/**
* @param FileHandler $fh
*/
public function decode($fh)
{
$fh->seekForward(1);
$this->screenLeftPos = $fh->readUint16();
$this->screenTopPos = $fh->readUint16();
$this->screenWidth = $fh->readUint16();
$this->screenHeight = $fh->readUint16();
$packedFields = ord($fh->readByte());
$this->colorTableFlag = ($packedFields & 0x80) > 0;
$this->interlaceFlag = ($packedFields & 0x40) > 0;
$this->sortFlag = ($packedFields & 0x20) > 0;
$this->reserved = ($packedFields & 0x18) >> 3;
$ctSize = $packedFields & 0x7;
$this->colorTableSize = pow(2, $ctSize + 1);
$this->colorTable = "";
if ($this->colorTableFlag && $this->colorTableSize > 0) {
$this->colorTable = $fh->readData($this->colorTableSize * 3);
}
// Here comes the image frame:
$this->lzwMinCodeSize = $fh->readByte();
// After the Min Code Size, the LZW stream behaves similarly to the data sub-blocks, and the data will be stored in that variable.
$this->readDataSubBlocks($fh);
// Spool past the \x00 terminator byte. There *should* only be one.
while ($fh->peekByte() == "") {
$fh->seekForward(1);
}
}
/**
* @param FileHandler $fh
*/
public function decode($fh)
{
$fh->seekForward(1);
// skip block label.
$this->blockLength = $fh->readByteUint();
// 4
$packedFields = $fh->readByteUint();
$this->reserved = ($packedFields & 0x70) >> 5;
$this->disposalMethod = ($packedFields & 0x1c) >> 2;
$this->userInputFlag = ($packedFields & 0x2) > 0;
$this->transparentColorFlag = ($packedFields & 0x1) > 0;
$this->delayTime = $fh->readUint16();
$this->transparentColorIndex = $fh->readByteUint();
// Spool past the \x00 terminator byte. There *should* only be one.
while ($fh->compareByte("")) {
$fh->readByte();
}
// The GCE will always be followed by the Image Descriptor.
$this->imageDescriptor = new ImageDescriptor($fh);
$this->imageDescriptor->parentGCE = $this;
}
/**
* @param FileHandler $fh
*
* @throws Exception
*/
public function decode($fh)
{
if ($fh->getRemainingBytes() < 7) {
throw new Exception("Insufficient data. Need 7 bytes, got " . $fh->getRemainingBytes());
}
$this->screenWidth = $fh->readUint16();
$this->screenHeight = $fh->readUint16();
$packedFields = ord($fh->readByte());
$this->colorTableFlag = ($packedFields & 0x80) > 0;
$this->colorResolution = ($packedFields & 0x70) >> 4;
$this->sortFlag = ($packedFields & 0x8) > 0;
// For just 8 possible values, the lookup table is faster.
// the commented lines below is the pedantic way of doing it.
// $v = ($packedFields & 0x07);
// $this->colorTableSize = pow(2, $v + 1);
$this->colorTableSize = $this->ctSizeListRev[$packedFields & 0x7];
$this->bgColorIndex = $fh->readByteUint();
$v = $fh->readByteUint();
$this->pixelAspectRatio = $v > 0 ? ($v + 15) / 64 : 0;
if ($this->colorTableFlag && $this->colorTableSize > 0) {
$this->colorTable = $fh->readData($this->colorTableSize * 3);
}
}
/**
* @param FileHandler $fh
* @param FileHandler $fhW
* @param float $ratio
* @param LogicalScreenDescriptor $lsd
*/
private static function readExtensionBlock($fh, $fhW, $ratio, $lsd)
{
$fh->seekForward(1);
$blockLabel = $fh->peekByte();
switch (ord($blockLabel)) {
case AbstractExtensionBlock::LABEL_APPLICATION:
$adb = new ApplicationExtension($fh);
$adb->encodeToFile($fhW);
break;
case AbstractExtensionBlock::LABEL_COMMENT:
$ceb = new CommentExtension($fh);
$ceb->encodeToFile($fhW);
break;
case AbstractExtensionBlock::LABEL_GRAPHICS_CONTROL:
$gce = new GraphicControlExtension($fh);
self::resizeGraphicControlExtensionBlock($gce, $ratio, $fhW, $lsd);
break;
case AbstractExtensionBlock::LABEL_PLAIN_TEXT:
$pte = new PlainTextExtension($fh);
$pte->encodeToFile($fhW);
break;
case AbstractExtensionBlock::CONTROL_TRAILER:
break;
default:
$fh->seekForward(1);
while (!$fh->compareByte("")) {
$fh->seekForward(1);
}
}
if ($fh->compareByte("")) {
$fh->readByte();
}
}
/**
* @param FileHandler $fh
* @param int $frameCount
* @param LogicalScreenDescriptor $lsd
* @param string $dstPath
*/
private static function readExtensionBlock($fh, &$frameCount, $lsd, $dstPath)
{
$fh->seekForward(1);
$blockLabel = $fh->peekByte();
switch (ord($blockLabel)) {
case AbstractExtensionBlock::LABEL_APPLICATION:
new ApplicationExtension($fh);
break;
case AbstractExtensionBlock::LABEL_COMMENT:
new CommentExtension($fh);
break;
case AbstractExtensionBlock::LABEL_GRAPHICS_CONTROL:
$gce = new GraphicControlExtension($fh);
self::writeFrame($dstPath, $frameCount, $lsd, $gce);
break;
case AbstractExtensionBlock::LABEL_PLAIN_TEXT:
new PlainTextExtension($fh);
break;
case AbstractExtensionBlock::CONTROL_TRAILER:
break;
default:
$fh->seekForward(1);
while (!$fh->compareByte("")) {
$fh->seekForward(1);
}
}
if ($fh->compareByte("")) {
$fh->readByte();
}
}
/**
* @param FileHandler $fh
* @param int $frameCount
* @param LogicalScreenDescriptor $lsd
* @param string $dstPath
*/
public static function dumpExtensionBlock($fh, &$frameCount, $lsd, $dstPath = null)
{
$fh->seekForward(1);
$blockLabel = $fh->peekByte();
switch (ord($blockLabel)) {
case AbstractExtensionBlock::LABEL_APPLICATION:
$adb = new ApplicationExtension($fh);
self::dumpApplicationExtensionBlock($adb);
break;
case AbstractExtensionBlock::LABEL_COMMENT:
$ceb = new CommentExtension($fh);
self::dumpCommentExtensionBlock($ceb);
break;
case AbstractExtensionBlock::LABEL_GRAPHICS_CONTROL:
$gce = new GraphicControlExtension($fh);
$frameCount++;
self::dumpGraphicControlExtensionBlock($gce, $frameCount, $lsd, $dstPath);
break;
case AbstractExtensionBlock::LABEL_PLAIN_TEXT:
$pte = new PlainTextExtension($fh);
self::dumpPlainTextExtensionBlock($pte);
break;
case AbstractExtensionBlock::CONTROL_TRAILER:
break;
default:
$fh->seekForward(1);
echo "Unknown Extension block found.......: 0x" . bin2hex($blockLabel) . " (" . ord($blockLabel) . ")\n";
while (!$fh->compareByte("")) {
$fh->seekForward(1);
}
}
if ($fh->compareByte("")) {
$fh->readByte();
}
}
