private TensorFloat TensorizeWithVideoFrame()
{
var s = new System.Diagnostics.Stopwatch();
s.Start();
var bitmap = decoder_.GetSoftwareBitmapAsync(BitmapPixelFormat.Bgra8, BitmapAlphaMode.Premultiplied).GetAwaiter().GetResult();
var videoFrame = VideoFrame.CreateWithSoftwareBitmap(bitmap);
var outputTensorI64 = TensorInt64Bit.Create();
Evaluate(shapeSession_, videoFrame, outputTensorI64);
s.Stop();
PerformanceMetricsMonitor.Log("VideoFrame Tensorization", s.ElapsedMilliseconds * 1000000);
return(null);
}
static SoftwareBitmap GetMelspectrogramFromSignal(
IEnumerable <float> rawSignal,
int batchSize = 1,
int windowSize = 256,
int dftSize = 256,
int hopSize = 3,
int nMelBins = 1024,
int samplingRate = 8192,
int amplitude = 5000
)
{
float[] signal = rawSignal.ToArray();
//Scale the signal by a given amplitude
for (int i = 0; i < signal.Length; i++)
{
signal[i] = signal[i] * amplitude;
}
int signalSize = signal.Length;
var nDFT = 1 + (signalSize - dftSize) / hopSize;
var onesidedDftSize = (dftSize >> 1) + 1;
long[] signalShape = { batchSize, signalSize };
long[] melSpectrogramShape = { batchSize, 1, nDFT, nMelBins };
var builder = LearningModelBuilder.Create(13)
.Inputs.Add(LearningModelBuilder.CreateTensorFeatureDescriptor("Input.TimeSignal", TensorKind.Float, signalShape))
.Outputs.Add(LearningModelBuilder.CreateTensorFeatureDescriptor("Output.MelSpectrogram", TensorKind.Float, melSpectrogramShape))
.Operators.Add(new Operator("HannWindow", MicrosoftExperimentalDomain)
.SetConstant("size", TensorInt64Bit.CreateFromArray(new List <long>(), new long[] { windowSize }))
.SetOutput("output", "hann_window"))
.Operators.Add(new Operator("STFT", MicrosoftExperimentalDomain)
.SetName("STFT_NAMED_NODE")
.SetInput("signal", "Input.TimeSignal")
.SetInput("window", "hann_window")
.SetConstant("frame_length", TensorInt64Bit.CreateFromArray(new List <long>(), new long[] { dftSize }))
.SetConstant("frame_step", TensorInt64Bit.CreateFromArray(new List <long>(), new long[] { hopSize }))
.SetOutput("output", "stft_output"))
.Operators.Add(new Operator("ReduceSumSquare")
.SetInput("data", "stft_output")
.SetAttribute("axes", TensorInt64Bit.CreateFromArray(new List <long>()
{
1
}, new long[] { 3 }))
.SetAttribute("keepdims", TensorInt64Bit.CreateFromArray(new List <long>(), new long[] { 0 }))
.SetOutput("reduced", "magnitude_squared"))
.Operators.Add(new Operator("Div")
.SetInput("A", "magnitude_squared")
.SetConstant("B", TensorFloat.CreateFromArray(new List <long>(), new float[] { dftSize }))
.SetOutput("C", "power_frames"))
.Operators.Add(new Operator("MelWeightMatrix", MicrosoftExperimentalDomain)
.SetConstant("num_mel_bins", TensorInt64Bit.CreateFromArray(new List <long>(), new long[] { nMelBins }))
.SetConstant("dft_length", TensorInt64Bit.CreateFromArray(new List <long>(), new long[] { dftSize }))
.SetConstant("sample_rate", TensorInt64Bit.CreateFromArray(new List <long>(), new long[] { samplingRate }))
.SetConstant("lower_edge_hertz", TensorFloat.CreateFromArray(new List <long>(), new float[] { 0 }))
.SetConstant("upper_edge_hertz", TensorFloat.CreateFromArray(new List <long>(), new float[] { (float)(samplingRate / 2.0) }))
.SetOutput("output", "mel_weight_matrix"))
.Operators.Add(new Operator("Reshape")
.SetInput("data", "power_frames")
.SetConstant("shape", TensorInt64Bit.CreateFromArray(new List <long>()
{
2
}, new long[] { batchSize *nDFT, onesidedDftSize }))
.SetOutput("reshaped", "reshaped_output"))
.Operators.Add(new Operator("MatMul")
.SetInput("A", "reshaped_output")
.SetInput("B", "mel_weight_matrix")
.SetOutput("Y", "mel_spectrogram"))
.Operators.Add(new Operator("Reshape")
.SetInput("data", "mel_spectrogram")
.SetConstant("shape", TensorInt64Bit.CreateFromArray(new List <long>()
{
4
}, melSpectrogramShape))
.SetOutput("reshaped", "Output.MelSpectrogram"));
var model = builder.CreateModel();
LearningModelSession session = new LearningModelSession(model);
LearningModelBinding binding = new LearningModelBinding(session);
// Bind input
binding.Bind("Input.TimeSignal", TensorFloat.CreateFromArray(signalShape, signal));
// Bind output
var outputImage = new VideoFrame(
BitmapPixelFormat.Bgra8,
nMelBins,
nDFT);
binding.Bind("Output.MelSpectrogram", outputImage);
// Evaluate
var sw = Stopwatch.StartNew();
var result = session.Evaluate(binding, "");
sw.Stop();
Console.WriteLine("Evaluate Took: %f\n", sw.ElapsedMilliseconds);
return(outputImage.SoftwareBitmap);
}