PHP BSave Loader: broken CVShort function

Fatal error: Uncaught TypeError: Unsupported operand types: array & int in C:\xampp8\htdocs\Mind_Realm_Web_Builder\php\bsave support.php:53 Stack trace: #0 C:\xampp8\htdocs\Mind_Realm_Web_Builder\php\super bsave.php(38): load_bsave('C:/xampp8/htdoc...') #1 C:\xampp8\htdocs\Mind_Realm_Web_Builder\mk11SUPER.php(6): super_bsave() #2 {main} thrown in C:\xampp8\htdocs\Mind_Realm_Web_Builder\php\bsave support.php on line 53

===

<?php

function cvshort( $subject = '' )
{
	return unpack("S", $subject);
}

function load_bsave( $filename = '' )
{
	$z = intval(0);
	$w = intval(0);
	$h = intval(0);
	$x = intval(0);
	$y = intval(0);
	$b = intval(0);
	$cb = intval(0);


	//dim as integer filemode = freefile
	$header = '';
	$buffer = '';

	$ret = '';

	if( !is_file( $filename ) )
	{
		$image = imagecreate( 24, 24);
		for( $offset = 0; $offset <= 5; $offset++ )
		{
			switch( $offset & 1 )
			{
			case 0:
				imageline( $image, 5-$offset, 0, 23-$offset, 23,12 ); // ,,&HAAAA
			case 1:
				imageline( $image, 23-$offset, 0, 5-$offset, 23,12 ); // ,,&HAAAA
			}
		}
		return $image;
	}

	$buffer = file_get_contents( $filename );

	$header = substr( $buffer, 0, 11 );
	$buffer = substr( $buffer, strlen( $header ) + 1 );

	$magic = substr( $header, 0, 1 );

	if( ord( $magic ) !== 0xFD )
	{
		return false;
	}

	$z = cvshort( substr( $header, 5 , 2 ) ) & 32767;
	$w = cvshort( substr( $header, 7 , 2 ) ) & 32767;
	$h = cvshort( substr( $header, 9 , 2 ) ) & 32767;

	if( ( $w === 25 ) && ( $h === 25 ) )
	{
		$image = imagecreate( 24, 24 );
	}
	else
	{
		$image = imagecreate( $w, $h );
	}

	for( $y = 0; $y < $h; $y++ )
	{
		for( $b = 0; $b < 4; $b++ )
		{
			for( $x = 0; $x < $w; $x++ )
			{
				if(  ($x & 7) === 0 )
				{
					$cb = ord( substr( $buffer, 0, 1 ) );
					$buffer = substr( $buffer, 1 );
				}

				imagesetpixel( $image, $x, $y, imagecolorat( $image, $x, $y ) ^ ( ( 1 << $b ) & intdiv( -$cb, 0x80 ) ) );

				$cb += $cb & 0xFF;

			}
		}
	}

	return $image;
}

?>