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1 /*
2  *  Copyright (c) 2012 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 MODULES_AUDIO_DEVICE_AUDIO_DEVICE_BUFFER_H_
12 #define MODULES_AUDIO_DEVICE_AUDIO_DEVICE_BUFFER_H_
13 
14 #include <stddef.h>
15 #include <stdint.h>
16 
17 #include <atomic>
18 
19 #include "api/task_queue/task_queue_factory.h"
20 #include "modules/audio_device/include/audio_device_defines.h"
21 #include "rtc_base/buffer.h"
22 #include "rtc_base/synchronization/mutex.h"
23 #include "rtc_base/task_queue.h"
24 #include "rtc_base/thread_annotations.h"
25 #include "rtc_base/thread_checker.h"
26 
27 namespace webrtc {
28 
29 // Delta times between two successive playout callbacks are limited to this
30 // value before added to an internal array.
31 const size_t kMaxDeltaTimeInMs = 500;
32 // TODO(henrika): remove when no longer used by external client.
33 const size_t kMaxBufferSizeBytes = 3840;  // 10ms in stereo @ 96kHz
34 
35 class AudioDeviceBuffer {
36  public:
37   enum LogState {
38     LOG_START = 0,
39     LOG_STOP,
40     LOG_ACTIVE,
41   };
42 
43   struct Stats {
ResetRecStatsStats44     void ResetRecStats() {
45       rec_callbacks = 0;
46       rec_samples = 0;
47       max_rec_level = 0;
48     }
49 
ResetPlayStatsStats50     void ResetPlayStats() {
51       play_callbacks = 0;
52       play_samples = 0;
53       max_play_level = 0;
54     }
55 
56     // Total number of recording callbacks where the source provides 10ms audio
57     // data each time.
58     uint64_t rec_callbacks = 0;
59 
60     // Total number of playback callbacks where the sink asks for 10ms audio
61     // data each time.
62     uint64_t play_callbacks = 0;
63 
64     // Total number of recorded audio samples.
65     uint64_t rec_samples = 0;
66 
67     // Total number of played audio samples.
68     uint64_t play_samples = 0;
69 
70     // Contains max level (max(abs(x))) of recorded audio packets over the last
71     // 10 seconds where a new measurement is done twice per second. The level
72     // is reset to zero at each call to LogStats().
73     int16_t max_rec_level = 0;
74 
75     // Contains max level of recorded audio packets over the last 10 seconds
76     // where a new measurement is done twice per second.
77     int16_t max_play_level = 0;
78   };
79 
80   explicit AudioDeviceBuffer(TaskQueueFactory* task_queue_factory);
81   virtual ~AudioDeviceBuffer();
82 
83   int32_t RegisterAudioCallback(AudioTransport* audio_callback);
84 
85   void StartPlayout();
86   void StartRecording();
87   void StopPlayout();
88   void StopRecording();
89 
90   int32_t SetRecordingSampleRate(uint32_t fsHz);
91   int32_t SetPlayoutSampleRate(uint32_t fsHz);
92   uint32_t RecordingSampleRate() const;
93   uint32_t PlayoutSampleRate() const;
94 
95   int32_t SetRecordingChannels(size_t channels);
96   int32_t SetPlayoutChannels(size_t channels);
97   size_t RecordingChannels() const;
98   size_t PlayoutChannels() const;
99 
100   virtual int32_t SetRecordedBuffer(const void* audio_buffer,
101                                     size_t samples_per_channel);
102   virtual void SetVQEData(int play_delay_ms, int rec_delay_ms);
103   virtual int32_t DeliverRecordedData();
104   uint32_t NewMicLevel() const;
105 
106   virtual int32_t RequestPlayoutData(size_t samples_per_channel);
107   virtual int32_t GetPlayoutData(void* audio_buffer);
108 
109   int32_t SetTypingStatus(bool typing_status);
110 
111  private:
112   // Starts/stops periodic logging of audio stats.
113   void StartPeriodicLogging();
114   void StopPeriodicLogging();
115 
116   // Called periodically on the internal thread created by the TaskQueue.
117   // Updates some stats but dooes it on the task queue to ensure that access of
118   // members is serialized hence avoiding usage of locks.
119   // state = LOG_START => members are initialized and the timer starts.
120   // state = LOG_STOP => no logs are printed and the timer stops.
121   // state = LOG_ACTIVE => logs are printed and the timer is kept alive.
122   void LogStats(LogState state);
123 
124   // Updates counters in each play/record callback. These counters are later
125   // (periodically) read by LogStats() using a lock.
126   void UpdateRecStats(int16_t max_abs, size_t samples_per_channel);
127   void UpdatePlayStats(int16_t max_abs, size_t samples_per_channel);
128 
129   // Clears all members tracking stats for recording and playout.
130   // These methods both run on the task queue.
131   void ResetRecStats();
132   void ResetPlayStats();
133 
134   // This object lives on the main (creating) thread and most methods are
135   // called on that same thread. When audio has started some methods will be
136   // called on either a native audio thread for playout or a native thread for
137   // recording. Some members are not annotated since they are "protected by
138   // design" and adding e.g. a race checker can cause failures for very few
139   // edge cases and it is IMHO not worth the risk to use them in this class.
140   // TODO(henrika): see if it is possible to refactor and annotate all members.
141 
142   // Main thread on which this object is created.
143   rtc::ThreadChecker main_thread_checker_;
144 
145   Mutex lock_;
146 
147   // Task queue used to invoke LogStats() periodically. Tasks are executed on a
148   // worker thread but it does not necessarily have to be the same thread for
149   // each task.
150   rtc::TaskQueue task_queue_;
151 
152   // Raw pointer to AudioTransport instance. Supplied to RegisterAudioCallback()
153   // and it must outlive this object. It is not possible to change this member
154   // while any media is active. It is possible to start media without calling
155   // RegisterAudioCallback() but that will lead to ignored audio callbacks in
156   // both directions where native audio will be active but no audio samples will
157   // be transported.
158   AudioTransport* audio_transport_cb_;
159 
160   // Sample rate in Hertz. Accessed atomically.
161   std::atomic<uint32_t> rec_sample_rate_;
162   std::atomic<uint32_t> play_sample_rate_;
163 
164   // Number of audio channels. Accessed atomically.
165   std::atomic<size_t> rec_channels_;
166   std::atomic<size_t> play_channels_;
167 
168   // Keeps track of if playout/recording are active or not. A combination
169   // of these states are used to determine when to start and stop the timer.
170   // Only used on the creating thread and not used to control any media flow.
171   bool playing_ RTC_GUARDED_BY(main_thread_checker_);
172   bool recording_ RTC_GUARDED_BY(main_thread_checker_);
173 
174   // Buffer used for audio samples to be played out. Size can be changed
175   // dynamically. The 16-bit samples are interleaved, hence the size is
176   // proportional to the number of channels.
177   rtc::BufferT<int16_t> play_buffer_;
178 
179   // Byte buffer used for recorded audio samples. Size can be changed
180   // dynamically.
181   rtc::BufferT<int16_t> rec_buffer_;
182 
183   // Contains true of a key-press has been detected.
184   bool typing_status_;
185 
186   // Delay values used by the AEC.
187   int play_delay_ms_;
188   int rec_delay_ms_;
189 
190   // Counts number of times LogStats() has been called.
191   size_t num_stat_reports_ RTC_GUARDED_BY(task_queue_);
192 
193   // Time stamp of last timer task (drives logging).
194   int64_t last_timer_task_time_ RTC_GUARDED_BY(task_queue_);
195 
196   // Counts number of audio callbacks modulo 50 to create a signal when
197   // a new storage of audio stats shall be done.
198   int16_t rec_stat_count_;
199   int16_t play_stat_count_;
200 
201   // Time stamps of when playout and recording starts.
202   int64_t play_start_time_ RTC_GUARDED_BY(main_thread_checker_);
203   int64_t rec_start_time_ RTC_GUARDED_BY(main_thread_checker_);
204 
205   // Contains counters for playout and recording statistics.
206   Stats stats_ RTC_GUARDED_BY(lock_);
207 
208   // Stores current stats at each timer task. Used to calculate differences
209   // between two successive timer events.
210   Stats last_stats_ RTC_GUARDED_BY(task_queue_);
211 
212   // Set to true at construction and modified to false as soon as one audio-
213   // level estimate larger than zero is detected.
214   bool only_silence_recorded_;
215 
216   // Set to true when logging of audio stats is enabled for the first time in
217   // StartPeriodicLogging() and set to false by StopPeriodicLogging().
218   // Setting this member to false prevents (possiby invalid) log messages from
219   // being printed in the LogStats() task.
220   bool log_stats_ RTC_GUARDED_BY(task_queue_);
221 
222 // Should *never* be defined in production builds. Only used for testing.
223 // When defined, the output signal will be replaced by a sinus tone at 440Hz.
224 #ifdef AUDIO_DEVICE_PLAYS_SINUS_TONE
225   double phase_;
226 #endif
227 };
228 
229 }  // namespace webrtc
230 
231 #endif  // MODULES_AUDIO_DEVICE_AUDIO_DEVICE_BUFFER_H_
232