/**
* Extract gif frames, not the animation, just the frame components. Animation details are retained though.
*
* @param string $srcFile
* @param string $dstDir
* @param string $dstFilePrefix
*
* @throws Exception
*/
public static function extract($srcFile, $dstDir, $dstFilePrefix = null)
{
$fh = new FileHandler();
try {
$fh->openFile($srcFile);
} catch (Exception $e) {
throw $e;
}
$header = new Header($fh);
if ($header->signature !== "GIF" && $header->version !== "87a" && $header->version !== "89a") {
$fh->closeFile();
throw new Exception("Not a gif file.");
}
$dstDir = str_replace("\\", "/", $dstDir);
if ($dstFilePrefix == null) {
$dstFilePrefix = basename($srcFile, '.gif');
}
$lc = substr($dstDir, -1);
if ("/" !== $lc) {
$dstDir .= "/";
}
$dstPath = $dstDir . $dstFilePrefix . "_";
$lsd = new LogicalScreenDescriptor($fh);
self::processGifStream($fh, $lsd, $dstPath);
$fh->closeFile();
}
/**
* @param string $file
*
* @return array with "width" and "height" of the gif file.
* @throws Exception
*/
public static function getSize($file)
{
$fh = new FileHandler();
try {
$fh->openFile($file);
} catch (Exception $e) {
throw $e;
}
$header = new Header($fh);
if ($header->signature !== "GIF" && $header->version !== "87a" && $header->version !== "89a") {
$fh->closeFile();
throw new Exception("Not a gif file.");
}
$size = array("width" => $fh->readUint16(), "height" => $fh->readUint16());
$fh->closeFile();
return $size;
}
public static function dumpGif($file, $dstDir = null, $dstFilePrefix = null)
{
$fh = new FileHandler();
$frameCount = 0;
echo "Reading '{$file}'\n";
try {
$fh->openFile($file);
} catch (Exception $e) {
echo 'Caught exception: ', $e->getMessage(), "\n";
exit;
}
echo "\n\n------------------------------------------------------------------------\n";
echo "--- HEADER\n";
echo "------------------------------------------------------------------------\n\n";
$header = new Header($fh);
self::dumpHeader($header);
if ($header->signature !== "GIF" && $header->version !== "87a" && $header->version !== "89a") {
$fh->closeFile();
throw new Exception("Not a gif file.");
}
$dstPath = null;
if ($dstDir != null) {
$dstDir = str_replace("\\", "/", $dstDir);
if ($dstFilePrefix == null) {
$dstFilePrefix = basename($file, '.gif');
}
$lc = substr($dstDir, -1);
if ("/" !== $lc) {
$dstDir .= "/";
}
$dstPath = $dstDir . $dstFilePrefix . "_";
}
echo "\n\n------------------------------------------------------------------------\n";
echo "--- LOGICAL SCREEN DESCTIPTOR\n";
echo "------------------------------------------------------------------------\n\n";
$lsd = new LogicalScreenDescriptor($fh);
self::dumpLogicalScreenDescriptor($lsd);
while (!$fh->isEOF()) {
switch (ord($fh->peekByte())) {
case AbstractExtensionBlock::CONTROL_EXTENSION:
echo "\n\n------------------------------------------------------------------------\n";
echo "--- EXTENSION BLOCK\n";
echo "------------------------------------------------------------------------\n\n";
self::dumpExtensionBlock($fh, $frameCount, $lsd, $dstPath);
break;
case AbstractExtensionBlock::CONTROL_IMAGE:
$frameCount++;
echo "\n\n------------------------------------------------------------------------\n";
echo "--- FRAME " . $frameCount . "\n";
echo "------------------------------------------------------------------------\n\n";
$idb = new ImageDescriptor($fh);
self::dumpImageDescriptor($idb);
self::writeFrame($dstPath, $frameCount, $lsd, $idb);
break;
case AbstractExtensionBlock::CONTROL_TRAILER:
echo "\n\n------------------------------------------------------------------------\n";
echo "--- TRAILER FOUND - END OF IMAGE.\n";
echo "--- FRAMES " . $frameCount . "\n";
echo "------------------------------------------------------------------------\n\n";
$fh->seekForward(1);
break;
case AbstractExtensionBlock::CONTROL_TERMINATOR:
$fh->seekForward(1);
break;
default:
$c = $fh->readByte();
echo "\n\n------------------------------------------------------------------------\n";
echo "--- UNKNOWN CODE: 0x" . bin2hex($c) . " (" . ord($c) . ")\n";
echo "------------------------------------------------------------------------\n\n";
}
}
echo "\n";
$fh->closeFile();
}
/**
* @param $ratio
* @param LogicalScreenDescriptor $lsd
*
* @throws Exception
*/
public function resize($ratio, $lsd)
{
$scrLp = $this->screenLeftPos;
$scrTp = $this->screenTopPos;
$tFileS = tempnam("BewareOfGeeksBearingGifs", "grS");
$tFileD = tempnam("BewareOfGeeksBearingGifs", "grD");
$fhT = new FileHandler();
$fhT->openFile($tFileS, true);
$fhT->writeData($this->generateGif($lsd));
$fhT->closeFile();
ImageHandler::resizeGif($tFileS, $tFileD, $ratio, true);
$fhT->openFile($tFileD, false);
new Header($fhT);
$nLsd = new LogicalScreenDescriptor($fhT);
$nId = self::getFirstImageDescriptor($fhT, $this->parentGCE);
$fhT->closeFile();
unset($tFileD);
unset($tFileS);
$this->screenLeftPos = (int) round($scrLp * $ratio);
$this->screenTopPos = (int) round($scrTp * $ratio);
$this->screenWidth = $nId->screenWidth;
$this->screenHeight = $nId->screenHeight;
$this->reserved = $nId->reserved;
$this->interlaceFlag = $nId->interlaceFlag;
$this->sortFlag = $nLsd->sortFlag;
$this->colorTableFlag = $nLsd->colorTableFlag;
$this->colorTableSize = $nLsd->colorTableSize;
$this->colorTable = $nLsd->colorTable;
$this->lzwMinCodeSize = $nId->lzwMinCodeSize;
$this->dataSubBlocks = $nId->dataSubBlocks;
}
