public override int Read(byte[] buffer, int offset, int count)
{
MixAudioStreamChannels channels = Channels;
IntPtr pointer;
using (buffer.Pin(out pointer, offset, count))
{
int sourceCount = count * Source.Format.SampleChannelCount();
if (sourceCount > data.Length)
{
data = new byte[sourceCount];
}
int read = Source.Read(data, offset, sourceCount);
switch (Source.Format)
{
case AudioFormat.MonoByte:
case AudioFormat.MonoInt16:
case AudioFormat.MonoSingle:
return(Source.Read(buffer, offset, count));
case AudioFormat.StereoByte:
for (int index = 0; index < read - 1; index += 2)
{
switch (channels)
{
case MixAudioStreamChannels.Left: buffer[index / 2] = data[index]; break;
case MixAudioStreamChannels.Right: buffer[index / 2] = data[index + 1]; break;
case MixAudioStreamChannels.Mix: buffer[index / 2] = (byte)(((data[index] - 128) + (data[index + 1] - 128)) / 2 + 128); break;
default: throw new NotSupportedException();
}
}
return(read / 2);
case AudioFormat.StereoInt16:
for (int index = 0; index < read - 3; index += 4)
{
short left = BitConverter.ToInt16(data, index);
short right = BitConverter.ToInt16(data, index + 2);
short output;
switch (channels)
{
case MixAudioStreamChannels.Left: output = left; break;
case MixAudioStreamChannels.Right: output = right; break;
case MixAudioStreamChannels.Mix: output = (short)((left + right) / 2); break;
default: throw new NotSupportedException();
}
buffer[index / 2] = (byte)output;
buffer[index / 2 + 1] = (byte)(output >> 8);
}
return(read / 2);
case AudioFormat.StereoSingle:
for (int index = 0; index < read - 7; index += 8)
{
float left = BitConverter.ToSingle(data, index);
float right = BitConverter.ToSingle(data, index + 4);
float output;
switch (channels)
{
case MixAudioStreamChannels.Left: output = left; break;
case MixAudioStreamChannels.Right: output = right; break;
case MixAudioStreamChannels.Mix: output = (short)((left + right) / 2); break;
default: throw new NotSupportedException();
}
Marshal.WriteInt32(pointer + index / 2, output.ToBits());
}
return(read / 2);
default:
throw new NotSupportedException();
}
}
}
public MixAudioStream(AudioStream source, bool closeSourceOnClose = false, MixAudioStreamChannels channels = MixAudioStreamChannels.Mix)
: base(source, closeSourceOnClose)
{
Channels = channels;
}
public MixAudioStream(AudioStream source, bool closeSourceOnClose = false, MixAudioStreamChannels channels = MixAudioStreamChannels.Mix)
: base(source, closeSourceOnClose)
{
Channels = channels;
}
