Refactor how padding is calculated.

webrtc/call/bitrate_allocator.h

 /*
  *  Copyright (c) 2015 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.
  */
 
@@ skipping 13 matching lines @@
 
 // Used by all send streams with adaptive bitrate, to get the currently
 // allocated bitrate for the send stream. The current network properties are
 // given at the same time, to let the send stream decide about possible loss
 // protection.
 class BitrateAllocatorObserver {
  public:
   virtual void OnBitrateUpdated(uint32_t bitrate_bps,
                                 uint8_t fraction_loss,
                                 int64_t rtt) = 0;
+
+ protected:

[stefan-webrtc, 2016/06/08 09:25:13]

Why is this needed?

   virtual ~BitrateAllocatorObserver() {}
 };
 
 // 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 BitrateAllocatorObserver(s).
 class BitrateAllocator {
  public:
-  BitrateAllocator();
+  // Used to get notified when send stream limits such as the minimum send
+  // bitrate and max padding bitrate is changed.
+  class LimitObserver {
+   public:
+    virtual void OnAllocationLimitsChanged(
+        uint32_t min_send_bitrate_bps,
+        uint32_t max_padding_bitrate_bps) = 0;
+
+   protected:
+    virtual ~LimitObserver() {}
+  };
+
+  explicit BitrateAllocator(LimitObserver* limit_observer);
 
   // Allocate target_bitrate across the registered BitrateAllocatorObservers.
-  // Returns actual bitrate allocated (might be higher than target_bitrate if
-  // for instance EnforceMinBitrate() is enabled.
-  uint32_t OnNetworkChanged(uint32_t target_bitrate,
-                            uint8_t fraction_loss,
-                            int64_t rtt);
+  void OnNetworkChanged(uint32_t target_bitrate,
+                        uint8_t fraction_loss,
+                        int64_t rtt);
 
   // Set the start and max send bitrate used by the bandwidth management.
   //
   // |observer| updates bitrates if already in use.
   // |min_bitrate_bps| = 0 equals no min bitrate.
   // |max_bitrate_bps| = 0 equals no max bitrate.
   // |enforce_min_bitrate| = 'true' will allocate at least |min_bitrate_bps| for
   //    this observer, even if the BWE is too low, 'false' will allocate 0 to
   //    the observer if BWE doesn't allow |min_bitrate_bps|.
   // Returns initial bitrate allocated for |observer|.
   // Note that |observer|->OnBitrateUpdated() will be called within the scope of
   // this method with the current rtt, fraction_loss and available bitrate and
   // that the bitrate in OnBitrateUpdated will be zero if the |observer| is
   // currently not allowed to send data.
   int AddObserver(BitrateAllocatorObserver* observer,
                   uint32_t min_bitrate_bps,
                   uint32_t max_bitrate_bps,
+                  uint32_t pad_up_bitrate_bps,
                   bool enforce_min_bitrate);
 
   void RemoveObserver(BitrateAllocatorObserver* observer);
 
+  // Called by a BitrateAllocatorObserver when it is inactive, ie not producing
+  // encoded frames for one reason or the other.
+  // The observer will still be allocated a target bitrate but padding will
+  // not be sent.
+  void NotifyObserverInactive(BitrateAllocatorObserver* observer,
+                              bool inactive);
+
  private:
   struct ObserverConfig {
     ObserverConfig(BitrateAllocatorObserver* observer,
                    uint32_t min_bitrate_bps,
                    uint32_t max_bitrate_bps,
+                   uint32_t pad_up_bitrate_bps,
                    bool enforce_min_bitrate)
         : observer(observer),
+          active(true),
           min_bitrate_bps(min_bitrate_bps),
           max_bitrate_bps(max_bitrate_bps),
+          pad_up_bitrate_bps(pad_up_bitrate_bps),
           enforce_min_bitrate(enforce_min_bitrate) {}
     BitrateAllocatorObserver* const observer;
+    bool active;
     uint32_t min_bitrate_bps;
     uint32_t max_bitrate_bps;
+    uint32_t pad_up_bitrate_bps;
     bool enforce_min_bitrate;
   };
 
+  // Calculates the minimum requested send bitrate and max padding bitrate and
+  // calls LimitObserver::OnAllocationLimitsChanged.
+  void UpdateAllocationLimits() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
+
   // This method controls the behavior when the available bitrate is lower than
   // the minimum bitrate, or the sum of minimum bitrates.
   // When true, the bitrate will never be set lower than the minimum bitrate(s).
   // When false, the bitrate observers will be allocated rates up to their
   // respective minimum bitrate, satisfying one observer after the other.
   void EnforceMinBitrate(bool enforce_min_bitrate)
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
 
   typedef std::list<ObserverConfig> ObserverConfigList;
   ObserverConfigList::iterator FindObserverConfig(
       const BitrateAllocatorObserver* observer)
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
 
   typedef std::multimap<uint32_t, const ObserverConfig*> ObserverSortingMap;
   typedef std::map<BitrateAllocatorObserver*, int> ObserverAllocation;
 
   ObserverAllocation AllocateBitrates(uint32_t bitrate)
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
   ObserverAllocation NormalRateAllocation(uint32_t bitrate,
                                           uint32_t sum_min_bitrates)
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
 
   ObserverAllocation ZeroRateAllocation() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
   ObserverAllocation LowRateAllocation(uint32_t bitrate)
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
 
+  LimitObserver* const limit_observer_;
+
   rtc::CriticalSection crit_sect_;
   // Stored in a list to keep track of the insertion order.
   ObserverConfigList bitrate_observer_configs_ GUARDED_BY(crit_sect_);
   bool enforce_min_bitrate_ GUARDED_BY(crit_sect_);
   uint32_t last_bitrate_bps_ GUARDED_BY(crit_sect_);
   uint32_t last_non_zero_bitrate_bps_ GUARDED_BY(crit_sect_);
   uint8_t last_fraction_loss_ GUARDED_BY(crit_sect_);
   int64_t last_rtt_ GUARDED_BY(crit_sect_);
 };
 }  // namespace webrtc
 #endif  // WEBRTC_CALL_BITRATE_ALLOCATOR_H_