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 /* -*- 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(WMFDecoder_h_)

 #define WMFDecoder_h_

 #include "MediaDecoder.h"

 namespace mozilla {

 // Decoder that uses Windows Media Foundation to playback H.264/AAC in MP4

 // and M4A files, and MP3 files if the DirectShow backend is disabled.

 // Playback is strictly limited to only those codecs.

 class WMFDecoder : public MediaDecoder

 {

 public:

   virtual MediaDecoder* Clone() {

     if (!IsWMFEnabled()) {

       return nullptr;

     }

     return new WMFDecoder();

   }

   virtual MediaDecoderStateMachine* CreateStateMachine();

   // Loads the DLLs required by Windows Media Foundation. If this returns

   // failure, you can assume that WMF is not available on the user's system.

   static nsresult LoadDLLs();

   static void UnloadDLLs();

   // Returns true if the WMF backend is preffed on, and we're running on a

   // version of Windows which is likely to support WMF.

   static bool IsEnabled();

   // Returns true if MP3 decoding is enabled on this system. We block

   // MP3 playback on Windows 7 SP0, since it's crashy on that platform.

   static bool IsMP3Supported();

   // Returns the HTMLMediaElement.canPlayType() result for the mime type

   // and codecs parameter. aCodecs can be empty.

   static bool CanPlayType(const nsACString& aType,

                           const nsAString& aCodecs);

 };

 } // namespace mozilla

 #endif