name : module.graphic.gif.php <?php ///////////////////////////////////////////////////////////////// /// getID3() by James Heinrich <info@getid3.org> // // available at https://github.com/JamesHeinrich/getID3 // // or https://www.getid3.org // // or http://getid3.sourceforge.net // // see readme.txt for more details // ///////////////////////////////////////////////////////////////// // // // module.graphic.gif.php // // module for analyzing GIF Image files // // dependencies: NONE // // /// ///////////////////////////////////////////////////////////////// /** * @link https://www.w3.org/Graphics/GIF/spec-gif89a.txt * @link http://www.matthewflickinger.com/lab/whatsinagif/bits_and_bytes.asp * @link http://www.vurdalakov.net/misc/gif/netscape-looping-application-extension */ if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers exit; } class getid3_gif extends getid3_handler { /** * @return bool */ public function Analyze() { $info = &$this->getid3->info; $info['fileformat'] = 'gif'; $info['video']['dataformat'] = 'gif'; $info['video']['lossless'] = true; $info['video']['pixel_aspect_ratio'] = (float) 1; $this->fseek($info['avdataoffset']); $GIFheader = $this->fread(13); $offset = 0; $info['gif']['header']['raw']['identifier'] = substr($GIFheader, $offset, 3); $offset += 3; $magic = 'GIF'; if ($info['gif']['header']['raw']['identifier'] != $magic) { $this->error('Expecting "'.getid3_lib::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($info['gif']['header']['raw']['identifier']).'"'); unset($info['fileformat']); unset($info['gif']); return false; } //if (!$this->getid3->option_extra_info) { // $this->warning('GIF Extensions and Global Color Table not returned due to !getid3->option_extra_info'); //} $info['gif']['header']['raw']['version'] = substr($GIFheader, $offset, 3); $offset += 3; $info['gif']['header']['raw']['width'] = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2)); $offset += 2; $info['gif']['header']['raw']['height'] = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2)); $offset += 2; $info['gif']['header']['raw']['flags'] = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1)); $offset += 1; $info['gif']['header']['raw']['bg_color_index'] = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1)); $offset += 1; $info['gif']['header']['raw']['aspect_ratio'] = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1)); $offset += 1; $info['video']['resolution_x'] = $info['gif']['header']['raw']['width']; $info['video']['resolution_y'] = $info['gif']['header']['raw']['height']; $info['gif']['version'] = $info['gif']['header']['raw']['version']; $info['gif']['header']['flags']['global_color_table'] = (bool) ($info['gif']['header']['raw']['flags'] & 0x80); if ($info['gif']['header']['raw']['flags'] & 0x80) { // Number of bits per primary color available to the original image, minus 1 $info['gif']['header']['bits_per_pixel'] = 3 * ((($info['gif']['header']['raw']['flags'] & 0x70) >> 4) + 1); } else { $info['gif']['header']['bits_per_pixel'] = 0; } $info['gif']['header']['flags']['global_color_sorted'] = (bool) ($info['gif']['header']['raw']['flags'] & 0x40); if ($info['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] $info['gif']['header']['global_color_size'] = pow(2, ($info['gif']['header']['raw']['flags'] & 0x07) + 1); $info['video']['bits_per_sample'] = ($info['gif']['header']['raw']['flags'] & 0x07) + 1; } else { $info['gif']['header']['global_color_size'] = 0; } if ($info['gif']['header']['raw']['aspect_ratio'] != 0) { // Aspect Ratio = (Pixel Aspect Ratio + 15) / 64 $info['gif']['header']['aspect_ratio'] = ($info['gif']['header']['raw']['aspect_ratio'] + 15) / 64; } if ($info['gif']['header']['flags']['global_color_table']) { $GIFcolorTable = $this->fread(3 * $info['gif']['header']['global_color_size']); if ($this->getid3->option_extra_info) { $offset = 0; for ($i = 0; $i < $info['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)); $info['gif']['global_color_table'][$i] = (($red << 16) | ($green << 8) | ($blue)); $info['gif']['global_color_table_rgb'][$i] = sprintf('%02X%02X%02X', $red, $green, $blue); } } } // Image Descriptor $info['gif']['animation']['animated'] = false; while (!feof($this->getid3->fp)) { $NextBlockTest = $this->fread(1); switch ($NextBlockTest) { /* case ',': // ',' - Image separator character $ImageDescriptorData = $NextBlockTest.$this->fread(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); $info['gif']['image_descriptor'][] = $ImageDescriptor; if ($ImageDescriptor['flags']['use_local_color_map']) { $this->warning('This version of getID3() cannot parse local color maps for GIFs'); return true; } $RasterData = array(); $RasterData['code_size'] = getid3_lib::LittleEndian2Int($this->fread(1)); $RasterData['block_byte_count'] = getid3_lib::LittleEndian2Int($this->fread(1)); $info['gif']['raster_data'][count($info['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 = $this->GetLSBits($CurrentCodeSize); echo 'Clear Code: '.$NextValue.'<BR>'; $NextValue = $this->GetLSBits($CurrentCodeSize); echo 'First Color: '.$NextValue.'<BR>'; $Prefix = $NextValue; $i = 0; while ($i++ < 20) { $NextValue = $this->GetLSBits($CurrentCodeSize); echo $NextValue.'<br>'; } echo 'escaping<br>'; return true; break; */ case '!': // GIF Extension Block $ExtensionBlockData = $NextBlockTest.$this->fread(2); $ExtensionBlock = array(); $ExtensionBlock['function_code'] = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 1, 1)); $ExtensionBlock['byte_length'] = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 2, 1)); $ExtensionBlock['data'] = (($ExtensionBlock['byte_length'] > 0) ? $this->fread($ExtensionBlock['byte_length']) : null); switch ($ExtensionBlock['function_code']) { case 0xFF: // Application Extension if ($ExtensionBlock['byte_length'] != 11) { $this->warning('Expected block size of the Application Extension is 11 bytes, found '.$ExtensionBlock['byte_length'].' at offset '.$this->ftell()); break; } if (substr($ExtensionBlock['data'], 0, 11) !== 'NETSCAPE2.0' && substr($ExtensionBlock['data'], 0, 11) !== 'ANIMEXTS1.0' ) { $this->warning('Ignoring unsupported Application Extension '.substr($ExtensionBlock['data'], 0, 11)); break; } // Netscape Application Block (NAB) $ExtensionBlock['data'] .= $this->fread(4); if (substr($ExtensionBlock['data'], 11, 2) == "\x03\x01") { $info['gif']['animation']['animated'] = true; $info['gif']['animation']['loop_count'] = getid3_lib::LittleEndian2Int(substr($ExtensionBlock['data'], 13, 2)); } else { $this->warning('Expecting 03 01 at offset '.($this->ftell() - 4).', found "'.getid3_lib::PrintHexBytes(substr($ExtensionBlock['data'], 11, 2)).'"'); } break; } if ($this->getid3->option_extra_info) { $info['gif']['extension_blocks'][] = $ExtensionBlock; } break; case ';': $info['gif']['terminator_offset'] = $this->ftell() - 1; // GIF Terminator break; default: break; } } return true; } /** * @param int $bits * * @return float|int */ public function GetLSBits($bits) { static $bitbuffer = ''; while (strlen($bitbuffer) < $bits) { $bitbuffer = str_pad(decbin(ord($this->fread(1))), 8, '0', STR_PAD_LEFT).$bitbuffer; } $value = bindec(substr($bitbuffer, 0 - $bits)); $bitbuffer = substr($bitbuffer, 0, 0 - $bits); return $value; } }