Pulldown

[DivXExpert]

I am backing up a DVD and I used Forced Film in DVD2AVI. I want to make it VCD, but pulldown.exe only excepts MPEG-2. Right? What should I do? Change framerate when frameserving with AVISYNTH?
Thanks in advance.

[DivXExpert]

Also, does changing the FPS effect the audio-video sync. Do I need to modify the audio for 29.97fps?

[tonyp12]

VCD is mpeg1, and mpg1 does not support the 3:2 pulldown flag.

So you could encode it in 23.97 progressive
and play it back as so.

Some DVD players and TV's are OK with it, so try it.

Option2:
Create SVCD with VCD bitrates and screen size, this way
you are using mpg2 that support 3:2 pulldown flag.

But you are using VCD's smaller space requiriment.

If you DVD player Does not support SVCD, burn it as VCD
in NERO and do not let it re-encode and it MAY play in your DVD player.

My Toshiba3755 can be tricket to play mpg2 VCDs this way.

[DivXExpert]

Does changing the fps with avisynth result in jerky playback?

[tonyp12]

The framerate change you want to do is called Telecine (3:2 pulldown)

If you still have access to the VOBS you could UN-check the
Forcefilm option and DVD2AVI will do the telecine for you.

Short: it spreads 24 frames over 60 fields (30 interlaced frames)

As 60 and 24 is two nice numbers to work with, the playback is smooth.

As VCD are only 240 Vertical lines,no interlacing is done
on the final video.

[adam]

If you encode a VCD at 23.976fps it will still play back at 29.97fps, everything on a non-HDTV NTSC tv will. You don't need to apply the 3:2 pulldown, you don't need to do any addional framerate conversions, you don't need to worry about the audio. Encode at 23.976fps and burn it. Your dvd player will autotelecine it to 29.97 fps as it plays and everything will look fine. The audio syncs because the total playtime is still the same. The dvd player speeds the playback speed up by ~%20 but it also adds a proportional amount of new frames. This doesnt look jerky, however, because it duplicates fields, not frames.

Only SVCDs and DVDs require the 3:2 pulldown flag. Without it, the dvd player may or may not do the required telecine to 29.97fps.

The effects of a framerate conversion depend on what you start with and what you convert to, but generally, just telling avisynth to change the framerate won't result in jerky playback because no frames are added or removed (though you can do this with filters) BUT the speed of the film will be changed so unless your going from film to pal or vice versa, everyone is going to look like they are either on speed or valium.

If you really want to know how to do proper framerate changes then my advice to you is to do some research on telecining film to both PAL and NTSC. Once you know how this is done then you know how to reverse the process, if possible, and from there you will understand how to go from any format to another.

As an NTSC user, however, the actual process you need to do is very simple. As you have discovered, using forced film will give you 23.976fps progressive frames. If you are making a VCD, simply encode at this fps and burn it. If you are making a SVCD or DVD then encode at this fps but also include the 3:2 pulldown. Your DVD player will do the rest.

[DivXExpert]

Here is my situation, I have an interlaced anime movie at 29.97fps, I used forced film to automaticly deinterlace, should I not do that? Deinterlacing always results in jerky playback for me so I just use force film and its not interlaced anymore. But I need to get it back to 29.97. I understand that my dvdplayer can automaticly telecine for me, but say I was converting it to .avi and I wanted to change it back to 29.97fps from 23.976fps without a change in speed. From what I gather I need to duplicate fields not frames. How do I do that? VirtalDub?

[tonyp12]

Here is my situation, I have an interlaced anime movie at 29.97fps, I used forced film to automaticly deinterlace?

First of: using Force Film does not de-interlace.
Not having it on will telecine a progressive stored DVD movie.

But it can not de-interlace a interlaced NTSC DVD.

If it is a Hardcoded telecine, tmpgenc can do a inverse telecine.
Alot of Animes are hardcoded telecined.

There is a difference between interlaced telecine film and
true interlaced recorded source.

[DivXExpert]

It seems to work. The movie was interlaced 29.97fps, Then I put on forced film, it outputted the video as 23.976fps and I didn't get those freaky interlace lines anymore. It works for me, the only part obout it that doesn't work is getting it to 29.97fps progressive.

[tonyp12]

You need to find out if the movie is stored progressively or not.

load the first VOB, hit F5 (or preview in option menu)

Let it play for a few minutes, if it show Video Type: FILM 98%
(80-100%) it is progressive 23.97 FILM

The framerate will be 29.97 or 23.97 depending if forcefilm is on.

BUT does not have anything to do with if the source is 23.97 progressive or not.

NEVER use forcefilm if the Video type is NTSC.


Interlaced lines will only show up on the PC, and not on a TV.
PowerDVD can deinterlace on the fly during playback.

[DivXExpert]

Its like Film 70%, Frame type Progressive. But I tried it on a Interlaced, Frame type NTSC with forcefilm on, and all the interlacing went away. Why not always use forcefilm, it seems to make the movie playback more smothly after encoding, even if the source is interlaced.

[tonyp12]

But I tried it on a Interlaced, Frame type NTSC with forcefilm on, and all the interlacing went away.

That DVD must been a hardcoded Telecine, but should still
not come out good by using forcefilm.

HINT:
FORCEFILM option in DVD2AVI is only ignoring the 3:2 pulldown flag.

A interlaced DVD does not have this flag,
so ignoring it does not make sence.

By NOT having force film turned on, DVD2AVI will telecine a Film
if it sees a 3:2 pulldown flag (the same way a DVD player works)

[DivXExpert]

Well, now that I got the whole forced film thing figured out, I need to change the framerate to 29.97fps.

[DivXExpert]

I would disable forced film, so that DVD2AVI telecines for me. But that interlaces the video and interlaced video looks like crap.

[DivXExpert]

My source is 23.976fps progressive MPEG-2. I need it to be 29.97fps, progressive, MPEG-1 with smooth playback. How do I do that?

[tonyp12]

Why does it need to be 29.97 progressive?

Interlaced lines does not show up on a TV that is interlaced.

A PC monitor is not interlaced, and you have to learn to live
with the interlace line while previewing a video clip.

[TheLostTimberwolf]

Here is my situation, I have an interlaced anime movie at 29.97fps, I used forced film to automaticly deinterlace, should I not do that? Deinterlacing always results in jerky playback for me

Oh how I know the 'jerky' playback you speak of, eww I hated it until I found out how to get rid of it, theres a simple way around this, dont de-interlace it.

check out this web site, (possible you have already read it though) but anyway http://www.inwards.com/~dbb/interlace_myths.html

hope this helps clear somethings up