media/filters/video_frame_scheduler_proxy.h

   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_FILTERS_VIDEO_FRAME_SCHEDULER_PROXY_H_
   6 #define MEDIA_FILTERS_VIDEO_FRAME_SCHEDULER_PROXY_H_
   7
   8 #include "base/memory/weak_ptr.h"
   9 #include "media/filters/video_frame_scheduler.h"
  10
  11 namespace base {
  12 class SingleThreadTaskRunner;
  13 }
  14
  15 namespace media {
  16
  17 // Provides a thread-safe proxy for a VideoFrameScheduler. Typical use is to
  18 // use a real VideoFrameScheduler on the task runner responsible for graphics
  19 // display and provide a proxy on the task runner responsible for background
  20 // video decoding.
  21 class MEDIA_EXPORT VideoFrameSchedulerProxy : public VideoFrameScheduler {
  22  public:
  23   // |task_runner| is the runner that this object will be called on.
  24   // |scheduler_runner| is the runner that |scheduler| will be called on.
  25   // |scheduler| will be deleted on |scheduler_runner|.
  26   VideoFrameSchedulerProxy(
  27       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
  28       const scoped_refptr<base::SingleThreadTaskRunner>& scheduler_runner,
  29       scoped_ptr<VideoFrameScheduler> scheduler);
  30   virtual ~VideoFrameSchedulerProxy();
  31
  32   // VideoFrameScheduler implementation.
  33   virtual void ScheduleVideoFrame(const scoped_refptr<VideoFrame>& frame,
  34                                   base::TimeTicks wall_ticks,
  35                                   const DoneCB& done_cb) override;
  36   virtual void Reset() override;
  37
  38  private:
  39   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
  40   scoped_refptr<base::SingleThreadTaskRunner> scheduler_runner_;
  41   scoped_ptr<VideoFrameScheduler> scheduler_;
  42
  43   // NOTE: Weak pointers must be invalidated before all other member variables.
  44   base::WeakPtrFactory<VideoFrameSchedulerProxy> weak_factory_;
  45
  46   DISALLOW_COPY_AND_ASSIGN(VideoFrameSchedulerProxy);
  47 };
  48
  49 }  // namespace media
  50
  51 #endif  // MEDIA_FILTERS_VIDEO_FRAME_SCHEDULER_PROXY_H_