Add framerate to VideoSinkWants and ability to signal on overuse

webrtc/video_send_stream.h

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 196 matching lines @@
 
   // Starts stream activity.
   // When a stream is active, it can receive, process and deliver packets.
   virtual void Start() = 0;
   // Stops stream activity.
   // When a stream is stopped, it can't receive, process or deliver packets.
   virtual void Stop() = 0;
 
   // Based on the spec in
   // https://w3c.github.io/webrtc-pc/#idl-def-rtcdegradationpreference.
-  enum class DegradationPreference {
-    kMaintainResolution,
+  enum class DegradationPreference : size_t {
+    kMaintainResolution = 0,
     // TODO(perkj): Implement kMaintainFrameRate. kBalanced will drop frames
     // if the encoder overshoots or the encoder can not encode fast enough.
-    kBalanced,
+    kBalanced = 1,
   };
+  static const size_t kNumDegradationPreferences =
+      static_cast<size_t>(DegradationPreference::kBalanced) + 1;
+
   virtual void SetSource(
       rtc::VideoSourceInterface<webrtc::VideoFrame>* source,
       const DegradationPreference& degradation_preference) = 0;
 
   // Set which streams to send. Must have at least as many SSRCs as configured
   // in the config. Encoder settings are passed on to the encoder instance along
   // with the VideoStream settings.
   virtual void ReconfigureVideoEncoder(VideoEncoderConfig config) = 0;
 
   virtual Stats GetStats() = 0;
@@ skipping 14 matching lines @@
     EnableEncodedFrameRecording(std::vector<rtc::PlatformFile>(), 0);
   }
 
  protected:
   virtual ~VideoSendStream() {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_SEND_STREAM_H_