remote_bitrate_estimator.h revision fb609a1f57ef5aec3382bf28d8309154344d191d 
1/*
2 *  Copyright (c) 2012 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// This class estimates the incoming available bandwidth.
12
13#ifndef WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INCLUDE_REMOTE_BITRATE_ESTIMATOR_H_
14#define WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INCLUDE_REMOTE_BITRATE_ESTIMATOR_H_
15
16#include <map>
17#include <vector>
18
19#include "webrtc/common_types.h"
20#include "webrtc/modules/interface/module.h"
21#include "webrtc/modules/interface/module_common_types.h"
22#include "webrtc/typedefs.h"
23
24namespace webrtc {
25
26class Clock;
27
28enum RateControlType {
29  kMimdControl,
30  kAimdControl
31};
32
33// RemoteBitrateObserver is used to signal changes in bitrate estimates for
34// the incoming streams.
35class RemoteBitrateObserver {
36 public:
37  // Called when a receive channel group has a new bitrate estimate for the
38  // incoming streams.
39  virtual void OnReceiveBitrateChanged(const std::vector<unsigned int>& ssrcs,
40                                       unsigned int bitrate) = 0;
41
42  virtual ~RemoteBitrateObserver() {}
43};
44
45struct ReceiveBandwidthEstimatorStats {
46  ReceiveBandwidthEstimatorStats() : total_propagation_time_delta_ms(0) {}
47
48  // The "propagation_time_delta" of a frame is defined as (d_arrival - d_sent),
49  // where d_arrival is the delta of the arrival times of the frame and the
50  // previous frame, d_sent is the delta of the sent times of the frame and
51  // the previous frame. The sent time is calculated from the RTP timestamp.
52
53  // |total_propagation_time_delta_ms| is the sum of the propagation_time_deltas
54  // of all received frames, except that it's is adjusted to 0 when it becomes
55  // negative.
56  int total_propagation_time_delta_ms;
57  // The propagation_time_deltas for the frames arrived in the last
58  // kProcessIntervalMs using the clock passed to
59  // RemoteBitrateEstimatorFactory::Create.
60  std::vector<int> recent_propagation_time_delta_ms;
61  // The arrival times for the frames arrived in the last kProcessIntervalMs
62  // using the clock passed to RemoteBitrateEstimatorFactory::Create.
63  std::vector<int64_t> recent_arrival_time_ms;
64};
65
66struct PacketInfo {
67  PacketInfo(int64_t arrival_time_ms,
68             int64_t send_time_ms,
69             uint16_t sequence_number,
70             size_t payload_size)
71      : arrival_time_ms(arrival_time_ms),
72        send_time_ms(send_time_ms),
73        sequence_number(sequence_number),
74        payload_size(payload_size) {}
75  // Time corresponding to when the packet was received. Timestamped with the
76  // receiver's clock.
77  int64_t arrival_time_ms;
78  // Time corresponding to when the packet was sent, timestamped with the
79  // sender's clock.
80  int64_t send_time_ms;
81  // Packet identifier, incremented with 1 for every packet generated by the
82  // sender.
83  uint16_t sequence_number;
84  // Size of the packet excluding RTP headers.
85  size_t payload_size;
86};
87
88class RemoteBitrateEstimator : public CallStatsObserver, public Module {
89 public:
90  virtual ~RemoteBitrateEstimator() {}
91
92  virtual void IncomingPacketFeedbackVector(
93      const std::vector<PacketInfo>& packet_feedback_vector) {
94    assert(false);
95  }
96
97  // Called for each incoming packet. Updates the incoming payload bitrate
98  // estimate and the over-use detector. If an over-use is detected the
99  // remote bitrate estimate will be updated. Note that |payload_size| is the
100  // packet size excluding headers.
101  // Note that |arrival_time_ms| can be of an arbitrary time base.
102  virtual void IncomingPacket(int64_t arrival_time_ms,
103                              size_t payload_size,
104                              const RTPHeader& header) = 0;
105
106  // Removes all data for |ssrc|.
107  virtual void RemoveStream(unsigned int ssrc) = 0;
108
109  // Returns true if a valid estimate exists and sets |bitrate_bps| to the
110  // estimated payload bitrate in bits per second. |ssrcs| is the list of ssrcs
111  // currently being received and of which the bitrate estimate is based upon.
112  virtual bool LatestEstimate(std::vector<unsigned int>* ssrcs,
113                              unsigned int* bitrate_bps) const = 0;
114
115  // Returns true if the statistics are available.
116  virtual bool GetStats(ReceiveBandwidthEstimatorStats* output) const = 0;
117
118 protected:
119  static const int64_t kProcessIntervalMs = 1000;
120  static const int64_t kStreamTimeOutMs = 2000;
121};
122
123struct RemoteBitrateEstimatorFactory {
124  RemoteBitrateEstimatorFactory() {}
125  virtual ~RemoteBitrateEstimatorFactory() {}
126
127  virtual RemoteBitrateEstimator* Create(
128      RemoteBitrateObserver* observer,
129      Clock* clock,
130      RateControlType control_type,
131      uint32_t min_bitrate_bps) const;
132};
133
134struct AbsoluteSendTimeRemoteBitrateEstimatorFactory
135    : public RemoteBitrateEstimatorFactory {
136  AbsoluteSendTimeRemoteBitrateEstimatorFactory() {}
137  virtual ~AbsoluteSendTimeRemoteBitrateEstimatorFactory() {}
138
139  virtual RemoteBitrateEstimator* Create(
140      RemoteBitrateObserver* observer,
141      Clock* clock,
142      RateControlType control_type,
143      uint32_t min_bitrate_bps) const;
144};
145}  // namespace webrtc
146
147#endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INCLUDE_REMOTE_BITRATE_ESTIMATOR_H_
148