NeuralPi

Raspberry Pi guitar pedal using neural networks to emulate real amps and effects
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RTNeuralLSTM.cpp (2997B)

      1 #include "RTNeuralLSTM.h"
      2 
      3 using Vec2d = std::vector<std::vector<float>>;
      4 
      5 Vec2d transpose(const Vec2d& x)
      6 {
      7     auto outer_size = x.size();
      8     auto inner_size = x[0].size();
      9     Vec2d y(inner_size, std::vector<float>(outer_size, 0.0f));
     10 
     11     for (size_t i = 0; i < outer_size; ++i)
     12     {
     13         for (size_t j = 0; j < inner_size; ++j)
     14             y[j][i] = x[i][j];
     15     }
     16 
     17     return y;
     18 }
     19 
     20 template <typename T1>
     21 void RT_LSTM::set_weights(T1 model, const char* filename)
     22 {
     23     // Initialize the correct model
     24     auto& lstm = (*model).template get<0>();
     25     auto& dense = (*model).template get<1>();
     26 
     27     // read a JSON file
     28     std::ifstream i2(filename);
     29     nlohmann::json weights_json;
     30     i2 >> weights_json;
     31 
     32     Vec2d lstm_weights_ih = weights_json["/state_dict/rec.weight_ih_l0"_json_pointer];
     33     lstm.setWVals(transpose(lstm_weights_ih));
     34 
     35     Vec2d lstm_weights_hh = weights_json["/state_dict/rec.weight_hh_l0"_json_pointer];
     36     lstm.setUVals(transpose(lstm_weights_hh));
     37 
     38     std::vector<float> lstm_bias_ih = weights_json["/state_dict/rec.bias_ih_l0"_json_pointer];
     39     std::vector<float> lstm_bias_hh = weights_json["/state_dict/rec.bias_hh_l0"_json_pointer];
     40     for (int i = 0; i < 80; ++i)
     41         lstm_bias_hh[i] += lstm_bias_ih[i];
     42     lstm.setBVals(lstm_bias_hh);
     43 
     44     Vec2d dense_weights = weights_json["/state_dict/lin.weight"_json_pointer];
     45     dense.setWeights(dense_weights);
     46 
     47     std::vector<float> dense_bias = weights_json["/state_dict/lin.bias"_json_pointer];
     48     dense.setBias(dense_bias.data());
     49    
     50 }
     51 void RT_LSTM::load_json(const char* filename)
     52 {
     53     // Read in the JSON file
     54     std::ifstream i2(filename);
     55 	nlohmann::json weights_json;
     56 	i2 >> weights_json;
     57 
     58     // Get the input size of the JSON file
     59 	int input_size_json = weights_json["/model_data/input_size"_json_pointer];
     60 	input_size = input_size_json;
     61 
     62     // Load the appropriate model
     63     if (input_size == 1) {
     64 		set_weights(&model, filename);
     65     }
     66     else if (input_size == 2) {
     67 		set_weights(&model_cond1, filename);
     68     } 
     69     else if (input_size == 3) {
     70 		set_weights(&model_cond2, filename);
     71     } 
     72 }
     73 
     74 
     75 void RT_LSTM::reset()
     76 {
     77     if (input_size == 1) {
     78         model.reset();
     79     } else {
     80         model_cond1.reset();
     81     }
     82 }
     83 
     84 void RT_LSTM::process(const float* inData, float* outData, int numSamples)
     85 {
     86     for (int i = 0; i < numSamples; ++i)
     87         outData[i] = model.forward(inData + i) + inData[i];
     88 }
     89 
     90 void RT_LSTM::process(const float* inData, float param, float* outData, int numSamples)
     91 {
     92     for (int i = 0; i < numSamples; ++i) {
     93         inArray1[0] = inData[i];
     94         inArray1[1] = param;
     95         outData[i] = model_cond1.forward(inArray1) + inData[i];
     96     }
     97 }
     98 
     99 void RT_LSTM::process(const float* inData, float param1, float param2, float* outData, int numSamples)
    100 {
    101     for (int i = 0; i < numSamples; ++i) {
    102         inArray2[0] = inData[i];
    103         inArray2[1] = param1;
    104         inArray2[2] = param2;
    105         outData[i] = model_cond2.forward(inArray2) + inData[i];
    106     }
    107 }
    108