using System;

using System.Collections.Generic;

using System.Drawing;

using System.Text;

namespace Spectrogram

{

public static class Tools

{

private static string FindFile(string filePath)

{

// look for it in this folder

string pathFileHere = System.IO.Path.GetFullPath(filePath);

if (System.IO.File.Exists(pathFileHere))

return pathFileHere;

else

Console.WriteLine($"File not found in same folder: {pathFileHere}");

// look for it in the package data folder

string fileName = System.IO.Path.GetFileName(filePath);

string pathDataFolder = System.IO.Path.GetFullPath("../../../../data/");

string pathInDataFolder = System.IO.Path.Combine(pathDataFolder, fileName);

if (System.IO.File.Exists(pathInDataFolder))

return pathInDataFolder;

else

Console.WriteLine($"File not found in data folder: {pathInDataFolder}");

throw new ArgumentException($"Could not locate {filePath}");

}

public static float[] FloatsFromBytesINT16(byte[] bytes, int skipFirstBytes = 0)

{

float[] pcm = new float[(bytes.Length - skipFirstBytes) / 2];

for (int i = skipFirstBytes; i < bytes.Length - 2; i += 2)

{

if (i / 2 >= pcm.Length)

break;

pcm[i / 2] = BitConverter.ToInt16(bytes, i);

}

return pcm;

}

public static float[] ReadWav(string wavFilePath, int? sampleLimit = null)

{

// quick and drity WAV file reader (only for 16-bit signed mono files)

string actualPath = FindFile(wavFilePath);

if (actualPath == null)

throw new ArgumentException("file not found: " + actualPath);

byte[] bytes = System.IO.File.ReadAllBytes(actualPath);

int sampleCount = bytes.Length / 2;

if (sampleLimit != null)

sampleCount = Math.Min(sampleCount, (int)sampleLimit);

return FloatsFromBytesINT16(bytes, skipFirstBytes: 44);

}

public static float[] ReadMp3(string mp3FilePath, int? sampleLimit = null)

{

string actualPath = FindFile(mp3FilePath);

var reader = new NAudio.Wave.Mp3FileReader(actualPath);

int bytesToRead = (int)reader.Length;

if (sampleLimit != null)

bytesToRead = Math.Min(bytesToRead, (int)sampleLimit * 2);

byte[] bytes = new byte[bytesToRead];

reader.Read(bytes, 0, bytesToRead);

float[] pcm = FloatsFromBytesINT16(bytes);

return pcm;

}

}

}