diff -r 000000000000 -r 6474c204b198 content/media/directshow/DirectShowDecoder.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/directshow/DirectShowDecoder.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DirectShowDecoder.h"
+#include "DirectShowReader.h"
+#include "MediaDecoderStateMachine.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/WindowsVersion.h"
+
+namespace mozilla {
+
+MediaDecoderStateMachine* DirectShowDecoder::CreateStateMachine()
+{
+  return new MediaDecoderStateMachine(this, new DirectShowReader(this));
+}
+
+/* static */
+bool
+DirectShowDecoder::GetSupportedCodecs(const nsACString& aType,
+                                      char const *const ** aCodecList)
+{
+  if (!IsEnabled()) {
+    return false;
+  }
+
+  static char const *const mp3AudioCodecs[] = {
+    "mp3",
+    nullptr
+  };
+  if (aType.EqualsASCII("audio/mpeg") ||
+      aType.EqualsASCII("audio/mp3")) {
+    if (aCodecList) {
+      *aCodecList = mp3AudioCodecs;
+    }
+    return true;
+  }
+
+  return false;
+}
+
+/* static */
+bool
+DirectShowDecoder::IsEnabled()
+{
+  return Preferences::GetBool("media.directshow.enabled");
+}
+
+DirectShowDecoder::DirectShowDecoder()
+{
+  MOZ_COUNT_CTOR(DirectShowDecoder);
+}
+
+DirectShowDecoder::~DirectShowDecoder()
+{
+  MOZ_COUNT_DTOR(DirectShowDecoder);
+}
+
+} // namespace mozilla
+