Public Member Functions

getid3_gif Class Reference

getID3() by James Heinrich <info@getid3.org> // More...

Public Member Functions

 getid3_gif (&$fd, &$ThisFileInfo)
 GetLSBits ($fd, $bits)

Detailed Description

getID3() by James Heinrich <info@getid3.org> //

Definition at line 17 of file module.graphic.gif.php.


Member Function Documentation

getid3_gif::getid3_gif ( &$  fd,
&$  ThisFileInfo 
)

Definition at line 20 of file module.graphic.gif.php.

References getid3_lib::LittleEndian2Int().

                                                  {
                $ThisFileInfo['fileformat']                  = 'gif';
                $ThisFileInfo['video']['dataformat']         = 'gif';
                $ThisFileInfo['video']['lossless']           = true;
                $ThisFileInfo['video']['pixel_aspect_ratio'] = (float) 1;

                fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET);
                $GIFheader = fread($fd, 13);
                $offset = 0;

                $ThisFileInfo['gif']['header']['raw']['identifier']            =                              substr($GIFheader, $offset, 3);
                $offset += 3;

                if ($ThisFileInfo['gif']['header']['raw']['identifier'] != 'GIF') {
                        $ThisFileInfo['error'][] = 'Expecting "GIF" at offset '.$ThisFileInfo['avdataoffset'].', found "'.$ThisFileInfo['gif']['header']['raw']['identifier'].'"';
                        unset($ThisFileInfo['fileformat']);
                        unset($ThisFileInfo['gif']);
                        return false;
                }

                $ThisFileInfo['gif']['header']['raw']['version']               =                              substr($GIFheader, $offset, 3);
                $offset += 3;
                $ThisFileInfo['gif']['header']['raw']['width']                 = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2));
                $offset += 2;
                $ThisFileInfo['gif']['header']['raw']['height']                = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2));
                $offset += 2;
                $ThisFileInfo['gif']['header']['raw']['flags']                 = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
                $offset += 1;
                $ThisFileInfo['gif']['header']['raw']['bg_color_index']        = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
                $offset += 1;
                $ThisFileInfo['gif']['header']['raw']['aspect_ratio']          = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
                $offset += 1;

                $ThisFileInfo['video']['resolution_x']                         = $ThisFileInfo['gif']['header']['raw']['width'];
                $ThisFileInfo['video']['resolution_y']                         = $ThisFileInfo['gif']['header']['raw']['height'];
                $ThisFileInfo['gif']['version']                                = $ThisFileInfo['gif']['header']['raw']['version'];
                $ThisFileInfo['gif']['header']['flags']['global_color_table']  = (bool) ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x80);
                if ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x80) {
                        // Number of bits per primary color available to the original image, minus 1
                        $ThisFileInfo['gif']['header']['bits_per_pixel']  = 3 * ((($ThisFileInfo['gif']['header']['raw']['flags'] & 0x70) >> 4) + 1);
                } else {
                        $ThisFileInfo['gif']['header']['bits_per_pixel']  = 0;
                }
                $ThisFileInfo['gif']['header']['flags']['global_color_sorted'] = (bool) ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x40);
                if ($ThisFileInfo['gif']['header']['flags']['global_color_table']) {
                        // the number of bytes contained in the Global Color Table. To determine that
                        // actual size of the color table, raise 2 to [the value of the field + 1]
                        $ThisFileInfo['gif']['header']['global_color_size'] = pow(2, ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x07) + 1);
                        $ThisFileInfo['video']['bits_per_sample']           = ($ThisFileInfo['gif']['header']['raw']['flags'] & 0x07) + 1;
                } else {
                        $ThisFileInfo['gif']['header']['global_color_size'] = 0;
                }
                if ($ThisFileInfo['gif']['header']['raw']['aspect_ratio'] != 0) {
                        // Aspect Ratio = (Pixel Aspect Ratio + 15) / 64
                        $ThisFileInfo['gif']['header']['aspect_ratio'] = ($ThisFileInfo['gif']['header']['raw']['aspect_ratio'] + 15) / 64;
                }

//              if ($ThisFileInfo['gif']['header']['flags']['global_color_table']) {
//                      $GIFcolorTable = fread($fd, 3 * $ThisFileInfo['gif']['header']['global_color_size']);
//                      $offset = 0;
//                      for ($i = 0; $i < $ThisFileInfo['gif']['header']['global_color_size']; $i++) {
//                              $red   = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
//                              $green = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
//                              $blue  = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
//                              $ThisFileInfo['gif']['global_color_table'][$i] = (($red << 16) | ($green << 8) | ($blue));
//                      }
//              }
//
//              // Image Descriptor
//              while (!feof($fd)) {
//                      $NextBlockTest = fread($fd, 1);
//                      switch ($NextBlockTest) {
//
//                              case ',': // ',' - Image separator character
//
//                                      $ImageDescriptorData = $NextBlockTest.fread($fd, 9);
//                                      $ImageDescriptor = array();
//                                      $ImageDescriptor['image_left']   = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 1, 2));
//                                      $ImageDescriptor['image_top']    = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 3, 2));
//                                      $ImageDescriptor['image_width']  = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 5, 2));
//                                      $ImageDescriptor['image_height'] = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 7, 2));
//                                      $ImageDescriptor['flags_raw']    = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 9, 1));
//                                      $ImageDescriptor['flags']['use_local_color_map'] = (bool) ($ImageDescriptor['flags_raw'] & 0x80);
//                                      $ImageDescriptor['flags']['image_interlaced']    = (bool) ($ImageDescriptor['flags_raw'] & 0x40);
//                                      $ThisFileInfo['gif']['image_descriptor'][] = $ImageDescriptor;
//
//                                      if ($ImageDescriptor['flags']['use_local_color_map']) {
//
//                                              $ThisFileInfo['warning'][] = 'This version of getID3() cannot parse local color maps for GIFs';
//                                              return true;
//
//                                      }
//echo 'Start of raster data: '.ftell($fd).'<BR>';
//                                      $RasterData = array();
//                                      $RasterData['code_size']        = getid3_lib::LittleEndian2Int(fread($fd, 1));
//                                      $RasterData['block_byte_count'] = getid3_lib::LittleEndian2Int(fread($fd, 1));
//                                      $ThisFileInfo['gif']['raster_data'][count($ThisFileInfo['gif']['image_descriptor']) - 1] = $RasterData;
//
//                                      $CurrentCodeSize = $RasterData['code_size'] + 1;
//                                      for ($i = 0; $i < pow(2, $RasterData['code_size']); $i++) {
//                                              $DefaultDataLookupTable[$i] = chr($i);
//                                      }
//                                      $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 0] = ''; // Clear Code
//                                      $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 1] = ''; // End Of Image Code
//
//
//                                      $NextValue = $this->GetLSBits($fd, $CurrentCodeSize);
//                                      echo 'Clear Code: '.$NextValue.'<BR>';
//
//                                      $NextValue = $this->GetLSBits($fd, $CurrentCodeSize);
//                                      echo 'First Color: '.$NextValue.'<BR>';
//
//                                      $Prefix = $NextValue;
//$i = 0;
//                                      while ($i++ < 20) {
//                                              $NextValue = $this->GetLSBits($fd, $CurrentCodeSize);
//                                              echo $NextValue.'<BR>';
//                                      }
//return true;
//                                      break;
//
//                              case '!':
//                                      // GIF Extension Block
//                                      $ExtensionBlockData = $NextBlockTest.fread($fd, 2);
//                                      $ExtensionBlock = array();
//                                      $ExtensionBlock['function_code']  = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 1, 1));
//                                      $ExtensionBlock['byte_length']    = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 2, 1));
//                                      $ExtensionBlock['data']           = fread($fd, $ExtensionBlock['byte_length']);
//                                      $ThisFileInfo['gif']['extension_blocks'][] = $ExtensionBlock;
//                                      break;
//
//                              case ';':
//                                      $ThisFileInfo['gif']['terminator_offset'] = ftell($fd) - 1;
//                                      // GIF Terminator
//                                      break;
//
//                              default:
//                                      break;
//
//
//                      }
//              }

                return true;
        }

Here is the call graph for this function:

getid3_gif::GetLSBits ( fd,
bits 
)

Definition at line 167 of file module.graphic.gif.php.

                                       {
                static $bitbuffer = '';
                while (strlen($bitbuffer) < $bits) {
//echo 'Read another byte: '.ftell($fd).'<BR>';
                        $bitbuffer = str_pad(decbin(ord(fread($fd, 1))), 8, '0', STR_PAD_LEFT).$bitbuffer;
                }

                $value = bindec(substr($bitbuffer, 0 - $bits));
                $bitbuffer = substr($bitbuffer, 0, 0 - $bits);

                return $value;
        }


The documentation for this class was generated from the following file: