Add resize mode, move getMultiple method to FFMpeg

src/FFMpeg/Format/Video.php

@@ -18,6 +18,8 @@ namespace FFMpeg\Format;
  */
 interface Video extends Audio
 {
+    const RESIZEMODE_FIT = 'fit';
+    const RESIZEMODE_INSET = 'inset';
 
     /**
      * Returns the width
@@ -33,6 +35,13 @@ interface Video extends Audio
      */
     public function getHeight();
 
+    /**
+     * Get the current resize mode
+     * 
+     * @return string
+     */
+    public function getResizeMode();
+
     /**
      * Returns the frame rate
      *