module.graphic.gif.php

/common/libraries/plugin/getid3/module.graphic.gif.php

https://bitbucket.org/chamilo/chamilo-dev/
PHP | 193 lines | 74 code | 16 blank | 103 comment | 7 complexity | 4f6d2b8a9a1a52d9a24d8bf8e637e398 MD5 | raw file
Possible License(s): GPL-2.0, BSD-3-Clause, LGPL-2.1, LGPL-3.0, GPL-3.0, MIT

<?php

/////////////////////////////////////////////////////////////////
/// getID3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.graphic.gif.php                                      //
// module for analyzing GIF Image files                        //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////




class getid3_gif

{



    function __construct(&$fd, &$ThisFileInfo)

    {

        $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;

    }



    function GetLSBits($fd, $bits)

    {

        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;

    }



}



?>