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 };
44 int source_channel[2] { -1, -1 }; // Left and right. -1 = none.
47 std::vector<Bus> buses;
52 AudioMixer(unsigned num_cards);
53 void reset_device(DeviceSpec device_spec);
55 // frame_length is in TIMEBASE units.
56 void add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
57 void add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
58 std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
60 // See comments inside get_output().
61 void set_current_loudness(double level_lufs) { loudness_lufs = level_lufs; }
63 void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
64 std::vector<std::string> get_names() const;
65 void set_name(DeviceSpec device_spec, const std::string &name);
67 void set_input_mapping(const InputMapping &input_mapping);
68 InputMapping get_input_mapping() const;
70 void set_locut_cutoff(float cutoff_hz)
72 locut_cutoff_hz = cutoff_hz;
75 void set_locut_enabled(bool enabled)
77 locut_enabled = enabled;
80 bool get_locut_enabled() const
85 float get_limiter_threshold_dbfs() const
87 return limiter_threshold_dbfs;
90 float get_compressor_threshold_dbfs() const
92 return compressor_threshold_dbfs;
95 void set_limiter_threshold_dbfs(float threshold_dbfs)
97 limiter_threshold_dbfs = threshold_dbfs;
100 void set_compressor_threshold_dbfs(float threshold_dbfs)
102 compressor_threshold_dbfs = threshold_dbfs;
105 void set_limiter_enabled(bool enabled)
107 limiter_enabled = enabled;
110 bool get_limiter_enabled() const
112 return limiter_enabled;
115 void set_compressor_enabled(bool enabled)
117 compressor_enabled = enabled;
120 bool get_compressor_enabled() const
122 return compressor_enabled;
125 void set_gain_staging_db(float gain_db)
127 std::unique_lock<std::mutex> lock(compressor_mutex);
128 level_compressor_enabled = false;
129 gain_staging_db = gain_db;
132 float get_gain_staging_db() const
134 std::unique_lock<std::mutex> lock(compressor_mutex);
135 return gain_staging_db;
138 void set_gain_staging_auto(bool enabled)
140 std::unique_lock<std::mutex> lock(compressor_mutex);
141 level_compressor_enabled = enabled;
144 bool get_gain_staging_auto() const
146 std::unique_lock<std::mutex> lock(compressor_mutex);
147 return level_compressor_enabled;
150 void set_final_makeup_gain_db(float gain_db)
152 std::unique_lock<std::mutex> lock(compressor_mutex);
153 final_makeup_gain_auto = false;
154 final_makeup_gain = from_db(gain_db);
157 float get_final_makeup_gain_db()
159 std::unique_lock<std::mutex> lock(compressor_mutex);
160 return to_db(final_makeup_gain);
163 void set_final_makeup_gain_auto(bool enabled)
165 std::unique_lock<std::mutex> lock(compressor_mutex);
166 final_makeup_gain_auto = enabled;
169 bool get_final_makeup_gain_auto() const
171 std::unique_lock<std::mutex> lock(compressor_mutex);
172 return final_makeup_gain_auto;
177 std::unique_ptr<ResamplingQueue> resampling_queue;
178 int64_t next_local_pts = 0;
180 // Which channels we consider interesting (ie., are part of some input_mapping).
181 std::set<unsigned> interesting_channels;
183 AudioDevice *find_audio_device(DeviceSpec device_spec);
185 void find_sample_src_from_device(const std::vector<float> *samples_card, DeviceSpec device_spec, int source_channel, const float **srcptr, unsigned *stride);
186 void fill_audio_bus(const std::vector<float> *samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
187 void reset_device_mutex_held(DeviceSpec device_spec);
191 mutable std::mutex audio_mutex;
193 AudioDevice cards[MAX_CARDS]; // Under audio_mutex.
195 StereoFilter locut; // Default cutoff 120 Hz, 24 dB/oct.
196 std::atomic<float> locut_cutoff_hz;
197 std::atomic<bool> locut_enabled{true};
199 // First compressor; takes us up to about -12 dBFS.
200 mutable std::mutex compressor_mutex;
201 StereoCompressor level_compressor; // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
202 float gain_staging_db = 0.0f; // Under compressor_mutex.
203 bool level_compressor_enabled = true; // Under compressor_mutex.
205 static constexpr float ref_level_dbfs = -14.0f; // Chosen so that we end up around 0 LU in practice.
206 static constexpr float ref_level_lufs = -23.0f; // 0 LU, more or less by definition.
208 std::atomic<float> loudness_lufs{ref_level_lufs};
210 StereoCompressor limiter;
211 std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f}; // 4 dB.
212 std::atomic<bool> limiter_enabled{true};
213 StereoCompressor compressor;
214 std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f}; // -12 dB.
215 std::atomic<bool> compressor_enabled{true};
217 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.
218 bool final_makeup_gain_auto = true; // Under compressor_mutex.
220 InputMapping input_mapping; // Under audio_mutex.
221 std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
224 #endif // !defined(_AUDIO_MIXER_H)