remote_bitrate_estimator.h revision 5779ca478dd93193663b25a624749fe31e83de7a 
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
66class RemoteBitrateEstimator : public CallStatsObserver, public Module {
67 public:
68  virtual ~RemoteBitrateEstimator() {}
69
70  // Called for each incoming packet. Updates the incoming payload bitrate
71  // estimate and the over-use detector. If an over-use is detected the
72  // remote bitrate estimate will be updated. Note that |payload_size| is the
73  // packet size excluding headers.
74  // Note that |arrival_time_ms| can be of an arbitrary time base.
75  virtual void IncomingPacket(int64_t arrival_time_ms,
76                              int payload_size,
77                              const RTPHeader& header) = 0;
78
79  // Removes all data for |ssrc|.
80  virtual void RemoveStream(unsigned int ssrc) = 0;
81
82  // Returns true if a valid estimate exists and sets |bitrate_bps| to the
83  // estimated payload bitrate in bits per second. |ssrcs| is the list of ssrcs
84  // currently being received and of which the bitrate estimate is based upon.
85  virtual bool LatestEstimate(std::vector<unsigned int>* ssrcs,
86                              unsigned int* bitrate_bps) const = 0;
87
88  // Returns true if the statistics are available.
89  virtual bool GetStats(ReceiveBandwidthEstimatorStats* output) const = 0;
90
91 protected:
92  static const int kProcessIntervalMs = 1000;
93  static const int kStreamTimeOutMs = 2000;
94};
95
96struct RemoteBitrateEstimatorFactory {
97  RemoteBitrateEstimatorFactory() {}
98  virtual ~RemoteBitrateEstimatorFactory() {}
99
100  virtual RemoteBitrateEstimator* Create(
101      RemoteBitrateObserver* observer,
102      Clock* clock,
103      RateControlType control_type,
104      uint32_t min_bitrate_bps) const;
105};
106
107struct AbsoluteSendTimeRemoteBitrateEstimatorFactory
108    : public RemoteBitrateEstimatorFactory {
109  AbsoluteSendTimeRemoteBitrateEstimatorFactory() {}
110  virtual ~AbsoluteSendTimeRemoteBitrateEstimatorFactory() {}
111
112  virtual RemoteBitrateEstimator* Create(
113      RemoteBitrateObserver* observer,
114      Clock* clock,
115      RateControlType control_type,
116      uint32_t min_bitrate_bps) const;
117};
118}  // namespace webrtc
119
120#endif  // WEBRTC_MODULES_REMOTE_BITRATE_ESTIMATOR_INCLUDE_REMOTE_BITRATE_ESTIMATOR_H_
121