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;
51 unsigned num_channels;
54 static inline uint64_t DeviceSpec_to_key(const DeviceSpec &device_spec)
56 return (uint64_t(device_spec.type) << 32) | device_spec.index;
59 static inline DeviceSpec key_to_DeviceSpec(uint64_t key)
61 return DeviceSpec{ InputSourceType(key >> 32), unsigned(key & 0xffffffff) };
68 int source_channel[2] { -1, -1 }; // Left and right. -1 = none.
71 std::vector<Bus> buses;
76 AudioMixer(unsigned num_cards);
77 void reset_device(DeviceSpec device_spec);
79 // frame_length is in TIMEBASE units.
80 void add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
81 void add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
82 std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
84 // See comments inside get_output().
85 void set_current_loudness(double level_lufs) { loudness_lufs = level_lufs; }
87 void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
88 std::map<DeviceSpec, DeviceInfo> get_devices() const;
89 void set_name(DeviceSpec device_spec, const std::string &name);
91 void set_input_mapping(const InputMapping &input_mapping);
92 InputMapping get_input_mapping() const;
94 void set_locut_cutoff(float cutoff_hz)
96 locut_cutoff_hz = cutoff_hz;
99 void set_locut_enabled(bool enabled)
101 locut_enabled = enabled;
104 bool get_locut_enabled() const
106 return locut_enabled;
109 float get_limiter_threshold_dbfs() const
111 return limiter_threshold_dbfs;
114 float get_compressor_threshold_dbfs() const
116 return compressor_threshold_dbfs;
119 void set_limiter_threshold_dbfs(float threshold_dbfs)
121 limiter_threshold_dbfs = threshold_dbfs;
124 void set_compressor_threshold_dbfs(float threshold_dbfs)
126 compressor_threshold_dbfs = threshold_dbfs;
129 void set_limiter_enabled(bool enabled)
131 limiter_enabled = enabled;
134 bool get_limiter_enabled() const
136 return limiter_enabled;
139 void set_compressor_enabled(bool enabled)
141 compressor_enabled = enabled;
144 bool get_compressor_enabled() const
146 return compressor_enabled;
149 void set_gain_staging_db(float gain_db)
151 std::unique_lock<std::mutex> lock(compressor_mutex);
152 level_compressor_enabled = false;
153 gain_staging_db = gain_db;
156 float get_gain_staging_db() const
158 std::unique_lock<std::mutex> lock(compressor_mutex);
159 return gain_staging_db;
162 void set_gain_staging_auto(bool enabled)
164 std::unique_lock<std::mutex> lock(compressor_mutex);
165 level_compressor_enabled = enabled;
168 bool get_gain_staging_auto() const
170 std::unique_lock<std::mutex> lock(compressor_mutex);
171 return level_compressor_enabled;
174 void set_final_makeup_gain_db(float gain_db)
176 std::unique_lock<std::mutex> lock(compressor_mutex);
177 final_makeup_gain_auto = false;
178 final_makeup_gain = from_db(gain_db);
181 float get_final_makeup_gain_db()
183 std::unique_lock<std::mutex> lock(compressor_mutex);
184 return to_db(final_makeup_gain);
187 void set_final_makeup_gain_auto(bool enabled)
189 std::unique_lock<std::mutex> lock(compressor_mutex);
190 final_makeup_gain_auto = enabled;
193 bool get_final_makeup_gain_auto() const
195 std::unique_lock<std::mutex> lock(compressor_mutex);
196 return final_makeup_gain_auto;
201 std::unique_ptr<ResamplingQueue> resampling_queue;
202 int64_t next_local_pts = 0;
204 unsigned capture_frequency = OUTPUT_FREQUENCY;
205 // Which channels we consider interesting (ie., are part of some input_mapping).
206 std::set<unsigned> interesting_channels;
208 AudioDevice *find_audio_device(DeviceSpec device_spec);
210 void find_sample_src_from_device(const std::vector<float> *samples_card, DeviceSpec device_spec, int source_channel, const float **srcptr, unsigned *stride);
211 void fill_audio_bus(const std::vector<float> *samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
212 void reset_device_mutex_held(DeviceSpec device_spec);
216 mutable std::mutex audio_mutex;
218 AudioDevice video_cards[MAX_VIDEO_CARDS]; // Under audio_mutex.
220 StereoFilter locut; // Default cutoff 120 Hz, 24 dB/oct.
221 std::atomic<float> locut_cutoff_hz;
222 std::atomic<bool> locut_enabled{true};
224 // First compressor; takes us up to about -12 dBFS.
225 mutable std::mutex compressor_mutex;
226 StereoCompressor level_compressor; // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
227 float gain_staging_db = 0.0f; // Under compressor_mutex.
228 bool level_compressor_enabled = true; // Under compressor_mutex.
230 static constexpr float ref_level_dbfs = -14.0f; // Chosen so that we end up around 0 LU in practice.
231 static constexpr float ref_level_lufs = -23.0f; // 0 LU, more or less by definition.
233 std::atomic<float> loudness_lufs{ref_level_lufs};
235 StereoCompressor limiter;
236 std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f}; // 4 dB.
237 std::atomic<bool> limiter_enabled{true};
238 StereoCompressor compressor;
239 std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f}; // -12 dB.
240 std::atomic<bool> compressor_enabled{true};
242 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.
243 bool final_makeup_gain_auto = true; // Under compressor_mutex.
245 InputMapping input_mapping; // Under audio_mutex.
246 std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
249 #endif // !defined(_AUDIO_MIXER_H)