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_MIXER_AUDIO_MIXER_IMPL_H_ 12 #define MODULES_AUDIO_MIXER_AUDIO_MIXER_IMPL_H_ 13 14 #include <memory> 15 #include <vector> 16 17 #include "api/audio/audio_mixer.h" 18 #include "modules/audio_mixer/frame_combiner.h" 19 #include "modules/audio_mixer/output_rate_calculator.h" 20 #include "modules/audio_processing/include/audio_processing.h" 21 #include "modules/include/module_common_types.h" 22 #include "rtc_base/race_checker.h" 23 #include "rtc_base/scoped_ref_ptr.h" 24 #include "rtc_base/thread_annotations.h" 25 #include "typedefs.h" // NOLINT(build/include) 26 27 namespace webrtc { 28 29 typedef std::vector<AudioFrame*> AudioFrameList; 30 31 class AudioMixerImpl : public AudioMixer { 32 public: 33 struct SourceStatus { SourceStatusSourceStatus34 SourceStatus(Source* audio_source, bool is_mixed, float gain) 35 : audio_source(audio_source), is_mixed(is_mixed), gain(gain) {} 36 Source* audio_source = nullptr; 37 bool is_mixed = false; 38 float gain = 0.0f; 39 40 // A frame that will be passed to audio_source->GetAudioFrameWithInfo. 41 AudioFrame audio_frame; 42 }; 43 44 using SourceStatusList = std::vector<std::unique_ptr<SourceStatus>>; 45 46 // AudioProcessing only accepts 10 ms frames. 47 static const int kFrameDurationInMs = 10; 48 static const int kMaximumAmountOfMixedAudioSources = 3; 49 50 static rtc::scoped_refptr<AudioMixerImpl> Create(); 51 52 static rtc::scoped_refptr<AudioMixerImpl> Create( 53 std::unique_ptr<OutputRateCalculator> output_rate_calculator, 54 bool use_limiter); 55 56 ~AudioMixerImpl() override; 57 58 // AudioMixer functions 59 bool AddSource(Source* audio_source) override; 60 void RemoveSource(Source* audio_source) override; 61 62 void Mix(size_t number_of_channels, 63 AudioFrame* audio_frame_for_mixing) override 64 RTC_LOCKS_EXCLUDED(crit_); 65 66 // Returns true if the source was mixed last round. Returns 67 // false and logs an error if the source was never added to the 68 // mixer. 69 bool GetAudioSourceMixabilityStatusForTest(Source* audio_source) const; 70 71 protected: 72 AudioMixerImpl(std::unique_ptr<OutputRateCalculator> output_rate_calculator, 73 bool use_limiter); 74 75 private: 76 // Set mixing frequency through OutputFrequencyCalculator. 77 void CalculateOutputFrequency(); 78 // Get mixing frequency. 79 int OutputFrequency() const; 80 81 // Compute what audio sources to mix from audio_source_list_. Ramp 82 // in and out. Update mixed status. Mixes up to 83 // kMaximumAmountOfMixedAudioSources audio sources. 84 AudioFrameList GetAudioFromSources() RTC_EXCLUSIVE_LOCKS_REQUIRED(crit_); 85 86 // Add/remove the MixerAudioSource to the specified 87 // MixerAudioSource list. 88 bool AddAudioSourceToList(Source* audio_source, 89 SourceStatusList* audio_source_list) const; 90 bool RemoveAudioSourceFromList(Source* remove_audio_source, 91 SourceStatusList* audio_source_list) const; 92 93 // The critical section lock guards audio source insertion and 94 // removal, which can be done from any thread. The race checker 95 // checks that mixing is done sequentially. 96 rtc::CriticalSection crit_; 97 rtc::RaceChecker race_checker_; 98 99 std::unique_ptr<OutputRateCalculator> output_rate_calculator_; 100 // The current sample frequency and sample size when mixing. 101 int output_frequency_ RTC_GUARDED_BY(race_checker_); 102 size_t sample_size_ RTC_GUARDED_BY(race_checker_); 103 104 // List of all audio sources. Note all lists are disjunct 105 SourceStatusList audio_source_list_ RTC_GUARDED_BY(crit_); // May be mixed. 106 107 // Component that handles actual adding of audio frames. 108 FrameCombiner frame_combiner_ RTC_GUARDED_BY(race_checker_); 109 110 RTC_DISALLOW_COPY_AND_ASSIGN(AudioMixerImpl); 111 }; 112 } // namespace webrtc 113 114 #endif // MODULES_AUDIO_MIXER_AUDIO_MIXER_IMPL_H_ 115