/**
* @param FileHandler $fh
* @param LogicalScreenDescriptor $lsd
* @param string $dstPath
*/
private static function processGifStream($fh, $lsd, $dstPath)
{
$frameCount = 0;
while (!$fh->isEOF()) {
switch (ord($fh->peekByte())) {
case AbstractExtensionBlock::CONTROL_EXTENSION:
self::readExtensionBlock($fh, $frameCount, $lsd, $dstPath);
break;
case AbstractExtensionBlock::CONTROL_IMAGE:
$idb = new ImageDescriptor($fh);
self::writeFrame($dstPath, $frameCount, $lsd, $idb);
break;
case AbstractExtensionBlock::CONTROL_TRAILER:
$fh->seekForward(1);
break;
case AbstractExtensionBlock::CONTROL_TERMINATOR:
$fh->seekForward(1);
break;
default:
$fh->seekForward(1);
}
}
}
/**
* @param FileHandler $fh
* @param FileHandler $fhW
* @param float $ratio
* @param LogicalScreenDescriptor $lsd
*/
private static function processGifStream($fh, $fhW, $ratio, $lsd)
{
while (!$fh->isEOF()) {
switch (ord($fh->peekByte())) {
case AbstractExtensionBlock::CONTROL_EXTENSION:
self::readExtensionBlock($fh, $fhW, $ratio, $lsd);
break;
case AbstractExtensionBlock::CONTROL_IMAGE:
$idb = new ImageDescriptor($fh);
$idb->resize($ratio, $lsd);
$idb->encodeToFile($fhW);
break;
case AbstractExtensionBlock::CONTROL_TRAILER:
$fh->seekForward(1);
break;
case AbstractExtensionBlock::CONTROL_TERMINATOR:
$fh->seekForward(1);
break;
default:
$fh->seekForward(1);
}
}
$fhW->writeData(chr(AbstractExtensionBlock::CONTROL_TRAILER));
}
public static function dumpGif($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 FileHandler $fh
* @param GraphicControlExtension $gce
*
* @return ImageDescriptor|GraphicControlExtension
*/
public static function getFirstImageFrame($fh, $gce = null)
{
$nId = null;
while ($nId == null && !$fh->isEOF()) {
$blockLabel = $fh->peekByte();
if (ord($blockLabel) == AbstractExtensionBlock::CONTROL_IMAGE) {
$nId = new ImageDescriptor($fh);
if ($gce != null) {
$gce->transparentColorFlag = false;
$gce->transparentColorIndex = 0;
}
return $nId;
} else {
if (ord($blockLabel) == AbstractExtensionBlock::CONTROL_EXTENSION) {
$fh->seekForward(1);
$blockLabel = $fh->peekByte();
if (ord($blockLabel) == AbstractExtensionBlock::LABEL_GRAPHICS_CONTROL) {
$nGce = new GraphicControlExtension($fh);
if ($gce != null) {
$gce->transparentColorFlag = $nGce->transparentColorFlag;
$gce->transparentColorIndex = $nGce->transparentColorIndex;
}
return $nGce;
}
}
}
}
return null;
}
