gecko/content/media/VideoFrameContainer.h

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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 "ImageLayers.h"
#include "mozilla/Mutex.h"
#include "mozilla/TimeStamp.h"
#include "nsISupportsImpl.h"
#include "gfxPoint.h"
class nsHTMLMediaElement;
namespace mozilla {
/**
* 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 mozilla::layers::ImageContainer ImageContainer;
typedef mozilla::layers::Image Image;
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(VideoFrameContainer)
VideoFrameContainer(nsHTMLMediaElement* aElement,
already_AddRefed<ImageContainer> aContainer)
: mElement(aElement),
mImageContainer(aContainer), mMutex("nsVideoFrameContainer"),
mIntrinsicSizeChanged(false), mImageSizeChanged(false)
{
NS_ASSERTION(aElement, "aElement must not be null");
NS_ASSERTION(mImageContainer, "aContainer must not be null");
}
// Call on any thread
void SetCurrentFrame(const gfxIntSize& aIntrinsicSize, Image* aImage,
TimeStamp aTargetTime);
// 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
void Invalidate();
ImageContainer* GetImageContainer() { return mImageContainer; }
void ForgetElement() { mElement = nsnull; }
protected:
// Non-addreffed pointer to the element. The element calls ForgetElement
// to clear this reference when the element is destroyed.
nsHTMLMediaElement* 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_ */