File indexing completed on 2024-12-22 05:33:13

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.graphic.gif.php                                      //
0012 // module for analyzing GIF Image files                        //
0013 // dependencies: NONE                                          //
0014 //                                                            ///
0015 /////////////////////////////////////////////////////////////////
0016 
0017 
0018 class getid3_gif extends getid3_handler
0019 {
0020 
0021   public function Analyze() {
0022     $info = &$this->getid3->info;
0023 
0024     $info['fileformat']                  = 'gif';
0025     $info['video']['dataformat']         = 'gif';
0026     $info['video']['lossless']           = true;
0027     $info['video']['pixel_aspect_ratio'] = (float) 1;
0028 
0029     $this->fseek($info['avdataoffset']);
0030     $GIFheader = $this->fread(13);
0031     $offset = 0;
0032 
0033     $info['gif']['header']['raw']['identifier']            =                              substr($GIFheader, $offset, 3);
0034     $offset += 3;
0035 
0036     $magic = 'GIF';
0037     if ($info['gif']['header']['raw']['identifier'] != $magic) {
0038       $info['error'][] = 'Expecting "'.getid3_lib::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($info['gif']['header']['raw']['identifier']).'"';
0039       unset($info['fileformat']);
0040       unset($info['gif']);
0041       return false;
0042     }
0043 
0044     $info['gif']['header']['raw']['version']               =                              substr($GIFheader, $offset, 3);
0045     $offset += 3;
0046     $info['gif']['header']['raw']['width']                 = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2));
0047     $offset += 2;
0048     $info['gif']['header']['raw']['height']                = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2));
0049     $offset += 2;
0050     $info['gif']['header']['raw']['flags']                 = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
0051     $offset += 1;
0052     $info['gif']['header']['raw']['bg_color_index']        = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
0053     $offset += 1;
0054     $info['gif']['header']['raw']['aspect_ratio']          = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
0055     $offset += 1;
0056 
0057     $info['video']['resolution_x']                         = $info['gif']['header']['raw']['width'];
0058     $info['video']['resolution_y']                         = $info['gif']['header']['raw']['height'];
0059     $info['gif']['version']                                = $info['gif']['header']['raw']['version'];
0060     $info['gif']['header']['flags']['global_color_table']  = (bool) ($info['gif']['header']['raw']['flags'] & 0x80);
0061     if ($info['gif']['header']['raw']['flags'] & 0x80) {
0062       // Number of bits per primary color available to the original image, minus 1
0063       $info['gif']['header']['bits_per_pixel']  = 3 * ((($info['gif']['header']['raw']['flags'] & 0x70) >> 4) + 1);
0064     } else {
0065       $info['gif']['header']['bits_per_pixel']  = 0;
0066     }
0067     $info['gif']['header']['flags']['global_color_sorted'] = (bool) ($info['gif']['header']['raw']['flags'] & 0x40);
0068     if ($info['gif']['header']['flags']['global_color_table']) {
0069       // the number of bytes contained in the Global Color Table. To determine that
0070       // actual size of the color table, raise 2 to [the value of the field + 1]
0071       $info['gif']['header']['global_color_size'] = pow(2, ($info['gif']['header']['raw']['flags'] & 0x07) + 1);
0072       $info['video']['bits_per_sample']           = ($info['gif']['header']['raw']['flags'] & 0x07) + 1;
0073     } else {
0074       $info['gif']['header']['global_color_size'] = 0;
0075     }
0076     if ($info['gif']['header']['raw']['aspect_ratio'] != 0) {
0077       // Aspect Ratio = (Pixel Aspect Ratio + 15) / 64
0078       $info['gif']['header']['aspect_ratio'] = ($info['gif']['header']['raw']['aspect_ratio'] + 15) / 64;
0079     }
0080 
0081 //    if ($info['gif']['header']['flags']['global_color_table']) {
0082 //      $GIFcolorTable = $this->fread(3 * $info['gif']['header']['global_color_size']);
0083 //      $offset = 0;
0084 //      for ($i = 0; $i < $info['gif']['header']['global_color_size']; $i++) {
0085 //        $red   = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
0086 //        $green = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
0087 //        $blue  = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
0088 //        $info['gif']['global_color_table'][$i] = (($red << 16) | ($green << 8) | ($blue));
0089 //      }
0090 //    }
0091 //
0092 //    // Image Descriptor
0093 //    while (!feof($this->getid3->fp)) {
0094 //      $NextBlockTest = $this->fread(1);
0095 //      switch ($NextBlockTest) {
0096 //
0097 //        case ',': // ',' - Image separator character
0098 //
0099 //          $ImageDescriptorData = $NextBlockTest.$this->fread(9);
0100 //          $ImageDescriptor = array();
0101 //          $ImageDescriptor['image_left']   = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 1, 2));
0102 //          $ImageDescriptor['image_top']    = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 3, 2));
0103 //          $ImageDescriptor['image_width']  = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 5, 2));
0104 //          $ImageDescriptor['image_height'] = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 7, 2));
0105 //          $ImageDescriptor['flags_raw']    = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 9, 1));
0106 //          $ImageDescriptor['flags']['use_local_color_map'] = (bool) ($ImageDescriptor['flags_raw'] & 0x80);
0107 //          $ImageDescriptor['flags']['image_interlaced']    = (bool) ($ImageDescriptor['flags_raw'] & 0x40);
0108 //          $info['gif']['image_descriptor'][] = $ImageDescriptor;
0109 //
0110 //          if ($ImageDescriptor['flags']['use_local_color_map']) {
0111 //
0112 //            $info['warning'][] = 'This version of getID3() cannot parse local color maps for GIFs';
0113 //            return true;
0114 //
0115 //          }
0116 //echo 'Start of raster data: '.$this->ftell().'<BR>';
0117 //          $RasterData = array();
0118 //          $RasterData['code_size']        = getid3_lib::LittleEndian2Int($this->fread(1));
0119 //          $RasterData['block_byte_count'] = getid3_lib::LittleEndian2Int($this->fread(1));
0120 //          $info['gif']['raster_data'][count($info['gif']['image_descriptor']) - 1] = $RasterData;
0121 //
0122 //          $CurrentCodeSize = $RasterData['code_size'] + 1;
0123 //          for ($i = 0; $i < pow(2, $RasterData['code_size']); $i++) {
0124 //            $DefaultDataLookupTable[$i] = chr($i);
0125 //          }
0126 //          $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 0] = ''; // Clear Code
0127 //          $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 1] = ''; // End Of Image Code
0128 //
0129 //
0130 //          $NextValue = $this->GetLSBits($CurrentCodeSize);
0131 //          echo 'Clear Code: '.$NextValue.'<BR>';
0132 //
0133 //          $NextValue = $this->GetLSBits($CurrentCodeSize);
0134 //          echo 'First Color: '.$NextValue.'<BR>';
0135 //
0136 //          $Prefix = $NextValue;
0137 //$i = 0;
0138 //          while ($i++ < 20) {
0139 //            $NextValue = $this->GetLSBits($CurrentCodeSize);
0140 //            echo $NextValue.'<BR>';
0141 //          }
0142 //return true;
0143 //          break;
0144 //
0145 //        case '!':
0146 //          // GIF Extension Block
0147 //          $ExtensionBlockData = $NextBlockTest.$this->fread(2);
0148 //          $ExtensionBlock = array();
0149 //          $ExtensionBlock['function_code']  = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 1, 1));
0150 //          $ExtensionBlock['byte_length']    = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 2, 1));
0151 //          $ExtensionBlock['data']           = $this->fread($ExtensionBlock['byte_length']);
0152 //          $info['gif']['extension_blocks'][] = $ExtensionBlock;
0153 //          break;
0154 //
0155 //        case ';':
0156 //          $info['gif']['terminator_offset'] = $this->ftell() - 1;
0157 //          // GIF Terminator
0158 //          break;
0159 //
0160 //        default:
0161 //          break;
0162 //
0163 //
0164 //      }
0165 //    }
0166 
0167     return true;
0168   }
0169 
0170 
0171   public function GetLSBits($bits) {
0172     static $bitbuffer = '';
0173     while (strlen($bitbuffer) < $bits) {
0174       $bitbuffer = str_pad(decbin(ord($this->fread(1))), 8, '0', STR_PAD_LEFT).$bitbuffer;
0175     }
0176     $value = bindec(substr($bitbuffer, 0 - $bits));
0177     $bitbuffer = substr($bitbuffer, 0, 0 - $bits);
0178 
0179     return $value;
0180   }
0181 
0182 }