www/plugins-dist/medias/lib/getid3/module.graphic.gif.php

   1 <?php
   2
   3 /////////////////////////////////////////////////////////////////
   4 /// getID3() by James Heinrich <info@getid3.org>               //
   5 //  available at https://github.com/JamesHeinrich/getID3       //
   6 //            or https://www.getid3.org                        //
   7 //            or http://getid3.sourceforge.net                 //
   8 //  see readme.txt for more details                            //
   9 /////////////////////////////////////////////////////////////////
  10 //                                                             //
  11 // module.graphic.gif.php                                      //
  12 // module for analyzing GIF Image files                        //
  13 // dependencies: NONE                                          //
  14 //                                                            ///
  15 /////////////////////////////////////////////////////////////////
  16
  17 /**
  18  * @link https://www.w3.org/Graphics/GIF/spec-gif89a.txt
  19  * @link http://www.matthewflickinger.com/lab/whatsinagif/bits_and_bytes.asp
  20  */
  21
  22 if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers
  23         exit;
  24 }
  25
  26 class getid3_gif extends getid3_handler
  27 {
  28         /**
  29          * @return bool
  30          */
  31         public function Analyze() {
  32                 $info = &$this->getid3->info;
  33
  34                 $info['fileformat']                  = 'gif';
  35                 $info['video']['dataformat']         = 'gif';
  36                 $info['video']['lossless']           = true;
  37                 $info['video']['pixel_aspect_ratio'] = (float) 1;
  38
  39                 $this->fseek($info['avdataoffset']);
  40                 $GIFheader = $this->fread(13);
  41                 $offset = 0;
  42
  43                 $info['gif']['header']['raw']['identifier']            =                              substr($GIFheader, $offset, 3);
  44                 $offset += 3;
  45
  46                 $magic = 'GIF';
  47                 if ($info['gif']['header']['raw']['identifier'] != $magic) {
  48                         $this->error('Expecting "'.getid3_lib::PrintHexBytes($magic).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($info['gif']['header']['raw']['identifier']).'"');
  49                         unset($info['fileformat']);
  50                         unset($info['gif']);
  51                         return false;
  52                 }
  53
  54                 //if (!$this->getid3->option_extra_info) {
  55                 //      $this->warning('GIF Extensions and Global Color Table not returned due to !getid3->option_extra_info');
  56                 //}
  57
  58                 $info['gif']['header']['raw']['version']               =                              substr($GIFheader, $offset, 3);
  59                 $offset += 3;
  60                 $info['gif']['header']['raw']['width']                 = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2));
  61                 $offset += 2;
  62                 $info['gif']['header']['raw']['height']                = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 2));
  63                 $offset += 2;
  64                 $info['gif']['header']['raw']['flags']                 = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
  65                 $offset += 1;
  66                 $info['gif']['header']['raw']['bg_color_index']        = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
  67                 $offset += 1;
  68                 $info['gif']['header']['raw']['aspect_ratio']          = getid3_lib::LittleEndian2Int(substr($GIFheader, $offset, 1));
  69                 $offset += 1;
  70
  71                 $info['video']['resolution_x']                         = $info['gif']['header']['raw']['width'];
  72                 $info['video']['resolution_y']                         = $info['gif']['header']['raw']['height'];
  73                 $info['gif']['version']                                = $info['gif']['header']['raw']['version'];
  74                 $info['gif']['header']['flags']['global_color_table']  = (bool) ($info['gif']['header']['raw']['flags'] & 0x80);
  75                 if ($info['gif']['header']['raw']['flags'] & 0x80) {
  76                         // Number of bits per primary color available to the original image, minus 1
  77                         $info['gif']['header']['bits_per_pixel']  = 3 * ((($info['gif']['header']['raw']['flags'] & 0x70) >> 4) + 1);
  78                 } else {
  79                         $info['gif']['header']['bits_per_pixel']  = 0;
  80                 }
  81                 $info['gif']['header']['flags']['global_color_sorted'] = (bool) ($info['gif']['header']['raw']['flags'] & 0x40);
  82                 if ($info['gif']['header']['flags']['global_color_table']) {
  83                         // the number of bytes contained in the Global Color Table. To determine that
  84                         // actual size of the color table, raise 2 to [the value of the field + 1]
  85                         $info['gif']['header']['global_color_size'] = pow(2, ($info['gif']['header']['raw']['flags'] & 0x07) + 1);
  86                         $info['video']['bits_per_sample']           = ($info['gif']['header']['raw']['flags'] & 0x07) + 1;
  87                 } else {
  88                         $info['gif']['header']['global_color_size'] = 0;
  89                 }
  90                 if ($info['gif']['header']['raw']['aspect_ratio'] != 0) {
  91                         // Aspect Ratio = (Pixel Aspect Ratio + 15) / 64
  92                         $info['gif']['header']['aspect_ratio'] = ($info['gif']['header']['raw']['aspect_ratio'] + 15) / 64;
  93                 }
  94
  95                 if ($info['gif']['header']['flags']['global_color_table']) {
  96                         $GIFcolorTable = $this->fread(3 * $info['gif']['header']['global_color_size']);
  97                         if ($this->getid3->option_extra_info) {
  98                                 $offset = 0;
  99                                 for ($i = 0; $i < $info['gif']['header']['global_color_size']; $i++) {
 100                                         $red   = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
 101                                         $green = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
 102                                         $blue  = getid3_lib::LittleEndian2Int(substr($GIFcolorTable, $offset++, 1));
 103                                         $info['gif']['global_color_table'][$i] = (($red << 16) | ($green << 8) | ($blue));
 104                                         $info['gif']['global_color_table_rgb'][$i] = sprintf('%02X%02X%02X', $red, $green, $blue);
 105                                 }
 106                         }
 107                 }
 108
 109                 // Image Descriptor
 110                 $info['gif']['animation']['animated'] = false;
 111                 while (!feof($this->getid3->fp)) {
 112                         $NextBlockTest = $this->fread(1);
 113                         switch ($NextBlockTest) {
 114
 115 /*
 116                                 case ',': // ',' - Image separator character
 117                                         $ImageDescriptorData = $NextBlockTest.$this->fread(9);
 118                                         $ImageDescriptor = array();
 119                                         $ImageDescriptor['image_left']   = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 1, 2));
 120                                         $ImageDescriptor['image_top']    = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 3, 2));
 121                                         $ImageDescriptor['image_width']  = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 5, 2));
 122                                         $ImageDescriptor['image_height'] = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 7, 2));
 123                                         $ImageDescriptor['flags_raw']    = getid3_lib::LittleEndian2Int(substr($ImageDescriptorData, 9, 1));
 124                                         $ImageDescriptor['flags']['use_local_color_map'] = (bool) ($ImageDescriptor['flags_raw'] & 0x80);
 125                                         $ImageDescriptor['flags']['image_interlaced']    = (bool) ($ImageDescriptor['flags_raw'] & 0x40);
 126                                         $info['gif']['image_descriptor'][] = $ImageDescriptor;
 127
 128                                         if ($ImageDescriptor['flags']['use_local_color_map']) {
 129
 130                                                 $this->warning('This version of getID3() cannot parse local color maps for GIFs');
 131                                                 return true;
 132
 133                                         }
 134                                         $RasterData = array();
 135                                         $RasterData['code_size']        = getid3_lib::LittleEndian2Int($this->fread(1));
 136                                         $RasterData['block_byte_count'] = getid3_lib::LittleEndian2Int($this->fread(1));
 137                                         $info['gif']['raster_data'][count($info['gif']['image_descriptor']) - 1] = $RasterData;
 138
 139                                         $CurrentCodeSize = $RasterData['code_size'] + 1;
 140                                         for ($i = 0; $i < pow(2, $RasterData['code_size']); $i++) {
 141                                                 $DefaultDataLookupTable[$i] = chr($i);
 142                                         }
 143                                         $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 0] = ''; // Clear Code
 144                                         $DefaultDataLookupTable[pow(2, $RasterData['code_size']) + 1] = ''; // End Of Image Code
 145
 146                                         $NextValue = $this->GetLSBits($CurrentCodeSize);
 147                                         echo 'Clear Code: '.$NextValue.'<BR>';
 148
 149                                         $NextValue = $this->GetLSBits($CurrentCodeSize);
 150                                         echo 'First Color: '.$NextValue.'<BR>';
 151
 152                                         $Prefix = $NextValue;
 153                                         $i = 0;
 154                                         while ($i++ < 20) {
 155                                                 $NextValue = $this->GetLSBits($CurrentCodeSize);
 156                                                 echo $NextValue.'<br>';
 157                                         }
 158                                         echo 'escaping<br>';
 159                                         return true;
 160                                         break;
 161 */
 162
 163                                 case '!':
 164                                         // GIF Extension Block
 165                                         $ExtensionBlockData = $NextBlockTest.$this->fread(2);
 166                                         $ExtensionBlock = array();
 167                                         $ExtensionBlock['function_code']  = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 1, 1));
 168                                         $ExtensionBlock['byte_length']    = getid3_lib::LittleEndian2Int(substr($ExtensionBlockData, 2, 1));
 169                                         $ExtensionBlock['data']           = (($ExtensionBlock['byte_length'] > 0) ? $this->fread($ExtensionBlock['byte_length']) : null);
 170
 171                                         if (substr($ExtensionBlock['data'], 0, 11) == 'NETSCAPE2.0') { // Netscape Application Block (NAB)
 172                                                 $ExtensionBlock['data'] .= $this->fread(4);
 173                                                 if (substr($ExtensionBlock['data'], 11, 2) == "\x03\x01") {
 174                                                         $info['gif']['animation']['animated']   = true;
 175                                                         $info['gif']['animation']['loop_count'] = getid3_lib::LittleEndian2Int(substr($ExtensionBlock['data'], 13, 2));
 176                                                 } else {
 177                                                         $this->warning('Expecting 03 01 at offset '.($this->ftell() - 4).', found "'.getid3_lib::PrintHexBytes(substr($ExtensionBlock['data'], 11, 2)).'"');
 178                                                 }
 179                                         }
 180
 181                                         if ($this->getid3->option_extra_info) {
 182                                                 $info['gif']['extension_blocks'][] = $ExtensionBlock;
 183                                         }
 184                                         break;
 185
 186                                 case ';':
 187                                         $info['gif']['terminator_offset'] = $this->ftell() - 1;
 188                                         // GIF Terminator
 189                                         break;
 190
 191                                 default:
 192                                         break;
 193
 194
 195                         }
 196                 }
 197
 198                 return true;
 199         }
 200
 201         /**
 202          * @param int $bits
 203          *
 204          * @return float|int
 205          */
 206         public function GetLSBits($bits) {
 207                 static $bitbuffer = '';
 208                 while (strlen($bitbuffer) < $bits) {
 209                         $bitbuffer = str_pad(decbin(ord($this->fread(1))), 8, '0', STR_PAD_LEFT).$bitbuffer;
 210                 }
 211                 $value = bindec(substr($bitbuffer, 0 - $bits));
 212                 $bitbuffer = substr($bitbuffer, 0, 0 - $bits);
 213
 214                 return $value;
 215         }
 216
 217 }