SFF.GetPixelInfo()

Author: swharden

src/Spectrogram/SFF.cs

@@ -27,6 +27,7 @@ public class SFF
  public int OffsetHz { get; private set; }
  public int MelBinCount { get; private set; }
  public bool Decibels { get; private set; }
+ public bool IsMel { get { return MelBinCount > 0; } }
 
  // FFT details
  public int FftHeight { get { return Ffts[0].Length; } }
@@ -220,5 +221,20 @@ public void Save(string filePath)
  // write file to disk
  File.WriteAllBytes(filePath, fileBytes);
  }
+
+ public (double timeSec, double freqHz, double magRms) GetPixelInfo(int x, int y)
+ {
+ double timeSec = (double)x * StepSize / SampleRate;
+
+ double maxFreq = SampleRate / 2;
+ double maxMel = FftSharp.Transform.MelFromFreq(maxFreq);
+ double frac = (FftHeight - y) / (double)FftHeight;
+ double freq = IsMel ? FftSharp.Transform.MelToFreq(frac * maxMel) : frac * maxFreq;
+
+ double mag = double.NaN;
+ try { mag = Ffts[x][FftHeight - y - 1]; } catch { }
+
+ return (timeSec, freq, mag);
+ }
  }
 }