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>
24 #include "alsa_pool.h"
25 #include "correlation_measurer.h"
28 #include "ebu_r128_proc.h"
30 #include "input_mapping.h"
31 #include "resampling_queue.h"
32 #include "stereocompressor.h"
34 class DeviceSpecProto;
49 AudioMixer(unsigned num_cards);
50 void reset_resampler(DeviceSpec device_spec);
53 // Add audio (or silence) to the given device's queue. Can return false if
54 // the lock wasn't successfully taken; if so, you should simply try again.
55 // (This is to avoid a deadlock where a card hangs on the mutex in add_audio()
56 // while we are trying to shut it down from another thread that also holds
57 // the mutex.) frame_length is in TIMEBASE units.
58 bool add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length, std::chrono::steady_clock::time_point frame_time);
59 bool add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
61 // If a given device is offline for whatever reason and cannot deliver audio
62 // (by means of add_audio() or add_silence()), you can call put it in silence mode,
63 // where it will be taken to only output silence. Note that when taking it _out_
64 // of silence mode, the resampler will be reset, so that old audio will not
65 // affect it. Same true/false behavior as add_audio().
66 bool silence_card(DeviceSpec device_spec, bool silence);
68 std::vector<float> get_output(std::chrono::steady_clock::time_point ts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
70 float get_fader_volume(unsigned bus_index) const { return fader_volume_db[bus_index]; }
71 void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
73 bool get_mute(unsigned bus_index) const { return mute[bus_index]; }
74 void set_mute(unsigned bus_index, bool muted) { mute[bus_index] = muted; }
76 // Note: This operation holds all ALSA devices (see ALSAPool::get_devices()).
77 // You will need to call set_input_mapping() to get the hold state correctly,
78 // or every card will be held forever.
79 std::map<DeviceSpec, DeviceInfo> get_devices();
81 // See comments on ALSAPool::get_card_state().
82 ALSAPool::Device::State get_alsa_card_state(unsigned index)
84 return alsa_pool.get_card_state(index);
87 // See comments on ALSAPool::create_dead_card().
88 DeviceSpec create_dead_card(const std::string &name, const std::string &info, unsigned num_channels)
90 unsigned dead_card_index = alsa_pool.create_dead_card(name, info, num_channels);
91 return DeviceSpec{InputSourceType::ALSA_INPUT, dead_card_index};
94 void set_display_name(DeviceSpec device_spec, const std::string &name);
96 // Note: The card should be held (currently this isn't enforced, though).
97 void serialize_device(DeviceSpec device_spec, DeviceSpecProto *device_spec_proto);
99 enum class MappingMode {
100 // A single bus, only from a video card (no ALSA devices),
101 // only channel 1 and 2, locked to +0 dB. Note that this is
102 // only an UI abstraction around exactly the same audio code
103 // as MULTICHANNEL; it's just less flexible.
106 // Full, arbitrary mappings.
110 // Automatically sets mapping mode to MappingMode::SIMPLE.
111 void set_simple_input(unsigned card_index);
113 // If mapping mode is not representable as a MappingMode::SIMPLE type
114 // mapping, returns numeric_limits<unsigned>::max().
115 unsigned get_simple_input() const;
117 // Implicitly sets mapping mode to MappingMode::MULTICHANNEL.
118 void set_input_mapping(const InputMapping &input_mapping);
120 MappingMode get_mapping_mode() const;
121 InputMapping get_input_mapping() const;
123 unsigned num_buses() const;
125 void set_locut_cutoff(float cutoff_hz)
127 locut_cutoff_hz = cutoff_hz;
130 float get_locut_cutoff() const
132 return locut_cutoff_hz;
135 void set_locut_enabled(unsigned bus, bool enabled)
137 locut_enabled[bus] = enabled;
140 bool get_locut_enabled(unsigned bus)
142 return locut_enabled[bus];
145 void set_eq(unsigned bus_index, EQBand band, float db_gain)
147 assert(band >= 0 && band < NUM_EQ_BANDS);
148 eq_level_db[bus_index][band] = db_gain;
151 float get_eq(unsigned bus_index, EQBand band) const
153 assert(band >= 0 && band < NUM_EQ_BANDS);
154 return eq_level_db[bus_index][band];
157 float get_limiter_threshold_dbfs() const
159 return limiter_threshold_dbfs;
162 float get_compressor_threshold_dbfs(unsigned bus_index) const
164 return compressor_threshold_dbfs[bus_index];
167 void set_limiter_threshold_dbfs(float threshold_dbfs)
169 limiter_threshold_dbfs = threshold_dbfs;
172 void set_compressor_threshold_dbfs(unsigned bus_index, float threshold_dbfs)
174 compressor_threshold_dbfs[bus_index] = threshold_dbfs;
177 void set_limiter_enabled(bool enabled)
179 limiter_enabled = enabled;
182 bool get_limiter_enabled() const
184 return limiter_enabled;
187 void set_compressor_enabled(unsigned bus_index, bool enabled)
189 compressor_enabled[bus_index] = enabled;
192 bool get_compressor_enabled(unsigned bus_index) const
194 return compressor_enabled[bus_index];
197 void set_gain_staging_db(unsigned bus_index, float gain_db)
199 std::unique_lock<std::mutex> lock(compressor_mutex);
200 level_compressor_enabled[bus_index] = false;
201 gain_staging_db[bus_index] = gain_db;
204 float get_gain_staging_db(unsigned bus_index) const
206 std::unique_lock<std::mutex> lock(compressor_mutex);
207 return gain_staging_db[bus_index];
210 void set_gain_staging_auto(unsigned bus_index, bool enabled)
212 std::unique_lock<std::mutex> lock(compressor_mutex);
213 level_compressor_enabled[bus_index] = enabled;
216 bool get_gain_staging_auto(unsigned bus_index) const
218 std::unique_lock<std::mutex> lock(compressor_mutex);
219 return level_compressor_enabled[bus_index];
222 void set_final_makeup_gain_db(float gain_db)
224 std::unique_lock<std::mutex> lock(compressor_mutex);
225 final_makeup_gain_auto = false;
226 final_makeup_gain = from_db(gain_db);
229 float get_final_makeup_gain_db()
231 std::unique_lock<std::mutex> lock(compressor_mutex);
232 return to_db(final_makeup_gain);
235 void set_final_makeup_gain_auto(bool enabled)
237 std::unique_lock<std::mutex> lock(compressor_mutex);
238 final_makeup_gain_auto = enabled;
241 bool get_final_makeup_gain_auto() const
243 std::unique_lock<std::mutex> lock(compressor_mutex);
244 return final_makeup_gain_auto;
247 void reset_peak(unsigned bus_index);
250 float current_level_dbfs[2]; // Digital peak of last frame, left and right.
251 float peak_level_dbfs[2]; // Digital peak with hold, left and right.
252 float historic_peak_dbfs;
253 float gain_staging_db;
254 float compressor_attenuation_db; // A positive number; 0.0 for no attenuation.
257 typedef std::function<void(float level_lufs, float peak_db,
258 std::vector<BusLevel> bus_levels,
259 float global_level_lufs, float range_low_lufs, float range_high_lufs,
260 float final_makeup_gain_db,
261 float correlation)> audio_level_callback_t;
262 void set_audio_level_callback(audio_level_callback_t callback)
264 audio_level_callback = callback;
267 typedef std::function<void()> state_changed_callback_t;
268 void set_state_changed_callback(state_changed_callback_t callback)
270 state_changed_callback = callback;
273 state_changed_callback_t get_state_changed_callback() const
275 return state_changed_callback;
278 void trigger_state_changed_callback()
280 if (state_changed_callback != nullptr) {
281 state_changed_callback();
285 // A combination of all settings for a bus. Useful if you want to get
286 // or store them as a whole without bothering to call all of the get_*
287 // or set_* functions for that bus.
289 float fader_volume_db;
292 float eq_level_db[NUM_EQ_BANDS];
293 float gain_staging_db;
294 bool level_compressor_enabled;
295 float compressor_threshold_dbfs;
296 bool compressor_enabled;
298 static BusSettings get_default_bus_settings();
299 BusSettings get_bus_settings(unsigned bus_index) const;
300 void set_bus_settings(unsigned bus_index, const BusSettings &settings);
304 std::unique_ptr<ResamplingQueue> resampling_queue;
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)