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Unity3D: script to save an AudioClip as a .wav file.
// Copyright (c) 2012 Calvin Rien
// http://the.darktable.com
//
// This software is provided 'as-is', without any express or implied warranty. In
// no event will the authors be held liable for any damages arising from the use
// of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not claim
// that you wrote the original software. If you use this software in a product,
// an acknowledgment in the product documentation would be appreciated but is not
// required.
//
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
// =============================================================================
//
// derived from Gregorio Zanon's script
// http://forum.unity3d.com/threads/119295-Writing-AudioListener.GetOutputData-to-wav-problem?p=806734&viewfull=1#post806734
// forked by nanmo ( @nanimosa )
// * check sample float overflow
// * catch FileStream exception
// * direct input save filepath in Save function
// * add function SaveWithRawData, ConvertAndWriteRawData
// * less memory usage in save process.
using System;
using System.IO;
using UnityEngine;
using System.Collections.Generic;
public static class SavWav {
const int HEADER_SIZE = 44;
public static bool Save(string filepath, AudioClip clip) {
float[] tempNull = new float[0];
return SaveWithRawData(filepath, clip, ref tempNull);
}
public static bool SaveWithRawData( string filepath, AudioClip clip, ref float[] rawData) {
Debug.Log(filepath);
try {
// Make sure directory exists if user is saving to sub dir.
Directory.CreateDirectory(Path.GetDirectoryName(filepath));
using (var fileStream = CreateEmpty(filepath)) {
if ( rawData.Length == 0 ) {
ConvertAndWrite(fileStream, clip);
}
else {
ConvertAndWriteRawData(fileStream, clip, ref rawData);
}
WriteHeader(fileStream, clip);
}
return true;
}
catch ( Exception e ) {
Debug.LogError( e );
return false;
}
}
public static AudioClip TrimSilence(AudioClip clip, float min) {
var samples = new float[clip.samples];
clip.GetData(samples, 0);
return TrimSilence(new List<float>(samples), min, clip.channels, clip.frequency);
}
public static AudioClip TrimSilence(List<float> samples, float min, int channels, int hz) {
return TrimSilence(samples, min, channels, hz, false, false);
}
public static AudioClip TrimSilence(List<float> samples, float min, int channels, int hz, bool _3D, bool stream) {
int i;
for (i=0; i<samples.Count; i++) {
if (Mathf.Abs(samples[i]) > min) {
break;
}
}
samples.RemoveRange(0, i);
for (i=samples.Count - 1; i>0; i--) {
if (Mathf.Abs(samples[i]) > min) {
break;
}
}
samples.RemoveRange(i, samples.Count - i);
var clip = AudioClip.Create("TempClip", samples.Count, channels, hz, _3D, stream);
clip.SetData(samples.ToArray(), 0);
return clip;
}
static FileStream CreateEmpty(string filepath) {
var fileStream = new FileStream(filepath, FileMode.Create);
byte emptyByte = new byte();
for(int i = 0; i < HEADER_SIZE; i++) //preparing the header
{
fileStream.WriteByte(emptyByte);
}
return fileStream;
}
static void ConvertAndWrite(FileStream fileStream, AudioClip clip) {
var samples = new float[clip.samples];
clip.GetData(samples, 0);
ConvertAndWriteRawData( fileStream, clip, ref samples);
}
static void ConvertAndWriteRawData(FileStream fileStream, AudioClip clip, ref float[] rawData) {
Int16 intData;
//converting in 2 float[] steps to Int16[], //then Int16[] to Byte[]
Byte[] bytesData = new Byte[rawData.Length * 2];
//bytesData array is twice the size of
//dataSource array because a float converted in Int16 is 2 bytes.
int rescaleFactor = 32767;
//to convert float to Int16
for (int i = 0; i<rawData.Length; i++) {
//check sample float overflow
if ( rawData[i] > 1.0f ) {
intData = (short) rescaleFactor;
}
else if ( rawData[i] < -1.0f ) {
intData = (short) -rescaleFactor;
}
else {
intData = (short) (rawData[i] * rescaleFactor);
}
BitConverter.GetBytes(intData).CopyTo(bytesData, i * 2);
}
fileStream.Write(bytesData, 0, bytesData.Length);
}
static void WriteHeader(FileStream fileStream, AudioClip clip) {
var hz = clip.frequency;
var channels = clip.channels;
var samples = clip.samples;
fileStream.Seek(0, SeekOrigin.Begin);
Byte[] riff = System.Text.Encoding.UTF8.GetBytes("RIFF");
fileStream.Write(riff, 0, 4);
Byte[] chunkSize = BitConverter.GetBytes(fileStream.Length - 8);
fileStream.Write(chunkSize, 0, 4);
Byte[] wave = System.Text.Encoding.UTF8.GetBytes("WAVE");
fileStream.Write(wave, 0, 4);
Byte[] fmt = System.Text.Encoding.UTF8.GetBytes("fmt ");
fileStream.Write(fmt, 0, 4);
Byte[] subChunk1 = BitConverter.GetBytes(16);
fileStream.Write(subChunk1, 0, 4);
//UInt16 two = 2;
UInt16 one = 1;
Byte[] audioFormat = BitConverter.GetBytes(one);
fileStream.Write(audioFormat, 0, 2);
Byte[] numChannels = BitConverter.GetBytes(channels);
fileStream.Write(numChannels, 0, 2);
Byte[] sampleRate = BitConverter.GetBytes(hz);
fileStream.Write(sampleRate, 0, 4);
Byte[] byteRate = BitConverter.GetBytes(hz * channels * 2); // sampleRate * bytesPerSample*number of channels, here 44100*2*2
fileStream.Write(byteRate, 0, 4);
UInt16 blockAlign = (ushort) (channels * 2);
fileStream.Write(BitConverter.GetBytes(blockAlign), 0, 2);
UInt16 bps = 16;
Byte[] bitsPerSample = BitConverter.GetBytes(bps);
fileStream.Write(bitsPerSample, 0, 2);
Byte[] datastring = System.Text.Encoding.UTF8.GetBytes("data");
fileStream.Write(datastring, 0, 4);
Byte[] subChunk2 = BitConverter.GetBytes(samples * channels * 2);
fileStream.Write(subChunk2, 0, 4);
// fileStream.Close();
}
}
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