git.sesse.net Git - nageru/blob - audio_mixer.h

   1 #ifndef _AUDIO_MIXER_H
   2 #define _AUDIO_MIXER_H 1
   3
   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.
   8 //
   9 // All operations on AudioMixer (except destruction) are thread-safe.
  10
  11 #include <math.h>
  12 #include <stdint.h>
  13 #include <atomic>
  14 #include <map>
  15 #include <memory>
  16 #include <mutex>
  17 #include <set>
  18 #include <vector>
  19 #include <zita-resampler/resampler.h>
  20
  21 #include "alsa_input.h"
  22 #include "bmusb/bmusb.h"
  23 #include "correlation_measurer.h"
  24 #include "db.h"
  25 #include "defs.h"
  26 #include "ebu_r128_proc.h"
  27 #include "filter.h"
  28 #include "resampling_queue.h"
  29 #include "stereocompressor.h"
  30
  31 namespace bmusb {
  32 struct AudioFormat;
  33 }  // namespace bmusb
  34
  35 enum class InputSourceType { SILENCE, CAPTURE_CARD, ALSA_INPUT };
  36 struct DeviceSpec {
  37         InputSourceType type;
  38         unsigned index;
  39
  40         bool operator== (const DeviceSpec &other) const {
  41                 return type == other.type && index == other.index;
  42         }
  43
  44         bool operator< (const DeviceSpec &other) const {
  45                 if (type != other.type)
  46                         return type < other.type;
  47                 return index < other.index;
  48         }
  49 };
  50 struct DeviceInfo {
  51         std::string name;
  52         unsigned num_channels;
  53 };
  54
  55 enum EQBand {
  56         EQ_BAND_BASS = 0,
  57         EQ_BAND_MID,
  58         EQ_BAND_TREBLE,
  59         NUM_EQ_BANDS
  60 };
  61
  62 static inline uint64_t DeviceSpec_to_key(const DeviceSpec &device_spec)
  63 {
  64         return (uint64_t(device_spec.type) << 32) | device_spec.index;
  65 }
  66
  67 static inline DeviceSpec key_to_DeviceSpec(uint64_t key)
  68 {
  69         return DeviceSpec{ InputSourceType(key >> 32), unsigned(key & 0xffffffff) };
  70 }
  71
  72 struct InputMapping {
  73         struct Bus {
  74                 std::string name;
  75                 DeviceSpec device;
  76                 int source_channel[2] { -1, -1 };  // Left and right. -1 = none.
  77         };
  78
  79         std::vector<Bus> buses;
  80 };
  81
  82 class AudioMixer {
  83 public:
  84         AudioMixer(unsigned num_cards);
  85         void reset_resampler(DeviceSpec device_spec);
  86         void reset_meters();
  87
  88         // Add audio (or silence) to the given device's queue. Can return false if
  89         // the lock wasn't successfully taken; if so, you should simply try again.
  90         // (This is to avoid a deadlock where a card hangs on the mutex in add_audio()
  91         // while we are trying to shut it down from another thread that also holds
  92         // the mutex.) frame_length is in TIMEBASE units.
  93         bool add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
  94         bool add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
  95
  96         std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
  97
  98         void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
  99
 100         // Note: This operation holds all ALSA devices (see ALSAPool::get_devices()).
 101         // You will need to call set_input_mapping() to get the hold state correctly,
 102         // or every card will be held forever.
 103         std::map<DeviceSpec, DeviceInfo> get_devices();
 104
 105         // See comments on ALSAPool::get_card_state().
 106         ALSAPool::Device::State get_alsa_card_state(unsigned index)
 107         {
 108                 return alsa_pool.get_card_state(index);
 109         }
 110
 111         void set_name(DeviceSpec device_spec, const std::string &name);
 112
 113         void set_input_mapping(const InputMapping &input_mapping);
 114         InputMapping get_input_mapping() const;
 115
 116         void set_locut_cutoff(float cutoff_hz)
 117         {
 118                 locut_cutoff_hz = cutoff_hz;
 119         }
 120
 121         float get_locut_cutoff() const
 122         {
 123                 return locut_cutoff_hz;
 124         }
 125
 126         void set_locut_enabled(unsigned bus, bool enabled)
 127         {
 128                 locut_enabled[bus] = enabled;
 129         }
 130
 131         bool get_locut_enabled(unsigned bus)
 132         {
 133                 return locut_enabled[bus];
 134         }
 135
 136         void set_eq(unsigned bus_index, EQBand band, float db_gain)
 137         {
 138                 assert(band >= 0 && band < NUM_EQ_BANDS);
 139                 eq_level_db[bus_index][band] = db_gain;
 140         }
 141
 142         float get_eq(unsigned bus_index, EQBand band) const
 143         {
 144                 assert(band >= 0 && band < NUM_EQ_BANDS);
 145                 return eq_level_db[bus_index][band];
 146         }
 147
 148         float get_limiter_threshold_dbfs() const
 149         {
 150                 return limiter_threshold_dbfs;
 151         }
 152
 153         float get_compressor_threshold_dbfs(unsigned bus_index) const
 154         {
 155                 return compressor_threshold_dbfs[bus_index];
 156         }
 157
 158         void set_limiter_threshold_dbfs(float threshold_dbfs)
 159         {
 160                 limiter_threshold_dbfs = threshold_dbfs;
 161         }
 162
 163         void set_compressor_threshold_dbfs(unsigned bus_index, float threshold_dbfs)
 164         {
 165                 compressor_threshold_dbfs[bus_index] = threshold_dbfs;
 166         }
 167
 168         void set_limiter_enabled(bool enabled)
 169         {
 170                 limiter_enabled = enabled;
 171         }
 172
 173         bool get_limiter_enabled() const
 174         {
 175                 return limiter_enabled;
 176         }
 177
 178         void set_compressor_enabled(unsigned bus_index, bool enabled)
 179         {
 180                 compressor_enabled[bus_index] = enabled;
 181         }
 182
 183         bool get_compressor_enabled(unsigned bus_index) const
 184         {
 185                 return compressor_enabled[bus_index];
 186         }
 187
 188         void set_gain_staging_db(unsigned bus_index, float gain_db)
 189         {
 190                 std::unique_lock<std::mutex> lock(compressor_mutex);
 191                 level_compressor_enabled[bus_index] = false;
 192                 gain_staging_db[bus_index] = gain_db;
 193         }
 194
 195         float get_gain_staging_db(unsigned bus_index) const
 196         {
 197                 std::unique_lock<std::mutex> lock(compressor_mutex);
 198                 return gain_staging_db[bus_index];
 199         }
 200
 201         void set_gain_staging_auto(unsigned bus_index, bool enabled)
 202         {
 203                 std::unique_lock<std::mutex> lock(compressor_mutex);
 204                 level_compressor_enabled[bus_index] = enabled;
 205         }
 206
 207         bool get_gain_staging_auto(unsigned bus_index) const
 208         {
 209                 std::unique_lock<std::mutex> lock(compressor_mutex);
 210                 return level_compressor_enabled[bus_index];
 211         }
 212
 213         void set_final_makeup_gain_db(float gain_db)
 214         {
 215                 std::unique_lock<std::mutex> lock(compressor_mutex);
 216                 final_makeup_gain_auto = false;
 217                 final_makeup_gain = from_db(gain_db);
 218         }
 219
 220         float get_final_makeup_gain_db()
 221         {
 222                 std::unique_lock<std::mutex> lock(compressor_mutex);
 223                 return to_db(final_makeup_gain);
 224         }
 225
 226         void set_final_makeup_gain_auto(bool enabled)
 227         {
 228                 std::unique_lock<std::mutex> lock(compressor_mutex);
 229                 final_makeup_gain_auto = enabled;
 230         }
 231
 232         bool get_final_makeup_gain_auto() const
 233         {
 234                 std::unique_lock<std::mutex> lock(compressor_mutex);
 235                 return final_makeup_gain_auto;
 236         }
 237
 238         void reset_peak(unsigned bus_index);
 239
 240         struct BusLevel {
 241                 float current_level_dbfs[2];  // Digital peak of last frame, left and right.
 242                 float peak_level_dbfs[2];  // Digital peak with hold, left and right.
 243                 float historic_peak_dbfs;
 244                 float gain_staging_db;
 245                 float compressor_attenuation_db;  // A positive number; 0.0 for no attenuation.
 246         };
 247
 248         typedef std::function<void(float level_lufs, float peak_db,
 249                                    std::vector<BusLevel> bus_levels,
 250                                    float global_level_lufs, float range_low_lufs, float range_high_lufs,
 251                                    float final_makeup_gain_db,
 252                                    float correlation)> audio_level_callback_t;
 253         void set_audio_level_callback(audio_level_callback_t callback)
 254         {
 255                 audio_level_callback = callback;
 256         }
 257
 258 private:
 259         struct AudioDevice {
 260                 std::unique_ptr<ResamplingQueue> resampling_queue;
 261                 int64_t next_local_pts = 0;
 262                 std::string name;
 263                 unsigned capture_frequency = OUTPUT_FREQUENCY;
 264                 // Which channels we consider interesting (ie., are part of some input_mapping).
 265                 std::set<unsigned> interesting_channels;
 266         };
 267
 268         const AudioDevice *find_audio_device(DeviceSpec device_spec) const
 269         {
 270                 return const_cast<AudioMixer *>(this)->find_audio_device(device_spec);
 271         }
 272
 273         AudioDevice *find_audio_device(DeviceSpec device_spec);
 274
 275         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);
 276         void fill_audio_bus(const std::map<DeviceSpec, std::vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
 277         void reset_resampler_mutex_held(DeviceSpec device_spec);
 278         void apply_eq(unsigned bus_index, std::vector<float> *samples_bus);
 279         void update_meters(const std::vector<float> &samples);
 280         void add_bus_to_master(unsigned bus_index, const std::vector<float> &samples_bus, std::vector<float> *samples_out);
 281         void measure_bus_levels(unsigned bus_index, const std::vector<float> &left, const std::vector<float> &right);
 282         void send_audio_level_callback();
 283         std::vector<DeviceSpec> get_active_devices() const;
 284
 285         unsigned num_cards;
 286
 287         mutable std::timed_mutex audio_mutex;
 288
 289         ALSAPool alsa_pool;
 290         AudioDevice video_cards[MAX_VIDEO_CARDS];  // Under audio_mutex.
 291         AudioDevice alsa_inputs[MAX_ALSA_CARDS];  // Under audio_mutex.
 292
 293         std::atomic<float> locut_cutoff_hz{120};
 294         StereoFilter locut[MAX_BUSES];  // Default cutoff 120 Hz, 24 dB/oct.
 295         std::atomic<bool> locut_enabled[MAX_BUSES];
 296         StereoFilter eq[MAX_BUSES][NUM_EQ_BANDS];  // The one for EQBand::MID isn't actually used (see comments in apply_eq()).
 297
 298         // First compressor; takes us up to about -12 dBFS.
 299         mutable std::mutex compressor_mutex;
 300         std::unique_ptr<StereoCompressor> level_compressor[MAX_BUSES];  // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
 301         float gain_staging_db[MAX_BUSES];  // Under compressor_mutex.
 302         bool level_compressor_enabled[MAX_BUSES];  // Under compressor_mutex.
 303
 304         static constexpr float ref_level_dbfs = -14.0f;  // Chosen so that we end up around 0 LU in practice.
 305         static constexpr float ref_level_lufs = -23.0f;  // 0 LU, more or less by definition.
 306
 307         StereoCompressor limiter;
 308         std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f};   // 4 dB.
 309         std::atomic<bool> limiter_enabled{true};
 310         std::unique_ptr<StereoCompressor> compressor[MAX_BUSES];
 311         std::atomic<float> compressor_threshold_dbfs[MAX_BUSES];
 312         std::atomic<bool> compressor_enabled[MAX_BUSES];
 313
 314         // Note: The values here are not in dB.
 315         struct PeakHistory {
 316                 float current_level = 0.0f;  // Peak of the last frame.
 317                 float historic_peak = 0.0f;  // Highest peak since last reset; no falloff.
 318                 float current_peak = 0.0f;  // Current peak of the peak meter.
 319                 float last_peak = 0.0f;
 320                 float age_seconds = 0.0f;   // Time since "last_peak" was set.
 321         };
 322         PeakHistory peak_history[MAX_BUSES][2];  // Separate for each channel. Under audio_mutex.
 323
 324         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.
 325         bool final_makeup_gain_auto = true;  // Under compressor_mutex.
 326
 327         InputMapping input_mapping;  // Under audio_mutex.
 328         std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
 329         float last_fader_volume_db[MAX_BUSES] { 0.0f };  // Under audio_mutex.
 330         std::atomic<float> eq_level_db[MAX_BUSES][NUM_EQ_BANDS] {{{ 0.0f }}};
 331
 332         audio_level_callback_t audio_level_callback = nullptr;
 333         mutable std::mutex audio_measure_mutex;
 334         Ebu_r128_proc r128;  // Under audio_measure_mutex.
 335         CorrelationMeasurer correlation;  // Under audio_measure_mutex.
 336         Resampler peak_resampler;  // Under audio_measure_mutex.
 337         std::atomic<float> peak{0.0f};
 338 };
 339
 340 extern AudioMixer *global_audio_mixer;
 341
 342 #endif  // !defined(_AUDIO_MIXER_H)