Pass dng/grw mode down to mpegize.

mpegize.py

@@ -396,7 +396,7 @@ class Mpegize:
         return s[2], s[1], i
 
     def help(m):
-        print("mpegize command base-dir destination-movie fps")
+        print("mpegize command base-dir destination-movie fps dng|grw")
 
     def run(m, argv):
         if len(argv) > 2:
@@ -411,7 +411,7 @@ class Mpegize:
                 print("Phase 2: mpegize -- ", argv[3])
                 print("Message: enc")
                 sys.stdout.flush()
-                gst_convert(m.base, argv[3], True)
+                gst_convert(m.base, argv[3], argv[4]=="dng")
                 return
             if mode == "gaps":
                 print("Video gaps")