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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/. */

 #ifndef VIDEOFRAMECONTAINER_H_

 #define VIDEOFRAMECONTAINER_H_

 #include "mozilla/Mutex.h"

 #include "mozilla/TimeStamp.h"

 #include "gfxPoint.h"

 #include "nsCOMPtr.h"

 #include "nsAutoPtr.h"

 namespace mozilla {

 namespace dom {

 class HTMLMediaElement;

 }

 namespace layers {

 class Image;

 class ImageContainer;

 }

 /**

  * This object is used in the decoder backend threads and the main thread

  * to manage the "current video frame" state. This state includes timing data

  * and an intrinsic size (see below).

  * This has to be a thread-safe object since it's accessed by resource decoders

  * and other off-main-thread components. So we can't put this state in the media

  * element itself ... well, maybe we could, but it could be risky and/or

  * confusing.

  */

 class VideoFrameContainer {

 public:

   typedef layers::ImageContainer ImageContainer;

   typedef layers::Image Image;

   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(VideoFrameContainer)

   VideoFrameContainer(dom::HTMLMediaElement* aElement,

                       already_AddRefed<ImageContainer> aContainer);

   ~VideoFrameContainer();

   // Call on any thread

   void SetCurrentFrame(const gfxIntSize& aIntrinsicSize, Image* aImage,

                        TimeStamp aTargetTime);

   void ClearCurrentFrame(bool aResetSize = false);

   // Reset the VideoFrameContainer

   void Reset();

   // Time in seconds by which the last painted video frame was late by.

   // E.g. if the last painted frame should have been painted at time t,

   // but was actually painted at t+n, this returns n in seconds. Threadsafe.

   double GetFrameDelay();

   // Call on main thread

   enum {

     INVALIDATE_DEFAULT,

     INVALIDATE_FORCE

   };

   void Invalidate() { InvalidateWithFlags(INVALIDATE_DEFAULT); }

   void InvalidateWithFlags(uint32_t aFlags);

   ImageContainer* GetImageContainer();

   void ForgetElement() { mElement = nullptr; }

 protected:

   // Non-addreffed pointer to the element. The element calls ForgetElement

   // to clear this reference when the element is destroyed.

   dom::HTMLMediaElement* mElement;

   nsRefPtr<ImageContainer> mImageContainer;

   // mMutex protects all the fields below.

   Mutex mMutex;

   // The intrinsic size is the ideal size which we should render the

   // ImageContainer's current Image at.

   // This can differ from the Image's actual size when the media resource

   // specifies that the Image should be stretched to have the correct aspect

   // ratio.

   gfxIntSize mIntrinsicSize;

   // The time at which the current video frame should have been painted.

   // Access protected by mVideoUpdateLock.

   TimeStamp mPaintTarget;

   // The delay between the last video frame being presented and it being

   // painted. This is time elapsed after mPaintTarget until the most recently

   // painted frame appeared on screen.

   TimeDuration mPaintDelay;

   // True when the intrinsic size has been changed by SetCurrentFrame() since

   // the last call to Invalidate().

   // The next call to Invalidate() will recalculate

   // and update the intrinsic size on the element, request a frame reflow and

   // then reset this flag.

   bool mIntrinsicSizeChanged;

   // True when the Image size has changed since the last time Invalidate() was

   // called. When set, the next call to Invalidate() will ensure that the

   // frame is fully invalidated instead of just invalidating for the image change

   // in the ImageLayer.

   bool mImageSizeChanged;

 };

 }

 #endif /* VIDEOFRAMECONTAINER_H_ */