;-----------------------------------------------------------------------
Graphics 640,480,16,2
Print "Umrechnen"
ok=shWAVE("a.wav","b.wav")
If ok=1 Then
 Print "Ready"
 Print "Load"
 Musik   = LoadSound("b.wav") 
 Print "Play"
 Channel = PlaySound(Musik) 
 Print "Wait Key"
 WaitKey : FreeSound Musik 
 End 
Else
 Print "Fehler beim laden !?"
EndIf
;-----------------------------------------------------------------------

;-----------------------------------------------------------------------
Function shWAVE(FileIn$,FileOut$) 

   Local StreamIn,Dummy$,Wav_Length,Wav_fmt,Wav_Length2 
   Local Wav_Format,Wav_Kanal,Wav_Sample,Wav_BPS1 
   Local Wav_BPS2,Wav_Length3 
    
   ;Datei öffnen
   If FileType(FileIn$) <> 1 Then Return 0
   StreamIn = ReadFile(FileIn$) 

   Local h=0    
 
   ;Kopf Daten lesen (44 Bytes)
   Dummy$      = Read_Wav_Bytes$(StreamIn,4) :h=h+4 ; Read 'RIFF' 
   Wav_Length  = ReadInt(StreamIn)           :h=h+4 ; Read Length 
   Dummy$      = Read_Wav_Bytes$(StreamIn,4) :h=h+4 ; Read 'WAVE' 
   Wav_fmt     = Read_Wav_Bytes$(StreamIn,4) :h=h+4 ; Read 'fmt'  
   Wav_Length2 = ReadInt(StreamIn)           :h=h+4 ; Read Length 
   Wav_Format  = ReadShort(StreamIn)         :h=h+2 ; Read Format (0=Mono ; 1=Stereo) 
   Wav_Kanal   = ReadShort(StreamIn)         :h=h+2 ; Read Kanal  
   Wav_Sample  = ReadInt(StreamIn)           :h=h+4 ; Read Sample e.g. 41MHz 
   Wav_BPS1    = ReadInt(StreamIn)           :h=h+4 ; Read Bytes  per second 
   Wav_BPS2    = ReadShort(StreamIn)         :h=h+2 ; Read Bytes  per sample 
   Dummy$      = ReadShort(StreamIn)         :h=h+2 ; Read Bits   per sample 

   ;Print "Wav_Length "+Wav_Length
   ;Print "Wav_Length2 "+Wav_Length2 

   Local ok=0
   While True 
    h=h+1
    ok=ok+1 
    Dummy$ = Dummy$ + Chr(ReadByte(StreamIn)) 
    If Right$(Dummy,4) = "data" Then 
     Exit 
    EndIf 
    If ok>32 Then Exit 
   Wend 

   If Right(Dummy$,4) <> "data" Then 
    DebugLog "Wave Header stimmt nicht !? Kein 'data' drinne !?" 
    Return 0 
   EndIf 

   Wav_Length3 = ReadInt(StreamIn) : h=h+4

   Print "Wav_Length3 "+Wav_Length3

   ;Speicher Bank für Kopf Daten
    
   Print "Header länge = "+h+" Bytes"

   Header = CreateBank(h) 
   SeekFile StreamIn,0 
   For I = 0 To h-1
    PokeByte Header,I,ReadByte(StreamIn) 
   Next 

   ;Speicher Bank für Wave Daten
   Amplitudes = CreateBank(Wav_Length3 ) 
   For I = 0 To Wav_Length3 -1
    PokeByte Amplitudes,I,ReadByte(StreamIn) -128
   Next 
    
   ;erste Datei schließen und zweite öffnen
   CloseFile StreamIn 
   StreamOut = WriteFile(FileOut$) 
    
   ;Kopf Daten wieder speichern 1:1
   For I = 0 To h-1
    WriteByte StreamOut,PeekByte(Header,I) 
   Next 

   If Wav_Kanal = 1 Then Print "Mono"
   If Wav_Kanal = 2 Then Print "Stereo"
   
   If Wav_BPS2=1 Then Print "8 Bit"
   If Wav_BPS2=2 Then Print "16 Bit"
   If Wav_BPS2=4 Then Print "32 Bit"
 
   ;Wave Daten speichern
   Local i1=0 
   Local w1,w2
   ;i=Wav_Length3-1-3
   i=0 ;176400*8*3

   For I1 =0 To Wav_Length3-1 Step 1 
      If Wav_Kanal = 2 Then 
         If Wav_BPS2 = 4 Then 
            ; 16Bit - Stereo 
            w1v#=PeekShort(Amplitudes,I1) 
            w1r#=PeekShort(Amplitudes,I )
            w2v#=PeekShort(Amplitudes,I1+2)
            w2r#=PeekShort(Amplitudes,I+2)
            I1 = I1 + 3

            ;w1=(w1v*0.75+w1r*0.25) ;vorwärts
            ;w2=(w2v*0.75+w2r*0.25)
            ;w1=w1r ;nur Rückwärts
            ;w2=w2r
            w1=(w1v*0.5+w1r*0.5) 
            w2=(w2v*0.5+w2r*0.5)

            WriteShort StreamOut,myShort(w1)
            WriteShort StreamOut,myShort(w2)
            ;If c=0 Then i=i-4
            If c=0 Then i=i+ 4
            c=c+1:If c=8 Then c=0
         EndIf 
      EndIf 
   Next 

   ;zweite Datei schließen
   CloseFile StreamOut 

   FreeBank Header 
   FreeBank Amplitudes 

   Return 1

End Function 
; ============================================================== 
    
; ==============================================================    
Function Read_Wav_Bytes$(Stream,Number) 
   Local I,Out$,Character 
   For I = 1 To Number 
      Character = ReadByte(Stream) 
      If Character = 0 Then 
         Exit 
      Else 
         Out$ = Out$ + Chr$(Character) 
      EndIf 
   Next 
   Return Out$ 
End Function 
; ==============================================================

Function myShort(i)

 Local b1,b2,b3,b4

 b4 = i And $FF
 b3 = Int(i / $100) And $FF        ;normal mit \ aber das kennt BB wohl nicht !?
 b2 = Int(i / $10000) And $FF
 b1 = Int(i / $1000000) And $FF

 b1=b1+128
 b2=b2+128
 b3=b3+128
 b4=b4+128

 Return b4+(b3*$100)+(b2*$10000)+(b1*$1000000)

End Function