#7 Option to get timing information via frame number rather than GOP or PTS

[Man]

Would it be possible to have an extra option to allow the timing source to be calculated from the frame number rather than GOP or PTS? We have some MPEG files whereby the timing in each GOP is set at zero so when the file is processed by CCExtractor, all the text is at time zero. If there is an option to use the frame number (and frame rate), then this will overcome the issue where the GOP's timings are all set to zero.