text: /*
   *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   *
   *  Usage: this class will register multiple RtcpBitrateObserver's one at each
   *  RTCP module. It will aggregate the results and run one bandwidth estimation
   *  and push the result to the encoders via BitrateObserver(s).
   */
  
  #ifndef WEBRTC_MODULES_BITRATE_CONTROLLER_INCLUDE_BITRATE_CONTROLLER_H_
  #define WEBRTC_MODULES_BITRATE_CONTROLLER_INCLUDE_BITRATE_CONTROLLER_H_
  
  #include <map>
  
  #include "webrtc/modules/include/module.h"
  #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
  
  namespace webrtc {
  
  class CriticalSectionWrapper;
  class RtcEventLog;
  struct PacketInfo;
  
  class BitrateObserver {
    // Observer class for bitrate changes announced due to change in bandwidth
    // estimate or due to bitrate allocation changes. Fraction loss and rtt is
    // also part of this callback to allow the obsevrer to optimize its settings
    // for different types of network environments. The bitrate does not include
    // packet headers and is measured in bits per second.
   public:
    virtual void OnNetworkChanged(uint32_t bitrate_bps,
                                  uint8_t fraction_loss,  // 0 - 255.
                                  int64_t rtt_ms) = 0;
  
    virtual ~BitrateObserver() {}
  };
  
  class BitrateController : public Module {
    // This class collects feedback from all streams sent to a peer (via
    // RTCPBandwidthObservers). It does one  aggregated send side bandwidth
    // estimation and divide the available bitrate between all its registered
    // BitrateObservers.
   public:
    static const int kDefaultStartBitrateKbps = 300;
  
    static BitrateController* CreateBitrateController(Clock* clock,
                                                      BitrateObserver* observer);
    virtual ~BitrateController() {}
  
    virtual RtcpBandwidthObserver* CreateRtcpBandwidthObserver() = 0;
  
    virtual void SetStartBitrate(int start_bitrate_bps) = 0;
    virtual void SetMinMaxBitrate(int min_bitrate_bps, int max_bitrate_bps) = 0;
  
    virtual void SetEventLog(RtcEventLog* event_log) = 0;
  
    // Gets the available payload bandwidth in bits per second. Note that
    // this bandwidth excludes packet headers.
    virtual bool AvailableBandwidth(uint32_t* bandwidth) const = 0;
  
    virtual void SetReservedBitrate(uint32_t reserved_bitrate_bps) = 0;
  };
  }  // namespace webrtc
  #endif  // WEBRTC_MODULES_BITRATE_CONTROLLER_INCLUDE_BITRATE_CONTROLLER_H_
  