public function convertImageData()
{
$format = (int) $this->getField('BitmapFormat');
$width = (int) $this->getField('BitmapWidth');
$height = (int) $this->getField('BitmapHeight');
$bitmapdata = gzuncompress($this->getField('ZlibBitmapData'));
$bitmapReader = new Media_SWF_Parser();
$bitmapReader->input($bitmapdata);
$im = imagecreatetruecolor($width, $height);
if ($im === false) {
throw new Exception('Cannot Initialize new GD image stream.');
}
$color_palette = array();
if ($format == 3) {
// color palette
$palette_size = (int) $this->getField('BitmapColorTableSize');
if ($this->code == 20) {
for ($i = 0; $i <= $palette_size; $i++) {
$r = $bitmapReader->getUI8();
$g = $bitmapReader->getUI8();
$b = $bitmapReader->getUI8();
$color_palette[$i] = imagecolorallocate($im, $r, $g, $b);
}
} else {
// alpha
imagealphablending($im, false);
imagesavealpha($im, true);
for ($i = 0; $i <= $palette_size; $i++) {
$r = $bitmapReader->getUI8();
$g = $bitmapReader->getUI8();
$b = $bitmapReader->getUI8();
$a = $bitmapReader->getUI8();
$a = (1 - $a / 255) * 127;
$color_palette[$i] = imagecolorallocatealpha($im, $r, $g, $b, $a);
}
}
// widthの読み出しbyte数を32bitで丸める(must be rounded up to the next 32-bit word boundary)
$padding = ($width + 3 & -4) - $width;
for ($y = 0; $y < $height; ++$y) {
for ($x = 0; $x < $width; ++$x) {
$bi = $bitmapReader->getUI8();
imagesetpixel($im, $x, $y, $color_palette[$bi]);
}
$bi = $bitmapReader->incrementOffset($padding, 0);
// skip
}
} else {
// non parette
if ($format == 4) {
// PIX15
for ($y = 0; $y < $height; ++$y) {
for ($x = 0; $x < $width; ++$x) {
$a = $bitmapReader->getUIBit();
// Pix15Reserved always 0
$r = $bitmapReader->getUIBits(5);
$g = $bitmapReader->getUIBits(5);
$b = $bitmapReader->getUIBits(5);
$c = imagecolorallocate($im, $r, $g, $b);
imagesetpixel($im, $x, $y, $c);
}
}
} elseif ($this->code == 20) {
// PIX24
for ($y = 0; $y < $height; ++$y) {
for ($x = 0; $x < $width; ++$x) {
$a = $bitmapReader->getUI8();
// 0 // Pix24Reserved always0
$r = $bitmapReader->getUI8();
$g = $bitmapReader->getUI8();
$b = $bitmapReader->getUI8();
$c = imagecolorallocate($im, $r, $g, $b);
imagesetpixel($im, $x, $y, $c);
}
}
} else {
// alpha
imagealphablending($im, false);
imagesavealpha($im, true);
for ($y = 0; $y < $height; ++$y) {
for ($x = 0; $x < $width; ++$x) {
$a = $bitmapReader->getUI8();
$a = (1 - $a / 255) * 127;
$r = $bitmapReader->getUI8();
$g = $bitmapReader->getUI8();
$b = $bitmapReader->getUI8();
$c = imagecolorallocatealpha($im, $r, $g, $b, $a);
imagesetpixel($im, $x, $y, $c);
}
}
}
}
ob_start();
imagepng($im);
$image_data = ob_get_contents();
ob_end_clean();
imagedestroy($im);
return $image_data;
}