Hello,
I want to build an Application which allows me to Playback some Audiofiles (.wav and .mp3), this was realy easy with an online Tutorial on Youtube [1].
My Problem is that i want to have an FadeIn when i press "Play" and an FadeOut when i press Stop. I found an solution[2] for naudio to do this but i cant bring this solution together with my existing code for normal Playback without Fading.
My Code:
OpenFileDialog dialog = new OpenFileDialog();
dialog.Filter = "Audio File (*.mp3;*.wav)|*.mp3;*.wav;";
if (dialog.ShowDialog() != DialogResult.OK) return;
if (this.audioFile.EndsWith(".mp3"))
{
NAudio.Wave.WaveStream pcm = NAudio.Wave.WaveFormatConversionStream.CreatePcmStream(new NAudio.Wave.Mp3FileReader(this.audioFile));
stream = new NAudio.Wave.BlockAlignReductionStream(pcm);
}
else if (this.audioFile.EndsWith(".wav"))
{
NAudio.Wave.WaveStream pcm = new NAudio.Wave.WaveChannel32(new NAudio.Wave.WaveFileReader(this.audioFile));
stream = new NAudio.Wave.BlockAlignReductionStream(pcm);
}
else throw new InvalidOperationException("Not a correct audio file type.");
output = new NAudio.Wave.DirectSoundOut();
output.Init(stream);
this.btn_play.Enabled = true;
My "Play" button Click-Event triggers only the output.play() function.
The Code i found online for Fading:
public class FadeInOutSampleProvider : ISampleProvider
{
enum FadeState
{
Silence,
FadingIn,
FullVolume,
FadingOut,
}
private readonly object lockObject = new object();
private readonly ISampleProvider source;
private int fadeSamplePosition;
private int fadeSampleCount;
private FadeState fadeState;
public FadeInOutSampleProvider(ISampleProvider source)
{
this.source = source;
this.fadeState = FadeState.FullVolume;
}
public void BeginFadeIn(double fadeDurationInMilliseconds)
{
lock (lockObject)
{
fadeSamplePosition = 0;
fadeSampleCount = (int)((fadeDurationInMilliseconds * source.WaveFormat.SampleRate) / 1000);
fadeState = FadeState.FadingIn;
}
}
public void BeginFadeOut(double fadeDurationInMilliseconds)
{
lock (lockObject)
{
fadeSamplePosition = 0;
fadeSampleCount = (int)((fadeDurationInMilliseconds * source.WaveFormat.SampleRate) / 1000);
fadeState = FadeState.FadingOut;
}
}
public int Read(float[] buffer, int offset, int count)
{
int sourceSamplesRead = source.Read(buffer, offset, count);
lock (lockObject)
{
if (fadeState == FadeState.FadingIn)
{
FadeIn(buffer, offset, sourceSamplesRead);
}
else if (fadeState == FadeState.FadingOut)
{
FadeOut(buffer, offset, sourceSamplesRead);
}
else if (fadeState == FadeState.Silence)
{
ClearBuffer(buffer, offset, count);
}
}
return sourceSamplesRead;
}
private static void ClearBuffer(float[] buffer, int offset, int count)
{
for (int n = 0; n < count; n++)
{
buffer[n + offset] = 0;
}
}
private void FadeOut(float[] buffer, int offset, int sourceSamplesRead)
{
int sample = 0;
while (sample < sourceSamplesRead)
{
float multiplier = 1.0f - (fadeSamplePosition / (float)fadeSampleCount);
for (int ch = 0; ch < source.WaveFormat.Channels; ch++)
{
buffer[offset + sample++] *= multiplier;
}
fadeSamplePosition++;
if (fadeSamplePosition > fadeSampleCount)
{
fadeState = FadeState.Silence;
// clear out the end
ClearBuffer(buffer, sample + offset, sourceSamplesRead - sample);
break;
}
}
}
private void FadeIn(float[] buffer, int offset, int sourceSamplesRead)
{
int sample = 0;
while (sample < sourceSamplesRead)
{
float multiplier = (fadeSamplePosition / (float)fadeSampleCount);
for (int ch = 0; ch < source.WaveFormat.Channels; ch++)
{
buffer[offset + sample++] *= multiplier;
}
fadeSamplePosition++;
if (fadeSamplePosition > fadeSampleCount)
{
fadeState = FadeState.FullVolume;
// no need to multiply any more
break;
}
}
}
public WaveFormat WaveFormat
{
get { return source.WaveFormat; }
}
}
my problem is to connect this sampleProvider to my Playback. Can somebody show a small example on how i do this.
Thanks in advance and sorry for my bad english.
Links:
[1]
https://www.youtube.com/watch?v=2ij2vqgprU0
[2]
http://stackoverflow.com/a/9471208