Implement the EQ in AudioMixer. (No UI yet.)

[nageru] / audio_mixer.h

diff --git a/audio_mixer.h b/audio_mixer.h
index d00e8ecb4eeb3dd968940575944b9de5e8eba77e..c332671e0bebd6f385d66b8ddc40fd426fd765ad 100644 (file)
--- a/audio_mixer.h
+++ b/audio_mixer.h
@@ -52,6 +52,13 @@ struct DeviceInfo {
        unsigned num_channels;
 };
 
+enum EQBand {
+       EQ_BAND_BASS = 0,
+       EQ_BAND_MID,
+       EQ_BAND_TREBLE,
+       NUM_EQ_BANDS
+};
+
 static inline uint64_t DeviceSpec_to_key(const DeviceSpec &device_spec)
 {
        return (uint64_t(device_spec.type) << 32) | device_spec.index;
@@ -111,6 +118,12 @@ public:
                return locut_enabled[bus];
        }
 
+       void set_eq(unsigned bus_index, EQBand band, float db_gain)
+       {
+               assert(band >= 0 && band < NUM_EQ_BANDS);
+               eq_level_db[bus_index][band] = db_gain;
+       }
+
        float get_limiter_threshold_dbfs() const
        {
                return limiter_threshold_dbfs;
@@ -201,10 +214,20 @@ public:
                return final_makeup_gain_auto;
        }
 
+       void reset_peak(unsigned bus_index);
+
+       struct BusLevel {
+               float current_level_dbfs[2];  // Digital peak of last frame, left and right.
+               float peak_level_dbfs[2];  // Digital peak with hold, left and right.
+               float historic_peak_dbfs;
+               float gain_staging_db;
+               float compressor_attenuation_db;  // A positive number; 0.0 for no attenuation.
+       };
+
        typedef std::function<void(float level_lufs, float peak_db,
-                                  std::vector<float> bus_level_lufs,
+                                  std::vector<BusLevel> bus_levels,
                                   float global_level_lufs, float range_low_lufs, float range_high_lufs,
-                                  std::vector<float> gain_staging_db, float final_makeup_gain_db,
+                                  float final_makeup_gain_db,
                                   float correlation)> audio_level_callback_t;
        void set_audio_level_callback(audio_level_callback_t callback)
        {
@@ -229,7 +252,9 @@ private:
        void reset_resampler_mutex_held(DeviceSpec device_spec);
        void reset_alsa_mutex_held(DeviceSpec device_spec);
        std::map<DeviceSpec, DeviceInfo> get_devices_mutex_held() const;
+       void apply_eq(unsigned bus_index, std::vector<float> *samples_bus);
        void update_meters(const std::vector<float> &samples);
+       void add_bus_to_master(unsigned bus_index, const std::vector<float> &samples_bus, std::vector<float> *samples_out);
        void measure_bus_levels(unsigned bus_index, const std::vector<float> &left, const std::vector<float> &right);
        void send_audio_level_callback();
 
@@ -246,6 +271,7 @@ private:
        std::atomic<float> locut_cutoff_hz;
        StereoFilter locut[MAX_BUSES];  // Default cutoff 120 Hz, 24 dB/oct.
        std::atomic<bool> locut_enabled[MAX_BUSES];
+       StereoFilter eq[MAX_BUSES][NUM_EQ_BANDS];  // The one for EQBand::MID isn't actually used (see comments in apply_eq()).
 
        // First compressor; takes us up to about -12 dBFS.
        mutable std::mutex compressor_mutex;
@@ -263,11 +289,23 @@ private:
        std::atomic<float> compressor_threshold_dbfs[MAX_BUSES];
        std::atomic<bool> compressor_enabled[MAX_BUSES];
 
+       // Note: The values here are not in dB.
+       struct PeakHistory {
+               float current_level = 0.0f;  // Peak of the last frame.
+               float historic_peak = 0.0f;  // Highest peak since last reset; no falloff.
+               float current_peak = 0.0f;  // Current peak of the peak meter.
+               float last_peak = 0.0f;
+               float age_seconds = 0.0f;   // Time since "last_peak" was set.
+       };
+       PeakHistory peak_history[MAX_BUSES][2];  // Separate for each channel. Under audio_mutex.
+
        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.
        bool final_makeup_gain_auto = true;  // Under compressor_mutex.
 
        InputMapping input_mapping;  // Under audio_mutex.
        std::atomic<float> fader_volume_db[MAX_BUSES] {{ 0.0f }};
+       float last_fader_volume_db[MAX_BUSES] { 0.0f };  // Under audio_mutex.
+       std::atomic<float> eq_level_db[MAX_BUSES][NUM_EQ_BANDS] {{{ 0.0f }}};
 
        audio_level_callback_t audio_level_callback = nullptr;
        mutable std::mutex audio_measure_mutex;
@@ -275,12 +313,6 @@ private:
        CorrelationMeasurer correlation;  // Under audio_measure_mutex.
        Resampler peak_resampler;  // Under audio_measure_mutex.
        std::atomic<float> peak{0.0f};
-
-       // Under audio_measure_mutex. Note that Ebu_r128_proc has a broken
-       // copy constructor (it uses the default, but holds arrays),
-       // so we can't just use raw Ebu_r128_proc elements, but need to use
-       // unique_ptrs.
-       std::vector<std::unique_ptr<Ebu_r128_proc>> bus_r128;
 };
 
 #endif  // !defined(_AUDIO_MIXER_H)