Finding the correct framerate

[martino]

I'm not sure whether I'm using the right thread...

I have an anime, which has a resolution of 640x480, is encoded in xVid and has a framerate of around 119.88fps. The framerate imo is very strange. I know that framerates come at something like 23.978, 25, 29.98fps and so on... How could I find the correct framerate of this video, and then encode it to this framerate?

Also, there are 2 black lines at the top of the video. I know that I could use the crop function, but this would leave the video at 640x478, which isn't a really nice & standard number. Do you think that it would be a good idea to crop those two lines at the top and then resize it back again to 640x480.


Thanks!

[G_M_C]

I'm not sure whether I'm using the right thread...

I have an anime, which has a resolution of 640x480, is encoded in xVid and has a framerate of around 118.88fps. The framerate imo is very strange. I know that framerates come at something like 23.978, 25, 29.98fps and so on... How could I find the correct framerate of this video, and then encode it to this framerate?

Also, there are 2 black lines at the top of the video. I know that I could use the crop function, but this would leave the video at 640x478, which isn't a really nice & standard number. Do you think that it would be a good idea to crop those two lines at the top and then resize it back again to 640x480.


Thanks!

looks like someone attempted a faulty deinterlecing on it, since it has allmost DOUBLE the framerate that NTSC interlaced would have.

The dinterlacing job was probably done very poorly, interpolating both fields, and in between 1 or 2 frames have been dropped. So in the end you end up with this strange value.

Mind you, i'm from PAL land, and am no expert on NTSC & its interlacing; So there are probably better experts around here ;)

But can you report is the source actually still looks like it it were interlaced, or if there are sequences of frames that seem to be repeating ?

[Daodan]

119.88 fps is nothing really new. It's one of the ways (the poorer way I would say) to store hybrid video. Get avi2tc package from tritical to reduce it to a normal mkv vfr. As for cropping..you could leave that black there, but cropping and resizing is also an option, depends what bothers you more: wrong AR or that black bar (or you could compensate with anamorphic playback for the wrong AR).

[martino]

I just found out that by dividing 119.88 by 4 and 5 respectively I get 29.97 and 23.976. I tried to decimate the framerate in VirtualDubMod by 5, but the resulting video is about 5 times slower and is much shorter. I'll give avi2tc a try...

UPDATE:
I tried VirtualDub, decimated the frames by 5 and this worked and gave me a very smooth video. Decimate by 4 made the video a bit laggy. I gave avi2tc a try, but I couldn't get it to work. IT just gave me loads of error messages, and since VD worked I don't think that there is a need.

Also, how would I make an anamorphic video?


Thanks!

[Daodan]

When you remux in mkv you have an option there to change the aspect ratio. But you probably don't want to reencode cropped or you'll lose mod16 resolution (try to at least make it mod8). The VD method may work but you get decimated video parts (29.97) to 23.976 so some parts will be jerky. avi2tc gives real vfr output.

[martino]

But when I tried to decimate by 4 to give me 29.97 the video came out jerky, compared to the smooth 23.976 one...

But you probably don't want to reencode cropped or you'll lose mod16 resolution (try to at least make it mod8)
What do you exactly mean by this. I'm not a very advanced user, I started with avisynth and everything around it just a few weeks ago...

[Daodan]

But when I tried to decimate by 4 to give me 29.97 the video came out jerky, compared to the smooth 23.976 one...

Well, those video sequences may be very few. Usually they are the opening and ending.

What do you exactly mean by this. I'm not a very advanced user, I started with avisynth and everything around it just a few weeks ago...

It means that the vertical and horizontal resolution should be dividable to 16 (or 8) resulting interger numbers. This is a requirement for most filters to work ok, and also for the encoding application to give optimal output (even if x264 for example claims to be able to encode mod4, I got corruption in the stream when I tried).

[martino]

So you are suggesting that I should either encode it with the black lines at the top, or crop them and resize to 640x480, right?

Also, I found another encode of this (not licensed) anime by a chinese group and they seem to be using 23.976 as well...

[foxyshadis]

The vast majority of anime subbers will convert to 23.976, regardless of what the input is, because that's what AGK does (unless it's almost entirely 29.97 content). Meanwhile, some raw cappers will expand it to 120fps whether they are or aren't hybrid, and leave the subbers to deal with it - except they'll use some barely watchable deinterlace, instead of just leaving the raw 60i. They tend to use wmv.

Can't really help, though, I don't want bond mad at me. >.>