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      1 /*
      2  *  Copyright (c) 2013 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 
     11 #ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_DECISION_LOGIC_NORMAL_H_
     12 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_DECISION_LOGIC_NORMAL_H_
     13 
     14 #include "webrtc/base/constructormagic.h"
     15 #include "webrtc/modules/audio_coding/neteq/decision_logic.h"
     16 #include "webrtc/typedefs.h"
     17 
     18 namespace webrtc {
     19 
     20 // Implementation of the DecisionLogic class for playout modes kPlayoutOn and
     21 // kPlayoutStreaming.
     22 class DecisionLogicNormal : public DecisionLogic {
     23  public:
     24   // Constructor.
     25   DecisionLogicNormal(int fs_hz,
     26                       size_t output_size_samples,
     27                       NetEqPlayoutMode playout_mode,
     28                       DecoderDatabase* decoder_database,
     29                       const PacketBuffer& packet_buffer,
     30                       DelayManager* delay_manager,
     31                       BufferLevelFilter* buffer_level_filter)
     32       : DecisionLogic(fs_hz, output_size_samples, playout_mode,
     33                       decoder_database, packet_buffer, delay_manager,
     34                       buffer_level_filter) {
     35   }
     36 
     37  protected:
     38   static const int kAllowMergeWithoutExpandMs = 20;  // 20 ms.
     39   static const int kReinitAfterExpands = 100;
     40   static const int kMaxWaitForPacket = 10;
     41 
     42   // Returns the operation that should be done next. |sync_buffer| and |expand|
     43   // are provided for reference. |decoder_frame_length| is the number of samples
     44   // obtained from the last decoded frame. If there is a packet available, the
     45   // packet header should be supplied in |packet_header|; otherwise it should
     46   // be NULL. The mode resulting form the last call to NetEqImpl::GetAudio is
     47   // supplied in |prev_mode|. If there is a DTMF event to play, |play_dtmf|
     48   // should be set to true. The output variable |reset_decoder| will be set to
     49   // true if a reset is required; otherwise it is left unchanged (i.e., it can
     50   // remain true if it was true before the call).
     51   Operations GetDecisionSpecialized(const SyncBuffer& sync_buffer,
     52                                     const Expand& expand,
     53                                     size_t decoder_frame_length,
     54                                     const RTPHeader* packet_header,
     55                                     Modes prev_mode,
     56                                     bool play_dtmf,
     57                                     bool* reset_decoder) override;
     58 
     59   // Returns the operation to do given that the expected packet is not
     60   // available, but a packet further into the future is at hand.
     61   virtual Operations FuturePacketAvailable(
     62       const SyncBuffer& sync_buffer,
     63       const Expand& expand,
     64       size_t decoder_frame_length,
     65       Modes prev_mode,
     66       uint32_t target_timestamp,
     67       uint32_t available_timestamp,
     68       bool play_dtmf);
     69 
     70   // Returns the operation to do given that the expected packet is available.
     71   virtual Operations ExpectedPacketAvailable(Modes prev_mode, bool play_dtmf);
     72 
     73   // Returns the operation given that no packets are available (except maybe
     74   // a DTMF event, flagged by setting |play_dtmf| true).
     75   virtual Operations NoPacket(bool play_dtmf);
     76 
     77  private:
     78   // Returns the operation given that the next available packet is a comfort
     79   // noise payload (RFC 3389 only, not codec-internal).
     80   Operations CngOperation(Modes prev_mode, uint32_t target_timestamp,
     81                           uint32_t available_timestamp);
     82 
     83   // Checks if enough time has elapsed since the last successful timescale
     84   // operation was done (i.e., accelerate or preemptive expand).
     85   bool TimescaleAllowed() const { return timescale_hold_off_ == 0; }
     86 
     87   // Checks if the current (filtered) buffer level is under the target level.
     88   bool UnderTargetLevel() const;
     89 
     90   // Checks if |timestamp_leap| is so long into the future that a reset due
     91   // to exceeding kReinitAfterExpands will be done.
     92   bool ReinitAfterExpands(uint32_t timestamp_leap) const;
     93 
     94   // Checks if we still have not done enough expands to cover the distance from
     95   // the last decoded packet to the next available packet, the distance beeing
     96   // conveyed in |timestamp_leap|.
     97   bool PacketTooEarly(uint32_t timestamp_leap) const;
     98 
     99   // Checks if num_consecutive_expands_ >= kMaxWaitForPacket.
    100   bool MaxWaitForPacket() const;
    101 
    102   RTC_DISALLOW_COPY_AND_ASSIGN(DecisionLogicNormal);
    103 };
    104 
    105 }  // namespace webrtc
    106 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_DECISION_LOGIC_NORMAL_H_
    107