private static byte[] GetMonoMix(Sound sound) {
/*
* Convert integer samples to floating-point samples.
*/
float[][] samples;
if (sound.Bytes.Length == 1 || sound.Bytes[0].Length == 0) {
return sound.Bytes[0];
}
switch (sound.BitsPerSample)
{
case 8:
samples = new float[sound.Bytes.Length][];
for (int i = 0; i < sound.Bytes.Length; i++) {
samples[i] = new float[sound.Bytes[i].Length];
for (int j = 0; j < sound.Bytes[i].Length; j++) {
byte value = sound.Bytes[i][j];
samples[i][j] = ((float)value - 128.0f) / (value < 128 ? 128.0f : 127.0f);
}
}
break;
case 16:
samples = new float[sound.Bytes.Length][];
for (int i = 0; i < sound.Bytes.Length; i++) {
samples[i] = new float[sound.Bytes[i].Length >> 1];
for (int j = 0; j < sound.Bytes[i].Length; j += 2) {
short value = (short)(ushort)((int)sound.Bytes[i][j] | ((int)sound.Bytes[i][j + 1] << 8));
samples[i][j >> 1] = (float)value / (value < 0 ? 32768.0f : 32767.0f);
}
}
break;
default:
throw new NotSupportedException();
}
/*
* Mix floating-point samples to mono.
* */
float[] mix = GetNormalizedMonoMix(samples);
/*
* Convert floating-point samples to integer samples.
*/
byte[] result;
switch (sound.BitsPerSample)
{
case 8:
result = new byte[mix.Length];
for (int i = 0; i < mix.Length; i++) {
result[i] = (byte)((mix[i] < 0.0f ? 128.0f : 127.0f) * mix[i] + 128.0f);
}
break;
case 16:
result = new byte[2 * mix.Length];
for (int i = 0; i < mix.Length; i++) {
int value = (int)(ushort)(short)((mix[i] < 0.0f ? 32768.0f : 32767.0f) * mix[i]);
result[2 * i + 0] = (byte)value;
result[2 * i + 1] = (byte)(value >> 8);
}
break;
default:
throw new NotSupportedException();
}
return result;
}
