/// <summary>
/// Applys the effects of the audio mixer to the given audio data.
/// </summary>
/// <param name="data">The Data.</param>
/// <param name="format">The WaveFormat.</param>
/// <remarks>Currently supports volume and panning for stereo sources and volume only for mono sources.</remarks>
public void ApplyEffects(byte[] data, WaveFormat format)
{
if (format.BitsPerSample != 8 && format.BitsPerSample != 16 || format.Channels != 2)
{
return;
}
var left = System.Math.Min(1, Pan + 1);
var right = System.Math.Abs(System.Math.Max(-1, Pan - 1));
left *= Volume;
right *= Volume;
if (format.Channels == 2)
{
switch (format.BitsPerSample)
{
case 8:
for (var n = 0; n < data.Length; n += 2)
{
var leftChannel = data[n];
var rightChannel = data[n + 1];
data[n] = (byte) (leftChannel*left);
data[n + 1] = (byte) (rightChannel*right);
}
break;
case 16:
for (int n = 0; n < data.Length; n += 4)
{
int leftChannel = BitConverter.ToInt16(data, n);
int rightChannel = BitConverter.ToInt16(data, n + 2);
byte[] sampleleft = BitConverter.GetBytes((short) (leftChannel*left));
byte[] sampleright = BitConverter.GetBytes((short) (rightChannel*right));
data[n] = sampleleft[0];
data[n + 1] = sampleleft[1];
data[n + 2] = sampleright[0];
data[n + 3] = sampleright[1];
}
break;
}
}
else if (format.Channels == 1)
{
switch (format.BitsPerSample)
{
case 8:
for (var n = 0; n < data.Length; n += 1)
{
var channel = data[n];
data[n] = (byte) (channel*_volume);
}
break;
case 16:
for (int n = 0; n < data.Length; n += 2)
{
int channel = BitConverter.ToInt16(data, n);
byte[] sample = BitConverter.GetBytes((short) (channel*_volume));
data[n] = sample[0];
data[n + 1] = sample[1];
}
break;
}
}
}
/// <summary>
/// Reads the Header.
/// </summary>
private void ReadHeader()
{
var reader = new BinaryReader(_stream);
if (ReadChunk(reader) != "RIFF")
{
throw new Exception("Invalid file format.");
}
reader.ReadInt32();
if (ReadChunk(reader) != "WAVE")
{
throw new Exception("Invalid file format.");
}
if (ReadChunk(reader) != "fmt ")
{
throw new Exception("Invalid file format.");
}
int len = reader.ReadInt32();
if (len < 16)
{
throw new Exception("Invalid file format.");
}
Format = new WaveFormat(22050, 16, 2)
{
Format = (WaveFormats) reader.ReadInt16(),
Channels = reader.ReadInt16(),
SamplesPerSec = reader.ReadInt32(),
AvgBytesPerSec = reader.ReadInt32(),
BlockAlign = reader.ReadInt16(),
BitsPerSample = reader.ReadInt16()
};
len -= 16;
while (len > 0)
{
reader.ReadByte();
len--;
}
while (_stream.Position < _stream.Length && ReadChunk(reader) != "data")
{
}
if (_stream.Position >= _stream.Length)
throw new Exception("Invalid file format.");
_length = reader.ReadInt32();
_position = _stream.Position;
if (_length <= 0)
{
throw new Exception("Invalid WAV file.");
}
if (Format.Format != WaveFormats.Pcm && Format.Format != WaveFormats.Float)
{
throw new Exception("Only PCM files are supported.");
}
Position = 0;
}
/// <summary>
/// Applys the effects of the audio mixer to the given audio data.
/// </summary>
/// <param name="data">The Data.</param>
/// <param name="format">The WaveFormat.</param>
/// <remarks>Currently supports volume and panning for stereo sources and volume only for mono sources.</remarks>
public void ApplyEffects(byte[] data, WaveFormat format)
{
if (format.BitsPerSample != 8 && format.BitsPerSample != 16 || format.Channels != 2)
{
return;
}
var left = System.Math.Min(1, Pan + 1);
var right = System.Math.Abs(System.Math.Max(-1, Pan - 1));
left *= Volume;
right *= Volume;
if (format.Channels == 2)
{
switch (format.BitsPerSample)
{
case 8:
for (var n = 0; n < data.Length; n += 2)
{
var leftChannel = data[n];
var rightChannel = data[n + 1];
data[n] = (byte)(leftChannel * left);
data[n + 1] = (byte)(rightChannel * right);
}
break;
case 16:
for (int n = 0; n < data.Length; n += 4)
{
int leftChannel = BitConverter.ToInt16(data, n);
int rightChannel = BitConverter.ToInt16(data, n + 2);
byte[] sampleleft = BitConverter.GetBytes((short)(leftChannel * left));
byte[] sampleright = BitConverter.GetBytes((short)(rightChannel * right));
data[n] = sampleleft[0];
data[n + 1] = sampleleft[1];
data[n + 2] = sampleright[0];
data[n + 3] = sampleright[1];
}
break;
}
}
else if (format.Channels == 1)
{
switch (format.BitsPerSample)
{
case 8:
for (var n = 0; n < data.Length; n += 1)
{
var channel = data[n];
data[n] = (byte)(channel * _volume);
}
break;
case 16:
for (int n = 0; n < data.Length; n += 2)
{
int channel = BitConverter.ToInt16(data, n);
byte[] sample = BitConverter.GetBytes((short)(channel * _volume));
data[n] = sample[0];
data[n + 1] = sample[1];
}
break;
}
}
}
