Frames Per Seconds

[skippyd]

The original movies I decode are at 29fps but when I use autogk it decodes at 23fps. Is there a way to change autogk so it decodes at 29fps so its the same as the original?

[len0x]

AutoGK always restores original fps of the source, so unless you're using pure NTSC video (from camera, tv etc) it brings it down to 24 fps.

[manono]

Hi skippyd and welcome to the forum-

Film, like what you see in a movie theater, is 24fps. DVDs output at 29.97fps (actually 59.94 fields p/s) because that's what is required by the NTSC television systems. If your DVD is of a movie, then in almost cases you want it restored to 23.976fps. Believe me, 29.97fps, for a variety of reasons, will look bad as an .avi

[eb]

Originally posted by manono


Film, like what you see in a movie theater, is 24fps. DVDs output at 29.97fps (actually 59.94 fields p/s) because that's what is required by the NTSC television systems. If your DVD is of a movie, then in almost cases you want it restored to 23.976fps. Believe me, 29.97fps, for a variety of reasons, will look bad as an .avi
Why .avi is worse? see my sample mmmm.avi with 60 frames/s.
http://forum.doom9.org/showthread.php?s=&threadid=77653&perpage=20&pagenumber=1

@lenOx
you promised to make assesment of this sample

eb

[len0x]

Originally posted by eb
Why .avi is worse? see my sample mmmm.avi with 60 frames/s.
http://forum.doom9.org/showthread.php?s=&threadid=77653&perpage=20&pagenumber=1


I think first reading this helps: http://www.doom9.org/ivtc-tut.htm

Originally posted by eb

@lenOx
you promised to make assesment of this sample


I haven't downloaded it yet...

[eb]

lenOx wrote
I think first reading this helps: http://www.doom9.org/ivtc-tut.htm

Yes I am familiar with this.
As you know i am inerested mainly with sattv records and there more than 80% can be processed in an easy way,simply resizing,denoising keeping interlaced forms or only using fast transcoding.Time to time there are some old materials that are difficult for me and cos i have troubles with decimating and IVICTing then I am going to 100frames/s.
It will be nice if some samples will be presented to better understand all this problems. I am going to write short comments about this in relations to TVsat records but I must prepare it carefuly presenting my point of view.
Because of this 80% i am molesting neuron2 also for demuxing video streams together with audios.For now DGIndex is the second universal program than can deal with any types of streams /mpeg,vob,ts/ besides ProjectX.

eb

[manono]

Sorry eb, but I can't get it. I fill in the info, and it keeps coming back to do it again. Maybe it's my fault, I don't know. I haven't had any experience with that stuff. I wouldn't mind seeing it though. If you like, PM me and I can give you an account on my server to upload it. Or give me some instructions about what to do to get it.

However, I did specifically mention DVDs. I know nothing about captures and the additional problems they present. But to answer your question, if at all possible, you want to restore it to the source 24fps (if that's what it is). Say you're encoding to a fixed size, such as 1 or 2 CDs, as is often the case. By encoding at 29.97fps, when it can be IVTC'd back to 23.976fps, you'll be encoding 25% more frames unnecessarily, and the result will be 25% lesser quality for the same file size. In addition, those extra frames will be either duplicates, or blended or otherwise deinterlaced frames, depending on how you treat the source. This will result in either a slight stutter on playback, or a blurriness/softness in the resulting .avi, or both. If it can be IVTC'd to restore the progressive frames, rather than deinterlaced, the quality/detail/sharpness will be greater.

[jggimi]

My analog captures of broadcast NTSC have either been Telecined sources or been fully interlaced. And the Telecined sources have included some pretty terrible sitcoms that I wouldn't think they'd waste film with.

(I was capturing terrible sitcoms not to collect them, but to see which ones were video taped and which were filmed. Can you believe Dharma and Greg is filmed? :rolleyes: )

[len0x]

Although I don't think skippyd was asking about HDTV sources - as we started dicussion. I'll join in as well. :)

NTSC first (although its not what eb mostly care living in the PAL land). 60 fps sources can be of several types(assuming they started as FILM, not VIDEO):

1. The Best. Started as 24 fps FILM -> converted directly to 60fps via 3:2:3:2 pattern of dupes. Resulting in 720p usually.
2. The Good. Started as 24 fps FILM -> telecined to 30 fps -> 2:2:2 dupes pattern. Resulting in 1080i usually.
3. The Bad. The same as number 1 but pattern can be broken, so manual selection of frames or FDecimate is the best solution.
4. The Ugly. starting from 24 fps movie is blended and some dupes inserted which result in sort of "pure" 60 fps progressive source. Typical example is that faf.ts example which Neuron2 pointed us to. You may or may not use FDecimate successfully on it (haven't tried yet), but probably the best solution is to keep 60 fps if you don't see too much duplicates there.

Now PAL 50 fps sources. To be honest I have no idea what is used for broadcast on HDTV - 24 or 25 fps sources. I guess if first, then we automatically enter "the ugly" area. If proper 25fps source is used you should be able to restore it if its blended 50i stream. In case 50p - its ugly again unless 2:2:2 pattern of dupes used.

So to sum up - the amount of dupes in the source should tell you what is the best fps to convert it to (and if convert at all).

[eb]

Because of the nature of captured/recorded analog/digital TV signals with their discontinuites, droped frames I prefer not to use metods to convert them to the original status.
Practicly any rebuildings or correctings are ending with even worse picture.
As experimented by Zep, manual corrections are avesome.
I am not talking here about croping/cliping or denoising.
And all of this is independent of NTSC or PAL systems.

eb

[eb]

Because of the nature of captured/recorded analog/digital TV signals with their discontinuites, droped frames I prefer not to use metods to convert them to the original status.
Practicly any rebuildings or correctings are ending with even worse picture.
As experimented by Zep, manual corrections are avesome.
I am not talking here about croping/cliping or denoising.
And all of this is independent of NTSC or PAL systems.

eb

[len0x]

Originally posted by eb
Because of the nature of captured/recorded analog/digital TV signals with their discontinuites, droped frames I prefer not to use metods to convert them to the original status.
Practicly any rebuildings or correctings are ending with even worse picture.


I can't comment on quality of broadcast/reception in your area. But I saw quite a bit of 24fps material converted from HTDV sources in the US - and they are perfect!

But as I said - PAL land may be very different in that respect...