diff --git a/lib/dtsc.cpp b/lib/dtsc.cpp
index 87a29c94..33948afd 100644
--- a/lib/dtsc.cpp
+++ b/lib/dtsc.cpp
@@ -968,12 +968,6 @@ DTSC::File::~File(){
 
 
 bool DTSC::isFixed(JSON::Value & metadata){
-  if (metadata.isMember("is_fixed")){return true;}
-  if ( !metadata.isMember("tracks")){return false;}
-  for (JSON::ObjIter it = metadata["tracks"].ObjBegin(); it != metadata["tracks"].ObjEnd(); it++){
-    if (!(it->second.isMember("keys") && it->second["keys"].isArray() && it->second["keys"][0u].isMember("bpos"))){
-      return false;
-    }
-  }
-  return true;
+  DTSC::Meta testFixed(metadata);
+  return testFixed.isFixed();
 }