2 #define _AUDIO_MIXER_H 1
4 // The audio mixer, dealing with extracting the right signals from
5 // each capture card, resampling signals so that they are in sync,
6 // processing them with effects (if desired), and then mixing them
7 // all together into one final audio signal.
9 // All operations on AudioMixer (except destruction) are thread-safe.
11 // TODO: There might be more audio stuff that should be moved here
23 #include "bmusb/bmusb.h"
27 #include "resampling_queue.h"
28 #include "stereocompressor.h"
34 enum class InputSourceType { SILENCE, CAPTURE_CARD };
39 InputSourceType input_source_type;
40 unsigned input_source_index;
41 int source_channel[2] { -1, -1 }; // Left and right. -1 = none.
44 std::vector<Bus> buses;
49 AudioMixer(unsigned num_cards);
50 void reset_card(unsigned card_index);
52 // frame_length is in TIMEBASE units.
53 void add_audio(unsigned card_index, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
54 void add_silence(unsigned card_index, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
55 std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
57 // See comments inside get_output().
58 void set_current_loudness(double level_lufs) { loudness_lufs = level_lufs; }
60 void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
61 std::vector<std::string> get_names() const;
62 void set_name(unsigned card_index, const std::string &name);
64 void set_input_mapping(const InputMapping &input_mapping);
65 InputMapping get_input_mapping() const;
67 void set_locut_cutoff(float cutoff_hz)
69 locut_cutoff_hz = cutoff_hz;
72 void set_locut_enabled(bool enabled)
74 locut_enabled = enabled;
77 bool get_locut_enabled() const
82 float get_limiter_threshold_dbfs() const
84 return limiter_threshold_dbfs;
87 float get_compressor_threshold_dbfs() const
89 return compressor_threshold_dbfs;
92 void set_limiter_threshold_dbfs(float threshold_dbfs)
94 limiter_threshold_dbfs = threshold_dbfs;
97 void set_compressor_threshold_dbfs(float threshold_dbfs)
99 compressor_threshold_dbfs = threshold_dbfs;
102 void set_limiter_enabled(bool enabled)
104 limiter_enabled = enabled;
107 bool get_limiter_enabled() const
109 return limiter_enabled;
112 void set_compressor_enabled(bool enabled)
114 compressor_enabled = enabled;
117 bool get_compressor_enabled() const
119 return compressor_enabled;
122 void set_gain_staging_db(float gain_db)
124 std::unique_lock<std::mutex> lock(compressor_mutex);
125 level_compressor_enabled = false;
126 gain_staging_db = gain_db;
129 float get_gain_staging_db() const
131 std::unique_lock<std::mutex> lock(compressor_mutex);
132 return gain_staging_db;
135 void set_gain_staging_auto(bool enabled)
137 std::unique_lock<std::mutex> lock(compressor_mutex);
138 level_compressor_enabled = enabled;
141 bool get_gain_staging_auto() const
143 std::unique_lock<std::mutex> lock(compressor_mutex);
144 return level_compressor_enabled;
147 void set_final_makeup_gain_db(float gain_db)
149 std::unique_lock<std::mutex> lock(compressor_mutex);
150 final_makeup_gain_auto = false;
151 final_makeup_gain = from_db(gain_db);
154 float get_final_makeup_gain_db()
156 std::unique_lock<std::mutex> lock(compressor_mutex);
157 return to_db(final_makeup_gain);
160 void set_final_makeup_gain_auto(bool enabled)
162 std::unique_lock<std::mutex> lock(compressor_mutex);
163 final_makeup_gain_auto = enabled;
166 bool get_final_makeup_gain_auto() const
168 std::unique_lock<std::mutex> lock(compressor_mutex);
169 return final_makeup_gain_auto;
173 void find_sample_src_from_capture_card(const std::vector<float> *samples_card, unsigned card_index, int source_channel, const float **srcptr, unsigned *stride);
174 void reset_card_mutex_held(unsigned card_index);
178 mutable std::mutex audio_mutex;
181 std::unique_ptr<ResamplingQueue> resampling_queue;
182 int64_t next_local_pts = 0;
184 // Which channels we consider interesting (ie., are part of some input_mapping).
185 std::set<unsigned> interesting_channels;
187 CaptureCard cards[MAX_CARDS]; // Under audio_mutex.
189 StereoFilter locut; // Default cutoff 120 Hz, 24 dB/oct.
190 std::atomic<float> locut_cutoff_hz;
191 std::atomic<bool> locut_enabled{true};
193 // First compressor; takes us up to about -12 dBFS.
194 mutable std::mutex compressor_mutex;
195 StereoCompressor level_compressor; // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
196 float gain_staging_db = 0.0f; // Under compressor_mutex.
197 bool level_compressor_enabled = true; // Under compressor_mutex.
199 static constexpr float ref_level_dbfs = -14.0f; // Chosen so that we end up around 0 LU in practice.
200 static constexpr float ref_level_lufs = -23.0f; // 0 LU, more or less by definition.
202 std::atomic<float> loudness_lufs{ref_level_lufs};
204 StereoCompressor limiter;
205 std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f}; // 4 dB.
206 std::atomic<bool> limiter_enabled{true};
207 StereoCompressor compressor;
208 std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f}; // -12 dB.
209 std::atomic<bool> compressor_enabled{true};
211 double final_makeup_gain = 1.0; // Under compressor_mutex. Read/write by the user. Note: Not in dB, we want the numeric precision so that we can change it slowly.
212 bool final_makeup_gain_auto = true; // Under compressor_mutex.
214 InputMapping input_mapping; // Under audio_mutex.
215 std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
218 #endif // !defined(_AUDIO_MIXER_H)