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 static inline uint64_t DeviceSpec_to_key(const DeviceSpec &device_spec)
  56 {
  57         return (uint64_t(device_spec.type) << 32) | device_spec.index;
  58 }
  59
  60 static inline DeviceSpec key_to_DeviceSpec(uint64_t key)
  61 {
  62         return DeviceSpec{ InputSourceType(key >> 32), unsigned(key & 0xffffffff) };
  63 }
  64
  65 struct InputMapping {
  66         struct Bus {
  67                 std::string name;
  68                 DeviceSpec device;
  69                 int source_channel[2] { -1, -1 };  // Left and right. -1 = none.
  70         };
  71
  72         std::vector<Bus> buses;
  73 };
  74
  75 class AudioMixer {
  76 public:
  77         AudioMixer(unsigned num_cards);
  78         ~AudioMixer();
  79         void reset_resampler(DeviceSpec device_spec);
  80         void reset_meters();
  81
  82         // Add audio (or silence) to the given device's queue. Can return false if
  83         // the lock wasn't successfully taken; if so, you should simply try again.
  84         // (This is to avoid a deadlock where a card hangs on the mutex in add_audio()
  85         // while we are trying to shut it down from another thread that also holds
  86         // the mutex.) frame_length is in TIMEBASE units.
  87         bool add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
  88         bool add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
  89
  90         std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
  91
  92         void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
  93         std::map<DeviceSpec, DeviceInfo> get_devices() const;
  94         void set_name(DeviceSpec device_spec, const std::string &name);
  95
  96         void set_input_mapping(const InputMapping &input_mapping);
  97         InputMapping get_input_mapping() const;
  98
  99         void set_locut_cutoff(float cutoff_hz)
 100         {
 101                 locut_cutoff_hz = cutoff_hz;
 102         }
 103
 104         void set_locut_enabled(bool enabled)
 105         {
 106                 locut_enabled = enabled;
 107         }
 108
 109         bool get_locut_enabled() const
 110         {
 111                 return locut_enabled;
 112         }
 113
 114         float get_limiter_threshold_dbfs() const
 115         {
 116                 return limiter_threshold_dbfs;
 117         }
 118
 119         float get_compressor_threshold_dbfs() const
 120         {
 121                 return compressor_threshold_dbfs;
 122         }
 123
 124         void set_limiter_threshold_dbfs(float threshold_dbfs)
 125         {
 126                 limiter_threshold_dbfs = threshold_dbfs;
 127         }
 128
 129         void set_compressor_threshold_dbfs(float threshold_dbfs)
 130         {
 131                 compressor_threshold_dbfs = threshold_dbfs;
 132         }
 133
 134         void set_limiter_enabled(bool enabled)
 135         {
 136                 limiter_enabled = enabled;
 137         }
 138
 139         bool get_limiter_enabled() const
 140         {
 141                 return limiter_enabled;
 142         }
 143
 144         void set_compressor_enabled(bool enabled)
 145         {
 146                 compressor_enabled = enabled;
 147         }
 148
 149         bool get_compressor_enabled() const
 150         {
 151                 return compressor_enabled;
 152         }
 153
 154         void set_gain_staging_db(float gain_db)
 155         {
 156                 std::unique_lock<std::mutex> lock(compressor_mutex);
 157                 level_compressor_enabled = false;
 158                 gain_staging_db = gain_db;
 159         }
 160
 161         float get_gain_staging_db() const
 162         {
 163                 std::unique_lock<std::mutex> lock(compressor_mutex);
 164                 return gain_staging_db;
 165         }
 166
 167         void set_gain_staging_auto(bool enabled)
 168         {
 169                 std::unique_lock<std::mutex> lock(compressor_mutex);
 170                 level_compressor_enabled = enabled;
 171         }
 172
 173         bool get_gain_staging_auto() const
 174         {
 175                 std::unique_lock<std::mutex> lock(compressor_mutex);
 176                 return level_compressor_enabled;
 177         }
 178
 179         void set_final_makeup_gain_db(float gain_db)
 180         {
 181                 std::unique_lock<std::mutex> lock(compressor_mutex);
 182                 final_makeup_gain_auto = false;
 183                 final_makeup_gain = from_db(gain_db);
 184         }
 185
 186         float get_final_makeup_gain_db()
 187         {
 188                 std::unique_lock<std::mutex> lock(compressor_mutex);
 189                 return to_db(final_makeup_gain);
 190         }
 191
 192         void set_final_makeup_gain_auto(bool enabled)
 193         {
 194                 std::unique_lock<std::mutex> lock(compressor_mutex);
 195                 final_makeup_gain_auto = enabled;
 196         }
 197
 198         bool get_final_makeup_gain_auto() const
 199         {
 200                 std::unique_lock<std::mutex> lock(compressor_mutex);
 201                 return final_makeup_gain_auto;
 202         }
 203
 204         typedef std::function<void(float level_lufs, float peak_db,
 205                                    float global_level_lufs, float range_low_lufs, float range_high_lufs,
 206                                    float gain_staging_db, float final_makeup_gain_db,
 207                                    float correlation)> audio_level_callback_t;
 208         void set_audio_level_callback(audio_level_callback_t callback)
 209         {
 210                 audio_level_callback = callback;
 211         }
 212
 213 private:
 214         struct AudioDevice {
 215                 std::unique_ptr<ResamplingQueue> resampling_queue;
 216                 int64_t next_local_pts = 0;
 217                 std::string name;
 218                 unsigned capture_frequency = OUTPUT_FREQUENCY;
 219                 // Which channels we consider interesting (ie., are part of some input_mapping).
 220                 std::set<unsigned> interesting_channels;
 221                 // Only used for ALSA cards, obviously.
 222                 std::unique_ptr<ALSAInput> alsa_device;
 223         };
 224         AudioDevice *find_audio_device(DeviceSpec device_spec);
 225
 226         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);
 227         void fill_audio_bus(const std::map<DeviceSpec, std::vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
 228         void reset_resampler_mutex_held(DeviceSpec device_spec);
 229         void reset_alsa_mutex_held(DeviceSpec device_spec);
 230         std::map<DeviceSpec, DeviceInfo> get_devices_mutex_held() const;
 231         void update_meters(const std::vector<float> &samples);
 232         void send_audio_level_callback();
 233
 234         unsigned num_cards;
 235
 236         mutable std::timed_mutex audio_mutex;
 237
 238         AudioDevice video_cards[MAX_VIDEO_CARDS];  // Under audio_mutex.
 239
 240         // TODO: Figure out a better way to unify these two, as they are sharing indexing.
 241         AudioDevice alsa_inputs[MAX_ALSA_CARDS];  // Under audio_mutex.
 242         std::vector<ALSAInput::Device> available_alsa_cards;
 243
 244         StereoFilter locut;  // Default cutoff 120 Hz, 24 dB/oct.
 245         std::atomic<float> locut_cutoff_hz;
 246         std::atomic<bool> locut_enabled{true};
 247
 248         // First compressor; takes us up to about -12 dBFS.
 249         mutable std::mutex compressor_mutex;
 250         StereoCompressor level_compressor;  // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
 251         float gain_staging_db = 0.0f;  // Under compressor_mutex.
 252         bool level_compressor_enabled = true;  // Under compressor_mutex.
 253
 254         static constexpr float ref_level_dbfs = -14.0f;  // Chosen so that we end up around 0 LU in practice.
 255         static constexpr float ref_level_lufs = -23.0f;  // 0 LU, more or less by definition.
 256
 257         StereoCompressor limiter;
 258         std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f};   // 4 dB.
 259         std::atomic<bool> limiter_enabled{true};
 260         StereoCompressor compressor;
 261         std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f};  // -12 dB.
 262         std::atomic<bool> compressor_enabled{true};
 263
 264         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.
 265         bool final_makeup_gain_auto = true;  // Under compressor_mutex.
 266
 267         InputMapping input_mapping;  // Under audio_mutex.
 268         std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
 269
 270         audio_level_callback_t audio_level_callback = nullptr;
 271         mutable std::mutex audio_measure_mutex;
 272         Ebu_r128_proc r128;  // Under audio_measure_mutex.
 273         CorrelationMeasurer correlation;  // Under audio_measure_mutex.
 274         Resampler peak_resampler;  // Under audio_measure_mutex.
 275         std::atomic<float> peak{0.0f};
 276 };
 277
 278 #endif  // !defined(_AUDIO_MIXER_H)