JPEG Image in Stream schreiben

[Zodi]

Mit dem BMP file funktioniert es mit meinere Compression unit.
Da ich es mit Stream.writeBuffer in den stream schreibe.

Delphi-Quellcode:

function SaveBitmapToFile(HBM: HBitmap;BitCount: word): string;
const
  BMType = $4D42;
type
  TBitmap = record
    bmType: Integer;
    bmWidth: Integer;
    bmHeight: Integer;
    bmWidthBytes: Integer;
    bmPlanes: Byte;
    bmBitsPixel: Byte;
    bmBits: Pointer;
  end;
var
  BM: TBitmap;
  BFH: TBitmapFileHeader;
  BIP: PBitmapInfo;
  DC: HDC;
  HMem: THandle;
  Buf: Pointer;
  ColorSize, DataSize: Longint;
  stream: tmemorystream;

  function AlignDouble(Size: Longint): Longint;
  begin
    Result := (Size + 31) div 32 * 4;
  end;

begin
  if GetObject(HBM, SizeOf(TBitmap), @BM) = 0 then Exit;



  //BitCount := 4;
  if (BitCount <> 24) then ColorSize := SizeOf(TRGBQuad) * (1 shl BitCount) else ColorSize := 0;

  DataSize := AlignDouble(bm.bmWidth * BitCount) * bm.bmHeight;
  GetMem(BIP, SizeOf(TBitmapInfoHeader) + ColorSize);

  if BIP <> nil then begin
    with BIP^.bmiHeader do begin
      biSize := SizeOf(TBitmapInfoHeader);
      biWidth := bm.bmWidth;
      biHeight := bm.bmHeight;
      biPlanes := 1;
      biBitCount := BitCount;
      biCompression := 0;
      biSizeImage := DataSize;
      biXPelsPerMeter := 0;
      biYPelsPerMeter := 0;
      biClrUsed := 0;
      biClrImportant := 0;
    end;

    with BFH do begin
      bfOffBits := SizeOf(BFH) + SizeOf(TBitmapInfo) + ColorSize;
      bfReserved1 := 0;
      bfReserved2 := 0;
      bfSize := longint(bfOffBits) + DataSize;
      bfType := BMType;
    end;

    HMem := GlobalAlloc(gmem_Fixed, DataSize);
    if HMem <> 0 then begin
      Buf := GlobalLock(HMem);
      DC := GetDC(0);
      if GetDIBits(DC, hbm, 0, bm.bmHeight,Buf, BIP^, dib_RGB_Colors) <> 0 then begin

        Stream := TMemoryStream.Create;
        Stream.WriteBuffer(BFH, SizeOf(BFH));
        Stream.WriteBuffer(PChar(BIP)^, SizeOf(TBitmapInfo) + ColorSize);
        Stream.WriteBuffer(Buf^, DataSize);
        SetString(Result, PChar(Stream.Memory), Stream.Size);
        stream.Free;

      end;
      ReleaseDC(0, DC);
      GlobalUnlock(HMem);
      GlobalFree(HMem);
    end;

  end;
  FreeMem(BIP, SizeOf(TBitmapInfoHeader) + ColorSize);
  DeleteObject(HBM);
end;

Gibts da nicht auch nen ansatz für jpeg oder PNG