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                 return type == other.type && index == other.index;
  41         }
  42
  43         bool operator< (const DeviceSpec &other) const {
  44                 if (type != other.type)
  45                         return type < other.type;
  46                 return index < other.index;
  47         }
  48 };
  49 struct DeviceInfo {
  50         std::string name;
  51         unsigned num_channels;
  52 };
  53
  54 static inline uint64_t DeviceSpec_to_key(const DeviceSpec &device_spec)
  55 {
  56         return (uint64_t(device_spec.type) << 32) | device_spec.index;
  57 }
  58
  59 static inline DeviceSpec key_to_DeviceSpec(uint64_t key)
  60 {
  61         return DeviceSpec{ InputSourceType(key >> 32), unsigned(key & 0xffffffff) };
  62 }
  63
  64 struct InputMapping {
  65         struct Bus {
  66                 std::string name;
  67                 DeviceSpec device;
  68                 int source_channel[2] { -1, -1 };  // Left and right. -1 = none.
  69         };
  70
  71         std::vector<Bus> buses;
  72 };
  73
  74 class AudioMixer {
  75 public:
  76         AudioMixer(unsigned num_cards);
  77         void reset_resampler(DeviceSpec device_spec);
  78
  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);
  83
  84         // See comments inside get_output().
  85         void set_current_loudness(double level_lufs) { loudness_lufs = level_lufs; }
  86
  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);
  90
  91         void set_input_mapping(const InputMapping &input_mapping);
  92         InputMapping get_input_mapping() const;
  93
  94         void set_locut_cutoff(float cutoff_hz)
  95         {
  96                 locut_cutoff_hz = cutoff_hz;
  97         }
  98
  99         void set_locut_enabled(bool enabled)
 100         {
 101                 locut_enabled = enabled;
 102         }
 103
 104         bool get_locut_enabled() const
 105         {
 106                 return locut_enabled;
 107         }
 108
 109         float get_limiter_threshold_dbfs() const
 110         {
 111                 return limiter_threshold_dbfs;
 112         }
 113
 114         float get_compressor_threshold_dbfs() const
 115         {
 116                 return compressor_threshold_dbfs;
 117         }
 118
 119         void set_limiter_threshold_dbfs(float threshold_dbfs)
 120         {
 121                 limiter_threshold_dbfs = threshold_dbfs;
 122         }
 123
 124         void set_compressor_threshold_dbfs(float threshold_dbfs)
 125         {
 126                 compressor_threshold_dbfs = threshold_dbfs;
 127         }
 128
 129         void set_limiter_enabled(bool enabled)
 130         {
 131                 limiter_enabled = enabled;
 132         }
 133
 134         bool get_limiter_enabled() const
 135         {
 136                 return limiter_enabled;
 137         }
 138
 139         void set_compressor_enabled(bool enabled)
 140         {
 141                 compressor_enabled = enabled;
 142         }
 143
 144         bool get_compressor_enabled() const
 145         {
 146                 return compressor_enabled;
 147         }
 148
 149         void set_gain_staging_db(float gain_db)
 150         {
 151                 std::unique_lock<std::mutex> lock(compressor_mutex);
 152                 level_compressor_enabled = false;
 153                 gain_staging_db = gain_db;
 154         }
 155
 156         float get_gain_staging_db() const
 157         {
 158                 std::unique_lock<std::mutex> lock(compressor_mutex);
 159                 return gain_staging_db;
 160         }
 161
 162         void set_gain_staging_auto(bool enabled)
 163         {
 164                 std::unique_lock<std::mutex> lock(compressor_mutex);
 165                 level_compressor_enabled = enabled;
 166         }
 167
 168         bool get_gain_staging_auto() const
 169         {
 170                 std::unique_lock<std::mutex> lock(compressor_mutex);
 171                 return level_compressor_enabled;
 172         }
 173
 174         void set_final_makeup_gain_db(float gain_db)
 175         {
 176                 std::unique_lock<std::mutex> lock(compressor_mutex);
 177                 final_makeup_gain_auto = false;
 178                 final_makeup_gain = from_db(gain_db);
 179         }
 180
 181         float get_final_makeup_gain_db()
 182         {
 183                 std::unique_lock<std::mutex> lock(compressor_mutex);
 184                 return to_db(final_makeup_gain);
 185         }
 186
 187         void set_final_makeup_gain_auto(bool enabled)
 188         {
 189                 std::unique_lock<std::mutex> lock(compressor_mutex);
 190                 final_makeup_gain_auto = enabled;
 191         }
 192
 193         bool get_final_makeup_gain_auto() const
 194         {
 195                 std::unique_lock<std::mutex> lock(compressor_mutex);
 196                 return final_makeup_gain_auto;
 197         }
 198
 199 private:
 200         struct AudioDevice {
 201                 std::unique_ptr<ResamplingQueue> resampling_queue;
 202                 int64_t next_local_pts = 0;
 203                 std::string name;
 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;
 207         };
 208         AudioDevice *find_audio_device(DeviceSpec device_spec);
 209
 210         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);
 211         void fill_audio_bus(const std::map<DeviceSpec, std::vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
 212         void reset_resampler_mutex_held(DeviceSpec device_spec);
 213         std::map<DeviceSpec, DeviceInfo> get_devices_mutex_held() const;
 214
 215         unsigned num_cards;
 216
 217         mutable std::mutex audio_mutex;
 218
 219         AudioDevice video_cards[MAX_VIDEO_CARDS];  // Under audio_mutex.
 220
 221         StereoFilter locut;  // Default cutoff 120 Hz, 24 dB/oct.
 222         std::atomic<float> locut_cutoff_hz;
 223         std::atomic<bool> locut_enabled{true};
 224
 225         // First compressor; takes us up to about -12 dBFS.
 226         mutable std::mutex compressor_mutex;
 227         StereoCompressor level_compressor;  // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
 228         float gain_staging_db = 0.0f;  // Under compressor_mutex.
 229         bool level_compressor_enabled = true;  // Under compressor_mutex.
 230
 231         static constexpr float ref_level_dbfs = -14.0f;  // Chosen so that we end up around 0 LU in practice.
 232         static constexpr float ref_level_lufs = -23.0f;  // 0 LU, more or less by definition.
 233
 234         std::atomic<float> loudness_lufs{ref_level_lufs};
 235
 236         StereoCompressor limiter;
 237         std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f};   // 4 dB.
 238         std::atomic<bool> limiter_enabled{true};
 239         StereoCompressor compressor;
 240         std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f};  // -12 dB.
 241         std::atomic<bool> compressor_enabled{true};
 242
 243         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.
 244         bool final_makeup_gain_auto = true;  // Under compressor_mutex.
 245
 246         InputMapping input_mapping;  // Under audio_mutex.
 247         std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
 248 };
 249
 250 #endif  // !defined(_AUDIO_MIXER_H)