Move logic for calculating needed bitrate overhead used by NACK and FEC to VideoSender.

webrtc/modules/video_coding/protection_bitrate_calculator.h

 /*
  *  Copyright (c) 2016 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.
  */
 
-#ifndef WEBRTC_VIDEO_SEND_DELAY_STATS_H_
-#define WEBRTC_VIDEO_SEND_DELAY_STATS_H_
+#ifndef WEBRTC_MODULES_VIDEO_CODING_PROTECTION_BITRATE_CALCULATOR_H_
+#define WEBRTC_MODULES_VIDEO_CODING_PROTECTION_BITRATE_CALCULATOR_H_
 
-#include <map>
+#include <list>
 #include <memory>
-#include <set>
 
 #include "webrtc/base/criticalsection.h"
-#include "webrtc/base/thread_annotations.h"
-#include "webrtc/common_types.h"
 #include "webrtc/modules/include/module_common_types.h"
+#include "webrtc/modules/video_coding/include/video_coding.h"
+#include "webrtc/modules/video_coding/media_opt_util.h"
 #include "webrtc/system_wrappers/include/clock.h"
-#include "webrtc/video_send_stream.h"
 
 namespace webrtc {
 
-class SendDelayStats : public SendPacketObserver {
+// ProtectionBitrateCalculator calculates how much of the allocated network
+// capacity that can be used by an encoder and how much that
+// is needed for redundant packets such as FEC and NACK. It uses an
+// implementation of |VCMProtectionCallback| to set new FEC parameters and get
+// the bitrate currently used for FEC and NACK.
+// Usage:
+// Setup by calling SetProtectionMethod and SetEncodingData.
+// For each encoded image, call UpdateWithEncodedData.
+// Each time the bandwidth estimate change, call SetTargetRates. SetTargetRates
+// will return the bitrate that can be used by an encoder.
+// A lock is used to protect internal states, so methods can be called on an
+// arbitrary thread.
+class ProtectionBitrateCalculator {
  public:
-  explicit SendDelayStats(Clock* clock);
-  virtual ~SendDelayStats();
+  ProtectionBitrateCalculator(Clock* clock,
+                              VCMProtectionCallback* protection_callback);
+  ~ProtectionBitrateCalculator();
 
-  // Adds the configured ssrcs for the rtp streams.
-  // Stats will be calculated for these streams.
-  void AddSsrcs(const VideoSendStream::Config& config);
+  void SetProtectionMethod(bool enable_fec, bool enable_nack);
 
-  // Called when a packet is sent (leaving socket).
-  bool OnSentPacket(int packet_id, int64_t time_ms);
+  // Informs media optimization of initial encoding state.
+  void SetEncodingData(uint32_t estimated_bitrate_bps,
+                       uint16_t width,
+                       uint16_t height,
+                       uint32_t frame_rate,
+                       size_t num_temporal_layers,
+                       size_t max_payload_size);
 
- protected:
-  // From SendPacketObserver.
-  // Called when a packet is sent to the transport.
-  void OnSendPacket(uint16_t packet_id,
-                    int64_t capture_time_ms,
-                    uint32_t ssrc) override;
+  // Returns target rate for the encoder given the channel parameters.
+  // Inputs:  estimated_bitrate_bps - the estimated network bitrate in bits/s.
+  //          actual_framerate - encoder frame rate.
+  //          fraction_lost - packet loss rate in % in the network.
+  //          round_trip_time_ms - round trip time in milliseconds.
+  uint32_t SetTargetRates(uint32_t estimated_bitrate_bps,
+                          int actual_framerate,
+                          uint8_t fraction_lost,
+                          int64_t round_trip_time_ms);
+
+  // Informs of encoded output.
+  void UpdateWithEncodedData(const EncodedImage& encoded_image);
 
  private:
-  // Map holding sent packets (mapped by sequence number).
-  struct SequenceNumberOlderThan {
-    bool operator()(uint16_t seq1, uint16_t seq2) const {
-      return IsNewerSequenceNumber(seq2, seq1);
-    }
-  };
-  struct Packet {
-    Packet(uint32_t ssrc, int64_t capture_time_ms, int64_t send_time_ms)
-        : ssrc(ssrc),
-          capture_time_ms(capture_time_ms),
-          send_time_ms(send_time_ms) {}
-    uint32_t ssrc;
-    int64_t capture_time_ms;
-    int64_t send_time_ms;
-  };
-  typedef std::map<uint16_t, Packet, SequenceNumberOlderThan> PacketMap;
-
-  class SampleCounter {
-   public:
-    SampleCounter() : sum(0), num_samples(0) {}
-    ~SampleCounter() {}
-    void Add(int sample);
-    int Avg(int min_required_samples) const;
-
-   private:
-    int sum;
-    int num_samples;
-  };
-
-  void UpdateHistograms();
-  void RemoveOld(int64_t now, PacketMap* packets)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
+  struct EncodedFrameSample;
+  enum { kBitrateAverageWinMs = 1000 };
 
   Clock* const clock_;
-  rtc::CriticalSection crit_;
+  VCMProtectionCallback* const protection_callback_;
 
-  PacketMap packets_ GUARDED_BY(crit_);
-  size_t num_old_packets_ GUARDED_BY(crit_);
-  size_t num_skipped_packets_ GUARDED_BY(crit_);
+  rtc::CriticalSection crit_sect_;
+  std::unique_ptr<media_optimization::VCMLossProtectionLogic> loss_prot_logic_
+      GUARDED_BY(crit_sect_);
+  size_t max_payload_size_ GUARDED_BY(crit_sect_);
 
-  std::set<uint32_t> ssrcs_ GUARDED_BY(crit_);
-  std::map<uint32_t, SampleCounter> send_delay_counters_
-      GUARDED_BY(crit_);  // Mapped by SSRC.
+  RTC_DISALLOW_COPY_AND_ASSIGN(ProtectionBitrateCalculator);
 };
 
 }  // namespace webrtc
-#endif  // WEBRTC_VIDEO_SEND_DELAY_STATS_H_
+#endif  // WEBRTC_MODULES_VIDEO_CODING_PROTECTION_BITRATE_CALCULATOR_H_