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function DecodeJPGFileToBMP(const AStream: TMemoryStream;
var ABitmap: TBitmap): Boolean;
var
Width, Height, nChannels, dibPadBytes: DWord;
jcprops : TJPEG_CORE_PROPERTIES;
DIB: TDIBSection;
Res: Integer;
begin
Result := False;
if ijlInit(@jcprops) = IJL_OK then begin
jcprops.JPGFile := nil;
jcprops.JPGBytes := AStream.Memory;
jcprops.JPGSizeBytes := AStream.Size;
Res := ijlRead(@jcprops, IJL_JBUFF_READPARAMS);
if Res = IJL_OK then begin
Width := jcprops.JPGWidth;
Height := jcprops.JPGHeight;
nChannels := jcprops.JPGChannels;
dibPadBytes := ((((Width * nChannels) + 3) div 4) * 4) -
(Width * nChannels);
FillChar (DIB, SizeOf(DIB), 0);
if GetObject(ABitmap.Handle, SizeOf(DIB), @DIB) <> 0 then begin
DIB.dsBmih.biSize := SizeOf(TBitmapInfoHeader);
DIB.dsBmih.biWidth := Width;
DIB.dsBmih.biHeight := Height;
DIB.dsBmih.biPlanes := 1;
DIB.dsBmih.biBitCount := 24;
DIB.dsBmih.biCompression := BI_RGB;
DIB.dsBmih.biSizeImage := 0;
DIB.dsBmih.biXPelsPerMeter := 0;
DIB.dsBmih.biYPelsPerMeter := 0;
DIB.dsBmih.biClrUsed := 0;
DIB.dsBmih.biClrImportant := 0;
jcprops.DIBWidth := Width;
jcprops.DIBHeight := -Height;
jcprops.DIBChannels := 3;
jcprops.DIBColor := IJL_BGR;
jcprops.DIBPadBytes := dibPadBytes;
jcprops.DIBBytes := PByte (DIB.dsBm.bmBits);
case jcprops.JPGChannels of
1:
jcprops.JPGColor := IJL_G;
3:
jcprops.JPGColor := IJL_YCBCR;
else begin
jcprops.DIBColor := TIJL_COLOR(IJL_OTHER);
jcprops.JPGColor := TIJL_COLOR(IJL_OTHER);
end;
end;
Res := ijlRead(@jcprops, IJL_JBUFF_READWHOLEIMAGE);
if Res = IJL_OK then begin
ABitmap.Modified := True;
Result := True;
end
else
MessageDlg(ijlErrorStr(Res), mtError, [mbOk], 0);
end;
end
else
MessageDlg(ijlErrorStr(Res), mtError, [mbOk], 0);
end;
ijlFree(@jcprops);
end;
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