From 60d6959198e0ca64e41882b8b59a89a05d549637 Mon Sep 17 00:00:00 2001
From: Michael Yang <mikkyangg@gmail.com>
Date: Fri, 24 Jan 2014 23:34:21 -0500
Subject: [PATCH] Add utility for flag bytes

---
 v2/id3v2.go | 10 +++++-----
 v2/util.go  |  8 ++++++++
 2 files changed, 13 insertions(+), 5 deletions(-)
 create mode 100644 v2/util.go

diff --git a/v2/id3v2.go b/v2/id3v2.go
index fc8919b..f61e3b8 100644
--- a/v2/id3v2.go
+++ b/v2/id3v2.go
@@ -297,12 +297,12 @@ func ParseHeader(reader io.Reader) *Header {
 
 	switch header.version {
 	case 2:
-		header.unsynchronization = (header.flags & 1 << 7) == 1
-		header.compression = (header.flags & 1 << 6) == 1
+		header.unsynchronization = isBitSet(header.flags, 7)
+		header.compression = isBitSet(header.flags, 6)
 	case 3:
-		header.unsynchronization = (header.flags & 1 << 7) == 1
-		header.extendedHeader = (header.flags & 1 << 6) == 1
-		header.experimental = (header.flags & 1 << 5) == 1
+		header.unsynchronization = isBitSet(header.flags, 7)
+		header.extendedHeader = isBitSet(header.flags, 6)
+		header.experimental = isBitSet(header.flags, 5)
 	}
 
 	return header
diff --git a/v2/util.go b/v2/util.go
new file mode 100644
index 0000000..160144a
--- /dev/null
+++ b/v2/util.go
@@ -0,0 +1,8 @@
+// Copyright 2013 Michael Yang. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package v2
+
+func isBitSet(flag, index byte) bool {
+	return flag&(1<<index) == 1
+}