bitrate_controller.h revision 29dd0de5b35f757289895b7af7c9c5905878270f 
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 *  Usage: this class will register multiple RtcpBitrateObserver's one at each
11 *  RTCP module. It will aggregate the results and run one bandwidth estimation
12 *  and push the result to the encoders via BitrateObserver(s).
13 */
14
15#ifndef WEBRTC_MODULES_BITRATE_CONTROLLER_INCLUDE_BITRATE_CONTROLLER_H_
16#define WEBRTC_MODULES_BITRATE_CONTROLLER_INCLUDE_BITRATE_CONTROLLER_H_
17
18#include "webrtc/modules/rtp_rtcp/interface/rtp_rtcp_defines.h"
19
20namespace webrtc {
21
22class BitrateObserver {
23 /*
24  * Observer class for the encoders, each encoder should implement this class
25  * to get the target bitrate. It also get the fraction loss and rtt to
26  * optimize its settings for this type of network. |target_bitrate| is the
27  * target media/payload bitrate excluding packet headers, measured in bits
28  * per second.
29  */
30 public:
31  virtual void OnNetworkChanged(const uint32_t target_bitrate,
32                                const uint8_t fraction_loss,  // 0 - 255.
33                                const uint32_t rtt) = 0;
34
35  virtual ~BitrateObserver() {}
36};
37
38class BitrateController {
39/*
40 * This class collects feedback from all streams sent to a peer (via
41 * RTCPBandwidthObservers). It does one  aggregated send side bandwidth
42 * estimation and divide the available bitrate between all its registered
43 * BitrateObservers.
44 */
45 public:
46  // The argument |enforce_min_bitrate| controls the behavior when the available
47  // bitrate is lower than the minimum bitrate, or the sum of minimum bitrates.
48  // When true, the bitrate will never be set lower than the minimum bitrate(s).
49  // When false, the bitrate observers will be allocated rates up to their
50  // respective minimum bitrate, satisfying one observer after the other.
51  static BitrateController* CreateBitrateController(bool enforce_min_bitrate);
52  virtual ~BitrateController() {}
53
54  virtual RtcpBandwidthObserver* CreateRtcpBandwidthObserver() = 0;
55
56  // Gets the available payload bandwidth in bits per second. Note that
57  // this bandwidth excludes packet headers.
58  virtual bool AvailableBandwidth(uint32_t* bandwidth) const = 0;
59
60  /*
61  *  Set the start and max send bitrate used by the bandwidth management.
62  *
63  *  observer, updates bitrates if already in use.
64  *  min_bitrate_kbit = 0 equals no min bitrate.
65  *  max_bitrate_kit = 0 equals no max bitrate.
66  */
67  virtual void SetBitrateObserver(BitrateObserver* observer,
68                                  const uint32_t start_bitrate,
69                                  const uint32_t min_bitrate,
70                                  const uint32_t max_bitrate) = 0;
71
72  virtual void RemoveBitrateObserver(BitrateObserver* observer) = 0;
73};
74}  // namespace webrtc
75#endif  // WEBRTC_MODULES_BITRATE_CONTROLLER_INCLUDE_BITRATE_CONTROLLER_H_
76