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.
19 #include <zita-resampler/resampler.h>
21 #include "alsa_input.h"
22 #include "alsa_pool.h"
23 #include "bmusb/bmusb.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"
46 AudioMixer(unsigned num_cards);
47 void reset_resampler(DeviceSpec device_spec);
50 // Add audio (or silence) to the given device's queue. Can return false if
51 // the lock wasn't successfully taken; if so, you should simply try again.
52 // (This is to avoid a deadlock where a card hangs on the mutex in add_audio()
53 // while we are trying to shut it down from another thread that also holds
54 // the mutex.) frame_length is in TIMEBASE units.
55 bool add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
56 bool add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
58 // If a given device is offline for whatever reason and cannot deliver audio
59 // (by means of add_audio() or add_silence()), you can call put it in silence mode,
60 // where it will be taken to only output silence. Note that when taking it _out_
61 // of silence mode, the resampler will be reset, so that old audio will not
62 // affect it. Same true/false behavior as add_audio().
63 bool silence_card(DeviceSpec device_spec, bool silence);
65 std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
67 float get_fader_volume(unsigned bus_index) const { return fader_volume_db[bus_index]; }
68 void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
70 // Note: This operation holds all ALSA devices (see ALSAPool::get_devices()).
71 // You will need to call set_input_mapping() to get the hold state correctly,
72 // or every card will be held forever.
73 std::map<DeviceSpec, DeviceInfo> get_devices();
75 // See comments on ALSAPool::get_card_state().
76 ALSAPool::Device::State get_alsa_card_state(unsigned index)
78 return alsa_pool.get_card_state(index);
81 // See comments on ALSAPool::create_dead_card().
82 DeviceSpec create_dead_card(const std::string &name, const std::string &info, unsigned num_channels)
84 unsigned dead_card_index = alsa_pool.create_dead_card(name, info, num_channels);
85 return DeviceSpec{InputSourceType::ALSA_INPUT, dead_card_index};
88 void set_display_name(DeviceSpec device_spec, const std::string &name);
90 // Note: The card should be held (currently this isn't enforced, though).
91 void serialize_device(DeviceSpec device_spec, DeviceSpecProto *device_spec_proto);
93 enum class MappingMode {
94 // A single bus, only from a video card (no ALSA devices),
95 // only channel 1 and 2, locked to +0 dB. Note that this is
96 // only an UI abstraction around exactly the same audio code
97 // as MULTICHANNEL; it's just less flexible.
100 // Full, arbitrary mappings.
104 // Automatically sets mapping mode to MappingMode::SIMPLE.
105 void set_simple_input(unsigned card_index);
107 // If mapping mode is not representable as a MappingMode::SIMPLE type
108 // mapping, returns numeric_limits<unsigned>::max().
109 unsigned get_simple_input() const;
111 // Implicitly sets mapping mode to MappingMode::MULTICHANNEL.
112 void set_input_mapping(const InputMapping &input_mapping);
114 MappingMode get_mapping_mode() const;
115 InputMapping get_input_mapping() const;
117 void set_locut_cutoff(float cutoff_hz)
119 locut_cutoff_hz = cutoff_hz;
122 float get_locut_cutoff() const
124 return locut_cutoff_hz;
127 void set_locut_enabled(unsigned bus, bool enabled)
129 locut_enabled[bus] = enabled;
132 bool get_locut_enabled(unsigned bus)
134 return locut_enabled[bus];
137 void set_eq(unsigned bus_index, EQBand band, float db_gain)
139 assert(band >= 0 && band < NUM_EQ_BANDS);
140 eq_level_db[bus_index][band] = db_gain;
143 float get_eq(unsigned bus_index, EQBand band) const
145 assert(band >= 0 && band < NUM_EQ_BANDS);
146 return eq_level_db[bus_index][band];
149 float get_limiter_threshold_dbfs() const
151 return limiter_threshold_dbfs;
154 float get_compressor_threshold_dbfs(unsigned bus_index) const
156 return compressor_threshold_dbfs[bus_index];
159 void set_limiter_threshold_dbfs(float threshold_dbfs)
161 limiter_threshold_dbfs = threshold_dbfs;
164 void set_compressor_threshold_dbfs(unsigned bus_index, float threshold_dbfs)
166 compressor_threshold_dbfs[bus_index] = threshold_dbfs;
169 void set_limiter_enabled(bool enabled)
171 limiter_enabled = enabled;
174 bool get_limiter_enabled() const
176 return limiter_enabled;
179 void set_compressor_enabled(unsigned bus_index, bool enabled)
181 compressor_enabled[bus_index] = enabled;
184 bool get_compressor_enabled(unsigned bus_index) const
186 return compressor_enabled[bus_index];
189 void set_gain_staging_db(unsigned bus_index, float gain_db)
191 std::unique_lock<std::mutex> lock(compressor_mutex);
192 level_compressor_enabled[bus_index] = false;
193 gain_staging_db[bus_index] = gain_db;
196 float get_gain_staging_db(unsigned bus_index) const
198 std::unique_lock<std::mutex> lock(compressor_mutex);
199 return gain_staging_db[bus_index];
202 void set_gain_staging_auto(unsigned bus_index, bool enabled)
204 std::unique_lock<std::mutex> lock(compressor_mutex);
205 level_compressor_enabled[bus_index] = enabled;
208 bool get_gain_staging_auto(unsigned bus_index) const
210 std::unique_lock<std::mutex> lock(compressor_mutex);
211 return level_compressor_enabled[bus_index];
214 void set_final_makeup_gain_db(float gain_db)
216 std::unique_lock<std::mutex> lock(compressor_mutex);
217 final_makeup_gain_auto = false;
218 final_makeup_gain = from_db(gain_db);
221 float get_final_makeup_gain_db()
223 std::unique_lock<std::mutex> lock(compressor_mutex);
224 return to_db(final_makeup_gain);
227 void set_final_makeup_gain_auto(bool enabled)
229 std::unique_lock<std::mutex> lock(compressor_mutex);
230 final_makeup_gain_auto = enabled;
233 bool get_final_makeup_gain_auto() const
235 std::unique_lock<std::mutex> lock(compressor_mutex);
236 return final_makeup_gain_auto;
239 void reset_peak(unsigned bus_index);
242 float current_level_dbfs[2]; // Digital peak of last frame, left and right.
243 float peak_level_dbfs[2]; // Digital peak with hold, left and right.
244 float historic_peak_dbfs;
245 float gain_staging_db;
246 float compressor_attenuation_db; // A positive number; 0.0 for no attenuation.
249 typedef std::function<void(float level_lufs, float peak_db,
250 std::vector<BusLevel> bus_levels,
251 float global_level_lufs, float range_low_lufs, float range_high_lufs,
252 float final_makeup_gain_db,
253 float correlation)> audio_level_callback_t;
254 void set_audio_level_callback(audio_level_callback_t callback)
256 audio_level_callback = callback;
259 typedef std::function<void()> state_changed_callback_t;
260 void set_state_changed_callback(state_changed_callback_t callback)
262 state_changed_callback = callback;
265 state_changed_callback_t get_state_changed_callback() const
267 return state_changed_callback;
270 void trigger_state_changed_callback()
272 if (state_changed_callback != nullptr) {
273 state_changed_callback();
277 // A combination of all settings for a bus. Useful if you want to get
278 // or store them as a whole without bothering to call all of the get_*
279 // or set_* functions for that bus.
281 float fader_volume_db;
283 float eq_level_db[NUM_EQ_BANDS];
284 float gain_staging_db;
285 bool level_compressor_enabled;
286 float compressor_threshold_dbfs;
287 bool compressor_enabled;
289 static BusSettings get_default_bus_settings();
290 BusSettings get_bus_settings(unsigned bus_index) const;
291 void set_bus_settings(unsigned bus_index, const BusSettings &settings);
295 std::unique_ptr<ResamplingQueue> resampling_queue;
296 int64_t next_local_pts = 0;
297 std::string display_name;
298 unsigned capture_frequency = OUTPUT_FREQUENCY;
299 // Which channels we consider interesting (ie., are part of some input_mapping).
300 std::set<unsigned> interesting_channels;
301 bool silenced = false;
304 const AudioDevice *find_audio_device(DeviceSpec device_spec) const
306 return const_cast<AudioMixer *>(this)->find_audio_device(device_spec);
309 AudioDevice *find_audio_device(DeviceSpec device_spec);
311 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);
312 void fill_audio_bus(const std::map<DeviceSpec, std::vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
313 void reset_resampler_mutex_held(DeviceSpec device_spec);
314 void apply_eq(unsigned bus_index, std::vector<float> *samples_bus);
315 void update_meters(const std::vector<float> &samples);
316 void add_bus_to_master(unsigned bus_index, const std::vector<float> &samples_bus, std::vector<float> *samples_out);
317 void measure_bus_levels(unsigned bus_index, const std::vector<float> &left, const std::vector<float> &right);
318 void send_audio_level_callback();
319 std::vector<DeviceSpec> get_active_devices() const;
320 void set_input_mapping_lock_held(const InputMapping &input_mapping);
324 mutable std::timed_mutex audio_mutex;
327 AudioDevice video_cards[MAX_VIDEO_CARDS]; // Under audio_mutex.
328 AudioDevice alsa_inputs[MAX_ALSA_CARDS]; // Under audio_mutex.
330 std::atomic<float> locut_cutoff_hz{120};
331 StereoFilter locut[MAX_BUSES]; // Default cutoff 120 Hz, 24 dB/oct.
332 std::atomic<bool> locut_enabled[MAX_BUSES];
333 StereoFilter eq[MAX_BUSES][NUM_EQ_BANDS]; // The one for EQBand::MID isn't actually used (see comments in apply_eq()).
335 // First compressor; takes us up to about -12 dBFS.
336 mutable std::mutex compressor_mutex;
337 std::unique_ptr<StereoCompressor> level_compressor[MAX_BUSES]; // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
338 float gain_staging_db[MAX_BUSES]; // Under compressor_mutex.
339 float last_gain_staging_db[MAX_BUSES]; // Under compressor_mutex.
340 bool level_compressor_enabled[MAX_BUSES]; // Under compressor_mutex.
342 static constexpr float ref_level_dbfs = -14.0f; // Chosen so that we end up around 0 LU in practice.
343 static constexpr float ref_level_lufs = -23.0f; // 0 LU, more or less by definition.
345 StereoCompressor limiter;
346 std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f}; // 4 dB.
347 std::atomic<bool> limiter_enabled{true};
348 std::unique_ptr<StereoCompressor> compressor[MAX_BUSES];
349 std::atomic<float> compressor_threshold_dbfs[MAX_BUSES];
350 std::atomic<bool> compressor_enabled[MAX_BUSES];
352 // Note: The values here are not in dB.
354 float current_level = 0.0f; // Peak of the last frame.
355 float historic_peak = 0.0f; // Highest peak since last reset; no falloff.
356 float current_peak = 0.0f; // Current peak of the peak meter.
357 float last_peak = 0.0f;
358 float age_seconds = 0.0f; // Time since "last_peak" was set.
360 PeakHistory peak_history[MAX_BUSES][2]; // Separate for each channel. Under audio_mutex.
362 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.
363 bool final_makeup_gain_auto = true; // Under compressor_mutex.
365 MappingMode current_mapping_mode; // Under audio_mutex.
366 InputMapping input_mapping; // Under audio_mutex.
367 std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
368 float last_fader_volume_db[MAX_BUSES] { 0.0f }; // Under audio_mutex.
369 std::atomic<float> eq_level_db[MAX_BUSES][NUM_EQ_BANDS] {{{ 0.0f }}};
370 float last_eq_level_db[MAX_BUSES][NUM_EQ_BANDS] {{ 0.0f }};
372 audio_level_callback_t audio_level_callback = nullptr;
373 state_changed_callback_t state_changed_callback = nullptr;
374 mutable std::mutex audio_measure_mutex;
375 Ebu_r128_proc r128; // Under audio_measure_mutex.
376 CorrelationMeasurer correlation; // Under audio_measure_mutex.
377 Resampler peak_resampler; // Under audio_measure_mutex.
378 std::atomic<float> peak{0.0f};
381 extern AudioMixer *global_audio_mixer;
383 #endif // !defined(_AUDIO_MIXER_H)