Introduce SelectSettings algorithm for MediaStream video tracks.

content/renderer/media/video_track_adapter.h

 // Copyright 2014 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_RENDERER_MEDIA_VIDEO_TRACK_ADAPTER_H_
 #define CONTENT_RENDERER_MEDIA_VIDEO_TRACK_ADAPTER_H_
 
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "content/renderer/media/media_stream_video_track.h"
 #include "media/base/video_frame.h"
 
 namespace content {
 
+struct VideoTrackAdapterSettings {
+  VideoTrackAdapterSettings() = default;
+  VideoTrackAdapterSettings(int max_width,
+                            int max_height,
+                            double min_aspect_ratio,
+                            double max_aspect_ratio,
+                            double max_frame_rate);
+  int max_width;
+  int max_height;
+  double min_aspect_ratio;
+  double max_aspect_ratio;
+  double max_frame_rate;
+};
+
 // VideoTrackAdapter is a helper class used by MediaStreamVideoSource used for
 // adapting the video resolution from a source implementation to the resolution
 // a track requires. Different tracks can have different resolution constraints.
 // The constraints can be set as max width and height as well as max and min
 // aspect ratio.
 // Video frames are delivered to a track using a VideoCaptureDeliverFrameCB on
 // the IO-thread.
 // Adaptations is done by wrapping the original media::VideoFrame in a new
 // media::VideoFrame with a new visible_rect and natural_size.
 class VideoTrackAdapter
     : public base::RefCountedThreadSafe<VideoTrackAdapter> {
  public:
   typedef base::Callback<void(bool mute_state)> OnMutedCallback;
 
   explicit VideoTrackAdapter(
       scoped_refptr<base::SingleThreadTaskRunner> io_task_runner);
 
   // Register |track| to receive video frames in |frame_callback| with
   // a resolution within the boundaries of the arguments.
   // Must be called on the main render thread. |frame_callback| is guaranteed to
   // be released on the main render thread.
   // |source_frame_rate| is used to calculate a prudent interval to check for
   // passing frames and inform of the result via |on_muted_state_callback|.
   void AddTrack(const MediaStreamVideoTrack* track,
                 VideoCaptureDeliverFrameCB frame_callback,
-                int max_width, int max_height,
-                double min_aspect_ratio,
-                double max_aspect_ratio,
-                double max_frame_rate);
+                const VideoTrackAdapterSettings& settings);
   void RemoveTrack(const MediaStreamVideoTrack* track);
 
   // Delivers |frame| to all tracks that have registered a callback.
   // Must be called on the IO-thread.
   void DeliverFrameOnIO(const scoped_refptr<media::VideoFrame>& frame,
                         base::TimeTicks estimated_capture_time);
 
   base::SingleThreadTaskRunner* io_task_runner() const {
     DCHECK(thread_checker_.CalledOnValidThread());
     return io_task_runner_.get();
   }
 
   // Start monitor that frames are delivered to this object. I.E, that
   // |DeliverFrameOnIO| is called with a frame rate of |source_frame_rate|.
   // |on_muted_callback| is triggered on the main render thread.
   void StartFrameMonitoring(double source_frame_rate,
                             const OnMutedCallback& on_muted_callback);
   void StopFrameMonitoring();
 
   static void CalculateTargetSize(const gfx::Size& input_size,
                                   const gfx::Size& max_frame_size,
                                   double min_aspect_ratio,
                                   double max_aspect_ratio,
                                   gfx::Size* desired_size);
 
  private:
   virtual ~VideoTrackAdapter();
   friend class base::RefCountedThreadSafe<VideoTrackAdapter>;
 
-  void AddTrackOnIO(
-      const MediaStreamVideoTrack* track,
-      VideoCaptureDeliverFrameCB frame_callback,
-      const gfx::Size& max_frame_size,
-      double min_aspect_ratio,
-      double max_aspect_ratio,
-      double max_frame_rate);
+  void AddTrackOnIO(const MediaStreamVideoTrack* track,
+                    VideoCaptureDeliverFrameCB frame_callback,
+                    const VideoTrackAdapterSettings& settings);
   void RemoveTrackOnIO(const MediaStreamVideoTrack* track);
 
   void StartFrameMonitoringOnIO(
     const OnMutedCallback& on_muted_state_callback,
     double source_frame_rate);
   void StopFrameMonitoringOnIO();
 
   // Compare |frame_counter_snapshot| with the current |frame_counter_|, and
   // inform of the situation (muted, not muted) via |set_muted_state_callback|.
   void CheckFramesReceivedOnIO(const OnMutedCallback& set_muted_state_callback,
@@ skipping 29 matching lines @@
 
   // Frame rate configured on the video source, accessed on the IO-thread.
   float source_frame_rate_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoTrackAdapter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_VIDEO_TRACK_ADAPTER_H_