1 files changed, 3 insertions, 10 deletions
diff --git a/src/audio/idct.cc b/src/audio/idct.cc
index f8e8769..4566f99 100644
--- a/src/audio/idct.cc
+++ b/src/audio/idct.cc
@@ -3,16 +3,9 @@
 // Used for real-time synthesis of audio from spectral data.
 
 #include "dct.h"
-#include <math.h>
+#include "fft.h"
 
+// Fast O(N log N) implementation using FFT
 void idct_512(const float* input, float* output) {
-  const float PI = 3.14159265358979323846f;
-  for (int n = 0; n < DCT_SIZE; ++n) {
-    float sum = input[0] / 2.0f;
-    for (int k = 1; k < DCT_SIZE; ++k) {
-      sum +=
-          input[k] * cosf(PI / (float)DCT_SIZE * (float)k * ((float)n + 0.5f));
-    }
-    output[n] = sum * (2.0f / (float)DCT_SIZE);
-  }
+  idct_fft(input, output, DCT_SIZE);
 }