Adding a first simple version of overuse detection, but not hooked up.

BUG=
R=asapersson@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1717004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4268 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/video_engine/overuse_frame_detector.h

@@ -0,0 +1,73 @@
+/*
+ *  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.
+ */
+
+#ifndef WEBRTC_VIDEO_ENGINE_OVERUSE_FRAME_DETECTOR_H_
+#define WEBRTC_VIDEO_ENGINE_OVERUSE_FRAME_DETECTOR_H_
+
+#include <list>
+
+#include "webrtc/modules/interface/module.h"
+#include "webrtc/system_wrappers/interface/constructor_magic.h"
+#include "webrtc/system_wrappers/interface/scoped_ptr.h"
+
+namespace webrtc {
+
+class Clock;
+class CriticalSectionWrapper;
+
+class OveruseObserver {
+ public:
+  // Called when an overuse has been detected, based on the number of calls to
+  // 'CapturedFrame' and 'EncodedFrame'.
+  virtual void OveruseDetected() = 0;
+  virtual ~OveruseObserver() {}
+};
+
+// Use to detect system overuse based on the number of captured frames vs. the
+// number of encoded frames.
+class OveruseFrameDetector : public Module {
+ public:
+  OveruseFrameDetector(Clock* clock, OveruseObserver* observer);
+  ~OveruseFrameDetector();
+
+  // Called for each new captured frame.
+  void CapturedFrame();
+
+  // Called for every encoded frame.
+  void EncodedFrame();
+
+  // Implements Module.
+  virtual int32_t TimeUntilNextProcess();
+  virtual int32_t Process();
+
+ private:
+  void CleanOldSamples();
+
+  // Protecting all members.
+  scoped_ptr<CriticalSectionWrapper> crit_;
+
+  // Observer getting overuse reports.
+  OveruseObserver* observer_;
+
+  Clock* clock_;
+  int64_t last_process_time_;
+
+  // Capture time for frames.
+  std::list<int64_t> capture_times_;
+
+  // Start encode time for a frame.
+  std::list<int64_t> encode_times_;
+
+  DISALLOW_COPY_AND_ASSIGN(OveruseFrameDetector);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_VIDEO_ENGINE_OVERUSE_FRAME_DETECTOR_H_