public string GetLevelsFromAudioFX(string audioType, string audioFile)
{
string audioFilename = Path.Combine(Executor.Current.ExpanderSharedFiles, audioType, audioFile);
string levelsFilename = Path.Combine(Executor.Current.ExpanderSharedFiles, audioType, audioFile + ".levels");
if (!File.Exists(levelsFilename))
{
using (ISampleSource source = CodecFactory.Instance.GetCodec(audioFilename).ToSampleSource())
{
var fftProvider = new FftProvider(source.WaveFormat.Channels, FftSize.Fft1024);
int millisecondsPerFrame = 1000 / 40;
long maxBufferLengthInSamples = source.GetRawElements(millisecondsPerFrame);
long bufferLength = Math.Min(source.Length, maxBufferLengthInSamples);
float[] buffer = new float[bufferLength];
int read = 0;
int totalSamplesRead = 0;
var fftData = new float[1024];
var list = new List <float>();
float highest = 0;
do
{
//determine how many samples to read
int samplesToRead = (int)Math.Min(source.Length - totalSamplesRead, buffer.Length);
read = source.Read(buffer, 0, samplesToRead);
if (read == 0)
{
break;
}
totalSamplesRead += read;
//add read data to the fftProvider
fftProvider.Add(buffer, read);
fftProvider.GetFftData(fftData);
float highestAmplitude = 0;
for (int i = 0; i < fftData.Length / 2; i++)
{
if (fftData[i] > highestAmplitude)
{
highestAmplitude = fftData[i];
}
}
list.Add(highestAmplitude);
if (highestAmplitude > highest)
{
highest = highestAmplitude;
}
} while (totalSamplesRead < source.Length);
if (highest > 0)
{
// Adjust to equalize
float adjustment = 1 / highest;
for (int i = 0; i < list.Count; i++)
{
list[i] *= adjustment;
}
}
using (var fs = File.Create(levelsFilename))
{
fs.Write(list.Select(x => (byte)(x * 255)).ToArray(), 0, list.Count);
}
}
}
return(levelsFilename);
}
