NAudioで信号処理

NAudioで信号処理

www.giawa.comさんが公開している動画を参考にさせていただきます。

f:id:hope_is_dream:20170505222531p:plain

ソースコード

GitHub - peace098beat/NAudioDemos: Demo NAudio.

1. WAVファイルの再生

C# Audio Tutorial 1 - Wave File with NAudio

f:id:hope_is_dream:20170505192539p:plain

NAudioで信号処理 (その１) - Hope is a Dream. Dream is a Hope.

2. MP3/WAVファイルの再生

C# Audio Tutorial 2 - MP3/WAV File with NAudio

f:id:hope_is_dream:20170505221730p:plain

NAudioで信号処理 (その２) - Hope is a Dream. Dream is a Hope.

private NAudio.Wave.BlockAlignReductionStream stream = null; 
private NAudio.Wave.DirectSoundOut output = null;


if (open.FileName.EndsWith(".mp3"))
{
    NAudio.Wave.WaveStream pcm = 
        NAudio.Wave.WaveFormatConversionStream.CreatePcmStream(new NAudio.Wave.Mp3FileReader(open.FileName));
    stream = new NAudio.Wave.BlockAlignReductionStream(pcm);
}
else if (open.FileName.EndsWith(".wav"))
{
    NAudio.Wave.WaveStream pcm = 
        new NAudio.Wave.WaveChannel32(new NAudio.Wave.WaveFileReader(open.FileName));
    stream = new NAudio.Wave.BlockAlignReductionStream(pcm);
}

output = new NAudio.Wave.DirectSoundOut();
output.Init(new NAudio.Wave.WaveChannel32(stream));
output.Play();

3. MP3からWAVへコンバート

C# Audio Tutorial 3 - Convert MP3 File to Wave File

f:id:hope_is_dream:20170505232831p:plain

NAudioで信号処理 (その３) - Hope is a Dream. Dream is a Hope.

 // 3. Convert mp3 -> wav
using (Mp3FileReader mp3 = new Mp3FileReader(open.FileName))
{
    using(WaveStream pcm = WaveFormatConversionStream.CreatePcmStream(mp3))
    {
        WaveFileWriter.CreateWaveFile(save.FileName, pcm);
    }
}

4. SinWaveの生成と再生

C# Audio Tutorial 4 - Custom WaveStream Object

f:id:hope_is_dream:20170506085248p:plain

NAudioで信号処理 (その４) - Hope is a Dream. Dream is a Hope.

// 再生デバイス
private BlockAlignReductionStream stream = null;
private DirectSoundOut output = null;

// オーディオチェイン
WaveTone tone = new WaveTone(1000, 0.1);
stream = new BlockAlignReductionStream(tone);

output = new DirectSoundOut();
output.Init(stream);
output.Play();

以下 WaveTone:WaveStream
// SinWaveを生成
for (int i = 0; i < samples; i++)
{
    double sine = amplitude * Math.Sin(Math.PI * 2 * frequency * time);
    time += 1.0 / 44100;

    short truncated = (short)Math.Round(sine * (Math.Pow(2, 15) - 1)); //16bit

    buffer[i * 2] = (byte)(truncated & 0x00ff); // 下半分を取り出し 8bit
    buffer[i * 2 + 1] = (byte)((truncated & 0xff00) >> 8); // 上半分を取り出してシフト 8bit
}

5. エフェクト処理の準備

C# Audio Tutorial 5 - EffectStream Part 1

f:id:hope_is_dream:20170506124450p:plain

hope-is-dream.hatenablog.com

 // Audio Chain
WaveChannel32 wave = new WaveChannel32(new WaveFileReader(open.FileName));
EffectStream effect = new EffectStream(wave); // エフェクトをかけるためのパイプライン
stream = new BlockAlignReductionStream(effect);

output = new DirectSoundOut(200);
output.Init(stream);
output.Play();

6. オーディオの録音と再生

C# Audio Tutorial 6 - Audio Loopback using NAudio

hope-is-dream.hatenablog.com

f:id:hope_is_dream:20170506124002p:plain

#region Member
private NAudio.Wave.WaveIn sourceStream = null; // 録音なのでWaveInを使用
private NAudio.Wave.DirectSoundOut waveOut = null;
#endregion


// waveIn Select Recording Device
sourceStream = new NAudio.Wave.WaveIn();
sourceStream.DeviceNumber = deviceNumber; // 使用するデバイスを選択
sourceStream.WaveFormat = new NAudio.Wave.WaveFormat(44100, WaveIn.GetCapabilities(deviceNumber).Channels); 

// WaveInProviderで包み込む
WaveInProvider waveIn = new NAudio.Wave.WaveInProvider(sourceStream); // ?

// waveOut
waveOut = new DirectSoundOut();
waveOut.Init(waveIn);

sourceStream.StartRecording();
waveOut.Play();

f:id:hope_is_dream:20170507174215p:plain

7. Wavファイルへの録音

C# Audio Tutorial 7 : Recording to a Wave File

hope-is-dream.hatenablog.com

f:id:hope_is_dream:20170506131304p:plain

#region Member
private NAudio.Wave.WaveIn sourceStream = null;
private NAudio.Wave.DirectSoundOut waveOut = null;
private NAudio.Wave.WaveFileWriter waveWriter = null;
#endregion
// waveIn Select Recording Device
sourceStream = new NAudio.Wave.WaveIn();
sourceStream.DeviceNumber = deviceNumber;
sourceStream.WaveFormat = new NAudio.Wave.WaveFormat(44100, WaveIn.GetCapabilities(deviceNumber).Channels);

WaveInProvider waveIn = new NAudio.Wave.WaveInProvider(sourceStream); // ?

// waveOut
waveOut = new DirectSoundOut();
waveOut.Init(waveIn);

sourceStream.StartRecording();
waveOut.Play();

8. エフェクトの準備 Part2

C# Audio Tutorial 8 - EffectStream Part 2

f:id:hope_is_dream:20170506133840p:plain

hope-is-dream.hatenablog.com

// WAV File Open
OpenFileDialog open = new OpenFileDialog();
open.Filter = "WAV File (*.wav)|*.wav;";
if (open.ShowDialog() != DialogResult.OK) return;

// Audio Chain
WaveChannel32 wave = new WaveChannel32(new WaveFileReader(open.FileName));
EffectStream effect = new EffectStream(wave); // エフェクトをかけるためのパイプライン
stream = new BlockAlignReductionStream(effect);

// Out
output = new DirectSoundOut(200);
output.Init(stream);
output.Play();

namespace Tutorial
{
    public interface IEffect
    {
        float ApplyEffect(float sample);
    }
}

EffectStream:WaveStream