从2字节数组中添加值

Question

我想添加来自2个wav文件的信号并将每个字节转换为short，除以2以避免溢出，然后添加2个短值，然后在写入输出文件之前重新转换回字节。

有问题的wav文件是人类语音文件 - 不是纯正弦波。

我确保将来自同一频道的字节加在一起。 因此，来自一个文件的第0个位置的字节与来自第二个文件的偶数位置的字节混合，奇数定位的元素被添加到来自其他文件的奇数元素。

我的困难在于，当我使用一个静音（0声音）的wav时，过程完美无缺，输出声音完全可以听见但是当两个wav文件都有一些声音时，结果变成了一个响亮的声音。

问题：

1. 为什么即使我将它平均化，信号的幅度也会突然增加？
2. 为什么以与输入相同的速率采样的信号在与0值混合时保持可听，但在与其他声音信号混合时会完全混乱。？

我想在c＃中完全执行此操作，并且不想使用NAudio / Nyquist /或其他库

有人可以帮忙吗？

CODE

int idx=0;
int OverlapPCT=20;
byte[] arrfile = {};
byte[] arrfileNext = {};
byte[] arrfileOut = {};
string TmpOutFile = Application.StartupPath + "\\" + "tmp.wav";
if (File.Exists (TmpOutFile)){File.Delete (TmpOutFile); }
FileStream fo = new FileStream (@TmpOutFile, FileMode.Append, FileAccess.Write);
BinaryWriter bw = new BinaryWriter (fo);
//header part of output file written here -
// set the position within the filestreams 
// from where header ends and data is to be read
fs.Position = 44;
fsNext.Position = 44;
// read first stream into the arrfile, second into arrfileNext
fs.Read (arrfile, 0, fs.Length-44);
fsNext.Read (arrfileNext, 0, fsNext.Length-44);
// ---------------------------------
ThisArrOvlpWithPrev = 0;
ThisArrOvlpWithNext = arrfile.Length (OverlapPCT/100);
ThisArrNoOvlp = arrfile.Length - (ThisArrOvlpWithPrev+ThisArrOvlpWithNext);
Array.Clear (arrfileOut, 0, arrfileOut.Length);
// make sure arrfileOut is same size as overlap with previous
Array.Resize<byte> (ref arrfileOut, ThisArrOvlpWithPrev);

byte[] AmpAdjMergedByteArr= { };
short[] shArr = { };
short[] shArrNext = { };
// get both overlapping areas
// for first file, it begins at overlap with prev + part without overlap 
// size of the overlap is overlap with next
Buffer.BlockCopy (arrfile, ThisArrOvlpWithPrev+ThisArrNoOvlp, shArr,0,ThisArrOvlpWithNext);
Buffer.BlockCopy (arrfileNext, 0, shArrNext, 0, ThisArrOvlpWithNext);

Array.Resize<byte> (ref AmpAdjMergedByteArr, ThisArrOvlpWithNext);

for (idx=0; idx<ThisArrOvlpWithNext; idx++)
{
    AmpAdjMergedByteArr[idx] = (byte) (shArr[idx] /2 + shArrNext[idx]/2);
}

// now set the size of output file and write this to output
Buffer.BlockCopy (AmpAdjMergedByteArr, 0, arrfileOut, 0, AmpAdjMergedByteArr.Length);
bw.Write (arrfileOut);

#endregion