有那位高手知道关于WAV格式的编程

procedure TTrack.DrawWave;
type  OneBit = array[0..0] of Shortint;
      OneBitArray =^OneBit;
      TwoBit = array[0..0] of Smallint;
      TwoBitArray =^TwoBit;
var ByteRead : integer;
    Wave16 : TwoBitArray;
    Wave8  : OneBitArray;
    Up,Down,Oldy,Lever : Integer;
    k : real;
   procedure Draw8BitWav(X,Y,W,H,Count,pos,Add:Integer);
   var i,j,Bit8 : integer; //  区域   总量 偏移 累加
   begin
   k:=H/255;
   Lever:=Y+H;
   Getmem(Wave8,Count);
   OldY:=y+H div 2;
   for i:=X to X+W-1 do
      begin
      ByteRead:=FileStream.Read(Wave8^,Count);
      if ByteRead=0 then break;
      j:=Pos;
//************************
      Up:=0 ;Down:=256;
      Lever:=Y+H;
      While j< count do
        begin
        if Wave8[j]<0 then Bit8:=256+Wave8[j]
        else Bit8:=Wave8[j];
        if Bit8>Up then
           Up:=Bit8;
        if Bit8<Down then
           Down:=Bit8;
        j:=j+add;
        end;
      up:=round(up*k);
      Down:=round(Down*k);
      if Up=Down then Down:=Down-1;
      Up:=Lever-Up;
      Down:=Lever-Down;
      ViewImg.Canvas.MoveTo(i,Up);
      ViewImg.Canvas.LineTo(i,Down);
      ViewImg.Canvas.MoveTo(i,OldY);
      ViewImg.Canvas.LineTo(i,Up);
      if Up-1=Down then OldY:=Up else
      OldY:=(Up+Down)div 2;
      if Byteread<Count then break;
      end;
   Line(ViewImg.Canvas,x,Y+H div 2,x+w,Y+H div 2,0,1,clred);
   Freemem(Wave8,Count);
   end;
   procedure Draw16BitWav(X,Y,W,H,Count,pos,Add:Integer);
   var i,j,Bit16: integer;   //  区域   总量 偏移 累加
   begin
   k:=H/65535;
   Lever:=Y+H;
   OldY:=Y+H div 2;
   Getmem(Wave16,Count);
   for i:=X to X+W-1 do
      begin
      ByteRead:=FileStream.Read(Wave16^,Count);
      if ByteRead=0 then break;
      j:=pos;
//***************
      Up:=0 ;Down:=65535;
      While j< count div 2 do
        begin
        Bit16:=Wave16[j]+32767;
        if Bit16>Up then
           Up:=Bit16;
        if Bit16<Down then
           Down:=Bit16;
        j:=j+add;
        end;
      up:=round(up*k);
      Down:=round(Down*k);
      if Up=Down then Down:=Down-1;  
      Up:=Lever-Up;
      Down:=Lever-Down;
      ViewImg.Canvas.MoveTo(i,Up);
      ViewImg.Canvas.LineTo(i,Down);
      ViewImg.Canvas.MoveTo(i,OldY);
      ViewImg.Canvas.LineTo(i,Up);
      if Up-1=Down then OldY:=Up else
      OldY:=(Up+Down)div 2;
      if ByteRead<Count then break;
      end;
   Line(ViewImg.Canvas,x,Lever-h div 2,x+w,Lever-h div 2,0,1,clred);
   Freemem(Wave16,Count);
   end;
begin
if Not IsLoad then Exit;Fill(ViewImg.Canvas,Wx,Wy,Wx+Ww,Wy+Wh,$0);
ViewImg.Canvas.Pen.Color:=cllime;if FileStream.Size>=VBeg then
   begin
   FileStream.Position:=VBeg;
   case TypeFmt of
   1 : begin    ////////////// 111111111111
       Draw8BitWav(WX,WY,WW,WH,Zoom,0,1);
       end;
   2 : begin    ////////////// 222222222222
       Draw16BitWav(WX,WY,WW,WH,Zoom*2,0,1);
       end;
   3 : begin    ////////////// 333333333333
       Draw8BitWav(WX,WY,WW,WH div 2,Zoom*2,0,2);
       FileStream.Position:=VBeg;
       ViewImg.Canvas.Pen.Color:=cllime;
       Draw8BitWav(WX,WY+WH div 2,WW,WH div 2,Zoom*2,1,2);
       end;
   4 : begin    ////////////// 444444444444
       Draw16BitWav(WX,WY,WW,WH div 2,Zoom*4,0,2);
       FileStream.Position:=VBeg;
       ViewImg.Canvas.Pen.Color:=cllime;
       Draw16BitWav(WX,WY+WH div 2,WW,WH div 2,Zoom*4,1,2);
       end;
       end;
   end;    
Setselect(SeleBeg,SeleEnd);
BitBlt(Canvas.handle,Wx,Wy,Ww,Wh+RulerH,ViewImg.canvas.handle,Wx,Wy,SRCCOPY);
end;