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_MODULES_PACING_BITRATE_PROBER_H_ 12 #define WEBRTC_MODULES_PACING_BITRATE_PROBER_H_ 13 14 #include <cstddef> 15 #include <list> 16 17 #include "webrtc/typedefs.h" 18 19 namespace webrtc { 20 21 // Note that this class isn't thread-safe by itself and therefore relies 22 // on being protected by the caller. 23 class BitrateProber { 24 public: 25 BitrateProber(); 26 27 void SetEnabled(bool enable); 28 29 // Returns true if the prober is in a probing session, i.e., it currently 30 // wants packets to be sent out according to the time returned by 31 // TimeUntilNextProbe(). 32 bool IsProbing() const; 33 34 // Initializes a new probing session if the prober is allowed to probe. 35 void MaybeInitializeProbe(int bitrate_bps); 36 37 // Returns the number of milliseconds until the next packet should be sent to 38 // get accurate probing. 39 int TimeUntilNextProbe(int64_t now_ms); 40 41 // Returns the number of bytes that the prober recommends for the next probe 42 // packet. 43 size_t RecommendedPacketSize() const; 44 45 // Called to report to the prober that a packet has been sent, which helps the 46 // prober know when to move to the next packet in a probe. 47 void PacketSent(int64_t now_ms, size_t packet_size); 48 49 private: 50 enum ProbingState { kDisabled, kAllowedToProbe, kProbing, kWait }; 51 52 ProbingState probing_state_; 53 // Probe bitrate per packet. These are used to compute the delta relative to 54 // the previous probe packet based on the size and time when that packet was 55 // sent. 56 std::list<int> probe_bitrates_; 57 size_t packet_size_last_send_; 58 int64_t time_last_send_ms_; 59 }; 60 } // namespace webrtc 61 #endif // WEBRTC_MODULES_PACING_BITRATE_PROBER_H_ 62