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

[nageru] / audio_mixer.h

diff --git a/audio_mixer.h b/audio_mixer.h
index 88c2f880cac0fee500d087abec37d1ff9eed1230..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;
@@ -239,6 +252,7 @@ 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);
@@ -257,6 +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;
@@ -290,6 +305,7 @@ private:
        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;