1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_ 6 #define MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_ 7 8 #include "base/callback.h" 9 #include "base/memory/ref_counted.h" 10 #include "cc/layers/video_frame_provider.h" 11 #include "media/base/media_export.h" 12 #include "ui/gfx/size.h" 13 14 namespace media { 15 class VideoFrame; 16 17 // VideoFrameCompositor handles incoming frames by notifying the compositor and 18 // dispatching callbacks when detecting changes in video frames. 19 // 20 // Typical usage is to deliver ready-to-be-displayed video frames to 21 // UpdateCurrentFrame() so that VideoFrameCompositor can take care of tracking 22 // changes in video frames and firing callbacks as needed. 23 // 24 // VideoFrameCompositor must live on the same thread as the compositor. 25 class MEDIA_EXPORT VideoFrameCompositor NON_EXPORTED_BASE(public cc::VideoFrameProvider)26 : NON_EXPORTED_BASE(public cc::VideoFrameProvider) { 27 public: 28 // |natural_size_changed_cb| is run with the new natural size of the video 29 // frame whenever a change in natural size is detected. It is not called the 30 // first time UpdateCurrentFrame() is called. Run on the same thread as the 31 // caller of UpdateCurrentFrame(). 32 // 33 // |opacity_changed_cb| is run when a change in opacity is detected. It *is* 34 // called the first time UpdateCurrentFrame() is called. Run on the same 35 // thread as the caller of UpdateCurrentFrame(). 36 // 37 // TODO(scherkus): Investigate the inconsistency between the callbacks with 38 // respect to why we don't call |natural_size_changed_cb| on the first frame. 39 // I suspect it was for historical reasons that no longer make sense. 40 VideoFrameCompositor( 41 const base::Callback<void(gfx::Size)>& natural_size_changed_cb, 42 const base::Callback<void(bool)>& opacity_changed_cb); 43 virtual ~VideoFrameCompositor(); 44 45 // cc::VideoFrameProvider implementation. 46 virtual void SetVideoFrameProviderClient( 47 cc::VideoFrameProvider::Client* client) OVERRIDE; 48 virtual scoped_refptr<VideoFrame> GetCurrentFrame() OVERRIDE; 49 virtual void PutCurrentFrame( 50 const scoped_refptr<VideoFrame>& frame) OVERRIDE; 51 52 // Updates the current frame and notifies the compositor. 53 void UpdateCurrentFrame(const scoped_refptr<VideoFrame>& frame); 54 55 private: 56 base::Callback<void(gfx::Size)> natural_size_changed_cb_; 57 base::Callback<void(bool)> opacity_changed_cb_; 58 59 cc::VideoFrameProvider::Client* client_; 60 61 scoped_refptr<VideoFrame> current_frame_; 62 63 DISALLOW_COPY_AND_ASSIGN(VideoFrameCompositor); 64 }; 65 66 } // namespace media 67 68 #endif // MEDIA_BLINK_VIDEO_FRAME_COMPOSITOR_H_ 69