property Position: Longword read GetPosition write SetPosition;

procedure TfrmMain.SetPosition(Position: Longword);
var pos: Longword;
begin
  if Chan = 0 then Exit;

  if Modus = moSamples then
    BASS_ChannelSetPosition(Chan, BASS_ChannelSeconds2Bytes(Chan,
      position));

  if Modus = moMusik then
  begin
    startmodplaytime := timegettime - (position * 1000);
    pos := round(position * (SpeedinProzent / 100)) or $FFFF0000;
    BASS_ChannelSetPosition(Chan, pos);
  end;
end;

function TfrmMain.GetPosition: Longword;
var uptime: integer;
begin
  Result := 0;
  if Chan = 0 then Exit;

  if Modus = moSamples then
    Result := round(BASS_ChannelBytes2Seconds(Chan,
      BASS_ChannelGetPosition(Chan)));

  if Modus = moMusik then
  begin
    uptime := timegettime;
    Result := (uptime - startmodplaytime) div 1000;
  end;
end;

procedure TfrmMain.tb1Change(Sender: TObject);
begin
  if BASS_ChannelIsActive(chan) = BASS_ACTIVE_PLAYING then
  begin
    Position := tb1.Position;
  end;
end;

procedure TfrmMain.tbTimer(Sender: TObject);
var
  sectime, trackpos : Integer;
  str:string;
begin
  if BASS_ChannelIsActive(chan) = BASS_ACTIVE_PLAYING then
  begin
    tb1.Position := Position;

    sectime := trunc(BASS_ChannelBytes2Seconds(chan, BASS_ChannelGetPosition(chan)));

    str := '';
    if (sectime mod 60 < 10) then str := '0';
    str := str+inttostr(sectime mod 60);
    str := inttostr(sectime div 60)+':'+str;

    tbtime.Caption := str;
  end;
end;