我的音频规范化码是否正确？

Question

我想将音频文件规格化为最大值。

为了做到这一点，我用这个代码：

Dim iHighestDataValue As Integer 
Dim iLowestDataValue As Integer 

Dim i& 
For i = 1 To dc.wavedatasize/2 
    Get #iFile, , DataValue(i) ' reads data value into array 

    If DataValue(i) > iHighestDataValue Then 
     iHighestDataValue = DataValue(i) 
    End If 

    If DataValue(i) < iLowestDataValue Then 
     iLowestDataValue = DataValue(i) 
    End If 
Next 

Dim sngVolumeLevel As Single 
sngVolumeLevel = ((iHighestDataValue + (iLowestDataValue * -1))/2)/32767 

它工作得很好，几乎所有的文件，但对于一个文件，最后一行将失败。

iHighestDataValue是13445，iLowestDataValue是-21940。

我想最后一行有些问题。 这只是VB6发生的一个错误，因为它不能处理这个（正确的）计算，还是我引入了任何错误？

当我把最后一行到单独的计算，它工作正常：

Dim sngHighest As Single 
If iHighestDataValue > 32767 Then 
    sngHighest = 32767 
Else 
    sngHighest = iHighestDataValue 
End If 

Dim sngLowest As Single 
If iLowestDataValue < -32767 Then 
    sngLowest = -32767 
Else 
    sngLowest = iLowestDataValue 
End If 
sngLowest = sngLowest * -1 

Dim sngVolumeLevel As Single 
sngVolumeLevel = (sngHighest + sngLowest)/2 
sngVolumeLevel = (sngVolumeLevel/32767) 

谢谢！

PS： 下面是函数的最后，归一化部：

Dim tem As Long 

For i = 1 To dc.wavedatasize/2 
    tem = CLng(DataValue(i) * 1/sngVolumeLevel) 
    If tem > 32767 Then 
     tem = 32767 ' prevents integer overflow error 
    End If 
    If tem < -32767 Then 
     tem = -32767 ' prevents integer overflow error 
    End If 
    DataValue(i) = CInt(tem) ' changes data value 
Next i 

wh.riffdatasize = dc.wavedatasize + Len(wh) + Len(wf) 'Riff chunk size may be different 
' beacause some input wave files may contain information chunk which is not written in output file 

iFile = FreeFile 

Kill uPath 'Delete the original/source file. We will overwrite it with the normalized version of this file 

Open uPath For Binary As #iFile 
Put #iFile, , wh ' writes the wave header 
Put #iFile, , wf ' writes wave format 
Put #iFile, , dc ' writes the 8 byte string "data" and wave dataa size 

For i = 1 To dc.wavedatasize/2 
    Put #iFile, , DataValue(i) ' writes data value in ouput file 
Next i 

Close #iFile 

Answer 1

，因为它产生削波的显著量这是不正确的。

相反的：

sngVolumeLevel = ((iHighestDataValue + (iLowestDataValue * -1))/2)/32767 

更好地做到这一点：

If iHighestDataValue >= -iLowestDataValue Then 
    sngVolumeLevel = iHighestDataValue/32767. 
Else 
    sngVolumeLevel = iLowestDataValue/-32768. 
End If