qval = ($nominal_bitrate + 1300) / 180;
 809                 }
 810                 //return $qval; // 5.031324
 811                 //return intval($qval); // 5
 812                 return round($qval, 1); // 5 or 4.9
 813         }
 814
 815         public static function TheoraColorSpace($colorspace_id) {
 816                 // http://www.theora.org/doc/Theora.pdf (table 6.3)
 817                 static $TheoraColorSpaceLookup = array();
 818                 if (empty($TheoraColorSpaceLookup)) {
 819                         $TheoraColorSpaceLookup[0] = 'Undefined';
 820                         $TheoraColorSpaceLookup[1] = 'Rec. 470M';
 821                         $TheoraColorSpaceLookup[2] = 'Rec. 470BG';
 822                         $TheoraColorSpaceLookup[3] = 'Reserved';
 823                 }
 824                 return (isset($TheoraColorSpaceLookup[$colorspace_id]) ? $TheoraColorSpaceLookup[$colorspace_id] : null);
 825         }
 826
 827         public static function TheoraPixelFormat($pixelformat_id) {
 828                 // http://www.theora.org/doc/Theora.pdf (table 6.4)
 829                 static $TheoraPixelFormatLookup = array();
 830                 if (empty($TheoraPixelFormatLookup)) {
 831                         $TheoraPixelFormatLookup[0] = '4:2:0';
 832                         $TheoraPixelFormatLookup[1] = 'Reserved';
 833                         $TheoraPixelFormatLookup[2] = '4:2:2';
 834                         $TheoraPixelFormatLookup[3] = '4:4:4';
 835                 }
 836                 return (isset($TheoraPixelFormatLookup[$pixelformat_id]) ? $TheoraPixelFormatLookup[$pixelformat_id] : null);
 837         }
 838
 839 }