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<?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 getid3_gif(&$fd, &$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;
}
}
?>
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