120 FPS; How to decrease it?

[vemalas]

As the title says. I can decrease fps down from ntsc to pal and all that. But when i try to do it with avisynth when video has 120fps, source gets nasty looks, decrease in quality. I read in guides that sometimes it's done 120 for some reason. Didn't mention why though, and what should we do to make like 23.967 from 120 fps?

Thank you. ^^

[Kariudo]

If I remember correctly, you should end up using the avi_tc_package from Tritical's site (it's near the very bottom of the page)

Never had to use it seeing as I've used DVD footage for all my vids, so that's about as much help as I can give

[mirkosp]

What kariudo said. As for the usage, check out the "Dealing with 120fps AVI files" paragraf here. It doesn't say why, but says how to deal with it. It basically links you the same program that Kariudo linked you and tells you how to use it. It's pretty easy and straightforward.

Anyways, if you're interested in the why someone would do 120fps... as you might know, some sources are hybrid, meaning that they could be both telecined and full field interlaced. This means that some scenes would be animated at 29.97 and other scenes at 23.976. Now, a solution could be just IVTC'ing it all, and dropping some of the frames of the 29.97, which might make the motion a bit jerky. Similar issue if you just full field deinterlace, except that the scenes that'd have an odd motion would be the 23.976 ones. To fix this issue with a constant frame rate, the solution is to bring everything to 120fps, so that both parts will have smooth animation. This is the "perfect" choice if you need to make an avi encode. However the perfect solution would be to use YATTA or animeivtc so that one could output timecodes in order to make a VFR encode (requires an mkv container, though).

[vemalas]

Thanks, both of you, it worked. And now i understand the necessity of 120fps. Sadly i can't get 95% of anime on DVD's, because where i live, there are no shipments of it. And i can't order also. Hope for a better place in the future.
mirkosp, you must be quite respected in this community. You helped and explained to me not the first time. I really appreciate that. Really helps to progress much faster.

I don't know if you'll read this, or maybe someone other will notice - but here's the question - how should i know if footage are interlaced or progressive? If i don't have dvd footage i can't use DGIndex. Yes i can say by eye, and if i miss it, in most cases i see when i try to edit with interlaced footage, then i have to deinterlace and start all over again. Still thats not an ideal method. Would gladly learn other ways if there is.

[mirkosp]

I don't know if you'll read this, or maybe someone other will notice - but here's the question - how should i know if footage are interlaced or progressive? If i don't have dvd footage i can't use DGIndex. Yes i can say by eye, and if i miss it, in most cases i see when i try to edit with interlaced footage, then i have to deinterlace and start all over again. Still thats not an ideal method. Would gladly learn other ways if there is.

Well, generally, besides VOBs ripped out of DVDs, you'll hardly find any interlaced footage anyway. In case you can see interlacing, then it's probably just the one who made the encoding that screwed up - which means it wasn't deinterlaced and just encoded as progressive. You should be able to still fix it, but like you said, it's probably just a check to see thing. However, it is possible to have things like interlaced x264, or for example .ts raws are interlaced too.
So well, what you could do is using MediaInfo to check it. When installing, make sure that the Output Format is set to HTML. After you have installed, right click the file that you have to check and choose MediaInfo. Scroll until you see Scan Type in the Video box. If it's Progressive, then it's fine, if it's Interlaced... you'll have to deinterlace.

[Qyot27]

Anyways, if you're interested in the why someone would do 120fps... as you might know, some sources are hybrid, meaning that they could be both telecined and full field interlaced. This means that some scenes would be animated at 29.97 and other scenes at 23.976. Now, a solution could be just IVTC'ing it all, and dropping some of the frames of the 29.97, which might make the motion a bit jerky. Similar issue if you just full field deinterlace, except that the scenes that'd have an odd motion would be the 23.976 ones. To fix this issue with a constant frame rate, the solution is to bring everything to 120fps, so that both parts will have smooth animation. This is the "perfect" choice if you need to make an avi encode. However the perfect solution would be to use YATTA or animeivtc so that one could output timecodes in order to make a VFR encode (requires an mkv container, though).

To be a tad more specific, the additional frames are null frames, which contain no data, and are essentially 'ignored' on playback. This is required because AVI doesn't support VFR, and this is a way of hacking it in. 120fps is chosen simply because of the assumption that the least common denominator of 24 and 30 (which is 120) is the best solution. However in reality, it would be just as optimal to leave the 29.97fps parts alone and add null frames to the 23.976 sections, bringing everything up to 29.97fps instead, considering the null frames get ignored anyway. It'd also result in smaller container overhead.

avi_tc is used to remove the null frames and create a timecodes file, which is why it's important to do so prior to loading the video in a script - because AviSynth (or VirtualDub, for that matter, if you just loaded the AVI) will interpret those null frames as real frames.

All of this is essentially blamed on Japanese RAW cappers who don't want to use proper methods of storing video - you can even find 120fps H.264 MP4s, which just makes so little sense it's not even funny.

[vemalas]

I have new problem. Some episodes i can re-do in normal fps, some not.
Those episodes which doesn't let me to do that gives me error message:

[Qyot27]

Just a basic observation, but why are you running the app straight out of WinRAR? Unpack it first.

[vemalas]

Same thing happens unpacked. Actually it doesn't make any difference because when you run the program straight from winrar it still unpacks them for use.

[Qyot27]

I know it unpacks it (to the temp cache) if you run it like that, but I really don't see the point - besides the fact that programs aren't meant to be run that way.

In digging around, I found another thread on here (that I replied to, even) that had to do with this issue, but it was from almost exactly 2 years ago, give or take a few days. The solution I posited there was to separate the sections based on their true framerate and then run the segments through individually.

So for instance, find out which parts are 29.97 and which are 23.976, separate them using VirtualDub's Direct Stream Copy mode, and then run them through cfr2tc.


Post is here (which also has more lengthy instructions):
http://www.animemusicvideos.org/forum/v ... 3#p1046033