private async Task audio2spectrum_saveVideoAsync(string path)
{
var progressHandler = new Progress <string>(value =>
{
status_txt.Text = value;
});
var progress = progressHandler as IProgress <string>;
await Task.Run(() =>
{
long frameCount;
try
{
double samplesPerFrame = ((double)audio2spectrum_sampleRate) * frameRate.Denominator / frameRate.Numerator;
double totalFrameCount = Math.Ceiling(audio2spectrum_samples.Length / samplesPerFrame);
int roundedSamplesPerFrame = (int)Math.Ceiling(samplesPerFrame);
int outputWidth = 50;
int outputHeight = 50;
double samplesPerPixel = samplesPerFrame / outputWidth;
// Now find closest fft size (take next highest)
int fftSize = (int)Math.Pow(2, Math.Ceiling(Math.Log(samplesPerPixel, 2.0)));
progress.Report("Audio2Spectrum: Loading spectrogram library");
Spectrogram.Spectrogram spec = new Spectrogram.Spectrogram(audio2spectrum_sampleRate, fftSize: 2048, stepSize: 50);
spec.SetFixedWidth(outputWidth);
//outputWidth = spec.Width;
progress.Report("Audio2Spectrum: Initializing video writer");
VideoFileWriter writer = new VideoFileWriter();
writer.Open(path, outputWidth, outputHeight, frameRate, VideoCodec.FFV1);
/*
* Console.WriteLine("width: " + reader.Width);
* Console.WriteLine("height: " + reader.Height);
* Console.WriteLine("fps: " + reader.FrameRate);
* Console.WriteLine("codec: " + reader.CodecName);
* Console.WriteLine("length: " + reader.FrameCount);
*/
frameCount = (long)totalFrameCount;
// Enlarge the array to make sure we don't end up accessing nonexisting samples. We make it a tiny bit bigger than maybe necessary, just to be safe. (To be honest, I am just too lazy to calculate the precise number we need)
/*if((long)Math.Ceiling(frameCount * samplesPerFrame) > audio2spectrum_samples.Length)
* {
* progress.Report("Audio2Spectrum: Resizing array");
* Array.Resize<double>(ref audio2spectrum_samples, (int)Math.Ceiling(frameCount * samplesPerFrame));
* }*/
double[] frameSampleBuffer = new double[roundedSamplesPerFrame];
int currentFrame = 0;
long currentStartSample = 0;
progress.Report("Audio2Spectrum: Starting video generation");
Bitmap tmp;
for (int i = 0; i < frameCount; i++)
{
currentStartSample = (long)Math.Floor(i *samplesPerFrame);
// Doing this branching here now because the resizing the array first was just way way too slow and memory hungry
if (currentStartSample >= audio2spectrum_samples.Length) // Even the first sample is already outside the bounds, just make empty array.
{
frameSampleBuffer = new double[roundedSamplesPerFrame];
}
else if ((currentStartSample + (roundedSamplesPerFrame - 1)) > (audio2spectrum_samples.Length - 1)) // Copy as many samples as possible
{
long difference = (currentStartSample + (roundedSamplesPerFrame - 1)) - (audio2spectrum_samples.Length - 1);
frameSampleBuffer = new double[roundedSamplesPerFrame];
Array.Copy(audio2spectrum_samples, currentStartSample, frameSampleBuffer, 0, roundedSamplesPerFrame - difference);
}
else
{
Array.Copy(audio2spectrum_samples, currentStartSample, frameSampleBuffer, 0, roundedSamplesPerFrame);
}
spec.Add(frameSampleBuffer);
tmp = spec.GetBitmapMel(dB: true, melBinCount: outputHeight);
#if DEBUG
Console.WriteLine(tmp.Width + "x" + tmp.Height);
#endif
writer.WriteVideoFrame(tmp);
if (currentFrame % 1000 == 0)
{
progress.Report("Audio2Spectrum: Saving video: " + i + "/" + frameCount + " frames");
}
}
writer.Close();
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
});
status_txt.Text = "Audio2Spectrum: Completed saving video.";
videoIsLoaded = true;
}
