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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.
DecisionLogicNormal(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)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).
TimescaleAllowed()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