diff --git a/app/Media/QuickTime/FindQuicktimeAtoms.php b/app/Media/QuickTime/FindQuicktimeAtoms.php
index b7f05ec..c2473cb 100644
--- a/app/Media/QuickTime/FindQuicktimeAtoms.php
+++ b/app/Media/QuickTime/FindQuicktimeAtoms.php
@@ -23,31 +23,36 @@ trait FindQuicktimeAtoms
 
 		$result = collect();
 
+		$prelude = 8;
 		while ($rp < $size) {
-			$read = $atom ? substr($atom,$rp,8) : fread($fh,8);
+			$read = $atom ? substr($atom,$rp,$prelude) : fread($fh,$prelude);
+			$header = unpack('Nsize/a4atom',$read);
 			$rp += strlen($read);
 
-			$header = unpack('Nsize/a4atom',$read);
+			// For mdat atoms, if size = 1, the true size is in the 64 bit extended header, in the next 8 bytes
+			if (($header['atom'] === 'mdat') && ($header['size'] === 1)) {
+				$eheader = unpack('Jsize',fread($fh,8));
+				$rp += 8;
+				$prelude = 16;
 
-			// For mdat atoms, if size = 1, the true size is in the 64 bit extended header
-			if (($header['atom'] === 'mdat') && ($header['size'] === 1))
-				throw new \Exception(sprintf('%s:! We havent handed large QT files yet.',self::LOGKEY));
+				$header['size'] = $eheader['size'];
+			}
 
 			// Load our class for this supplier
 			$class = $class_prefix.$header['atom'];
 
 			$data = $atom
-				? substr($atom,$rp,$header['size']-8)
-				: ($header['size']-8 && ($header['size']-8 <= static::record_size) ? fread($fh,$header['size']-8) : NULL);
+				? substr($atom,$rp,$header['size']-$prelude)
+				: ($header['size']-$prelude && ($header['size']-$prelude <= self::record_size) ? fread($fh,$header['size']-$prelude) : NULL);
 
-			if ($header['size'] >= 8) {
+			if ($header['size'] >= $prelude) {
 				$o = class_exists($class)
-					? new $class($offset+$rp,$header['size']-8,$this->filename,$data,$passthru)
-					: new $unknown($offset+$rp,$header['size']-8,$this->filename,$header['atom'],$data);
+					? new $class($offset+$rp,$header['size']-$prelude,$this->filename,$data,$passthru)
+					: new $unknown($offset+$rp,$header['size']-$prelude,$this->filename,$header['atom'],$data);
 
 				$result->push($o);
 
-				$rp += $header['size']-8;
+				$rp += $header['size']-$prelude;
 
 				// Only need to seek if we didnt read all the data
 				if ((! $atom) && ($header['size']-8 > static::record_size))