NetEq: Replace timescale_holdoff_ with a Countdown timer

webrtc/modules/audio_coding/neteq/decision_logic.h

 /*
  *  Copyright (c) 2013 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_MODULES_AUDIO_CODING_NETEQ_DECISION_LOGIC_H_
 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_DECISION_LOGIC_H_
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/modules/audio_coding/neteq/defines.h"
 #include "webrtc/modules/audio_coding/neteq/include/neteq.h"
+#include "webrtc/modules/audio_coding/neteq/tick_timer.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 // Forward declarations.
 class BufferLevelFilter;
 class DecoderDatabase;
 class DelayManager;
 class Expand;
 class PacketBuffer;
 class SyncBuffer;
 struct RTPHeader;
 
 // This is the base class for the decision tree implementations. Derived classes
 // must implement the method GetDecisionSpecialized().
 class DecisionLogic {
  public:
   // Static factory function which creates different types of objects depending
   // on the |playout_mode|.
   static DecisionLogic* Create(int fs_hz,
                                size_t output_size_samples,
                                NetEqPlayoutMode playout_mode,
                                DecoderDatabase* decoder_database,
                                const PacketBuffer& packet_buffer,
                                DelayManager* delay_manager,
-                               BufferLevelFilter* buffer_level_filter);
+                               BufferLevelFilter* buffer_level_filter,
+                               const TickTimer* tick_timer);
 
   // Constructor.
   DecisionLogic(int fs_hz,
                 size_t output_size_samples,
                 NetEqPlayoutMode playout_mode,
                 DecoderDatabase* decoder_database,
                 const PacketBuffer& packet_buffer,
                 DelayManager* delay_manager,
-                BufferLevelFilter* buffer_level_filter);
+                BufferLevelFilter* buffer_level_filter,
+                const TickTimer* tick_timer);
 
-  // Destructor.
-  virtual ~DecisionLogic() {}
+  virtual ~DecisionLogic();
 
   // Resets object to a clean state.
   void Reset();
 
   // Resets parts of the state. Typically done when switching codecs.
   void SoftReset();
 
   // Sets the sample rate and the output block size.
   void SetSampleRate(int fs_hz, size_t output_size_samples);
 
@@ skipping 39 matching lines @@
   void set_sample_memory(int32_t value) { sample_memory_ = value; }
   size_t noise_fast_forward() const { return noise_fast_forward_; }
   size_t packet_length_samples() const { return packet_length_samples_; }
   void set_packet_length_samples(size_t value) {
     packet_length_samples_ = value;
   }
   void set_prev_time_scale(bool value) { prev_time_scale_ = value; }
   NetEqPlayoutMode playout_mode() const { return playout_mode_; }
 
  protected:
-  // The value 6 sets maximum time-stretch rate to about 100 ms/s.
-  static const int kMinTimescaleInterval = 6;
+  // The value 5 sets maximum time-stretch rate to about 100 ms/s.
+  static const int kMinTimescaleInterval = 5;

[hlundin-webrtc, 2016/05/03 19:09:10]

The change from 6 to 5 is motivated by the fact that the TickTimer is
incremented before the Countdown timer timescale_countdown_ is checked, while in
the old code the timescale_hold_off_ value was decreased after checking it.

 
   enum CngState {
     kCngOff,
     kCngRfc3389On,
     kCngInternalOn
   };
 
   // Returns the operation that should be done next. |sync_buffer| and |expand|
   // are provided for reference. |decoder_frame_length| is the number of samples
   // obtained from the last decoded frame. If there is a packet available, the
@@ skipping 14 matching lines @@
                                             size_t generated_noise_samples) = 0;
 
   // Updates the |buffer_level_filter_| with the current buffer level
   // |buffer_size_packets|.
   void FilterBufferLevel(size_t buffer_size_packets, Modes prev_mode);
 
   DecoderDatabase* decoder_database_;
   const PacketBuffer& packet_buffer_;
   DelayManager* delay_manager_;
   BufferLevelFilter* buffer_level_filter_;
+  const TickTimer* tick_timer_;
   int fs_mult_;
   size_t output_size_samples_;
   CngState cng_state_;  // Remember if comfort noise is interrupted by other
                         // event (e.g., DTMF).
   size_t noise_fast_forward_ = 0;
   size_t packet_length_samples_;
   int sample_memory_;
   bool prev_time_scale_;
-  int timescale_hold_off_;
+  std::unique_ptr<TickTimer::Countdown> timescale_countdown_;
   int num_consecutive_expands_;
   const NetEqPlayoutMode playout_mode_;
 
  private:
   RTC_DISALLOW_COPY_AND_ASSIGN(DecisionLogic);
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_DECISION_LOGIC_H_