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 bool operator== (const DeviceSpec &other) const {
40 return type == other.type && index == other.index;
43 bool operator< (const DeviceSpec &other) const {
44 if (type != other.type)
45 return type < other.type;
46 return index < other.index;
50 static inline uint64_t DeviceSpec_to_key(const DeviceSpec &device_spec)
52 return (uint64_t(device_spec.type) << 32) | device_spec.index;
55 static inline DeviceSpec key_to_DeviceSpec(uint64_t key)
57 return DeviceSpec{ InputSourceType(key >> 32), unsigned(key & 0xffffffff) };
64 int source_channel[2] { -1, -1 }; // Left and right. -1 = none.
67 std::vector<Bus> buses;
72 AudioMixer(unsigned num_cards);
73 void reset_device(DeviceSpec device_spec);
75 // frame_length is in TIMEBASE units.
76 void add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
77 void add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
78 std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
80 // See comments inside get_output().
81 void set_current_loudness(double level_lufs) { loudness_lufs = level_lufs; }
83 void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
84 std::map<DeviceSpec, std::string> get_names() const;
85 void set_name(DeviceSpec device_spec, const std::string &name);
87 void set_input_mapping(const InputMapping &input_mapping);
88 InputMapping get_input_mapping() const;
90 void set_locut_cutoff(float cutoff_hz)
92 locut_cutoff_hz = cutoff_hz;
95 void set_locut_enabled(bool enabled)
97 locut_enabled = enabled;
100 bool get_locut_enabled() const
102 return locut_enabled;
105 float get_limiter_threshold_dbfs() const
107 return limiter_threshold_dbfs;
110 float get_compressor_threshold_dbfs() const
112 return compressor_threshold_dbfs;
115 void set_limiter_threshold_dbfs(float threshold_dbfs)
117 limiter_threshold_dbfs = threshold_dbfs;
120 void set_compressor_threshold_dbfs(float threshold_dbfs)
122 compressor_threshold_dbfs = threshold_dbfs;
125 void set_limiter_enabled(bool enabled)
127 limiter_enabled = enabled;
130 bool get_limiter_enabled() const
132 return limiter_enabled;
135 void set_compressor_enabled(bool enabled)
137 compressor_enabled = enabled;
140 bool get_compressor_enabled() const
142 return compressor_enabled;
145 void set_gain_staging_db(float gain_db)
147 std::unique_lock<std::mutex> lock(compressor_mutex);
148 level_compressor_enabled = false;
149 gain_staging_db = gain_db;
152 float get_gain_staging_db() const
154 std::unique_lock<std::mutex> lock(compressor_mutex);
155 return gain_staging_db;
158 void set_gain_staging_auto(bool enabled)
160 std::unique_lock<std::mutex> lock(compressor_mutex);
161 level_compressor_enabled = enabled;
164 bool get_gain_staging_auto() const
166 std::unique_lock<std::mutex> lock(compressor_mutex);
167 return level_compressor_enabled;
170 void set_final_makeup_gain_db(float gain_db)
172 std::unique_lock<std::mutex> lock(compressor_mutex);
173 final_makeup_gain_auto = false;
174 final_makeup_gain = from_db(gain_db);
177 float get_final_makeup_gain_db()
179 std::unique_lock<std::mutex> lock(compressor_mutex);
180 return to_db(final_makeup_gain);
183 void set_final_makeup_gain_auto(bool enabled)
185 std::unique_lock<std::mutex> lock(compressor_mutex);
186 final_makeup_gain_auto = enabled;
189 bool get_final_makeup_gain_auto() const
191 std::unique_lock<std::mutex> lock(compressor_mutex);
192 return final_makeup_gain_auto;
197 std::unique_ptr<ResamplingQueue> resampling_queue;
198 int64_t next_local_pts = 0;
200 unsigned capture_frequency = OUTPUT_FREQUENCY;
201 // Which channels we consider interesting (ie., are part of some input_mapping).
202 std::set<unsigned> interesting_channels;
204 AudioDevice *find_audio_device(DeviceSpec device_spec);
206 void find_sample_src_from_device(const std::vector<float> *samples_card, DeviceSpec device_spec, int source_channel, const float **srcptr, unsigned *stride);
207 void fill_audio_bus(const std::vector<float> *samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
208 void reset_device_mutex_held(DeviceSpec device_spec);
212 mutable std::mutex audio_mutex;
214 AudioDevice cards[MAX_CARDS]; // Under audio_mutex.
216 StereoFilter locut; // Default cutoff 120 Hz, 24 dB/oct.
217 std::atomic<float> locut_cutoff_hz;
218 std::atomic<bool> locut_enabled{true};
220 // First compressor; takes us up to about -12 dBFS.
221 mutable std::mutex compressor_mutex;
222 StereoCompressor level_compressor; // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
223 float gain_staging_db = 0.0f; // Under compressor_mutex.
224 bool level_compressor_enabled = true; // Under compressor_mutex.
226 static constexpr float ref_level_dbfs = -14.0f; // Chosen so that we end up around 0 LU in practice.
227 static constexpr float ref_level_lufs = -23.0f; // 0 LU, more or less by definition.
229 std::atomic<float> loudness_lufs{ref_level_lufs};
231 StereoCompressor limiter;
232 std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f}; // 4 dB.
233 std::atomic<bool> limiter_enabled{true};
234 StereoCompressor compressor;
235 std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f}; // -12 dB.
236 std::atomic<bool> compressor_enabled{true};
238 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.
239 bool final_makeup_gain_auto = true; // Under compressor_mutex.
241 InputMapping input_mapping; // Under audio_mutex.
242 std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
245 #endif // !defined(_AUDIO_MIXER_H)