How to change FPS from 59 to 29 in MeGUI?

[ellesshoo]

My source video is 720P at 59.XXX FPS but I want to bring it down to the standard 29.XXX... How do I do this in MeGUI? I can't find the option and every time I search I get results related to FPS with regard to encoding speed, not video frame rate. Thanks in advance.

[Mc Onyx]

The correct FPS for your source would be 23.976 fps all others, like 29.97 and 59.94 are duplicate frames which you have to remove with IVTC filter in AVISynth. In MeGUI under the AviSynth Script Creator, choose "Analyse" under the source info, or just enter the field order manually if you know the correct field order... Or just enter something like FDecimate=() or tfm(order=1).tdecimate() in AviSynth.

[ellesshoo]

The correct FPS for your source would be 23.976 fps all others, like 29.97 and 59.94 are duplicate frames which you have to remove with IVTC filter in AVISynth. In MeGUI under the AviSynth Script Creator, choose "Analyse" under the source info, or just enter the field order manually if you know the correct field order... Or just enter something like FDecimate=() or tfm(order=1).tdecimate() in AviSynth.

I'm a bit of a beginner so I'm not sure I fully understand but I'm in North America and it seems that if my source frame rate is approximately 60fps I'd want it to be NTSC standard at approximately 30 fps, no?

[pandy]

If your source is film like (ie 24fps converted to the 60fps or 23.976fps converted to the 59.94fps) then you must recover orginal progressive video. If video have native 60fps or 59.94fps frame rate (most of video camera sources) then you may discard every second picture or you may reinterlace (smoother movements).
Search doom9 for examples, there is plenty of discussions how and when.

[berrinam]

MeGUI has no native support for changing the FPS. You have to modify your avisynth script to do this. The AviSynth documentation has two functions you can try: ConvertFPS and ChangeFPS. Try inserting one of the two just after your deinterlacing in the avisynth script. If you are exactly halving the framerate, it shouldn't matter which you choose.

However, as other people have commented in this thread, reducing the framerate is not a common thing to do, and if you have a source with framerate of 59.???, then it probably needs some form of deinterlacing. MeGUI's Avisynth Script Creator has an automated interlace detector, which should suggest good video filters to handle your source.

[check]

The original source is one of three types:
1. film speed capture: ie 23.976fps. If this is the case, you must decimate by two (taking you to 29.97), and then run a standard IVTC.
2. bobbed NTSC rate capture: ie 29.97fps. Just decimate by two as above.
3. true 60fps capture. Either leave as is, or decimate by two to reduce bitrate requirements.

How do you tell what you have? Either analyse a short segment (say 50 frames) frame by frame (ones with moderate motion are the best), or see what the megui deinterlacing analyser says.

MeGUI has no native support for changing the FPS.Don't forget IVTC ;).

[ellesshoo]

The source is from a digital cable box, ESPNHD to be exact. Gspot says the frame-rate is 59.941... I'd like to approximately half that number to 29.XXX or whatever it is for normal NTSC. I don't want to encode twice as many frames. The video source is already progressive (720P) so why the need for deinterlacing? What do I need to put in the avs script to accomplish this? Also, is there a certain spot in the script where it should go? I really have no idea. I tried searching but I can't find a topic involving the same situation I'm dealing with. Thanks for the replies and patience from everyone that has replied. I really appreciate it.

[berrinam]

I think you should re-read my last post. I say how to drop the framerate, and where to insert these filters into the script:

MeGUI has no native support for changing the FPS. You have to modify your avisynth script to do this. The AviSynth documentation has two functions you can try: ConvertFPS and ChangeFPS. Try inserting one of the two just after your deinterlacing in the avisynth script. If you are exactly halving the framerate, it shouldn't matter which you choose.

However, I still recommend running MeGUI's source analysis on your input. It is possible that it has a recurring pattern of duplicate frames, which MeGUI will be able to detect.