1 files changed, 13 insertions, 47 deletions
diff --git a/tools/mq_editor/mq_extract.js b/tools/mq_editor/mq_extract.js
index c7ead4d..237f1ab 100644
--- a/tools/mq_editor/mq_extract.js
+++ b/tools/mq_editor/mq_extract.js
@@ -2,21 +2,17 @@
 // McAulay-Quatieri sinusoidal analysis
 
 // Extract partials from audio buffer
-function extractPartials(audioBuffer, params) {
-  const {fftSize, hopSize, threshold, sampleRate} = params;
+function extractPartials(params, stftCache) {
+  const {fftSize, threshold, sampleRate} = params;
 
-  // Get mono channel (mix to mono if stereo)
-  const signal = getMono(audioBuffer);
-  const numFrames = Math.floor((signal.length - fftSize) / hopSize);
-
-  // Analyze frames
+  // Analyze frames from cache
   const frames = [];
+  const numFrames = stftCache.getNumFrames();
   for (let i = 0; i < numFrames; ++i) {
-    const offset = i * hopSize;
-    const frame = signal.slice(offset, offset + fftSize);
-    const peaks = detectPeaks(frame, fftSize, sampleRate, threshold);
-    const time = offset / sampleRate;
-    frames.push({time, peaks});
+    const cachedFrame = stftCache.getFrameAtIndex(i);
+    const squaredAmp = stftCache.getSquaredAmplitude(cachedFrame.time);
+    const peaks = detectPeaks(squaredAmp, fftSize, sampleRate, threshold);
+    frames.push({time: cachedFrame.time, peaks});
   }
 
   // Track trajectories
@@ -28,45 +24,15 @@ function extractPartials(audioBuffer, params) {
     partial.ampCurve = fitBezier(partial.times, partial.amps);
   }
 
-  return partials;
-}
-
-// Get mono signal
-function getMono(audioBuffer) {
-  const data = audioBuffer.getChannelData(0);
-  if (audioBuffer.numberOfChannels === 1) {
-    return data;
-  }
-
-  // Mix to mono
-  const left = audioBuffer.getChannelData(0);
-  const right = audioBuffer.getChannelData(1);
-  const mono = new Float32Array(left.length);
-  for (let i = 0; i < left.length; ++i) {
-    mono[i] = (left[i] + right[i]) * 0.5;
-  }
-  return mono;
+  return {partials, frames};
 }
 
-// Detect peaks in FFT frame
-function detectPeaks(frame, fftSize, sampleRate, thresholdDB) {
-  // Apply Hann window
-  const windowed = new Float32Array(fftSize);
-  for (let i = 0; i < fftSize; ++i) {
-    const w = 0.5 - 0.5 * Math.cos(2 * Math.PI * i / fftSize);
-    windowed[i] = frame[i] * w;
-  }
-
-  // FFT (using built-in)
-  const spectrum = realFFT(windowed);
-
-  // Convert to magnitude dB
+// Detect peaks in FFT frame (squaredAmp is pre-computed cached re*re+im*im)
+function detectPeaks(squaredAmp, fftSize, sampleRate, thresholdDB) {
+  // Convert squared amplitude to dB (10*log10 == 20*log10 of magnitude)
   const mag = new Float32Array(fftSize / 2);
   for (let i = 0; i < fftSize / 2; ++i) {
-    const re = spectrum[i * 2];
-    const im = spectrum[i * 2 + 1];
-    const magLin = Math.sqrt(re * re + im * im);
-    mag[i] = 20 * Math.log10(Math.max(magLin, 1e-10));
+    mag[i] = 10 * Math.log10(Math.max(squaredAmp[i], 1e-20));
   }
 
   // Find local maxima above threshold