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swhardenswharden
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capitalize all field names
1 parent c6152b6 commit 7798cd5

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+66
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‎src/Spectrogram/SpectrogramGenerator.cs

Lines changed: 66 additions & 50 deletions
Original file line numberDiff line numberDiff line change
@@ -73,12 +73,27 @@ public class SpectrogramGenerator
7373
/// <summary>
7474
/// The spectrogram is trimmed to cut-off frequencies above this value.
7575
/// </summary>
76-
public double FreqMin { get { return settings.FreqMin; } }
76+
public double FreqMin { get => Settings.FreqMin; }
77+
78+
/// <summary>
79+
/// This module contains detailed FFT/Spectrogram settings
80+
/// </summary>
81+
private readonly Settings Settings;
82+
83+
/// <summary>
84+
/// This is the list of FFTs which is translated to the spectrogram image when it is requested.
85+
/// The length of this list is the spectrogram width.
86+
/// The length of the arrays in this list is the spectrogram height.
87+
/// </summary>
88+
private readonly List<double[]> FFTs = new List<double[]>();
89+
90+
/// <summary>
91+
/// This list contains data values which have not yet been processed.
92+
/// Process() processes all unprocessed data.
93+
/// This list may not be empty after processing if there aren't enough values to fill a full FFT (FftSize).
94+
/// </summary>
95+
private readonly List<double> UnprocessedData;
7796

78-
private readonly Settings settings;
79-
private readonly List<double[]> ffts = new List<double[]>();
80-
private readonly List<double> newAudio;
81-
private Colormap cmap = Colormap.Viridis;
8297
/// <summary>
8398
/// Colormap to use when generating future FFTs.
8499
/// </summary>
@@ -107,30 +122,30 @@ public SpectrogramGenerator(
107122
int offsetHz = 0,
108123
List<double> initialAudioList = null)
109124
{
110-
settings = new Settings(sampleRate, fftSize, stepSize, minFreq, maxFreq, offsetHz);
125+
Settings = new Settings(sampleRate, fftSize, stepSize, minFreq, maxFreq, offsetHz);
111126

112-
newAudio = initialAudioList ?? new List<double>();
127+
UnprocessedData = initialAudioList ?? new List<double>();
113128

114129
if (fixedWidth.HasValue)
115130
SetFixedWidth(fixedWidth.Value);
116131
}
117132

118133
public override string ToString()
119134
{
120-
double processedSamples = ffts.Count * settings.StepSize + settings.FftSize;
121-
double processedSec = processedSamples / settings.SampleRate;
135+
double processedSamples = FFTs.Count * Settings.StepSize + Settings.FftSize;
136+
double processedSec = processedSamples / Settings.SampleRate;
122137
string processedTime = (processedSec < 60) ? $"{processedSec:N2} sec" : $"{processedSec / 60.0:N2} min";
123138

124139
return $"Spectrogram ({Width}, {Height})" +
125140
$"\n Vertical ({Height} px): " +
126-
$"{settings.FreqMin:N0} - {settings.FreqMax:N0} Hz, " +
127-
$"FFT size: {settings.FftSize:N0} samples, " +
128-
$"{settings.HzPerPixel:N2} Hz/px" +
141+
$"{Settings.FreqMin:N0} - {Settings.FreqMax:N0} Hz, " +
142+
$"FFT size: {Settings.FftSize:N0} samples, " +
143+
$"{Settings.HzPerPixel:N2} Hz/px" +
129144
$"\n Horizontal ({Width} px): " +
130145
$"{processedTime}, " +
131-
$"window: {settings.FftLengthSec:N2} sec, " +
132-
$"step: {settings.StepLengthSec:N2} sec, " +
133-
$"overlap: {settings.StepOverlapFrac * 100:N0}%";
146+
$"window: {Settings.FftLengthSec:N2} sec, " +
147+
$"step: {Settings.StepLengthSec:N2} sec, " +
148+
$"overlap: {Settings.StepOverlapFrac * 100:N0}%";
134149
}
135150

136151
[Obsolete("Assign to the Colormap field")]
@@ -148,14 +163,14 @@ public void SetColormap(Colormap cmap)
148163
/// </summary>
149164
public void SetWindow(double[] newWindow)
150165
{
151-
if (newWindow.Length > settings.FftSize)
166+
if (newWindow.Length > Settings.FftSize)
152167
throw new ArgumentException("window length cannot exceed FFT size");
153168

154-
for (int i = 0; i < settings.FftSize; i++)
155-
settings.Window[i] = 0;
169+
for (int i = 0; i < Settings.FftSize; i++)
170+
Settings.Window[i] = 0;
156171

157-
int offset = (settings.FftSize - newWindow.Length) / 2;
158-
Array.Copy(newWindow, 0, settings.Window, offset, newWindow.Length);
172+
int offset = (Settings.FftSize - newWindow.Length) / 2;
173+
Array.Copy(newWindow, 0, Settings.Window, offset, newWindow.Length);
159174
}
160175

161176
[Obsolete("use the Add() method", true)]
@@ -172,7 +187,7 @@ public void AddScroll(float[] values) { }
172187
/// </summary>
173188
public void Add(IEnumerable<double> audio, bool process = true)
174189
{
175-
newAudio.AddRange(audio);
190+
UnprocessedData.AddRange(audio);
176191
if (process)
177192
Process();
178193
}
@@ -207,23 +222,23 @@ public double[][] Process()
207222

208223
Parallel.For(0, newFftCount, newFftIndex =>
209224
{
210-
FftSharp.Complex[] buffer = new FftSharp.Complex[settings.FftSize];
211-
int sourceIndex = newFftIndex * settings.StepSize;
212-
for (int i = 0; i < settings.FftSize; i++)
213-
buffer[i].Real = newAudio[sourceIndex + i] * settings.Window[i];
225+
FftSharp.Complex[] buffer = new FftSharp.Complex[Settings.FftSize];
226+
int sourceIndex = newFftIndex * Settings.StepSize;
227+
for (int i = 0; i < Settings.FftSize; i++)
228+
buffer[i].Real = UnprocessedData[sourceIndex + i] * Settings.Window[i];
214229

215230
FftSharp.Transform.FFT(buffer);
216231

217-
newFfts[newFftIndex] = new double[settings.Height];
218-
for (int i = 0; i < settings.Height; i++)
219-
newFfts[newFftIndex][i] = buffer[settings.FftIndex1 + i].Magnitude / settings.FftSize;
232+
newFfts[newFftIndex] = new double[Settings.Height];
233+
for (int i = 0; i < Settings.Height; i++)
234+
newFfts[newFftIndex][i] = buffer[Settings.FftIndex1 + i].Magnitude / Settings.FftSize;
220235
});
221236

222237
foreach (var newFft in newFfts)
223-
ffts.Add(newFft);
238+
FFTs.Add(newFft);
224239
FftsProcessed += newFfts.Length;
225240

226-
newAudio.RemoveRange(0, newFftCount * settings.StepSize);
241+
UnprocessedData.RemoveRange(0, newFftCount * Settings.StepSize);
227242
PadOrTrimForFixedWidth();
228243

229244
return newFfts;
@@ -235,11 +250,11 @@ public double[][] Process()
235250
/// <param name="melBinCount">Total number of output bins to use. Choose a value significantly smaller than Height.</param>
236251
public List<double[]> GetMelFFTs(int melBinCount)
237252
{
238-
if (settings.FreqMin != 0)
253+
if (Settings.FreqMin != 0)
239254
throw new InvalidOperationException("cannot get Mel spectrogram unless minimum frequency is 0Hz");
240255

241256
var fftsMel = new List<double[]>();
242-
foreach (var fft in ffts)
257+
foreach (var fft in FFTs)
243258
fftsMel.Add(FftSharp.Transform.MelScale(fft, SampleRate, melBinCount));
244259

245260
return fftsMel;
@@ -255,7 +270,7 @@ public List<double[]> GetMelFFTs(int melBinCount)
255270
/// Roll (true) adds new columns on the left overwriting the oldest ones.
256271
/// Scroll (false) slides the whole image to the left and adds new columns to the right.</param>
257272
public Bitmap GetBitmap(double intensity = 1, bool dB = false, double dBScale = 1, bool roll = false) =>
258-
Image.GetBitmap(ffts, cmap, intensity, dB, dBScale, roll, NextColumnIndex);
273+
Image.GetBitmap(FFTs, Colormap, intensity, dB, dBScale, roll, NextColumnIndex);
259274

260275
/// <summary>
261276
/// Create a Mel-scaled spectrogram.
@@ -268,7 +283,7 @@ public Bitmap GetBitmap(double intensity = 1, bool dB = false, double dBScale =
268283
/// Roll (true) adds new columns on the left overwriting the oldest ones.
269284
/// Scroll (false) slides the whole image to the left and adds new columns to the right.</param>
270285
public Bitmap GetBitmapMel(int melBinCount = 25, double intensity = 1, bool dB = false, double dBScale = 1, bool roll = false) =>
271-
Image.GetBitmap(GetMelFFTs(melBinCount), cmap, intensity, dB, dBScale, roll, NextColumnIndex);
286+
Image.GetBitmap(GetMelFFTs(melBinCount), Colormap, intensity, dB, dBScale, roll, NextColumnIndex);
272287

273288
[Obsolete("use SaveImage()", true)]
274289
public void SaveBitmap(Bitmap bmp, string fileName) { }
@@ -285,7 +300,7 @@ public void SaveBitmap(Bitmap bmp, string fileName) { }
285300
/// Scroll (false) slides the whole image to the left and adds new columns to the right.</param>
286301
public void SaveImage(string fileName, double intensity = 1, bool dB = false, double dBScale = 1, bool roll = false)
287302
{
288-
if (ffts.Count == 0)
303+
if (FFTs.Count == 0)
289304
throw new InvalidOperationException("Spectrogram contains no data. Use Add() to add signal data.");
290305

291306
string extension = Path.GetExtension(fileName).ToLower();
@@ -302,7 +317,7 @@ public void SaveImage(string fileName, double intensity = 1, bool dB = false, do
302317
else
303318
throw new ArgumentException("unknown file extension");
304319

305-
Image.GetBitmap(ffts, cmap, intensity, dB, dBScale, roll, NextColumnIndex).Save(fileName, fmt);
320+
Image.GetBitmap(FFTs, Colormap, intensity, dB, dBScale, roll, NextColumnIndex).Save(fileName, fmt);
306321
}
307322

308323
/// <summary>
@@ -317,16 +332,16 @@ public void SaveImage(string fileName, double intensity = 1, bool dB = false, do
317332
public Bitmap GetBitmapMax(double intensity = 1, bool dB = false, double dBScale = 1, bool roll = false, int reduction = 4)
318333
{
319334
List<double[]> ffts2 = new List<double[]>();
320-
for (int i = 0; i < ffts.Count; i++)
335+
for (int i = 0; i < FFTs.Count; i++)
321336
{
322-
double[] d1 = ffts[i];
337+
double[] d1 = FFTs[i];
323338
double[] d2 = new double[d1.Length / reduction];
324339
for (int j = 0; j < d2.Length; j++)
325340
for (int k = 0; k < reduction; k++)
326341
d2[j] = Math.Max(d2[j], d1[j * reduction + k]);
327342
ffts2.Add(d2);
328343
}
329-
return Image.GetBitmap(ffts2, cmap, intensity, dB, dBScale, roll, NextColumnIndex);
344+
return Image.GetBitmap(ffts2, Colormap, intensity, dB, dBScale, roll, NextColumnIndex);
330345
}
331346

332347
/// <summary>
@@ -360,10 +375,10 @@ private void PadOrTrimForFixedWidth()
360375
{
361376
int overhang = Width - fixedWidth;
362377
if (overhang > 0)
363-
ffts.RemoveRange(0, overhang);
378+
FFTs.RemoveRange(0, overhang);
364379

365-
while (ffts.Count < fixedWidth)
366-
ffts.Insert(0, new double[Height]);
380+
while (FFTs.Count < fixedWidth)
381+
FFTs.Insert(0, new double[Height]);
367382
}
368383
}
369384

@@ -376,26 +391,27 @@ private void PadOrTrimForFixedWidth()
376391
/// <param name="reduction">bin size for vertical data reduction</param>
377392
public Bitmap GetVerticalScale(int width, int offsetHz = 0, int tickSize = 3, int reduction = 1)
378393
{
379-
return Scale.Vertical(width, settings, offsetHz, tickSize, reduction);
394+
return Scale.Vertical(width, Settings, offsetHz, tickSize, reduction);
380395
}
381396

382397
/// <summary>
383398
/// Return the vertical position (pixel units) for the given frequency
384399
/// </summary>
385400
public int PixelY(double frequency, int reduction = 1)
386401
{
387-
int pixelsFromZeroHz = (int)(settings.PxPerHz * frequency / reduction);
388-
int pixelsFromMinFreq = pixelsFromZeroHz - settings.FftIndex1 / reduction + 1;
389-
int pixelRow = settings.Height / reduction - 1 - pixelsFromMinFreq;
402+
int pixelsFromZeroHz = (int)(Settings.PxPerHz * frequency / reduction);
403+
int pixelsFromMinFreq = pixelsFromZeroHz - Settings.FftIndex1 / reduction + 1;
404+
int pixelRow = Settings.Height / reduction - 1 - pixelsFromMinFreq;
390405
return pixelRow - 1;
391406
}
392407

393408
/// <summary>
394-
/// Return a list of the FFTs in memory underlying the spectrogram
409+
/// Return the list of FFTs in memory underlying the spectrogram.
410+
/// This list may continue to evolve after it is returned.
395411
/// </summary>
396412
public List<double[]> GetFFTs()
397413
{
398-
return ffts;
414+
return FFTs;
399415
}
400416

401417
/// <summary>
@@ -404,13 +420,13 @@ public List<double[]> GetFFTs()
404420
/// <param name="latestFft">If true, only the latest FFT will be assessed.</param>
405421
public (double freqHz, double magRms) GetPeak(bool latestFft = true)
406422
{
407-
if (ffts.Count == 0)
423+
if (FFTs.Count == 0)
408424
return (double.NaN, double.NaN);
409425

410426
if (latestFft == false)
411427
throw new NotImplementedException("peak of mean of all FFTs not yet supported");
412428

413-
double[] freqs = ffts[ffts.Count - 1];
429+
double[] freqs = FFTs[FFTs.Count - 1];
414430

415431
int peakIndex = 0;
416432
double peakMagnitude = 0;

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