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_eq(unsigned bus_index, EQBand band) const
 128         {
 129                 assert(band >= 0 && band < NUM_EQ_BANDS);
 130                 return eq_level_db[bus_index][band];
 131         }
 132
 133         float get_limiter_threshold_dbfs() const
 134         {
 135                 return limiter_threshold_dbfs;
 136         }
 137
 138         float get_compressor_threshold_dbfs(unsigned bus_index) const
 139         {
 140                 return compressor_threshold_dbfs[bus_index];
 141         }
 142
 143         void set_limiter_threshold_dbfs(float threshold_dbfs)
 144         {
 145                 limiter_threshold_dbfs = threshold_dbfs;
 146         }
 147
 148         void set_compressor_threshold_dbfs(unsigned bus_index, float threshold_dbfs)
 149         {
 150                 compressor_threshold_dbfs[bus_index] = threshold_dbfs;
 151         }
 152
 153         void set_limiter_enabled(bool enabled)
 154         {
 155                 limiter_enabled = enabled;
 156         }
 157
 158         bool get_limiter_enabled() const
 159         {
 160                 return limiter_enabled;
 161         }
 162
 163         void set_compressor_enabled(unsigned bus_index, bool enabled)
 164         {
 165                 compressor_enabled[bus_index] = enabled;
 166         }
 167
 168         bool get_compressor_enabled(unsigned bus_index) const
 169         {
 170                 return compressor_enabled[bus_index];
 171         }
 172
 173         void set_gain_staging_db(unsigned bus_index, float gain_db)
 174         {
 175                 std::unique_lock<std::mutex> lock(compressor_mutex);
 176                 level_compressor_enabled[bus_index] = false;
 177                 gain_staging_db[bus_index] = gain_db;
 178         }
 179
 180         float get_gain_staging_db(unsigned bus_index) const
 181         {
 182                 std::unique_lock<std::mutex> lock(compressor_mutex);
 183                 return gain_staging_db[bus_index];
 184         }
 185
 186         void set_gain_staging_auto(unsigned bus_index, bool enabled)
 187         {
 188                 std::unique_lock<std::mutex> lock(compressor_mutex);
 189                 level_compressor_enabled[bus_index] = enabled;
 190         }
 191
 192         bool get_gain_staging_auto(unsigned bus_index) const
 193         {
 194                 std::unique_lock<std::mutex> lock(compressor_mutex);
 195                 return level_compressor_enabled[bus_index];
 196         }
 197
 198         void set_final_makeup_gain_db(float gain_db)
 199         {
 200                 std::unique_lock<std::mutex> lock(compressor_mutex);
 201                 final_makeup_gain_auto = false;
 202                 final_makeup_gain = from_db(gain_db);
 203         }
 204
 205         float get_final_makeup_gain_db()
 206         {
 207                 std::unique_lock<std::mutex> lock(compressor_mutex);
 208                 return to_db(final_makeup_gain);
 209         }
 210
 211         void set_final_makeup_gain_auto(bool enabled)
 212         {
 213                 std::unique_lock<std::mutex> lock(compressor_mutex);
 214                 final_makeup_gain_auto = enabled;
 215         }
 216
 217         bool get_final_makeup_gain_auto() const
 218         {
 219                 std::unique_lock<std::mutex> lock(compressor_mutex);
 220                 return final_makeup_gain_auto;
 221         }
 222
 223         void reset_peak(unsigned bus_index);
 224
 225         struct BusLevel {
 226                 float current_level_dbfs[2];  // Digital peak of last frame, left and right.
 227                 float peak_level_dbfs[2];  // Digital peak with hold, left and right.
 228                 float historic_peak_dbfs;
 229                 float gain_staging_db;
 230                 float compressor_attenuation_db;  // A positive number; 0.0 for no attenuation.
 231         };
 232
 233         typedef std::function<void(float level_lufs, float peak_db,
 234                                    std::vector<BusLevel> bus_levels,
 235                                    float global_level_lufs, float range_low_lufs, float range_high_lufs,
 236                                    float final_makeup_gain_db,
 237                                    float correlation)> audio_level_callback_t;
 238         void set_audio_level_callback(audio_level_callback_t callback)
 239         {
 240                 audio_level_callback = callback;
 241         }
 242
 243 private:
 244         struct AudioDevice {
 245                 std::unique_ptr<ResamplingQueue> resampling_queue;
 246                 int64_t next_local_pts = 0;
 247                 std::string name;
 248                 unsigned capture_frequency = OUTPUT_FREQUENCY;
 249                 // Which channels we consider interesting (ie., are part of some input_mapping).
 250                 std::set<unsigned> interesting_channels;
 251                 // Only used for ALSA cards, obviously.
 252                 std::unique_ptr<ALSAInput> alsa_device;
 253         };
 254         AudioDevice *find_audio_device(DeviceSpec device_spec);
 255
 256         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);
 257         void fill_audio_bus(const std::map<DeviceSpec, std::vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
 258         void reset_resampler_mutex_held(DeviceSpec device_spec);
 259         void reset_alsa_mutex_held(DeviceSpec device_spec);
 260         std::map<DeviceSpec, DeviceInfo> get_devices_mutex_held() const;
 261         void apply_eq(unsigned bus_index, std::vector<float> *samples_bus);
 262         void update_meters(const std::vector<float> &samples);
 263         void add_bus_to_master(unsigned bus_index, const std::vector<float> &samples_bus, std::vector<float> *samples_out);
 264         void measure_bus_levels(unsigned bus_index, const std::vector<float> &left, const std::vector<float> &right);
 265         void send_audio_level_callback();
 266
 267         unsigned num_cards;
 268
 269         mutable std::timed_mutex audio_mutex;
 270
 271         AudioDevice video_cards[MAX_VIDEO_CARDS];  // Under audio_mutex.
 272
 273         // TODO: Figure out a better way to unify these two, as they are sharing indexing.
 274         AudioDevice alsa_inputs[MAX_ALSA_CARDS];  // Under audio_mutex.
 275         std::vector<ALSAInput::Device> available_alsa_cards;
 276
 277         std::atomic<float> locut_cutoff_hz;
 278         StereoFilter locut[MAX_BUSES];  // Default cutoff 120 Hz, 24 dB/oct.
 279         std::atomic<bool> locut_enabled[MAX_BUSES];
 280         StereoFilter eq[MAX_BUSES][NUM_EQ_BANDS];  // The one for EQBand::MID isn't actually used (see comments in apply_eq()).
 281
 282         // First compressor; takes us up to about -12 dBFS.
 283         mutable std::mutex compressor_mutex;
 284         std::unique_ptr<StereoCompressor> level_compressor[MAX_BUSES];  // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
 285         float gain_staging_db[MAX_BUSES];  // Under compressor_mutex.
 286         bool level_compressor_enabled[MAX_BUSES];  // Under compressor_mutex.
 287
 288         static constexpr float ref_level_dbfs = -14.0f;  // Chosen so that we end up around 0 LU in practice.
 289         static constexpr float ref_level_lufs = -23.0f;  // 0 LU, more or less by definition.
 290
 291         StereoCompressor limiter;
 292         std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f};   // 4 dB.
 293         std::atomic<bool> limiter_enabled{true};
 294         std::unique_ptr<StereoCompressor> compressor[MAX_BUSES];
 295         std::atomic<float> compressor_threshold_dbfs[MAX_BUSES];
 296         std::atomic<bool> compressor_enabled[MAX_BUSES];
 297
 298         // Note: The values here are not in dB.
 299         struct PeakHistory {
 300                 float current_level = 0.0f;  // Peak of the last frame.
 301                 float historic_peak = 0.0f;  // Highest peak since last reset; no falloff.
 302                 float current_peak = 0.0f;  // Current peak of the peak meter.
 303                 float last_peak = 0.0f;
 304                 float age_seconds = 0.0f;   // Time since "last_peak" was set.
 305         };
 306         PeakHistory peak_history[MAX_BUSES][2];  // Separate for each channel. Under audio_mutex.
 307
 308         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.
 309         bool final_makeup_gain_auto = true;  // Under compressor_mutex.
 310
 311         InputMapping input_mapping;  // Under audio_mutex.
 312         std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
 313         float last_fader_volume_db[MAX_BUSES] { 0.0f };  // Under audio_mutex.
 314         std::atomic<float> eq_level_db[MAX_BUSES][NUM_EQ_BANDS] {{{ 0.0f }}};
 315
 316         audio_level_callback_t audio_level_callback = nullptr;
 317         mutable std::mutex audio_measure_mutex;
 318         Ebu_r128_proc r128;  // Under audio_measure_mutex.
 319         CorrelationMeasurer correlation;  // Under audio_measure_mutex.
 320         Resampler peak_resampler;  // Under audio_measure_mutex.
 321         std::atomic<float> peak{0.0f};
 322 };
 323
 324 #endif  // !defined(_AUDIO_MIXER_H)