[Sommaire] [Imprimer]

   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  /////////////////////////////////////////////////////////////////
   7  // See readme.txt for more details                             //
   8  /////////////////////////////////////////////////////////////////
   9  //                                                             //
  10  // module.graphic.gif.php                                      //
  11  // module for analyzing GIF Image files                        //
  12  // dependencies: NONE                                          //
  13  //                                                            ///
  14  /////////////////////////////////////////////////////////////////
  15  
  16  
  17  class getid3_gif
  18  {
  19  
  20  	function getid3_gif(&$fd, &$ThisFileInfo) {
  21          $ThisFileInfo['fileformat']                  = 'gif';
  22          $ThisFileInfo['video']['dataformat']         = 'gif';
  23          $ThisFileInfo['video']['lossless']           = true;
  24          $ThisFileInfo['video']['pixel_aspect_ratio'] = (float) 1;
  25  
  26          fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
  27          $GIFheader = fread($fd, 13);
  28          $offset = 0;
  29  
  30          $ThisFileInfo['gif']['header']['raw']['identifier']            =                              substr($GIFheader, $offset, 3);
  31          $offset += 3;
  32  
  33          if ($ThisFileInfo['gif']['header']['raw']['identifier'] != 'GIF') {
  34              $ThisFileInfo['error'][] = 'Expecting "GIF" at offset '.$ThisFileInfo['avdataoffset'].', found "'.$ThisFileInfo['gif']['header']['raw']['identifier'].'"';
  35              unset($ThisFileInfo['fileformat']);
  36              unset($ThisFileInfo['gif']);
  37              return false;
  38          }
  39  
  40          $ThisFileInfo['gif']['header']['raw']['version']               =                              substr($GIFheader, $offset, 3);
  41          $offset += 3;
  42          $ThisFileInfo['gif']['header']['raw']['width']                 = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2));
  43          $offset += 2;
  44          $ThisFileInfo['gif']['header']['raw']['height']                = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2));
  45          $offset += 2;
  46          $ThisFileInfo['gif']['header']['raw']['flags']                 = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
  47          $offset += 1;
  48          $ThisFileInfo['gif']['header']['raw']['bg_color_index']        = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
  49          $offset += 1;
  50          $ThisFileInfo['gif']['header']['raw']['aspect_ratio']          = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
  51          $offset += 1;
  52  
  53          $ThisFileInfo['video']['resolution_x']                         = $ThisFileInfo['gif']['header']['raw']['width'];
  54          $ThisFileInfo['video']['resolution_y']                         = $ThisFileInfo['gif']['header']['raw']['height'];
  55          $ThisFileInfo['gif']['version']                                = $ThisFileInfo['gif']['header']['raw']['version'];
  56          $ThisFileInfo['gif']['header']['flags']['global_color_table']  = (bool) ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x80);
  57          if ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x80) {
  58              // Number of bits per primary color available to the original image, minus 1
  59              $ThisFileInfo['gif']['header']['bits_per_pixel']  = 3 * ((($ThisFileInfo['gif']['header']['raw']['flags'] & 0x70) >> 4) + 1);
  60          } else {
  61              $ThisFileInfo['gif']['header']['bits_per_pixel']  = 0;
  62          }
  63          $ThisFileInfo['gif']['header']['flags']['global_color_sorted'] = (bool) ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x40);
  64          if ($ThisFileInfo['gif']['header']['flags']['global_color_table']) {
  65              // the number of bytes contained in the Global Color Table. To determine that
  66              // actual size of the color table, raise 2 to [the value of the field + 1]
  67              $ThisFileInfo['gif']['header']['global_color_size'] = pow(2, ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x07) + 1);
  68              $ThisFileInfo['video']['bits_per_sample']           = ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x07) + 1;
  69          } else {
  70              $ThisFileInfo['gif']['header']['global_color_size'] = 0;
  71          }
  72          if ($ThisFileInfo['gif']['header']['raw']['aspect_ratio'] != 0) {
  73              // Aspect Ratio = (Pixel Aspect Ratio + 15) / 64
  74              $ThisFileInfo['gif']['header']['aspect_ratio'] = ($ThisFileInfo['gif']['header']['raw']['aspect_ratio'] + 15) / 64;
  75          }
  76  
  77  //        if ($ThisFileInfo['gif']['header']['flags']['global_color_table']) {
  78  //            $GIFcolorTable = fread($fd, 3 * $ThisFileInfo['gif']['header']['global_color_size']);
  79  //            $offset = 0;
  80  //            for ($i = 0; $i < $ThisFileInfo['gif']['header']['global_color_size']; $i++) {
  81  //                $red   = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
  82  //                $green = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
  83  //                $blue  = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
  84  //                $ThisFileInfo['gif']['global_color_table'][$i] = (($red << 16) | ($green << 8) | ($blue));
  85  //            }
  86  //        }
  87  //
  88  //        // Image Descriptor
  89  //        while (!feof($fd)) {
  90  //            $NextBlockTest = fread($fd, 1);
  91  //            switch ($NextBlockTest) {
  92  //
  93  //                case ',': // ',' - Image separator character
  94  //
  95  //                    $ImageDescriptorData = $NextBlockTest.fread($fd, 9);
  96  //                    $ImageDescriptor = array();
  97  //                    $ImageDescriptor['image_left']   = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 1, 2));
  98  //                    $ImageDescriptor['image_top']    = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 3, 2));
  99  //                    $ImageDescriptor['image_width']  = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 5, 2));
 100  //                    $ImageDescriptor['image_height'] = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 7, 2));
 101  //                    $ImageDescriptor['flags_raw']    = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 9, 1));
 102  //                    $ImageDescriptor['flags']['use_local_color_map'] = (bool) ($ImageDescriptor['flags_raw'] & 0x80);
 103  //                    $ImageDescriptor['flags']['image_interlaced']    = (bool) ($ImageDescriptor['flags_raw'] & 0x40);
 104  //                    $ThisFileInfo['gif']['image_descriptor'][] = $ImageDescriptor;
 105  //
 106  //                    if ($ImageDescriptor['flags']['use_local_color_map']) {
 107  //
 108  //                        $ThisFileInfo['warning'][] = 'This version of getID3() cannot parse local color maps for GIFs';
 109  //                        return true;
 110  //
 111  //                    }
 112  //echo 'Start of raster data: '.ftell($fd).'<BR>';
 113  //                    $RasterData = array();
 114  //                    $RasterData['code_size']        = getid3_lib::LittleEndian2Int(fread($fd, 1));
 115  //                    $RasterData['block_byte_count'] = getid3_lib::LittleEndian2Int(fread($fd, 1));
 116  //                    $ThisFileInfo['gif']['raster_data'][count($ThisFileInfo['gif']['image_descriptor']) - 1] = $RasterData;
 117  //
 118  //                    $CurrentCodeSize = $RasterData['code_size'] + 1;
 119  //                    for ($i = 0; $i < pow(2, $RasterData['code_size']); $i++) {
 120  //                        $DefaultDataLookupTable[$i] = chr($i);
 121  //                    }
 122  //                    $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 0] = ''; // Clear Code
 123  //                    $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 1] = ''; // End Of Image Code
 124  //
 125  //
 126  //                    $NextValue = $this->GetLSBits($fd, $CurrentCodeSize);
 127  //                    echo 'Clear Code: '.$NextValue.'<BR>';
 128  //
 129  //                    $NextValue = $this->GetLSBits($fd, $CurrentCodeSize);
 130  //                    echo 'First Color: '.$NextValue.'<BR>';
 131  //
 132  //                    $Prefix = $NextValue;
 133  //$i = 0;
 134  //                    while ($i++ < 20) {
 135  //                        $NextValue = $this->GetLSBits($fd, $CurrentCodeSize);
 136  //                        echo $NextValue.'<BR>';
 137  //                    }
 138  //return true;
 139  //                    break;
 140  //
 141  //                case '!':
 142  //                    // GIF Extension Block
 143  //                    $ExtensionBlockData = $NextBlockTest.fread($fd, 2);
 144  //                    $ExtensionBlock = array();
 145  //                    $ExtensionBlock['function_code']  = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 1, 1));
 146  //                    $ExtensionBlock['byte_length']    = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 2, 1));
 147  //                    $ExtensionBlock['data']           = fread($fd, $ExtensionBlock['byte_length']);
 148  //                    $ThisFileInfo['gif']['extension_blocks'][] = $ExtensionBlock;
 149  //                    break;
 150  //
 151  //                case ';':
 152  //                    $ThisFileInfo['gif']['terminator_offset'] = ftell($fd) - 1;
 153  //                    // GIF Terminator
 154  //                    break;
 155  //
 156  //                default:
 157  //                    break;
 158  //
 159  //
 160  //            }
 161  //        }
 162  
 163          return true;
 164      }
 165  
 166  
 167  	function GetLSBits($fd, $bits) {
 168          static $bitbuffer = '';
 169          while (strlen($bitbuffer) < $bits) {
 170  //echo 'Read another byte: '.ftell($fd).'<BR>';
 171              $bitbuffer = str_pad(decbin(ord(fread($fd, 1))), 8, '0', STR_PAD_LEFT).$bitbuffer;
 172          }
 173  
 174          $value = bindec(substr($bitbuffer, 0 - $bits));
 175          $bitbuffer = substr($bitbuffer, 0, 0 - $bits);
 176  
 177          return $value;
 178      }
 179  
 180  }
 181  
 182  
 183  ?>