/* -*- 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 "ImageContainer.h"

#include "MediaSegment.h"

#include "MediaStreamVideoSink.h"

#include "VideoSegment.h"

namespace mozilla {

class MediaDecoderOwner;

/**

 * 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 MediaStreamVideoSink {

  virtual ~VideoFrameContainer();

public:

  typedef layers::ImageContainer ImageContainer;

  typedef layers::Image Image;

  VideoFrameContainer(MediaDecoderOwner* aOwner,

                      already_AddRefed<ImageContainer> aContainer);

  // Call on any thread

  virtual void SetCurrentFrames(const VideoSegment& aSegment) override;

  virtual void ClearFrames() override;

  void SetCurrentFrame(const gfx::IntSize& aIntrinsicSize, Image* aImage,

                       const TimeStamp& aTargetTime);

  // Returns the last principalHandle we notified mElement about.

  PrincipalHandle GetLastPrincipalHandle();

  PrincipalHandle GetLastPrincipalHandleLocked();

  // We will notify mElement that aPrincipalHandle has been applied when all

  // FrameIDs prior to aFrameID have been flushed out.

  // aFrameID is ignored if aPrincipalHandle already is our pending principalHandle.

  void UpdatePrincipalHandleForFrameID(const PrincipalHandle& aPrincipalHandle,

                                       const ImageContainer::FrameID& aFrameID);

  void UpdatePrincipalHandleForFrameIDLocked(const PrincipalHandle& aPrincipalHandle,

                                             const ImageContainer::FrameID& aFrameID);

  void SetCurrentFrames(const gfx::IntSize& aIntrinsicSize,

                        const nsTArray<ImageContainer::NonOwningImage>& aImages);

  void ClearCurrentFrame(const gfx::IntSize& aIntrinsicSize)

  {

    SetCurrentFrames(aIntrinsicSize, nsTArray<ImageContainer::NonOwningImage>());

  }

  VideoFrameContainer* AsVideoFrameContainer() override { return this; }

  void ClearCurrentFrame();

  // Make the current frame the only frame in the container, i.e. discard

  // all future frames.

  void ClearFutureFrames();

  // 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();

  // Clear any resources that are not immediately necessary.

  void ClearCachedResources();

  // Returns a new frame ID for SetCurrentFrames().  The client must either

  // call this on only one thread or provide barriers.  Do not use together

  // with SetCurrentFrame().

  ImageContainer::FrameID NewFrameID()

  {

    return ++mFrameID;

  }

  // Call on main thread

  enum {

    INVALIDATE_DEFAULT,

    INVALIDATE_FORCE

  };

  void Invalidate() override { InvalidateWithFlags(INVALIDATE_DEFAULT); }

  void InvalidateWithFlags(uint32_t aFlags);

  ImageContainer* GetImageContainer();

  void ForgetElement() { mOwner = nullptr; }

  uint32_t GetDroppedImageCount() { return mImageContainer->GetDroppedImageCount(); }

protected:

  void SetCurrentFramesLocked(const gfx::IntSize& aIntrinsicSize,

                              const nsTArray<ImageContainer::NonOwningImage>& aImages);

  // Non-addreffed pointer to the owner. The ownenr calls ForgetElement

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

  MediaDecoderOwner* mOwner;

  RefPtr<ImageContainer> mImageContainer;

  struct

  {

    // 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 = false;

    // The main thread mirror of the member of the same name below.

    gfx::IntSize mIntrinsicSize;

    // 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 = false;

  } mMainThreadState;

  // mMutex protects all the fields below.

  Mutex mMutex;

  // Once the frame is forced to black, we initialize mBlackImage for following

  // frames.

  RefPtr<Image> mBlackImage;

  // 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.

  gfx::IntSize mIntrinsicSize;

  // We maintain our own mFrameID which is auto-incremented at every

  // SetCurrentFrame() or NewFrameID() call.

  ImageContainer::FrameID mFrameID;

  // We record the last played video frame to avoid playing the frame again

  // with a different frame id.

  VideoFrame mLastPlayedVideoFrame;

  // The last PrincipalHandle we notified mElement about.

  PrincipalHandle mLastPrincipalHandle;

  // The PrincipalHandle the client has notified us is changing with FrameID

  // mFrameIDForPendingPrincipalHandle.

  PrincipalHandle mPendingPrincipalHandle;

  // The FrameID for which mPendingPrincipal is first valid.

  ImageContainer::FrameID mFrameIDForPendingPrincipalHandle;

  const RefPtr<AbstractThread> mMainThread;

};

} // namespace mozilla

#endif /* VIDEOFRAMECONTAINER_H_ */