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         ~AudioMixer();
  86         void reset_resampler(DeviceSpec device_spec);
  87         void reset_meters();
  88
  89         // Add audio (or silence) to the given device's queue. Can return false if
  90         // the lock wasn't successfully taken; if so, you should simply try again.
  91         // (This is to avoid a deadlock where a card hangs on the mutex in add_audio()
  92         // while we are trying to shut it down from another thread that also holds
  93         // the mutex.) frame_length is in TIMEBASE units.
  94         bool add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
  95         bool add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
  96
  97         std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
  98
  99         void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
 100         std::map<DeviceSpec, DeviceInfo> get_devices() const;
 101         void set_name(DeviceSpec device_spec, const std::string &name);
 102
 103         void set_input_mapping(const InputMapping &input_mapping);
 104         InputMapping get_input_mapping() const;
 105
 106         void set_locut_cutoff(float cutoff_hz)
 107         {
 108                 locut_cutoff_hz = cutoff_hz;
 109         }
 110
 111         void set_locut_enabled(unsigned bus, bool enabled)
 112         {
 113                 locut_enabled[bus] = enabled;
 114         }
 115
 116         bool get_locut_enabled(unsigned bus)
 117         {
 118                 return locut_enabled[bus];
 119         }
 120
 121         void set_eq(unsigned bus_index, EQBand band, float db_gain)
 122         {
 123                 assert(band >= 0 && band < NUM_EQ_BANDS);
 124                 eq_level_db[bus_index][band] = db_gain;
 125         }
 126
 127         float get_limiter_threshold_dbfs() const
 128         {
 129                 return limiter_threshold_dbfs;
 130         }
 131
 132         float get_compressor_threshold_dbfs(unsigned bus_index) const
 133         {
 134                 return compressor_threshold_dbfs[bus_index];
 135         }
 136
 137         void set_limiter_threshold_dbfs(float threshold_dbfs)
 138         {
 139                 limiter_threshold_dbfs = threshold_dbfs;
 140         }
 141
 142         void set_compressor_threshold_dbfs(unsigned bus_index, float threshold_dbfs)
 143         {
 144                 compressor_threshold_dbfs[bus_index] = threshold_dbfs;
 145         }
 146
 147         void set_limiter_enabled(bool enabled)
 148         {
 149                 limiter_enabled = enabled;
 150         }
 151
 152         bool get_limiter_enabled() const
 153         {
 154                 return limiter_enabled;
 155         }
 156
 157         void set_compressor_enabled(unsigned bus_index, bool enabled)
 158         {
 159                 compressor_enabled[bus_index] = enabled;
 160         }
 161
 162         bool get_compressor_enabled(unsigned bus_index) const
 163         {
 164                 return compressor_enabled[bus_index];
 165         }
 166
 167         void set_gain_staging_db(unsigned bus_index, float gain_db)
 168         {
 169                 std::unique_lock<std::mutex> lock(compressor_mutex);
 170                 level_compressor_enabled[bus_index] = false;
 171                 gain_staging_db[bus_index] = gain_db;
 172         }
 173
 174         float get_gain_staging_db(unsigned bus_index) const
 175         {
 176                 std::unique_lock<std::mutex> lock(compressor_mutex);
 177                 return gain_staging_db[bus_index];
 178         }
 179
 180         void set_gain_staging_auto(unsigned bus_index, bool enabled)
 181         {
 182                 std::unique_lock<std::mutex> lock(compressor_mutex);
 183                 level_compressor_enabled[bus_index] = enabled;
 184         }
 185
 186         bool get_gain_staging_auto(unsigned bus_index) const
 187         {
 188                 std::unique_lock<std::mutex> lock(compressor_mutex);
 189                 return level_compressor_enabled[bus_index];
 190         }
 191
 192         void set_final_makeup_gain_db(float gain_db)
 193         {
 194                 std::unique_lock<std::mutex> lock(compressor_mutex);
 195                 final_makeup_gain_auto = false;
 196                 final_makeup_gain = from_db(gain_db);
 197         }
 198
 199         float get_final_makeup_gain_db()
 200         {
 201                 std::unique_lock<std::mutex> lock(compressor_mutex);
 202                 return to_db(final_makeup_gain);
 203         }
 204
 205         void set_final_makeup_gain_auto(bool enabled)
 206         {
 207                 std::unique_lock<std::mutex> lock(compressor_mutex);
 208                 final_makeup_gain_auto = enabled;
 209         }
 210
 211         bool get_final_makeup_gain_auto() const
 212         {
 213                 std::unique_lock<std::mutex> lock(compressor_mutex);
 214                 return final_makeup_gain_auto;
 215         }
 216
 217         void reset_peak(unsigned bus_index);
 218
 219         struct BusLevel {
 220                 float current_level_dbfs[2];  // Digital peak of last frame, left and right.
 221                 float peak_level_dbfs[2];  // Digital peak with hold, left and right.
 222                 float historic_peak_dbfs;
 223                 float gain_staging_db;
 224                 float compressor_attenuation_db;  // A positive number; 0.0 for no attenuation.
 225         };
 226
 227         typedef std::function<void(float level_lufs, float peak_db,
 228                                    std::vector<BusLevel> bus_levels,
 229                                    float global_level_lufs, float range_low_lufs, float range_high_lufs,
 230                                    float final_makeup_gain_db,
 231                                    float correlation)> audio_level_callback_t;
 232         void set_audio_level_callback(audio_level_callback_t callback)
 233         {
 234                 audio_level_callback = callback;
 235         }
 236
 237 private:
 238         struct AudioDevice {
 239                 std::unique_ptr<ResamplingQueue> resampling_queue;
 240                 int64_t next_local_pts = 0;
 241                 std::string name;
 242                 unsigned capture_frequency = OUTPUT_FREQUENCY;
 243                 // Which channels we consider interesting (ie., are part of some input_mapping).
 244                 std::set<unsigned> interesting_channels;
 245                 // Only used for ALSA cards, obviously.
 246                 std::unique_ptr<ALSAInput> alsa_device;
 247         };
 248         AudioDevice *find_audio_device(DeviceSpec device_spec);
 249
 250         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);
 251         void fill_audio_bus(const std::map<DeviceSpec, std::vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
 252         void reset_resampler_mutex_held(DeviceSpec device_spec);
 253         void reset_alsa_mutex_held(DeviceSpec device_spec);
 254         std::map<DeviceSpec, DeviceInfo> get_devices_mutex_held() const;
 255         void apply_eq(unsigned bus_index, std::vector<float> *samples_bus);
 256         void update_meters(const std::vector<float> &samples);
 257         void add_bus_to_master(unsigned bus_index, const std::vector<float> &samples_bus, std::vector<float> *samples_out);
 258         void measure_bus_levels(unsigned bus_index, const std::vector<float> &left, const std::vector<float> &right);
 259         void send_audio_level_callback();
 260
 261         unsigned num_cards;
 262
 263         mutable std::timed_mutex audio_mutex;
 264
 265         AudioDevice video_cards[MAX_VIDEO_CARDS];  // Under audio_mutex.
 266
 267         // TODO: Figure out a better way to unify these two, as they are sharing indexing.
 268         AudioDevice alsa_inputs[MAX_ALSA_CARDS];  // Under audio_mutex.
 269         std::vector<ALSAInput::Device> available_alsa_cards;
 270
 271         std::atomic<float> locut_cutoff_hz;
 272         StereoFilter locut[MAX_BUSES];  // Default cutoff 120 Hz, 24 dB/oct.
 273         std::atomic<bool> locut_enabled[MAX_BUSES];
 274         StereoFilter eq[MAX_BUSES][NUM_EQ_BANDS];  // The one for EQBand::MID isn't actually used (see comments in apply_eq()).
 275
 276         // First compressor; takes us up to about -12 dBFS.
 277         mutable std::mutex compressor_mutex;
 278         std::unique_ptr<StereoCompressor> level_compressor[MAX_BUSES];  // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
 279         float gain_staging_db[MAX_BUSES];  // Under compressor_mutex.
 280         bool level_compressor_enabled[MAX_BUSES];  // Under compressor_mutex.
 281
 282         static constexpr float ref_level_dbfs = -14.0f;  // Chosen so that we end up around 0 LU in practice.
 283         static constexpr float ref_level_lufs = -23.0f;  // 0 LU, more or less by definition.
 284
 285         StereoCompressor limiter;
 286         std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f};   // 4 dB.
 287         std::atomic<bool> limiter_enabled{true};
 288         std::unique_ptr<StereoCompressor> compressor[MAX_BUSES];
 289         std::atomic<float> compressor_threshold_dbfs[MAX_BUSES];
 290         std::atomic<bool> compressor_enabled[MAX_BUSES];
 291
 292         // Note: The values here are not in dB.
 293         struct PeakHistory {
 294                 float current_level = 0.0f;  // Peak of the last frame.
 295                 float historic_peak = 0.0f;  // Highest peak since last reset; no falloff.
 296                 float current_peak = 0.0f;  // Current peak of the peak meter.
 297                 float last_peak = 0.0f;
 298                 float age_seconds = 0.0f;   // Time since "last_peak" was set.
 299         };
 300         PeakHistory peak_history[MAX_BUSES][2];  // Separate for each channel. Under audio_mutex.
 301
 302         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.
 303         bool final_makeup_gain_auto = true;  // Under compressor_mutex.
 304
 305         InputMapping input_mapping;  // Under audio_mutex.
 306         std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
 307         float last_fader_volume_db[MAX_BUSES] { 0.0f };  // Under audio_mutex.
 308         std::atomic<float> eq_level_db[MAX_BUSES][NUM_EQ_BANDS] {{{ 0.0f }}};
 309
 310         audio_level_callback_t audio_level_callback = nullptr;
 311         mutable std::mutex audio_measure_mutex;
 312         Ebu_r128_proc r128;  // Under audio_measure_mutex.
 313         CorrelationMeasurer correlation;  // Under audio_measure_mutex.
 314         Resampler peak_resampler;  // Under audio_measure_mutex.
 315         std::atomic<float> peak{0.0f};
 316 };
 317
 318 #endif  // !defined(_AUDIO_MIXER_H)