// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef CONTENT_PORT_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_ #define CONTENT_PORT_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_ #include "base/callback.h" #include "base/time/time.h" namespace gfx { class Rect; class Size; } // namespace gfx namespace media { class VideoFrame; } // namespace media namespace content { // Defines an interface for listening to events of frame presentation and to // instruct the platform layer (i.e. RenderWidgetHostViewPort) to copy a frame. // // Further processing is possible (e.g. scale and color space conversion) // through this interface. See ShouldCaptureFrame() for details. // // It is platform dependent which thread this object lives on, but it is // guaranteed to be used on a single thread. class RenderWidgetHostViewFrameSubscriber { public: virtual ~RenderWidgetHostViewFrameSubscriber() {} // Called when a captured frame is available or the frame is no longer // needed by the platform layer. // // If |frame_captured| is true then frame provided contains valid content and // |timestamp| is the time when the frame was painted. // // If |frame_captured| is false then the content in frame provided is // invalid. There was an error during the process of frame capture or the // platform layer is shutting down. |timestamp| is also invalid in this case. typedef base::Callback<void(base::TimeTicks /* timestamp */, bool /* frame_captured */)> DeliverFrameCallback; // Called when a new frame is going to be presented at time // |present_time|. Implementation can decide whether the current frame should // be captured or not. // // Return true if the current frame should be captured. If so, |storage| // should will be set to hold an appropriately sized and allocated buffer // into which to copy the frame. The platform presenter will perform scaling // and color space conversion to fit into the output frame. // // Destination format is determined by |storage|, currently only // media::VideoFrame::YV12 is supported. Platform layer will perform color // space conversion if needed. // // When the frame is available |callback| will be called. It is up to the // platform layer to decide when to deliver a captured frame. // // Return false if the current frame should not be captured. virtual bool ShouldCaptureFrame(base::TimeTicks present_time, scoped_refptr<media::VideoFrame>* storage, DeliverFrameCallback* callback) = 0; }; } // namespace content #endif // CONTENT_PORT_BROWSER_RENDER_WIDGET_HOST_VIEW_FRAME_SUBSCRIBER_H_