Line data    Source code

       1             : /**
       2             :  * \file GainMaxExpanderFilter.h
       3             :  */
       4             : 
       5             : #ifndef ATK_DYNAMIC_GAINMAXEXPANDERFILTER_H
       6             : #define ATK_DYNAMIC_GAINMAXEXPANDERFILTER_H
       7             : 
       8             : #include <ATK/Dynamic/GainFilter.h>
       9             : #include <ATK/Dynamic/config.h>
      10             : 
      11             : namespace ATK
      12             : {
      13             :   /// Gain "expander". Computes a new amplitude/volume gain based on threshold, slope and the power of the input signal
      14             :   /*!
      15             :    * The maximum reduction is given by max_reduction
      16             :    */
      17             :   template<typename DataType_>
      18             :   class ATK_DYNAMIC_EXPORT GainMaxExpanderFilter : public ParentGainFilter<DataType_>
      19             :   {
      20             :   public:
      21             :     /// Simplify parent calls
      22             :     using Parent = ParentGainFilter<DataType_>;
      23             :     using Parent::ratio;
      24             :     using Parent::start_recomputeLUT;
      25             :     using typename Parent::DataType;
      26             :     /*!
      27             :     * @brief Constructor
      28             :     * @param nb_channels is the number of input and output channels
      29             :     * @param LUTsize is the total LUT size used by the filter
      30             :     * @param LUTprecision is the number of elements used to compute values < 1
      31             :     */
      32             :     GainMaxExpanderFilter(gsl::index nb_channels = 1, size_t LUTsize = 128*1024, size_t LUTprecision = 1024);
      33             :     /// Destructor
      34          10 :     ~GainMaxExpanderFilter() override = default;
      35             : 
      36             :     /// Sets the softness of the knee of the filter (positive value)
      37             :     void set_softness(DataType_ softness);
      38             :     /// Retrieves the softness afctor
      39             :     DataType_ get_softness() const;
      40             : 
      41             :     /// Sets the maximum reduction factor of the filter (limit reduction to this factor instead of infinite)
      42             :     void set_max_reduction(DataType_ max_reduction);
      43             :     /// Sets the maximum reduction in dB
      44             :     void set_max_reduction_db(DataType_ max_reduction);
      45             :     /// Gets the maximum reduction factor
      46             :     DataType_ get_max_reduction() const;
      47             : 
      48             :   protected:
      49             :     DataType_ computeGain(DataType_ value) const;
      50             :   private:
      51             :     DataType_ softness{0.0001};
      52             :     DataType_ max_reduction{0.01};
      53             :   };
      54             : }
      55             : 
      56             : #endif