1 /*
2  *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef WEBRTC_VOICE_ENGINE_NETWORK_PREDICTOR_H_
12 #define WEBRTC_VOICE_ENGINE_NETWORK_PREDICTOR_H_
13 
14 #include "webrtc/base/exp_filter.h"
15 #include "webrtc/system_wrappers/include/clock.h"
16 
17 namespace webrtc {
18 
19 namespace voe {
20 
21 // NetworkPredictor is to predict network conditions e.g., packet loss rate, for
22 // sender and/or receiver to cope with changes in the network condition.
23 class NetworkPredictor {
24  public:
25   explicit NetworkPredictor(Clock* clock);
~NetworkPredictor()26   ~NetworkPredictor() {}
27 
28   // Gets the predicted packet loss rate.
29   uint8_t GetLossRate();
30 
31   // Updates the packet loss rate predictor, on receiving a new observation of
32   // packet loss rate from past. Input packet loss rate should be in the
33   // interval [0, 255].
34   void UpdatePacketLossRate(uint8_t loss_rate);
35 
36  private:
37   Clock* clock_;
38   int64_t last_loss_rate_update_time_ms_;
39 
40   // An exponential filter is used to predict packet loss rate.
41   rtc::scoped_ptr<rtc::ExpFilter> loss_rate_filter_;
42 };
43 
44 }  // namespace voe
45 }  // namespace webrtc
46 #endif  // WEBRTC_VOICE_ENGINE_NETWORK_PREDICTOR_H_
47