/**
* @return int
*/
public function encodeModeStructure()
{
try {
$bs = new BitStream();
$bs->appendNum(4, 0x3);
$bs->appendNum(4, ord($this->data[1]) - 1);
$bs->appendNum(4, ord($this->data[0]) - 1);
$bs->appendNum(8, ord($this->data[2]));
$this->bStream = $bs;
} catch (\Exception $e) {
return -1;
}
return 0;
}
/**
* @return BitStream|null
*/
public function mergeBitStream()
{
if ($this->convertData() < 0) {
return null;
}
$bStream = new BitStream();
foreach ($this->items as $item) {
$ret = $bStream->append($item->bStream);
if ($ret < 0) {
return null;
}
}
return $bStream;
}