| // 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. RenderWidgetHostView) 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_ |