If you want to generate *.wav files with random audio data in C#, you’ve come to the right place. Check out the code below, which you can simply dump into a fresh console application and test run. You can also use the code below to convert from floating point audio samples which have a range from -1 to 1 (both inclusive) into WAVE PCM audio files.
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
namespace RandomAudioGenerator
{
internal class Program
{
private static void Main(string[] args)
{
var random = new Random();
var data = new float[random.Next(1, 1000001)];
for (var i = 0; i < data.Length; i++)
{
data[i] = (float)random.Next(0, 65537) / 65536;
if (random.Next(0, 2) == 0)
data[i] = -data[i];
}
var directory = Directory.GetCurrentDirectory();
var path = Path.Combine(directory, Guid.NewGuid() + ".wav");
GenerateAudioFile(path, data, 1, 44000);
Process.Start("explorer.exe", "/select, " + path);
}
private static void GenerateAudioFile(string path, IReadOnlyCollection data, int channels, int frequency)
{
using (var stream = new FileStream(path, FileMode.CreateNew, FileAccess.Write))
{
// The following values are based on http://soundfile.sapp.org/doc/WaveFormat/
const ushort bitsPerSample = (ushort)16;
const string chunkId = "RIFF";
const string format = "WAVE";
const string subChunk1Id = "fmt ";
const uint subChunk1Size = (uint)16;
const ushort audioFormat = (ushort)1;
var numChannels = (ushort)channels;
var sampleRate = (uint)frequency;
var byteRate = (uint)(sampleRate * channels * bitsPerSample / 8); // SampleRate * NumChannels * BitsPerSample/8
var blockAlign = (ushort)(numChannels * bitsPerSample / 8); // NumChannels * BitsPerSample/8
const string subChunk2Id = "data";
var subChunk2Size = (uint)(data.Count * channels * bitsPerSample / 8); // NumSamples * NumChannels * BitsPerSample/8
var chunkSize = (uint)(36 + subChunk2Size); // 36 + SubChunk2Size
// Start writing the file.
WriteString(stream, chunkId);
WriteInteger(stream, chunkSize);
WriteString(stream, format);
WriteString(stream, subChunk1Id);
WriteInteger(stream, subChunk1Size);
WriteShort(stream, audioFormat);
WriteShort(stream, numChannels);
WriteInteger(stream, sampleRate);
WriteInteger(stream, byteRate);
WriteShort(stream, blockAlign);
WriteShort(stream, bitsPerSample);
WriteString(stream, subChunk2Id);
WriteInteger(stream, subChunk2Size);
foreach (var sample in data)
{
// De-normalize the samples to 16 bits.
var deNormalizedSample = (short)0;
if (sample > 0)
{
var temp = sample * short.MaxValue;
if (temp > short.MaxValue)
temp = short.MaxValue;
deNormalizedSample = (short)temp;
}
if (sample < 0)
{
var temp = sample * (-short.MinValue);
if (temp < short.MinValue)
temp = short.MinValue;
deNormalizedSample = (short)temp;
}
WriteShort(stream, (ushort)deNormalizedSample);
}
}
}
private static void WriteString(Stream stream, string value)
{
foreach (var character in value)
stream.WriteByte((byte)character);
}
private static void WriteInteger(Stream stream, uint value)
{
stream.WriteByte((byte)(value & 0xFF));
stream.WriteByte((byte)((value >> 8) & 0xFF));
stream.WriteByte((byte)((value >> 16) & 0xFF));
stream.WriteByte((byte)((value >> 24) & 0xFF));
}
private static void WriteShort(Stream stream, ushort value)
{
stream.WriteByte((byte)(value & 0xFF));
stream.WriteByte((byte)((value >> 8) & 0xFF));
}
}
}
