Update Blurhash util, add default hash for invalid media

app/Util/Media/Blurhash.php

@@ -7,19 +7,28 @@ use App\Media;
 
 class Blurhash {
 
+	const DEFAULT_HASH = 'U4Rfzst8?bt7ogayj[j[~pfQ9Goe%Mj[WBay';
+
 	public static function generate(Media $media)
 	{
-		if(!in_array($media->mime, ['image/png', 'image/jpeg'])) {
-			return;
+		if(!in_array($media->mime, ['image/png', 'image/jpeg', 'video/mp4'])) {
+			return self::DEFAULT_HASH;
+		}
+
+		if($media->thumbnail_path == null) {
+			return self::DEFAULT_HASH;
 		}
 
 		$file  = storage_path('app/' . $media->thumbnail_path);
 
 		if(!is_file($file)) {
-			return;
+			return self::DEFAULT_HASH;
 		}
 
 		$image = imagecreatefromstring(file_get_contents($file));
+		if(!$image) {
+			return self::DEFAULT_HASH;
+		}
 		$width = imagesx($image);
 		$height = imagesy($image);
 
@@ -39,7 +48,7 @@ class Blurhash {
 		$components_y = 4;
 		$blurhash = BlurhashEngine::encode($pixels, $components_x, $components_y);
 		if(strlen($blurhash) > 191) {
-			return;
+			return self::DEFAULT_HASH;
 		}
 		return $blurhash;
 	}