eml_fft: Use floats everywhere

emlearn · Dec 29, 2018 · d2ad0b1 · d2ad0b1
1 parent 4407c33
commit d2ad0b1
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Showing 4 changed files with 11 additions and 12 deletions.
diff --git a/bindings/eml_audio.cpp b/bindings/eml_audio.cpp
@@ -23,8 +23,8 @@ rfft_py(py::array_t<float, py::array::c_style | py::array::forcecast> in) {
 
     // Precompute FFT table
     const int n_fft_table = n_fft/2;
-    std::vector<double> fft_sin(n_fft_table);
-    std::vector<double> fft_cos(n_fft_table);
+    std::vector<float> fft_sin(n_fft_table);
+    std::vector<float> fft_cos(n_fft_table);
     EmlFFT fft = { n_fft_table, fft_sin.data(), fft_cos.data() };
     eml_fft_fill(fft, n_fft);
 
@@ -66,8 +66,8 @@ melspectrogram_py(py::array_t<float, py::array::c_style | py::array::forcecast>
 
     // FFT table
     const int n_fft_table = n_fft/2;
-    std::vector<double> fft_sin(n_fft_table);
-    std::vector<double> fft_cos(n_fft_table);
+    std::vector<float> fft_sin(n_fft_table);
+    std::vector<float> fft_cos(n_fft_table);
     EmlFFT fft = { n_fft_table, fft_sin.data(), fft_cos.data() };
     eml_fft_fill(fft, n_fft);
 

diff --git a/emlearn/eml_fft.h b/emlearn/eml_fft.h
@@ -45,8 +45,8 @@ static size_t reverse_bits(size_t x, int n) {
 
 typedef struct _EmlFFT {
     int length; // (n/2)
-    double *sin;    
-    double *cos;
+    float *sin;
+    float *cos;
 } EmlFFT;
 
 
@@ -77,7 +77,7 @@ eml_fft_forward(EmlFFT table, float real[], float imag[], size_t n) {
 	for (size_t i = 0; i < n; i++) {
 		size_t j = reverse_bits(i, levels);
 		if (j > i) {
-			double temp = real[i];
+			float temp = real[i];
 			real[i] = real[j];
 			real[j] = temp;
 			temp = imag[i];
@@ -93,8 +93,8 @@ eml_fft_forward(EmlFFT table, float real[], float imag[], size_t n) {
 		for (size_t i = 0; i < n; i += size) {
 			for (size_t j = i, k = 0; j < i + halfsize; j++, k += tablestep) {
 				size_t l = j + halfsize;
-				double tpre =  real[l] * table.cos[k] + imag[l] * table.sin[k];
-				double tpim = -real[l] * table.sin[k] + imag[l] * table.cos[k];
+				float tpre =  real[l] * table.cos[k] + imag[l] * table.sin[k];
+				float tpim = -real[l] * table.sin[k] + imag[l] * table.cos[k];
 				real[l] = real[j] - tpre;
 				imag[l] = imag[j] - tpim;
 				real[j] += tpre;

diff --git a/test/bench.c b/test/bench.c
@@ -19,8 +19,8 @@ bench_melspec()
     eml_benchmark_fill(input_data, frame_length);
 
     const int n_fft_table = n_fft/2;
-    double fft_sin[n_fft_table];
-    double fft_cos[n_fft_table];
+    float fft_sin[n_fft_table];
+    float fft_cos[n_fft_table];
     EmlFFT fft = { n_fft_table, fft_sin, fft_cos };
     EML_CHECK_ERROR(eml_fft_fill(fft, n_fft));
 

diff --git a/test/test_audio.py b/test/test_audio.py
@@ -14,7 +14,6 @@
     256,
     512,
     1024,
-    2048,
 ]
 @pytest.mark.parametrize('n_fft', FFT_SIZES)
 def test_rfft_simple(n_fft):