K210.ORG

function ReadMWord(f: TFileStream): word;

type

  TMotorolaWord = record

    case byte of

      0: (Value: word);

      1: (Byte1, Byte2: byte);

  end;

var

  MW: TMotorolaWord;

begin

  f.Read(MW.Byte2, SizeOf(Byte));

  f.Read(MW.Byte1, SizeOf(Byte));

  Result := MW.Value;

end;

 

procedure GetJPGSize(const sFile: string; var wWidth, wHeight: word);

const

  ValidSig : array[0..1] of byte = ($FF, $D8);

  Parameterless = [$01, $D0, $D1, $D2, $D3, $D4, $D5, $D6, $D7];

var

  Sig: array[0..1] of byte;

  f: TFileStream;

  x: integer;

  Seg: byte;

  Dummy: array[0..15] of byte;

  Len: word;

  ReadLen: LongInt;

begin

  FillChar(Sig, SizeOf(Sig), #0);

  f := TFileStream.Create(sFile, fmOpenRead);

  try

    ReadLen := f.Read(Sig[0], SizeOf(Sig));

 

    for x := Low(Sig) to High(Sig) do

      if Sig[x] <> ValidSig[x] then ReadLen := 0;

 

    if ReadLen > 0 then

    begin

      ReadLen := f.Read(Seg, 1);

      while (Seg = $FF) and (ReadLen > 0) do

      begin

        ReadLen := f.Read(Seg, 1);

        if Seg <> $FF then

        begin

          if (Seg = $C0) or (Seg = $C1) then

          begin

            ReadLen := f.Read(Dummy[0], 3);

            wHeight := ReadMWord(f);

            wWidth := ReadMWord(f);

          end else begin

            if not (Seg in Parameterless) then

            begin

              Len := ReadMWord(f);

              f.Seek(Len-2, 1);

              f.Read(Seg, 1);

            end else

              Seg := $FF;

          end;

        end;

      end;

    end;

  finally

    f.Free;

  end;

end;