diff -r 000000000000 -r 6474c204b198 content/media/gstreamer/GStreamerFormatHelper.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/gstreamer/GStreamerFormatHelper.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,78 @@
+/* -*- 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/. */
+
+#if !defined(GStreamerFormatHelper_h_)
+#define GStreamerFormatHelper_h_
+
+#include <gst/gst.h>
+#include <mozilla/Types.h>
+#include "nsXPCOMStrings.h"
+
+namespace mozilla {
+
+class GStreamerFormatHelper {
+  /* This class can be used to query the GStreamer registry for the required
+   * demuxers/decoders from nsHTMLMediaElement::CanPlayType.
+   * It implements looking at the GstRegistry to check if elements to
+   * demux/decode the formats passed to CanPlayType() are actually installed.
+   */
+  public:
+    static GStreamerFormatHelper* Instance();
+    ~GStreamerFormatHelper();
+
+    bool CanHandleMediaType(const nsACString& aMIMEType,
+                            const nsAString* aCodecs);
+
+    bool CanHandleContainerCaps(GstCaps* aCaps);
+    bool CanHandleCodecCaps(GstCaps* aCaps);
+
+    static GstCaps* ConvertFormatsToCaps(const char* aMIMEType,
+                                         const nsAString* aCodecs);
+
+    static void Shutdown();
+
+  private:
+    GStreamerFormatHelper();
+    char* const *CodecListFromCaps(GstCaps* aCaps);
+    bool HaveElementsToProcessCaps(GstCaps* aCaps);
+    GList* GetFactories();
+
+    static GStreamerFormatHelper* gInstance;
+
+    /* table to convert from container MIME types to GStreamer caps */
+    static char const *const mContainers[6][2];
+
+    /* table to convert from codec MIME types to GStreamer caps */
+    static char const *const mCodecs[9][2];
+
+    /*
+     * True iff we were able to find the proper GStreamer libs and the functions
+     * we need.
+     */
+    static bool sLoadOK;
+
+    /* whitelist of supported container/codec gst caps */
+    GstCaps* mSupportedContainerCaps;
+    GstCaps* mSupportedCodecCaps;
+
+    /* list of GStreamer element factories
+     * Element factories are the basic types retrieved from the GStreamer
+     * registry, they describe all plugins and elements that GStreamer can
+     * create.
+     * This means that element factories are useful for automated element
+     * instancing, such as what autopluggers do,
+     * and for creating lists of available elements. */
+    GList* mFactories;
+
+    /* Storage for the default registrys feature list cookie.
+     * It changes every time a feature is added to or removed from the
+     * GStreamer registry. */
+    uint32_t mCookie;
+};
+
+} //namespace mozilla
+
+#endif