23.976fps or 30fps

[n34g]

Im confused, since I read in a forum (or link) that TV can only display 30fps, do I encode my VCD's that I plan to play on my standalone DVD player on my TV 24fps or 30fps... If I use 24 fps as many Guides recommend using in DVD2AVI (checking "FORCED FILM") they say the video will look smoother but since TV's only play at 30fps, will my VCD look choppy or stutter.

Do you experts still recommend me use FORCE FILM if the DVD movie is film in DVD2AVI settings?

Thanks for your help....

[adam]

The ntsc standard is 29.97fps. Anything that plays on your ntsc tv will always be played at this framerate.

If your vcd or svcd, or dvd for that matter, is encoded in ntscfilm (23.976fps) then your dvd player will telecine it in real time as it plays. This converts the movie from 23.976fps to 29.97fps. Read here about telecining and you'll see why the playback is always smooth and what the benefits are of encoding in ntscfilm as opposed to ntsc. http://www.doom9.org/synch.htm

For DVD's and SVCD's the only supported ntsc framerate is 29.97fps. So DVD's use whats called a RFF/TFF flag to instruct the dvd player to perform the telecine and SVCDS use what's called a 3:2 pulldown flag to do the same. This way you can encode at 23.976fps but it still plays back at the 29.97fps required by the ntsc standard.

Vcds actually support both 23.976fps and 29.97fps in the standard. If you encode your VCD at 23.976fps the dvd player is supposed to autotelecine it as it plays. Unfortunately not all dvd players do this well, so you get jerky playback or audio desync. Try it out for yourself. If your player plays it fine than always encode at 23.976fps. It really makes a huge quality difference which is especially noticable on vcds. It actually increases quality by about
%20.

[n34g]

Thank you for your response. Yes I did try it at 23fps and it looks good on my VCD/DVD player. Im going to experiment with 23fps and 29fps to see if I notice a difference. Im also trying different settings in TMPGenc to get the best video for VCD playback. Can You advise me on that? Should I use Soften Block Noise and at what number? Should I mark "No Motion Search for Still Picture"? etc. Thank you very much...

[htc10825]

No.

Do it only when DVD2AVI says 95% or above "Film". But this is very, very scarce. The most NTSC DVD-Film(Movie) unsed the technologie "Tetecine". So in most case you have to apply a "Invers Telecine"(IVTC) during conversion. Leave the "Forced Film" in DVD2AVI unchecked. Load the movie in Vdb or Ndb via a simple .avs without filters. Check the moive frame for frame. IF there are allways 2 prograessive frames followed by 3 interlaced frames, you can use the IVTC filter to reduce the frame rate to 23.976 and enhance the encoding quality. If not, it is pure NTFS-Video, you have to leave the frame rate at 29.97 und most likely using a deinterlace filter, otherwise the needed bitrate for high motion scene may be astronomical high(for SVCD).

It is possible to convert slow motion NTSC-Video to frame rate at 23.976 to save bits. But i think it is another topic.

[adam]

No way. The vast majority of ntsc dvds are %95 or higher film and forced film will work. Maybe alot of older dvds arent like this but virtually every single newly theatrically released dvd is. I have ripped several dvd's every week for over 6 years now and there have only been a handful that forced film won't work on, not including live footage stuff like concerts which are almost always stored as ntsc.

I would say that forced film will work on at least %90 of the ntsc dvds out there. IVTC is not needed the majority of the time.

[n34g]

Yes, I have also ripped various new DVD movies lately (Collateral Damage, Mothman, 15 minutes, John Q, The Watcher, etc...) and they are all FILM 95% or above (but thank you all for the info).

BUT, the Trailer within the DVD and also usually the extra features of the DVD's are mostly NOT FILM they are usually 29fps. Do you recommend me forcing film also on the trailers and extra features or should I just use 29fps and then convert in TMPGenc (by using INVERSE TELECINE within TMPGenc) to convert to 24 fps? or do I just leave them at 29fps in the CD. In other words, is there a problem if I want the trailer at 29fps and the movie at 24fps within the same VCD?? (will it effect the quality or force the DVD player in any way during playback similar to when you record in a VHS at different speeds EP SLP that is not recommended)??

[adam]

Yes the extra's are almost always ntsc. I'm not exactly sure why, I suppose its because they are often broadcast on television where telecining is necessary.

If the movie is not stored as film and displays as being %95 or higher film than do not use forced film. If you do then any telecined portion of the movie will simply have frames decimated to make it 23.976fps. This will result in choppy movement and possibly even audio desync, and of course will surely leave some visible interlacing. There is nothing non-standard about having some video content at ntsc and some at ntscfilm. Whether or not you IVTC is up to you. The only drawback to not IVTC'ing is that you are essentially getting %20 less bitrate in those clips.

I do not like TMPGenc for IVT'ing. If you do it manually its ok but its time consuming. I find that the auto IVTC'ing is often very bad and leaves alot of interlacing artifacts. I prefer to use decomb in avisynth.