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 "alsa_input.h"
  24 #include "bmusb/bmusb.h"
  25 #include "db.h"
  26 #include "defs.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
  81         // frame_length is in TIMEBASE units.
  82         void add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length);
  83         void add_silence(DeviceSpec device_spec, unsigned samples_per_frame, unsigned num_frames, int64_t frame_length);
  84         std::vector<float> get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy);
  85
  86         // See comments inside get_output().
  87         void set_current_loudness(double level_lufs) { loudness_lufs = level_lufs; }
  88
  89         void set_fader_volume(unsigned bus_index, float level_db) { fader_volume_db[bus_index] = level_db; }
  90         std::map<DeviceSpec, DeviceInfo> get_devices() const;
  91         void set_name(DeviceSpec device_spec, const std::string &name);
  92
  93         void set_input_mapping(const InputMapping &input_mapping);
  94         InputMapping get_input_mapping() const;
  95
  96         void set_locut_cutoff(float cutoff_hz)
  97         {
  98                 locut_cutoff_hz = cutoff_hz;
  99         }
 100
 101         void set_locut_enabled(bool enabled)
 102         {
 103                 locut_enabled = enabled;
 104         }
 105
 106         bool get_locut_enabled() const
 107         {
 108                 return locut_enabled;
 109         }
 110
 111         float get_limiter_threshold_dbfs() const
 112         {
 113                 return limiter_threshold_dbfs;
 114         }
 115
 116         float get_compressor_threshold_dbfs() const
 117         {
 118                 return compressor_threshold_dbfs;
 119         }
 120
 121         void set_limiter_threshold_dbfs(float threshold_dbfs)
 122         {
 123                 limiter_threshold_dbfs = threshold_dbfs;
 124         }
 125
 126         void set_compressor_threshold_dbfs(float threshold_dbfs)
 127         {
 128                 compressor_threshold_dbfs = threshold_dbfs;
 129         }
 130
 131         void set_limiter_enabled(bool enabled)
 132         {
 133                 limiter_enabled = enabled;
 134         }
 135
 136         bool get_limiter_enabled() const
 137         {
 138                 return limiter_enabled;
 139         }
 140
 141         void set_compressor_enabled(bool enabled)
 142         {
 143                 compressor_enabled = enabled;
 144         }
 145
 146         bool get_compressor_enabled() const
 147         {
 148                 return compressor_enabled;
 149         }
 150
 151         void set_gain_staging_db(float gain_db)
 152         {
 153                 std::unique_lock<std::mutex> lock(compressor_mutex);
 154                 level_compressor_enabled = false;
 155                 gain_staging_db = gain_db;
 156         }
 157
 158         float get_gain_staging_db() const
 159         {
 160                 std::unique_lock<std::mutex> lock(compressor_mutex);
 161                 return gain_staging_db;
 162         }
 163
 164         void set_gain_staging_auto(bool enabled)
 165         {
 166                 std::unique_lock<std::mutex> lock(compressor_mutex);
 167                 level_compressor_enabled = enabled;
 168         }
 169
 170         bool get_gain_staging_auto() const
 171         {
 172                 std::unique_lock<std::mutex> lock(compressor_mutex);
 173                 return level_compressor_enabled;
 174         }
 175
 176         void set_final_makeup_gain_db(float gain_db)
 177         {
 178                 std::unique_lock<std::mutex> lock(compressor_mutex);
 179                 final_makeup_gain_auto = false;
 180                 final_makeup_gain = from_db(gain_db);
 181         }
 182
 183         float get_final_makeup_gain_db()
 184         {
 185                 std::unique_lock<std::mutex> lock(compressor_mutex);
 186                 return to_db(final_makeup_gain);
 187         }
 188
 189         void set_final_makeup_gain_auto(bool enabled)
 190         {
 191                 std::unique_lock<std::mutex> lock(compressor_mutex);
 192                 final_makeup_gain_auto = enabled;
 193         }
 194
 195         bool get_final_makeup_gain_auto() const
 196         {
 197                 std::unique_lock<std::mutex> lock(compressor_mutex);
 198                 return final_makeup_gain_auto;
 199         }
 200
 201 private:
 202         struct AudioDevice {
 203                 std::unique_ptr<ResamplingQueue> resampling_queue;
 204                 int64_t next_local_pts = 0;
 205                 std::string name;
 206                 unsigned capture_frequency = OUTPUT_FREQUENCY;
 207                 // Which channels we consider interesting (ie., are part of some input_mapping).
 208                 std::set<unsigned> interesting_channels;
 209                 // Only used for ALSA cards, obviously.
 210                 std::unique_ptr<ALSAInput> alsa_device;
 211         };
 212         AudioDevice *find_audio_device(DeviceSpec device_spec);
 213
 214         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);
 215         void fill_audio_bus(const std::map<DeviceSpec, std::vector<float>> &samples_card, const InputMapping::Bus &bus, unsigned num_samples, float *output);
 216         void reset_resampler_mutex_held(DeviceSpec device_spec);
 217         void reset_alsa_mutex_held(DeviceSpec device_spec);
 218         std::map<DeviceSpec, DeviceInfo> get_devices_mutex_held() const;
 219
 220         unsigned num_cards;
 221
 222         mutable std::mutex audio_mutex;
 223
 224         AudioDevice video_cards[MAX_VIDEO_CARDS];  // Under audio_mutex.
 225
 226         // TODO: Figure out a better way to unify these two, as they are sharing indexing.
 227         AudioDevice alsa_inputs[MAX_ALSA_CARDS];  // Under audio_mutex.
 228         std::vector<ALSAInput::Device> available_alsa_cards;
 229
 230         StereoFilter locut;  // Default cutoff 120 Hz, 24 dB/oct.
 231         std::atomic<float> locut_cutoff_hz;
 232         std::atomic<bool> locut_enabled{true};
 233
 234         // First compressor; takes us up to about -12 dBFS.
 235         mutable std::mutex compressor_mutex;
 236         StereoCompressor level_compressor;  // Under compressor_mutex. Used to set/override gain_staging_db if <level_compressor_enabled>.
 237         float gain_staging_db = 0.0f;  // Under compressor_mutex.
 238         bool level_compressor_enabled = true;  // Under compressor_mutex.
 239
 240         static constexpr float ref_level_dbfs = -14.0f;  // Chosen so that we end up around 0 LU in practice.
 241         static constexpr float ref_level_lufs = -23.0f;  // 0 LU, more or less by definition.
 242
 243         std::atomic<float> loudness_lufs{ref_level_lufs};
 244
 245         StereoCompressor limiter;
 246         std::atomic<float> limiter_threshold_dbfs{ref_level_dbfs + 4.0f};   // 4 dB.
 247         std::atomic<bool> limiter_enabled{true};
 248         StereoCompressor compressor;
 249         std::atomic<float> compressor_threshold_dbfs{ref_level_dbfs - 12.0f};  // -12 dB.
 250         std::atomic<bool> compressor_enabled{true};
 251
 252         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.
 253         bool final_makeup_gain_auto = true;  // Under compressor_mutex.
 254
 255         InputMapping input_mapping;  // Under audio_mutex.
 256         std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
 257 };
 258
 259 #endif  // !defined(_AUDIO_MIXER_H)