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.
13 #include <zita-resampler/resampler.h>
23 #include "alsa_pool.h"
24 #include "correlation_measurer.h"
27 #include "ebu_r128_proc.h"
29 #include "input_mapping.h"
30 #include "resampling_queue.h"
31 #include "stereocompressor.h"
33 class DeviceSpecProto;
48 AudioMixer(unsigned num_cards);
49 void reset_resampler(DeviceSpec device_spec);
52 // Add audio (or silence) to the given device's queue. Can return false if
53 // the lock wasn't successfully taken; if so, you should simply try again.
54 // (This is to avoid a deadlock where a card hangs on the mutex in add_audio()
55 // while we are trying to shut it down from another thread that also holds
56 // the mutex.) frame_length is in TIMEBASE units.
57 bool add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
58 bool add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
60 // If a given device is offline for whatever reason and cannot deliver audio
61 // (by means of add_audio() or add_silence()), you can call put it in silence mode,
62 // where it will be taken to only output silence. Note that when taking it _out_
63 // of silence mode, the resampler will be reset, so that old audio will not
64 // affect it. Same true/false behavior as add_audio().
65 bool silence_card(DeviceSpec device_spec, bool silence);
67 std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
69 float get_fader_volume(unsigned bus_index) const { return fader_volume_db[bus_index]; }
70 void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
72 bool get_mute(unsigned bus_index) const { return mute[bus_index]; }
73 void set_mute(unsigned bus_index, bool muted) { mute[bus_index] = muted; }
75 // Note: This operation holds all ALSA devices (see ALSAPool::get_devices()).
76 // You will need to call set_input_mapping() to get the hold state correctly,
77 // or every card will be held forever.
78 std::map<DeviceSpec, DeviceInfo> get_devices();
80 // See comments on ALSAPool::get_card_state().
81 ALSAPool::Device::State get_alsa_card_state(unsigned index)
83 return alsa_pool.get_card_state(index);
86 // See comments on ALSAPool::create_dead_card().
87 DeviceSpec create_dead_card(const std::string &name, const std::string &info, unsigned num_channels)
89 unsigned dead_card_index = alsa_pool.create_dead_card(name, info, num_channels);
90 return DeviceSpec{InputSourceType::ALSA_INPUT, dead_card_index};
93 void set_display_name(DeviceSpec device_spec, const std::string &name);
95 // Note: The card should be held (currently this isn't enforced, though).
96 void serialize_device(DeviceSpec device_spec, DeviceSpecProto *device_spec_proto);
98 enum class MappingMode {
99 // A single bus, only from a video card (no ALSA devices),
100 // only channel 1 and 2, locked to +0 dB. Note that this is
101 // only an UI abstraction around exactly the same audio code
102 // as MULTICHANNEL; it's just less flexible.
105 // Full, arbitrary mappings.
109 // Automatically sets mapping mode to MappingMode::SIMPLE.
110 void set_simple_input(unsigned card_index);
112 // If mapping mode is not representable as a MappingMode::SIMPLE type
113 // mapping, returns numeric_limits<unsigned>::max().
114 unsigned get_simple_input() const;
116 // Implicitly sets mapping mode to MappingMode::MULTICHANNEL.
117 void set_input_mapping(const InputMapping &input_mapping);
119 MappingMode get_mapping_mode() const;
120 InputMapping get_input_mapping() const;
122 unsigned num_buses() const;
124 void set_locut_cutoff(float cutoff_hz)
126 locut_cutoff_hz = cutoff_hz;
129 float get_locut_cutoff() const
131 return locut_cutoff_hz;
134 void set_locut_enabled(unsigned bus, bool enabled)
136 locut_enabled[bus] = enabled;
139 bool get_locut_enabled(unsigned bus)
141 return locut_enabled[bus];
144 void set_eq(unsigned bus_index, EQBand band, float db_gain)
146 assert(band >= 0 && band < NUM_EQ_BANDS);
147 eq_level_db[bus_index][band] = db_gain;
150 float get_eq(unsigned bus_index, EQBand band) const
152 assert(band >= 0 && band < NUM_EQ_BANDS);
153 return eq_level_db[bus_index][band];
156 float get_limiter_threshold_dbfs() const
158 return limiter_threshold_dbfs;
161 float get_compressor_threshold_dbfs(unsigned bus_index) const
163 return compressor_threshold_dbfs[bus_index];
166 void set_limiter_threshold_dbfs(float threshold_dbfs)
168 limiter_threshold_dbfs = threshold_dbfs;
171 void set_compressor_threshold_dbfs(unsigned bus_index, float threshold_dbfs)
173 compressor_threshold_dbfs[bus_index] = threshold_dbfs;
176 void set_limiter_enabled(bool enabled)
178 limiter_enabled = enabled;
181 bool get_limiter_enabled() const
183 return limiter_enabled;
186 void set_compressor_enabled(unsigned bus_index, bool enabled)
188 compressor_enabled[bus_index] = enabled;
191 bool get_compressor_enabled(unsigned bus_index) const
193 return compressor_enabled[bus_index];
196 void set_gain_staging_db(unsigned bus_index, float gain_db)
198 std::unique_lock<std::mutex> lock(compressor_mutex);
199 level_compressor_enabled[bus_index] = false;
200 gain_staging_db[bus_index] = gain_db;
203 float get_gain_staging_db(unsigned bus_index) const
205 std::unique_lock<std::mutex> lock(compressor_mutex);
206 return gain_staging_db[bus_index];
209 void set_gain_staging_auto(unsigned bus_index, bool enabled)
211 std::unique_lock<std::mutex> lock(compressor_mutex);
212 level_compressor_enabled[bus_index] = enabled;
215 bool get_gain_staging_auto(unsigned bus_index) const
217 std::unique_lock<std::mutex> lock(compressor_mutex);
218 return level_compressor_enabled[bus_index];
221 void set_final_makeup_gain_db(float gain_db)
223 std::unique_lock<std::mutex> lock(compressor_mutex);
224 final_makeup_gain_auto = false;
225 final_makeup_gain = from_db(gain_db);
228 float get_final_makeup_gain_db()
230 std::unique_lock<std::mutex> lock(compressor_mutex);
231 return to_db(final_makeup_gain);
234 void set_final_makeup_gain_auto(bool enabled)
236 std::unique_lock<std::mutex> lock(compressor_mutex);
237 final_makeup_gain_auto = enabled;
240 bool get_final_makeup_gain_auto() const
242 std::unique_lock<std::mutex> lock(compressor_mutex);
243 return final_makeup_gain_auto;
246 void reset_peak(unsigned bus_index);
249 float current_level_dbfs[2]; // Digital peak of last frame, left and right.
250 float peak_level_dbfs[2]; // Digital peak with hold, left and right.
251 float historic_peak_dbfs;
252 float gain_staging_db;
253 float compressor_attenuation_db; // A positive number; 0.0 for no attenuation.
256 typedef std::function<void(float level_lufs, float peak_db,
257 std::vector<BusLevel> bus_levels,
258 float global_level_lufs, float range_low_lufs, float range_high_lufs,
259 float final_makeup_gain_db,
260 float correlation)> audio_level_callback_t;
261 void set_audio_level_callback(audio_level_callback_t callback)
263 audio_level_callback = callback;
266 typedef std::function<void()> state_changed_callback_t;
267 void set_state_changed_callback(state_changed_callback_t callback)
269 state_changed_callback = callback;
272 state_changed_callback_t get_state_changed_callback() const
274 return state_changed_callback;
277 void trigger_state_changed_callback()
279 if (state_changed_callback != nullptr) {
280 state_changed_callback();
284 // A combination of all settings for a bus. Useful if you want to get
285 // or store them as a whole without bothering to call all of the get_*
286 // or set_* functions for that bus.
288 float fader_volume_db;
291 float eq_level_db[NUM_EQ_BANDS];
292 float gain_staging_db;
293 bool level_compressor_enabled;
294 float compressor_threshold_dbfs;
295 bool compressor_enabled;
297 static BusSettings get_default_bus_settings();
298 BusSettings get_bus_settings(unsigned bus_index) const;
299 void set_bus_settings(unsigned bus_index, const BusSettings &settings);
303 std::unique_ptr<ResamplingQueue> resampling_queue;
304 int64_t next_local_pts = 0;
305 std::string display_name;
306 unsigned capture_frequency = OUTPUT_FREQUENCY;
307 // Which channels we consider interesting (ie., are part of some input_mapping).
308 std::set<unsigned> interesting_channels;
309 bool silenced = false;
312 const AudioDevice *find_audio_device(DeviceSpec device_spec) const
314 return const_cast<AudioMixer *>(this)->find_audio_device(device_spec);
317 AudioDevice *find_audio_device(DeviceSpec device_spec);
319 void find_sample_src_from_device(const std::map<DeviceSpec, std::vector<float>> &samples_card, DeviceSpec device_spec, int source_channel, const float **srcptr, unsigned *stride);
320 void fill_audio_bus(const std::map<DeviceSpec, std::vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
321 void reset_resampler_mutex_held(DeviceSpec device_spec);
322 void apply_eq(unsigned bus_index, std::vector<float> *samples_bus);
323 void update_meters(const std::vector<float> &samples);
324 void add_bus_to_master(unsigned bus_index, const std::vector<float> &samples_bus, std::vector<float> *samples_out);
325 void measure_bus_levels(unsigned bus_index, const std::vector<float> &left, const std::vector<float> &right);
326 void send_audio_level_callback();
327 std::vector<DeviceSpec> get_active_devices() const;
328 void set_input_mapping_lock_held(const InputMapping &input_mapping);
332 mutable std::timed_mutex audio_mutex;
335 AudioDevice video_cards[MAX_VIDEO_CARDS]; // Under audio_mutex.
336 AudioDevice alsa_inputs[MAX_ALSA_CARDS]; // Under audio_mutex.
338 std::atomic<float> locut_cutoff_hz{120};
339 StereoFilter locut[MAX_BUSES]; // Default cutoff 120 Hz, 24 dB/oct.
340 std::atomic<bool> locut_enabled[MAX_BUSES];
341 StereoFilter eq[MAX_BUSES][NUM_EQ_BANDS]; // The one for EQBand::MID isn't actually used (see comments in apply_eq()).
343 // First compressor; takes us up to about -12 dBFS.
344 mutable std::mutex compressor_mutex;
345 std::unique_ptr<StereoCompressor> level_compressor[MAX_BUSES]; // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
346 float gain_staging_db[MAX_BUSES]; // Under compressor_mutex.
347 float last_gain_staging_db[MAX_BUSES]; // Under compressor_mutex.
348 bool level_compressor_enabled[MAX_BUSES]; // Under compressor_mutex.
350 static constexpr float ref_level_dbfs = -14.0f; // Chosen so that we end up around 0 LU in practice.
351 static constexpr float ref_level_lufs = -23.0f; // 0 LU, more or less by definition.
353 StereoCompressor limiter;
354 std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f}; // 4 dB.
355 std::atomic<bool> limiter_enabled{true};
356 std::unique_ptr<StereoCompressor> compressor[MAX_BUSES];
357 std::atomic<float> compressor_threshold_dbfs[MAX_BUSES];
358 std::atomic<bool> compressor_enabled[MAX_BUSES];
360 // Note: The values here are not in dB.
362 float current_level = 0.0f; // Peak of the last frame.
363 float historic_peak = 0.0f; // Highest peak since last reset; no falloff.
364 float current_peak = 0.0f; // Current peak of the peak meter.
365 float last_peak = 0.0f;
366 float age_seconds = 0.0f; // Time since "last_peak" was set.
368 PeakHistory peak_history[MAX_BUSES][2]; // Separate for each channel. Under audio_mutex.
370 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.
371 bool final_makeup_gain_auto = true; // Under compressor_mutex.
373 MappingMode current_mapping_mode; // Under audio_mutex.
374 InputMapping input_mapping; // Under audio_mutex.
375 std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
376 std::atomic<bool> mute[MAX_BUSES] {{ false }};
377 float last_fader_volume_db[MAX_BUSES] { 0.0f }; // Under audio_mutex.
378 std::atomic<float> eq_level_db[MAX_BUSES][NUM_EQ_BANDS] {{{ 0.0f }}};
379 float last_eq_level_db[MAX_BUSES][NUM_EQ_BANDS] {{ 0.0f }};
381 audio_level_callback_t audio_level_callback = nullptr;
382 state_changed_callback_t state_changed_callback = nullptr;
383 mutable std::mutex audio_measure_mutex;
384 Ebu_r128_proc r128; // Under audio_measure_mutex.
385 CorrelationMeasurer correlation; // Under audio_measure_mutex.
386 Resampler peak_resampler; // Under audio_measure_mutex.
387 std::atomic<float> peak{0.0f};
390 extern AudioMixer *global_audio_mixer;
392 #endif // !defined(_AUDIO_MIXER_H)