Added adjustable FFT block size

src/uk/co/majenko/audiobookrecorder/MainToolBar.java

@@ -165,6 +165,7 @@ public class MainToolBar extends JToolBar {
             "1.50x",
             "1.75x"
         });
+        playbackSpeed.setFocusable(false);
 
         playbackSpeed.setSelectedIndex(1);
         add(playbackSpeed);

src/uk/co/majenko/audiobookrecorder/Options.java

@@ -24,6 +24,7 @@ public class Options extends JDialog {
     JComboBox<KVPair> rateList;
     JComboBox<KVPair> bitDepth;
     JComboBox<KVPair> trimMethod;
+    JComboBox<KVPair> fftBlockSize;
     JTextField storageFolder;
     JTextField archiveFolder;
     JSpinner preChapterGap;
@@ -297,6 +298,7 @@ public class Options extends JDialog {
         bitDepth = addDropdown(optionsPanel, "Sample resolution:", getResolutionList(), get("audio.recording.resolution"));
         trimMethod = addDropdown(optionsPanel, "Auto-trim method:", getTrimMethods(), get("audio.recording.trim"));
         fftThreshold = addSpinner(optionsPanel, "FFT threshold:", 0, 100, 1, getInteger("audio.recording.trim.fft"), "");
+        fftBlockSize = addDropdown(optionsPanel, "FFT Block size:", getFFTBlockSizes(), get("audio.recording.trim.blocksize"));
 
         addSeparator(optionsPanel);
 
@@ -565,6 +567,7 @@ public class Options extends JDialog {
         } else {
             defaultPrefs.put("audio.playback.device", "");
         }
+        defaultPrefs.put("audio.recording.trim.blocksize", "4096");
 
         defaultPrefs.put("catenation.pre-chapter", "1000");
         defaultPrefs.put("catenation.post-chapter", "1500");
@@ -708,6 +711,7 @@ public class Options extends JDialog {
         set("editor.external", externalEditor.getText());
         set("cache.size", cacheSize.getValue());
         set("audio.recording.trim.fft", fftThreshold.getValue());
+        set("audio.recording.trim.blocksize", ((KVPair)fftBlockSize.getSelectedItem()).key);
 
         set("effects.ethereal.offset", etherealOffset.getValue());
         set("effects.ethereal.iterations", etherealIterations.getValue());
@@ -782,6 +786,19 @@ public class Options extends JDialog {
         return pairs;
     }
 
+    public static KVPair[] getFFTBlockSizes() {
+        KVPair[] pairs = new KVPair[8];
+        pairs[0] = new KVPair<String, String>("1024", "1024");
+        pairs[1] = new KVPair<String, String>("2048", "2048");
+        pairs[2] = new KVPair<String, String>("4096", "4096");
+        pairs[3] = new KVPair<String, String>("8192", "8192");
+        pairs[4] = new KVPair<String, String>("16384", "16384");
+        pairs[5] = new KVPair<String, String>("32768", "32768");
+        pairs[6] = new KVPair<String, String>("65536", "65537");
+        pairs[7] = new KVPair<String, String>("131072", "131072");
+        return pairs;
+    }
+
 
     public static void createEffectChains() {
         effectChains = new ArrayList<EffectGroup>();

src/uk/co/majenko/audiobookrecorder/Sentence.java

@@ -225,17 +225,18 @@ public class Sentence extends DefaultMutableTreeNode implements Cacheable {
             return;
         }
 
+        int fftSize = Options.getInteger("audio.recording.trim.blocksize");
 
-        int blocks = samples.length / 4096 + 1;
+        int blocks = samples.length / fftSize + 1;
 
         int[] intens = new int[blocks];
         int block = 0;
 
-        for (int i = 0; i < samples.length; i+= 4096) {
+        for (int i = 0; i < samples.length; i+= fftSize) {
-            double[] real = new double[4096];
+            double[] real = new double[fftSize];
-            double[] imag = new double[4096];
+            double[] imag = new double[fftSize];
 
-            for (int j = 0; j < 4096; j++) {
+            for (int j = 0; j < fftSize; j++) {
                 if (i + j < samples.length) {
                     real[j] = (samples[i+j][LEFT] + samples[i+j][RIGHT]) / 2d;
                     imag[j] = 0;
@@ -247,14 +248,14 @@ public class Sentence extends DefaultMutableTreeNode implements Cacheable {
 
             double[] buckets = FFT.fft(real, imag, true);
             double av = 0;
-            for (int j = 1; j < 2048; j++) {
+            for (int j = 1; j < fftSize/2; j++) {
                 av += Math.abs(buckets[j]);
             }
-            av /= 2047d;
+            av /= (fftSize / 2);
 
             intens[block] = 0;
 
-            for (int j = 2; j < 4096; j += 2) {
+            for (int j = 2; j < fftSize; j += 2) {
                 double d = Math.abs(av - buckets[j]);
                 if (d > 0.05) {
                     intens[block]++;
@@ -278,7 +279,7 @@ public class Sentence extends DefaultMutableTreeNode implements Cacheable {
             start = 0;
         }
 
-        startOffset = start * 4096;
+        startOffset = start * fftSize;
         if (startOffset < 0) startOffset = 0;
         if (startOffset >= samples.length) startOffset = samples.length;
 
@@ -295,9 +296,9 @@ public class Sentence extends DefaultMutableTreeNode implements Cacheable {
             end = blocks - 1;
         }
 
-        endOffset = end * 4096;
+        endOffset = (end+1) * fftSize;
 
-        if (endOffset <= startOffset) endOffset = startOffset + 4096;
+        if (endOffset <= startOffset) endOffset = startOffset + fftSize;
         if (endOffset < 0) endOffset = 0;
         if (endOffset >= samples.length) endOffset = samples.length;
         updateCrossings(useRaw);
@@ -337,7 +338,8 @@ public class Sentence extends DefaultMutableTreeNode implements Cacheable {
             startOffset = 0;
         }
 
-        startOffset -= 4096;
+        int fftSize = Options.getInteger("audio.recording.trim.blocksize");
+        startOffset -= fftSize;
 
         for (int i = samples.length-1; i >= 0; i--) {
             endOffset = i;
@@ -348,9 +350,9 @@ public class Sentence extends DefaultMutableTreeNode implements Cacheable {
             }
         }
 
-        endOffset += 4096;
+        endOffset += fftSize;
 
-        if (endOffset <= startOffset) endOffset = startOffset + 4096;
+        if (endOffset <= startOffset) endOffset = startOffset + fftSize;
         if (endOffset <= 0) {
             endOffset = samples.length-1;
         }