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 // TODO: There might be more audio stuff that should be moved here
  12 // from Mixer.
  13
  14 #include <math.h>
  15 #include <stdint.h>
  16 #include <atomic>
  17 #include <map>
  18 #include <memory>
  19 #include <mutex>
  20 #include <set>
  21 #include <vector>
  22
  23 #include "bmusb/bmusb.h"
  24 #include "db.h"
  25 #include "defs.h"
  26 #include "filter.h"
  27 #include "resampling_queue.h"
  28 #include "stereocompressor.h"
  29
  30 namespace bmusb {
  31 struct AudioFormat;
  32 }  // namespace bmusb
  33
  34 enum class InputSourceType { SILENCE, CAPTURE_CARD };
  35 struct DeviceSpec {
  36         InputSourceType type;
  37         unsigned index;
  38
  39         bool operator< (const DeviceSpec &other) const {
  40                 if (type != other.type)
  41                         return type < other.type;
  42                 return index < other.index;
  43         }
  44 };
  45
  46 struct InputMapping {
  47         struct Bus {
  48                 std::string name;
  49                 DeviceSpec device;
  50                 int source_channel[2] { -1, -1 };  // Left and right. -1 = none.
  51         };
  52
  53         std::vector<Bus> buses;
  54 };
  55
  56 class AudioMixer {
  57 public:
  58         AudioMixer(unsigned num_cards);
  59         void reset_device(DeviceSpec device_spec);
  60
  61         // frame_length is in TIMEBASE units.
  62         void add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
  63         void add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
  64         std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
  65
  66         // See comments inside get_output().
  67         void set_current_loudness(double level_lufs) { loudness_lufs = level_lufs; }
  68
  69         void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
  70         std::vector<std::string> get_names() const;
  71         void set_name(DeviceSpec device_spec, const std::string &name);
  72
  73         void set_input_mapping(const InputMapping &input_mapping);
  74         InputMapping get_input_mapping() const;
  75
  76         void set_locut_cutoff(float cutoff_hz)
  77         {
  78                 locut_cutoff_hz = cutoff_hz;
  79         }
  80
  81         void set_locut_enabled(bool enabled)
  82         {
  83                 locut_enabled = enabled;
  84         }
  85
  86         bool get_locut_enabled() const
  87         {
  88                 return locut_enabled;
  89         }
  90
  91         float get_limiter_threshold_dbfs() const
  92         {
  93                 return limiter_threshold_dbfs;
  94         }
  95
  96         float get_compressor_threshold_dbfs() const
  97         {
  98                 return compressor_threshold_dbfs;
  99         }
 100
 101         void set_limiter_threshold_dbfs(float threshold_dbfs)
 102         {
 103                 limiter_threshold_dbfs = threshold_dbfs;
 104         }
 105
 106         void set_compressor_threshold_dbfs(float threshold_dbfs)
 107         {
 108                 compressor_threshold_dbfs = threshold_dbfs;
 109         }
 110
 111         void set_limiter_enabled(bool enabled)
 112         {
 113                 limiter_enabled = enabled;
 114         }
 115
 116         bool get_limiter_enabled() const
 117         {
 118                 return limiter_enabled;
 119         }
 120
 121         void set_compressor_enabled(bool enabled)
 122         {
 123                 compressor_enabled = enabled;
 124         }
 125
 126         bool get_compressor_enabled() const
 127         {
 128                 return compressor_enabled;
 129         }
 130
 131         void set_gain_staging_db(float gain_db)
 132         {
 133                 std::unique_lock<std::mutex> lock(compressor_mutex);
 134                 level_compressor_enabled = false;
 135                 gain_staging_db = gain_db;
 136         }
 137
 138         float get_gain_staging_db() const
 139         {
 140                 std::unique_lock<std::mutex> lock(compressor_mutex);
 141                 return gain_staging_db;
 142         }
 143
 144         void set_gain_staging_auto(bool enabled)
 145         {
 146                 std::unique_lock<std::mutex> lock(compressor_mutex);
 147                 level_compressor_enabled = enabled;
 148         }
 149
 150         bool get_gain_staging_auto() const
 151         {
 152                 std::unique_lock<std::mutex> lock(compressor_mutex);
 153                 return level_compressor_enabled;
 154         }
 155
 156         void set_final_makeup_gain_db(float gain_db)
 157         {
 158                 std::unique_lock<std::mutex> lock(compressor_mutex);
 159                 final_makeup_gain_auto = false;
 160                 final_makeup_gain = from_db(gain_db);
 161         }
 162
 163         float get_final_makeup_gain_db()
 164         {
 165                 std::unique_lock<std::mutex> lock(compressor_mutex);
 166                 return to_db(final_makeup_gain);
 167         }
 168
 169         void set_final_makeup_gain_auto(bool enabled)
 170         {
 171                 std::unique_lock<std::mutex> lock(compressor_mutex);
 172                 final_makeup_gain_auto = enabled;
 173         }
 174
 175         bool get_final_makeup_gain_auto() const
 176         {
 177                 std::unique_lock<std::mutex> lock(compressor_mutex);
 178                 return final_makeup_gain_auto;
 179         }
 180
 181 private:
 182         struct AudioDevice {
 183                 std::unique_ptr<ResamplingQueue> resampling_queue;
 184                 int64_t next_local_pts = 0;
 185                 std::string name;
 186                 unsigned capture_frequency = OUTPUT_FREQUENCY;
 187                 // Which channels we consider interesting (ie., are part of some input_mapping).
 188                 std::set<unsigned> interesting_channels;
 189         };
 190         AudioDevice *find_audio_device(DeviceSpec device_spec);
 191
 192         void find_sample_src_from_device(const std::vector<float> *samples_card, DeviceSpec device_spec, int source_channel, const float **srcptr, unsigned *stride);
 193         void fill_audio_bus(const std::vector<float> *samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
 194         void reset_device_mutex_held(DeviceSpec device_spec);
 195
 196         unsigned num_cards;
 197
 198         mutable std::mutex audio_mutex;
 199
 200         AudioDevice cards[MAX_CARDS];  // Under audio_mutex.
 201
 202         StereoFilter locut;  // Default cutoff 120 Hz, 24 dB/oct.
 203         std::atomic<float> locut_cutoff_hz;
 204         std::atomic<bool> locut_enabled{true};
 205
 206         // First compressor; takes us up to about -12 dBFS.
 207         mutable std::mutex compressor_mutex;
 208         StereoCompressor level_compressor;  // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
 209         float gain_staging_db = 0.0f;  // Under compressor_mutex.
 210         bool level_compressor_enabled = true;  // Under compressor_mutex.
 211
 212         static constexpr float ref_level_dbfs = -14.0f;  // Chosen so that we end up around 0 LU in practice.
 213         static constexpr float ref_level_lufs = -23.0f;  // 0 LU, more or less by definition.
 214
 215         std::atomic<float> loudness_lufs{ref_level_lufs};
 216
 217         StereoCompressor limiter;
 218         std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f};   // 4 dB.
 219         std::atomic<bool> limiter_enabled{true};
 220         StereoCompressor compressor;
 221         std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f};  // -12 dB.
 222         std::atomic<bool> compressor_enabled{true};
 223
 224         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.
 225         bool final_makeup_gain_auto = true;  // Under compressor_mutex.
 226
 227         InputMapping input_mapping;  // Under audio_mutex.
 228         std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
 229 };
 230
 231 #endif  // !defined(_AUDIO_MIXER_H)