File indexing completed on 2024-12-22 05:33:11

0001 <?php
0002 /////////////////////////////////////////////////////////////////
0003 /// getID3() by James Heinrich <info@getid3.org>               //
0004 //  available at http://getid3.sourceforge.net                 //
0005 //            or http://www.getid3.org                         //
0006 //          also https://github.com/JamesHeinrich/getID3       //
0007 /////////////////////////////////////////////////////////////////
0008 // See readme.txt for more details                             //
0009 /////////////////////////////////////////////////////////////////
0010 //                                                             //
0011 // module.audio-video.mpeg.php                                 //
0012 // module for analyzing MPEG files                             //
0013 // dependencies: module.audio.mp3.php                          //
0014 //                                                            ///
0015 /////////////////////////////////////////////////////////////////
0016 
0017 getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio.mp3.php', __FILE__, true);
0018 
0019 class getid3_mpeg extends getid3_handler {
0020 
0021   const START_CODE_BASE       = "\x00\x00\x01";
0022   const VIDEO_PICTURE_START   = "\x00\x00\x01\x00";
0023   const VIDEO_USER_DATA_START = "\x00\x00\x01\xB2";
0024   const VIDEO_SEQUENCE_HEADER = "\x00\x00\x01\xB3";
0025   const VIDEO_SEQUENCE_ERROR  = "\x00\x00\x01\xB4";
0026   const VIDEO_EXTENSION_START = "\x00\x00\x01\xB5";
0027   const VIDEO_SEQUENCE_END    = "\x00\x00\x01\xB7";
0028   const VIDEO_GROUP_START     = "\x00\x00\x01\xB8";
0029   const AUDIO_START           = "\x00\x00\x01\xC0";
0030 
0031 
0032   public function Analyze() {
0033     $info = &$this->getid3->info;
0034 
0035     $info['fileformat'] = 'mpeg';
0036     $this->fseek($info['avdataoffset']);
0037 
0038     $MPEGstreamData = $this->fread($this->getid3->option_fread_buffer_size);
0039     $MPEGstreamBaseOffset = 0; // how far are we from the beginning of the file data ($info['avdataoffset'])
0040     $MPEGstreamDataOffset = 0; // how far are we from the beginning of the buffer data (~32kB)
0041 
0042     $StartCodeValue     = false;
0043     $prevStartCodeValue = false;
0044 
0045     $GOPcounter = -1;
0046     $FramesByGOP = array();
0047     $ParsedAVchannels = array();
0048 
0049     do {
0050 //echo $MPEGstreamDataOffset.' vs '.(strlen($MPEGstreamData) - 1024).'<Br>';
0051       if ($MPEGstreamDataOffset > (strlen($MPEGstreamData) - 16384)) {
0052         // buffer running low, get more data
0053 //echo 'reading more data<br>';
0054         $MPEGstreamData .= $this->fread($this->getid3->option_fread_buffer_size);
0055         if (strlen($MPEGstreamData) > $this->getid3->option_fread_buffer_size) {
0056           $MPEGstreamData = substr($MPEGstreamData, $MPEGstreamDataOffset);
0057           $MPEGstreamBaseOffset += $MPEGstreamDataOffset;
0058           $MPEGstreamDataOffset  = 0;
0059         }
0060       }
0061       if (($StartCodeOffset = strpos($MPEGstreamData, self::START_CODE_BASE, $MPEGstreamDataOffset)) === false) {
0062 //echo 'no more start codes found.<br>';
0063         break;
0064       } else {
0065         $MPEGstreamDataOffset = $StartCodeOffset;
0066         $prevStartCodeValue = $StartCodeValue;
0067         $StartCodeValue = ord(substr($MPEGstreamData, $StartCodeOffset + 3, 1));
0068 //echo 'Found "'.strtoupper(dechex($StartCodeValue)).'" at offset '.($MPEGstreamBaseOffset + $StartCodeOffset).' ($MPEGstreamDataOffset = '.$MPEGstreamDataOffset.')<br>';
0069       }
0070       $MPEGstreamDataOffset += 4;
0071       switch ($StartCodeValue) {
0072 
0073         case 0x00: // picture_start_code
0074           if (!empty($info['mpeg']['video']['bitrate_mode']) && ($info['mpeg']['video']['bitrate_mode'] == 'vbr')) {
0075             $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 4));
0076             $bitstreamoffset = 0;
0077 
0078             $PictureHeader = array();
0079 
0080             $PictureHeader['temporal_reference']  = self::readBitsFromStream($bitstream, $bitstreamoffset, 10); // 10-bit unsigned integer associated with each input picture. It is incremented by one, modulo 1024, for each input frame. When a frame is coded as two fields the temporal reference in the picture header of both fields is the same. Following a group start header the temporal reference of the earliest picture (in display order) shall be reset to zero.
0081             $PictureHeader['picture_coding_type'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); //  3 bits for picture_coding_type
0082             $PictureHeader['vbv_delay']           = self::readBitsFromStream($bitstream, $bitstreamoffset, 16); // 16 bits for vbv_delay
0083             //... etc
0084 
0085             $FramesByGOP[$GOPcounter][] = $PictureHeader;
0086           }
0087           break;
0088 
0089         case 0xB3: // sequence_header_code
0090           /*
0091           Note: purposely doing the less-pretty (and probably a bit slower) method of using string of bits rather than bitwise operations.
0092                 Mostly because PHP 32-bit doesn't handle unsigned integers well for bitwise operation.
0093                 Also the MPEG stream is designed as a bitstream and often doesn't align nicely with byte boundaries.
0094           */
0095           $info['video']['codec'] = 'MPEG-1'; // will be updated if extension_start_code found
0096 
0097           $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 8));
0098           $bitstreamoffset = 0;
0099 
0100           $info['mpeg']['video']['raw']['horizontal_size_value']       = self::readBitsFromStream($bitstream, $bitstreamoffset, 12); // 12 bits for horizontal frame size. Note: horizontal_size_extension, if present, will add 2 most-significant bits to this value
0101           $info['mpeg']['video']['raw']['vertical_size_value']         = self::readBitsFromStream($bitstream, $bitstreamoffset, 12); // 12 bits for vertical frame size.   Note: vertical_size_extension,   if present, will add 2 most-significant bits to this value
0102           $info['mpeg']['video']['raw']['aspect_ratio_information']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); //  4 bits for aspect_ratio_information
0103           $info['mpeg']['video']['raw']['frame_rate_code']             = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); //  4 bits for Frame Rate id code
0104           $info['mpeg']['video']['raw']['bitrate']                     = self::readBitsFromStream($bitstream, $bitstreamoffset, 18); // 18 bits for bit_rate_value (18 set bits = VBR, otherwise bitrate = this value * 400)
0105           $marker_bit                                                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
0106           $info['mpeg']['video']['raw']['vbv_buffer_size']             = self::readBitsFromStream($bitstream, $bitstreamoffset, 10); // 10 bits vbv_buffer_size_value
0107           $info['mpeg']['video']['raw']['constrained_param_flag']      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: constrained_param_flag
0108           $info['mpeg']['video']['raw']['load_intra_quantiser_matrix'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: load_intra_quantiser_matrix
0109 
0110           if ($info['mpeg']['video']['raw']['load_intra_quantiser_matrix']) {
0111             $bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 12, 64));
0112             for ($i = 0; $i < 64; $i++) {
0113               $info['mpeg']['video']['raw']['intra_quantiser_matrix'][$i] = self::readBitsFromStream($bitstream, $bitstreamoffset,  8);
0114             }
0115           }
0116           $info['mpeg']['video']['raw']['load_non_intra_quantiser_matrix'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  1);
0117 
0118           if ($info['mpeg']['video']['raw']['load_non_intra_quantiser_matrix']) {
0119             $bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 12 + ($info['mpeg']['video']['raw']['load_intra_quantiser_matrix'] ? 64 : 0), 64));
0120             for ($i = 0; $i < 64; $i++) {
0121               $info['mpeg']['video']['raw']['non_intra_quantiser_matrix'][$i] = self::readBitsFromStream($bitstream, $bitstreamoffset,  8);
0122             }
0123           }
0124 
0125           $info['mpeg']['video']['pixel_aspect_ratio']      =     self::videoAspectRatioLookup($info['mpeg']['video']['raw']['aspect_ratio_information']);
0126           $info['mpeg']['video']['pixel_aspect_ratio_text'] = self::videoAspectRatioTextLookup($info['mpeg']['video']['raw']['aspect_ratio_information']);
0127           $info['mpeg']['video']['frame_rate']              =       self::videoFramerateLookup($info['mpeg']['video']['raw']['frame_rate_code']);
0128           if ($info['mpeg']['video']['raw']['bitrate'] == 0x3FFFF) { // 18 set bits = VBR
0129             //$this->warning('This version of getID3() ['.$this->getid3->version().'] cannot determine average bitrate of VBR MPEG video files');
0130             $info['mpeg']['video']['bitrate_mode'] = 'vbr';
0131           } else {
0132             $info['mpeg']['video']['bitrate']      = $info['mpeg']['video']['raw']['bitrate'] * 400;
0133             $info['mpeg']['video']['bitrate_mode'] = 'cbr';
0134             $info['video']['bitrate']              = $info['mpeg']['video']['bitrate'];
0135           }
0136           $info['video']['resolution_x']       = $info['mpeg']['video']['raw']['horizontal_size_value'];
0137           $info['video']['resolution_y']       = $info['mpeg']['video']['raw']['vertical_size_value'];
0138           $info['video']['frame_rate']         = $info['mpeg']['video']['frame_rate'];
0139           $info['video']['bitrate_mode']       = $info['mpeg']['video']['bitrate_mode'];
0140           $info['video']['pixel_aspect_ratio'] = $info['mpeg']['video']['pixel_aspect_ratio'];
0141           $info['video']['lossless']           = false;
0142           $info['video']['bits_per_sample']    = 24;
0143           break;
0144 
0145         case 0xB5: // extension_start_code
0146           $info['video']['codec'] = 'MPEG-2';
0147 
0148           $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 8)); // 48 bits for Sequence Extension ID; 61 bits for Sequence Display Extension ID; 59 bits for Sequence Scalable Extension ID
0149           $bitstreamoffset = 0;
0150 
0151           $info['mpeg']['video']['raw']['extension_start_code_identifier'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); //  4 bits for extension_start_code_identifier
0152 //echo $info['mpeg']['video']['raw']['extension_start_code_identifier'].'<br>';
0153           switch ($info['mpeg']['video']['raw']['extension_start_code_identifier']) {
0154             case  1: // 0001 Sequence Extension ID
0155               $info['mpeg']['video']['raw']['profile_and_level_indication']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for profile_and_level_indication
0156               $info['mpeg']['video']['raw']['progressive_sequence']            = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: progressive_sequence
0157               $info['mpeg']['video']['raw']['chroma_format']                   = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for chroma_format
0158               $info['mpeg']['video']['raw']['horizontal_size_extension']       = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for horizontal_size_extension
0159               $info['mpeg']['video']['raw']['vertical_size_extension']         = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for vertical_size_extension
0160               $info['mpeg']['video']['raw']['bit_rate_extension']              = self::readBitsFromStream($bitstream, $bitstreamoffset, 12); // 12 bits for bit_rate_extension
0161               $marker_bit                                                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
0162               $info['mpeg']['video']['raw']['vbv_buffer_size_extension']       = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for vbv_buffer_size_extension
0163               $info['mpeg']['video']['raw']['low_delay']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: low_delay
0164               $info['mpeg']['video']['raw']['frame_rate_extension_n']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for frame_rate_extension_n
0165               $info['mpeg']['video']['raw']['frame_rate_extension_d']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for frame_rate_extension_d
0166 
0167               $info['video']['resolution_x']          = ($info['mpeg']['video']['raw']['horizontal_size_extension'] << 12) | $info['mpeg']['video']['raw']['horizontal_size_value'];
0168               $info['video']['resolution_y']          = ($info['mpeg']['video']['raw']['vertical_size_extension']   << 12) | $info['mpeg']['video']['raw']['vertical_size_value'];
0169               $info['video']['interlaced']            = !$info['mpeg']['video']['raw']['progressive_sequence'];
0170               $info['mpeg']['video']['interlaced']    = !$info['mpeg']['video']['raw']['progressive_sequence'];
0171               $info['mpeg']['video']['chroma_format'] = self::chromaFormatTextLookup($info['mpeg']['video']['raw']['chroma_format']);
0172               break;
0173 
0174             case  2: // 0010 Sequence Display Extension ID
0175               $info['mpeg']['video']['raw']['video_format']                    = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); //  3 bits for video_format
0176               $info['mpeg']['video']['raw']['colour_description']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: colour_description
0177               if ($info['mpeg']['video']['raw']['colour_description']) {
0178                 $info['mpeg']['video']['raw']['colour_primaries']            = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for colour_primaries
0179                 $info['mpeg']['video']['raw']['transfer_characteristics']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for transfer_characteristics
0180                 $info['mpeg']['video']['raw']['matrix_coefficients']         = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  8 bits for matrix_coefficients
0181               }
0182               $info['mpeg']['video']['raw']['display_horizontal_size']         = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for display_horizontal_size
0183               $marker_bit                                                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
0184               $info['mpeg']['video']['raw']['display_vertical_size']           = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for display_vertical_size
0185 
0186               $info['mpeg']['video']['video_format'] = self::videoFormatTextLookup($info['mpeg']['video']['raw']['video_format']);
0187               break;
0188 
0189             case  3: // 0011 Quant Matrix Extension ID
0190               break;
0191 
0192             case  5: // 0101 Sequence Scalable Extension ID
0193               $info['mpeg']['video']['raw']['scalable_mode']                              = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for scalable_mode
0194               $info['mpeg']['video']['raw']['layer_id']                                   = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); //  4 bits for layer_id
0195               if ($info['mpeg']['video']['raw']['scalable_mode'] == 1) { // "spatial scalability"
0196                 $info['mpeg']['video']['raw']['lower_layer_prediction_horizontal_size'] = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for lower_layer_prediction_horizontal_size
0197                 $marker_bit                                                             = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
0198                 $info['mpeg']['video']['raw']['lower_layer_prediction_vertical_size']   = self::readBitsFromStream($bitstream, $bitstreamoffset, 14); // 14 bits for lower_layer_prediction_vertical_size
0199                 $info['mpeg']['video']['raw']['horizontal_subsampling_factor_m']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for horizontal_subsampling_factor_m
0200                 $info['mpeg']['video']['raw']['horizontal_subsampling_factor_n']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for horizontal_subsampling_factor_n
0201                 $info['mpeg']['video']['raw']['vertical_subsampling_factor_m']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for vertical_subsampling_factor_m
0202                 $info['mpeg']['video']['raw']['vertical_subsampling_factor_n']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for vertical_subsampling_factor_n
0203               } elseif ($info['mpeg']['video']['raw']['scalable_mode'] == 3) { // "temporal scalability"
0204                 $info['mpeg']['video']['raw']['picture_mux_enable']                     = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: picture_mux_enable
0205                 if ($info['mpeg']['video']['raw']['picture_mux_enable']) {
0206                   $info['mpeg']['video']['raw']['mux_to_progressive_sequence']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: mux_to_progressive_sequence
0207                 }
0208                 $info['mpeg']['video']['raw']['picture_mux_order']                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); //  3 bits for picture_mux_order
0209                 $info['mpeg']['video']['raw']['picture_mux_factor']                     = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); //  3 bits for picture_mux_factor
0210               }
0211 
0212               $info['mpeg']['video']['scalable_mode'] = self::scalableModeTextLookup($info['mpeg']['video']['raw']['scalable_mode']);
0213               break;
0214 
0215             case  7: // 0111 Picture Display Extension ID
0216               break;
0217 
0218             case  8: // 1000 Picture Coding Extension ID
0219               $info['mpeg']['video']['raw']['f_code_00']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); // 4 bits for f_code[0][0] (forward horizontal)
0220               $info['mpeg']['video']['raw']['f_code_01']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); // 4 bits for f_code[0][1] (forward vertical)
0221               $info['mpeg']['video']['raw']['f_code_10']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); // 4 bits for f_code[1][0] (backward horizontal)
0222               $info['mpeg']['video']['raw']['f_code_11']                       = self::readBitsFromStream($bitstream, $bitstreamoffset,  4); // 4 bits for f_code[1][1] (backward vertical)
0223               $info['mpeg']['video']['raw']['intra_dc_precision']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); // 2 bits for intra_dc_precision
0224               $info['mpeg']['video']['raw']['picture_structure']               = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); // 2 bits for picture_structure
0225               $info['mpeg']['video']['raw']['top_field_first']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: top_field_first
0226               $info['mpeg']['video']['raw']['frame_pred_frame_dct']            = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: frame_pred_frame_dct
0227               $info['mpeg']['video']['raw']['concealment_motion_vectors']      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: concealment_motion_vectors
0228               $info['mpeg']['video']['raw']['q_scale_type']                    = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: q_scale_type
0229               $info['mpeg']['video']['raw']['intra_vlc_format']                = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: intra_vlc_format
0230               $info['mpeg']['video']['raw']['alternate_scan']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: alternate_scan
0231               $info['mpeg']['video']['raw']['repeat_first_field']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: repeat_first_field
0232               $info['mpeg']['video']['raw']['chroma_420_type']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: chroma_420_type
0233               $info['mpeg']['video']['raw']['progressive_frame']               = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: progressive_frame
0234               $info['mpeg']['video']['raw']['composite_display_flag']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: composite_display_flag
0235               if ($info['mpeg']['video']['raw']['composite_display_flag']) {
0236                 $info['mpeg']['video']['raw']['v_axis']                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: v_axis
0237                 $info['mpeg']['video']['raw']['field_sequence']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  3); // 3 bits for field_sequence
0238                 $info['mpeg']['video']['raw']['sub_carrier']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // 1 bit flag: sub_carrier
0239                 $info['mpeg']['video']['raw']['burst_amplitude']             = self::readBitsFromStream($bitstream, $bitstreamoffset,  7); // 7 bits for burst_amplitude
0240                 $info['mpeg']['video']['raw']['sub_carrier_phase']           = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); // 8 bits for sub_carrier_phase
0241               }
0242 
0243               $info['mpeg']['video']['intra_dc_precision_bits'] = $info['mpeg']['video']['raw']['intra_dc_precision'] + 8;
0244               $info['mpeg']['video']['picture_structure'] = self::pictureStructureTextLookup($info['mpeg']['video']['raw']['picture_structure']);
0245               break;
0246 
0247             case  9: // 1001 Picture Spatial Scalable Extension ID
0248               break;
0249             case 10: // 1010 Picture Temporal Scalable Extension ID
0250               break;
0251 
0252             default:
0253               $this->warning('Unexpected $info[mpeg][video][raw][extension_start_code_identifier] value of '.$info['mpeg']['video']['raw']['extension_start_code_identifier']);
0254               break;
0255           }
0256           break;
0257 
0258 
0259         case 0xB8: // group_of_pictures_header
0260           $GOPcounter++;
0261           if ($info['mpeg']['video']['bitrate_mode'] == 'vbr') {
0262             $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 4, 4)); // 27 bits needed for group_of_pictures_header
0263             $bitstreamoffset = 0;
0264 
0265             $GOPheader = array();
0266 
0267             $GOPheader['byte_offset'] = $MPEGstreamBaseOffset + $StartCodeOffset;
0268             $GOPheader['drop_frame_flag']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: drop_frame_flag
0269             $GOPheader['time_code_hours']    = self::readBitsFromStream($bitstream, $bitstreamoffset,  5); //  5 bits for time_code_hours
0270             $GOPheader['time_code_minutes']  = self::readBitsFromStream($bitstream, $bitstreamoffset,  6); //  6 bits for time_code_minutes
0271             $marker_bit                      = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); // The term "marker_bit" indicates a one bit field in which the value zero is forbidden. These marker bits are introduced at several points in the syntax to avoid start code emulation.
0272             $GOPheader['time_code_seconds']  = self::readBitsFromStream($bitstream, $bitstreamoffset,  6); //  6 bits for time_code_seconds
0273             $GOPheader['time_code_pictures'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  6); //  6 bits for time_code_pictures
0274             $GOPheader['closed_gop']         = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: closed_gop
0275             $GOPheader['broken_link']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: broken_link
0276 
0277             $time_code_separator = ($GOPheader['drop_frame_flag'] ? ';' : ':'); // While non-drop time code is displayed with colons separating the digit pairs—"HH:MM:SS:FF"—drop frame is usually represented with a semi-colon (;) or period (.) as the divider between all the digit pairs—"HH;MM;SS;FF", "HH.MM.SS.FF"
0278             $GOPheader['time_code'] = sprintf('%02d'.$time_code_separator.'%02d'.$time_code_separator.'%02d'.$time_code_separator.'%02d', $GOPheader['time_code_hours'], $GOPheader['time_code_minutes'], $GOPheader['time_code_seconds'], $GOPheader['time_code_pictures']);
0279 
0280             $info['mpeg']['group_of_pictures'][] = $GOPheader;
0281           }
0282           break;
0283 
0284         case 0xC0: // audio stream
0285         case 0xC1: // audio stream
0286         case 0xC2: // audio stream
0287         case 0xC3: // audio stream
0288         case 0xC4: // audio stream
0289         case 0xC5: // audio stream
0290         case 0xC6: // audio stream
0291         case 0xC7: // audio stream
0292         case 0xC8: // audio stream
0293         case 0xC9: // audio stream
0294         case 0xCA: // audio stream
0295         case 0xCB: // audio stream
0296         case 0xCC: // audio stream
0297         case 0xCD: // audio stream
0298         case 0xCE: // audio stream
0299         case 0xCF: // audio stream
0300         case 0xD0: // audio stream
0301         case 0xD1: // audio stream
0302         case 0xD2: // audio stream
0303         case 0xD3: // audio stream
0304         case 0xD4: // audio stream
0305         case 0xD5: // audio stream
0306         case 0xD6: // audio stream
0307         case 0xD7: // audio stream
0308         case 0xD8: // audio stream
0309         case 0xD9: // audio stream
0310         case 0xDA: // audio stream
0311         case 0xDB: // audio stream
0312         case 0xDC: // audio stream
0313         case 0xDD: // audio stream
0314         case 0xDE: // audio stream
0315         case 0xDF: // audio stream
0316         //case 0xE0: // video stream
0317         //case 0xE1: // video stream
0318         //case 0xE2: // video stream
0319         //case 0xE3: // video stream
0320         //case 0xE4: // video stream
0321         //case 0xE5: // video stream
0322         //case 0xE6: // video stream
0323         //case 0xE7: // video stream
0324         //case 0xE8: // video stream
0325         //case 0xE9: // video stream
0326         //case 0xEA: // video stream
0327         //case 0xEB: // video stream
0328         //case 0xEC: // video stream
0329         //case 0xED: // video stream
0330         //case 0xEE: // video stream
0331         //case 0xEF: // video stream
0332           if (isset($ParsedAVchannels[$StartCodeValue])) {
0333             break;
0334           }
0335           $ParsedAVchannels[$StartCodeValue] = $StartCodeValue;
0336           // http://en.wikipedia.org/wiki/Packetized_elementary_stream
0337           // http://dvd.sourceforge.net/dvdinfo/pes-hdr.html
0338 /*
0339           $PackedElementaryStream = array();
0340           if ($StartCodeValue >= 0xE0) {
0341             $PackedElementaryStream['stream_type'] = 'video';
0342             $PackedElementaryStream['stream_id']   = $StartCodeValue - 0xE0;
0343           } else {
0344             $PackedElementaryStream['stream_type'] = 'audio';
0345             $PackedElementaryStream['stream_id']   = $StartCodeValue - 0xC0;
0346           }
0347           $PackedElementaryStream['packet_length'] = getid3_lib::BigEndian2Int(substr($MPEGstreamData, $StartCodeOffset + 4, 2));
0348 
0349           $bitstream = getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 6, 3)); // more may be needed below
0350           $bitstreamoffset = 0;
0351 
0352           $PackedElementaryStream['marker_bits']               = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for marker_bits -- should be "10" = 2
0353 echo 'marker_bits = '.$PackedElementaryStream['marker_bits'].'<br>';
0354           $PackedElementaryStream['scrambling_control']        = self::readBitsFromStream($bitstream, $bitstreamoffset,  2); //  2 bits for scrambling_control -- 00 implies not scrambled
0355           $PackedElementaryStream['priority']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: priority
0356           $PackedElementaryStream['data_alignment_indicator']  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: data_alignment_indicator -- 1 indicates that the PES packet header is immediately followed by the video start code or audio syncword
0357           $PackedElementaryStream['copyright']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: copyright -- 1 implies copyrighted
0358           $PackedElementaryStream['original_or_copy']          = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: original_or_copy -- 1 implies original
0359           $PackedElementaryStream['pts_flag']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: pts_flag -- Presentation Time Stamp
0360           $PackedElementaryStream['dts_flag']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: dts_flag -- Decode Time Stamp
0361           $PackedElementaryStream['escr_flag']                 = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: escr_flag -- Elementary Stream Clock Reference
0362           $PackedElementaryStream['es_rate_flag']              = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: es_rate_flag -- Elementary Stream [data] Rate
0363           $PackedElementaryStream['dsm_trick_mode_flag']       = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: dsm_trick_mode_flag -- DSM trick mode - not used by DVD
0364           $PackedElementaryStream['additional_copy_info_flag'] = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: additional_copy_info_flag
0365           $PackedElementaryStream['crc_flag']                  = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: crc_flag
0366           $PackedElementaryStream['extension_flag']            = self::readBitsFromStream($bitstream, $bitstreamoffset,  1); //  1 bit flag: extension_flag
0367           $PackedElementaryStream['pes_remain_header_length']  = self::readBitsFromStream($bitstream, $bitstreamoffset,  8); //  1 bit flag: priority
0368 
0369           $additional_header_bytes = 0;
0370           $additional_header_bytes += ($PackedElementaryStream['pts_flag']                  ? 5 : 0);
0371           $additional_header_bytes += ($PackedElementaryStream['dts_flag']                  ? 5 : 0);
0372           $additional_header_bytes += ($PackedElementaryStream['escr_flag']                 ? 6 : 0);
0373           $additional_header_bytes += ($PackedElementaryStream['es_rate_flag']              ? 3 : 0);
0374           $additional_header_bytes += ($PackedElementaryStream['additional_copy_info_flag'] ? 1 : 0);
0375           $additional_header_bytes += ($PackedElementaryStream['crc_flag']                  ? 2 : 0);
0376           $additional_header_bytes += ($PackedElementaryStream['extension_flag']            ? 1 : 0);
0377 $PackedElementaryStream['additional_header_bytes'] = $additional_header_bytes;
0378           $bitstream .= getid3_lib::BigEndian2Bin(substr($MPEGstreamData, $StartCodeOffset + 9, $additional_header_bytes));
0379 
0380           $info['mpeg']['packed_elementary_streams'][$PackedElementaryStream['stream_type']][$PackedElementaryStream['stream_id']][] = $PackedElementaryStream;
0381 */
0382           $getid3_temp = new getID3();
0383           $getid3_temp->openfile($this->getid3->filename);
0384           $getid3_temp->info = $info;
0385           $getid3_mp3 = new getid3_mp3($getid3_temp);
0386           for ($i = 0; $i <= 7; $i++) {
0387             // some files have the MPEG-audio header 8 bytes after the end of the $00 $00 $01 $C0 signature, some have it up to 13 bytes (or more?) after
0388             // I have no idea why or what the difference is, so this is a stupid hack.
0389             // If anybody has any better idea of what's going on, please let me know - info@getid3.org
0390             $getid3_temp->info = $info; // only overwrite real data if valid header found
0391 //echo 'audio at? '.($MPEGstreamBaseOffset + $StartCodeOffset + 4 + 8 + $i).'<br>';
0392             if ($getid3_mp3->decodeMPEGaudioHeader($MPEGstreamBaseOffset + $StartCodeOffset + 4 + 8 + $i, $getid3_temp->info, false)) {
0393 //echo 'yes!<br>';
0394               $info = $getid3_temp->info;
0395               $info['audio']['bitrate_mode'] = 'cbr';
0396               $info['audio']['lossless']     = false;
0397               break;
0398             }
0399           }
0400           unset($getid3_temp, $getid3_mp3);
0401           break;
0402 
0403         case 0xBC: // Program Stream Map
0404         case 0xBD: // Private stream 1 (non MPEG audio, subpictures)
0405         case 0xBE: // Padding stream
0406         case 0xBF: // Private stream 2 (navigation data)
0407         case 0xF0: // ECM stream
0408         case 0xF1: // EMM stream
0409         case 0xF2: // DSM-CC stream
0410         case 0xF3: // ISO/IEC_13522_stream
0411         case 0xF4: // ITU-I Rec. H.222.1 type A
0412         case 0xF5: // ITU-I Rec. H.222.1 type B
0413         case 0xF6: // ITU-I Rec. H.222.1 type C
0414         case 0xF7: // ITU-I Rec. H.222.1 type D
0415         case 0xF8: // ITU-I Rec. H.222.1 type E
0416         case 0xF9: // ancilliary stream
0417         case 0xFA: // ISO/IEC 14496-1 SL-packtized stream
0418         case 0xFB: // ISO/IEC 14496-1 FlexMux stream
0419         case 0xFC: // metadata stream
0420         case 0xFD: // extended stream ID
0421         case 0xFE: // reserved data stream
0422         case 0xFF: // program stream directory
0423           // ignore
0424           break;
0425 
0426         default:
0427           // ignore
0428           break;
0429       }
0430     } while (true);
0431 
0432 
0433 
0434 //    // Temporary hack to account for interleaving overhead:
0435 //    if (!empty($info['video']['bitrate']) && !empty($info['audio']['bitrate'])) {
0436 //      $info['playtime_seconds'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / ($info['video']['bitrate'] + $info['audio']['bitrate']);
0437 //
0438 //      // Interleaved MPEG audio/video files have a certain amount of overhead that varies
0439 //      // by both video and audio bitrates, and not in any sensible, linear/logarithmic pattern
0440 //      // Use interpolated lookup tables to approximately guess how much is overhead, because
0441 //      // playtime is calculated as filesize / total-bitrate
0442 //      $info['playtime_seconds'] *= self::systemNonOverheadPercentage($info['video']['bitrate'], $info['audio']['bitrate']);
0443 //
0444 //      //switch ($info['video']['bitrate']) {
0445 //      //  case('5000000'):
0446 //      //    $multiplier = 0.93292642112380355828048824319889;
0447 //      //    break;
0448 //      //  case('5500000'):
0449 //      //    $multiplier = 0.93582895375200989965359777343219;
0450 //      //    break;
0451 //      //  case('6000000'):
0452 //      //    $multiplier = 0.93796247714820932532911373859139;
0453 //      //    break;
0454 //      //  case('7000000'):
0455 //      //    $multiplier = 0.9413264083635103463010117778776;
0456 //      //    break;
0457 //      //  default:
0458 //      //    $multiplier = 1;
0459 //      //    break;
0460 //      //}
0461 //      //$info['playtime_seconds'] *= $multiplier;
0462 //      //$info['warning'][] = 'Interleaved MPEG audio/video playtime may be inaccurate. With current hack should be within a few seconds of accurate. Report to info@getid3.org if off by more than 10 seconds.';
0463 //      if ($info['video']['bitrate'] < 50000) {
0464 //        $this->warning('Interleaved MPEG audio/video playtime may be slightly inaccurate for video bitrates below 100kbps. Except in extreme low-bitrate situations, error should be less than 1%. Report to info@getid3.org if greater than this.');
0465 //      }
0466 //    }
0467 //
0468 /*
0469 $time_prev = 0;
0470 $byte_prev = 0;
0471 $vbr_bitrates = array();
0472 foreach ($info['mpeg']['group_of_pictures'] as $gopkey => $gopdata) {
0473   $time_this = ($gopdata['time_code_hours'] * 3600) + ($gopdata['time_code_minutes'] * 60) + $gopdata['time_code_seconds'] + ($gopdata['time_code_seconds'] / 30);
0474   $byte_this = $gopdata['byte_offset'];
0475   if ($gopkey > 0) {
0476     if ($time_this > $time_prev) {
0477       $bytedelta = $byte_this - $byte_prev;
0478       $timedelta = $time_this - $time_prev;
0479       $this_bitrate = ($bytedelta * 8) / $timedelta;
0480 echo $gopkey.': ('.number_format($time_prev, 2).'-'.number_format($time_this, 2).') '.number_format($bytedelta).' bytes over '.number_format($timedelta, 3).' seconds = '.number_format($this_bitrate / 1000, 2).'kbps<br>';
0481       $time_prev = $time_this;
0482       $byte_prev = $byte_this;
0483       $vbr_bitrates[] = $this_bitrate;
0484     }
0485   }
0486 }
0487 echo 'average_File_bitrate = '.number_format(array_sum($vbr_bitrates) / count($vbr_bitrates), 1).'<br>';
0488 */
0489 //echo '<pre>'.print_r($FramesByGOP, true).'</pre>';
0490     if (!empty($info['mpeg']['video']['bitrate_mode']) && ($info['mpeg']['video']['bitrate_mode'] == 'vbr')) {
0491       $last_GOP_id = max(array_keys($FramesByGOP));
0492       $frames_in_last_GOP = count($FramesByGOP[$last_GOP_id]);
0493       $gopdata = &$info['mpeg']['group_of_pictures'][$last_GOP_id];
0494       $info['playtime_seconds'] = ($gopdata['time_code_hours'] * 3600) + ($gopdata['time_code_minutes'] * 60) + $gopdata['time_code_seconds'] + (($gopdata['time_code_pictures'] + $frames_in_last_GOP + 1) / $info['mpeg']['video']['frame_rate']);
0495       if (!isset($info['video']['bitrate'])) {
0496         $overall_bitrate = ($info['avdataend'] - $info['avdataoffset']) * 8 / $info['playtime_seconds'];
0497         $info['video']['bitrate'] = $overall_bitrate - (isset($info['audio']['bitrate']) ? $info['audio']['bitrate'] : 0);
0498       }
0499       unset($info['mpeg']['group_of_pictures']);
0500     }
0501 
0502     return true;
0503   }
0504 
0505   private function readBitsFromStream(&$bitstream, &$bitstreamoffset, $bits_to_read, $return_singlebit_as_boolean=true) {
0506     $return = bindec(substr($bitstream, $bitstreamoffset, $bits_to_read));
0507     $bitstreamoffset += $bits_to_read;
0508     if (($bits_to_read == 1) && $return_singlebit_as_boolean) {
0509       $return = (bool) $return;
0510     }
0511     return $return;
0512   }
0513 
0514 
0515   public static function systemNonOverheadPercentage($VideoBitrate, $AudioBitrate) {
0516     $OverheadPercentage = 0;
0517 
0518     $AudioBitrate = max(min($AudioBitrate / 1000,   384), 32); // limit to range of 32kbps - 384kbps (should be only legal bitrates, but maybe VBR?)
0519     $VideoBitrate = max(min($VideoBitrate / 1000, 10000), 10); // limit to range of 10kbps -  10Mbps (beyond that curves flatten anyways, no big loss)
0520 
0521 
0522     //OMBB[audiobitrate]              = array(video-10kbps,       video-100kbps,      video-1000kbps,     video-10000kbps)
0523     $OverheadMultiplierByBitrate[32]  = array(0, 0.9676287944368530, 0.9802276264360310, 0.9844916183244460, 0.9852821845179940);
0524     $OverheadMultiplierByBitrate[48]  = array(0, 0.9779100089209830, 0.9787770035359320, 0.9846738664076130, 0.9852683013799960);
0525     $OverheadMultiplierByBitrate[56]  = array(0, 0.9731249855367600, 0.9776624308938040, 0.9832606361852130, 0.9843922606633340);
0526     $OverheadMultiplierByBitrate[64]  = array(0, 0.9755642683275760, 0.9795256705493390, 0.9836573009193170, 0.9851122539404470);
0527     $OverheadMultiplierByBitrate[96]  = array(0, 0.9788025247497290, 0.9798553314148700, 0.9822956869792560, 0.9834815119124690);
0528     $OverheadMultiplierByBitrate[128] = array(0, 0.9816940050925480, 0.9821675936072120, 0.9829756927470870, 0.9839763420152050);
0529     $OverheadMultiplierByBitrate[160] = array(0, 0.9825894094561180, 0.9820913399073960, 0.9823907143253970, 0.9832821783651570);
0530     $OverheadMultiplierByBitrate[192] = array(0, 0.9832038474336260, 0.9825731694317960, 0.9821028622712400, 0.9828262076447620);
0531     $OverheadMultiplierByBitrate[224] = array(0, 0.9836516298538770, 0.9824718601823890, 0.9818302180625380, 0.9823735101626480);
0532     $OverheadMultiplierByBitrate[256] = array(0, 0.9845863022094920, 0.9837229411967540, 0.9824521662210830, 0.9828645172100790);
0533     $OverheadMultiplierByBitrate[320] = array(0, 0.9849565280263180, 0.9837683142805110, 0.9822885275960400, 0.9824424382727190);
0534     $OverheadMultiplierByBitrate[384] = array(0, 0.9856094774357600, 0.9844573394432720, 0.9825970399837330, 0.9824673808303890);
0535 
0536     $BitrateToUseMin = 32;
0537     $BitrateToUseMax = 32;
0538     $previousBitrate = 32;
0539     foreach ($OverheadMultiplierByBitrate as $key => $value) {
0540       if ($AudioBitrate >= $previousBitrate) {
0541         $BitrateToUseMin = $previousBitrate;
0542       }
0543       if ($AudioBitrate < $key) {
0544         $BitrateToUseMax = $key;
0545         break;
0546       }
0547       $previousBitrate = $key;
0548     }
0549     $FactorA = ($BitrateToUseMax - $AudioBitrate) / ($BitrateToUseMax - $BitrateToUseMin);
0550 
0551     $VideoBitrateLog10 = log10($VideoBitrate);
0552     $VideoFactorMin1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][floor($VideoBitrateLog10)];
0553     $VideoFactorMin2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][floor($VideoBitrateLog10)];
0554     $VideoFactorMax1 = $OverheadMultiplierByBitrate[$BitrateToUseMin][ceil($VideoBitrateLog10)];
0555     $VideoFactorMax2 = $OverheadMultiplierByBitrate[$BitrateToUseMax][ceil($VideoBitrateLog10)];
0556     $FactorV = $VideoBitrateLog10 - floor($VideoBitrateLog10);
0557 
0558     $OverheadPercentage  = $VideoFactorMin1 *      $FactorA  *      $FactorV;
0559     $OverheadPercentage += $VideoFactorMin2 * (1 - $FactorA) *      $FactorV;
0560     $OverheadPercentage += $VideoFactorMax1 *      $FactorA  * (1 - $FactorV);
0561     $OverheadPercentage += $VideoFactorMax2 * (1 - $FactorA) * (1 - $FactorV);
0562 
0563     return $OverheadPercentage;
0564   }
0565 
0566 
0567   public static function videoFramerateLookup($rawframerate) {
0568     $lookup = array(0, 23.976, 24, 25, 29.97, 30, 50, 59.94, 60);
0569     return (isset($lookup[$rawframerate]) ? (float) $lookup[$rawframerate] : (float) 0);
0570   }
0571 
0572   public static function videoAspectRatioLookup($rawaspectratio) {
0573     $lookup = array(0, 1, 0.6735, 0.7031, 0.7615, 0.8055, 0.8437, 0.8935, 0.9157, 0.9815, 1.0255, 1.0695, 1.0950, 1.1575, 1.2015, 0);
0574     return (isset($lookup[$rawaspectratio]) ? (float) $lookup[$rawaspectratio] : (float) 0);
0575   }
0576 
0577   public static function videoAspectRatioTextLookup($rawaspectratio) {
0578     $lookup = array('forbidden', 'square pixels', '0.6735', '16:9, 625 line, PAL', '0.7615', '0.8055', '16:9, 525 line, NTSC', '0.8935', '4:3, 625 line, PAL, CCIR601', '0.9815', '1.0255', '1.0695', '4:3, 525 line, NTSC, CCIR601', '1.1575', '1.2015', 'reserved');
0579     return (isset($lookup[$rawaspectratio]) ? $lookup[$rawaspectratio] : '');
0580   }
0581 
0582   public static function videoFormatTextLookup($video_format) {
0583     // ISO/IEC 13818-2, section 6.3.6, Table 6-6. Meaning of video_format
0584     $lookup = array('component', 'PAL', 'NTSC', 'SECAM', 'MAC', 'Unspecified video format', 'reserved(6)', 'reserved(7)');
0585     return (isset($lookup[$video_format]) ? $lookup[$video_format] : '');
0586   }
0587 
0588   public static function scalableModeTextLookup($scalable_mode) {
0589     // ISO/IEC 13818-2, section 6.3.8, Table 6-10. Definition of scalable_mode
0590     $lookup = array('data partitioning', 'spatial scalability', 'SNR scalability', 'temporal scalability');
0591     return (isset($lookup[$scalable_mode]) ? $lookup[$scalable_mode] : '');
0592   }
0593 
0594   public static function pictureStructureTextLookup($picture_structure) {
0595     // ISO/IEC 13818-2, section 6.3.11, Table 6-14 Meaning of picture_structure
0596     $lookup = array('reserved', 'Top Field', 'Bottom Field', 'Frame picture');
0597     return (isset($lookup[$picture_structure]) ? $lookup[$picture_structure] : '');
0598   }
0599 
0600   public static function chromaFormatTextLookup($chroma_format) {
0601     // ISO/IEC 13818-2, section 6.3.11, Table 6-14 Meaning of picture_structure
0602     $lookup = array('reserved', '4:2:0', '4:2:2', '4:4:4');
0603     return (isset($lookup[$chroma_format]) ? $lookup[$chroma_format] : '');
0604   }
0605 
0606 }