How to convert a video of 120 Fps to... well 23.9fps or 25 fps or 30 fps

[Chuba753]

Hi I recently dowload a video anime of "Saint Seiya", Is a RAW file and have 120 fps and obviously the video had a long size (almost 800 MB for just 22 minutes ), the file extention is ".avi" and i would like to converted to an other framerate to reduced the file size. Please anyone, HELP ME!!!
P.S.: I already tried to change the framerate across VirtuDub but the video just slow down during playing.

[aedipuss]

it may be some sort of 60i footage. i'd try encoding to HD mpeg-2 60i and see how it looks.

[Chuba753]

Well it's actually DivX 6.8 the codec of the file. Please another answer.

[träskmannen]

I already tried to change the framerate across VirtuDub but the video just slow down during playing.

Can you describe how you tried to do that? Most likely you made some mistake or it would have worked.

[jagabo]

Anime is often a mixture of 24p and 30i footage. This is sometimes converted to 120 progressive fps on a computer because that is the least common multiple of 60 fields per second and 24 frames per second. Each if the 60 fps fields is repeated twice, each of the 24 fps frames is repeated 5 times. The 120 fps file retains all the smoothness of the original video.

You might think 60 fps would work better. Each of the 60 fields could be displayed once but the 24 fps frames would have to alternate between being displayed 2 times and 3 times (24 * 2.5 = 60). That leaves the 24 fps sections with a distinct judder.

If you convert the whole video to 30 progressive fps the 24 fps sections will turn out jerky. If you convert to 24 progressive fps the 60 field/s sections will turn out jerky.

Reducing the frame rate of this type of video is not a good strategy for reducing the file size. Exact duplicate frames require very few bits to encode in a Divx AVI file. So throwing out all those duplicate frames won't reduce the file size by much.

Obviously, you can reduce the file size by reducing the bitrate, but doing so will likely reduce the quality.

On the other hand, few people have monitors or TVs that can display 120 fps. Most can only display 60 fps these days. So your video is going to have judder no matter what you do.

If you want to convert the frame rate:

1) Open the file in VirtualDub.
2) Select Video -> Fast Recompress.
3) Select Video -> Frame rate. In the middle section of the frame rate dialog checkmark the "Convert to fps" option and enter the frame rate you want.
4) Select Video -> Compression. Select the codec and its settings.
5) Select File -> Save as AVI.

[freebird73717]

Yep. Jagabo hit the nail on the head. 120fps is more than likely variable frame rate video. Serious pain in the arse to convert. I never could get those to come out right.

[manono]

120fps is more than likely variable frame rate video.

Maybe yes, maybe no. The people that create these things don't usually study them to see what's supposed to be the proper framerate, or if it's a true hybrid. It could very well be 23.976fps and jagabo's instructions (or better yet, a decent AviSynth script) will do the job. There's no real way to know without a study of the source AVI.

And if it is VFR, reencoding it for a container that can handle VFR playback might be the answer, and that way all the dupe frames will disappear and it'll play back absolutely smoothly, although, of course, at the moment that will be only for computer playback. Or maybe the main body of the episode is 23.976fps and the credits are 29.97fps interlaced. Steps can be taken to minimize jerky playback of the credits (or you can get rid of them entirely) while at the same time giving the main body of the episode the correct framerate. There are lots of possibilities here.

[Chuba753]

Wow thanks!!! "jagabo" but know i would like to add subtitles in color to this file, how can i do it??.