Smooth 30fps > 15 fps with mencoder?

[AlexeyS]

Hello guys,

I'm trying to change frame rate of uploaded movies from 24 fps, 25 fps, 30 fps to 15 fps. And I do it like this:

-ofps 15

I get really jerky movies that looks like they're 3 fps, for example this movie (http://www.roamearth.com/video/2/27.flv).

I wonder, how can I create smooth 15 fps movies with mencoder, like I can do with Adobe Premiere, Ulead MediaStudio, Final Cut etc?

[scharfis_brain]

this is cause mencoder drops or duplicates frames to reach the desired framerate.

with this method smooth results may only be achieved, if the ratio of source and destination framerate is integer.

only motion interpolation techniques such as offered by mvtools are able to suppress major judder during a framerate conversion.

[AlexeyS]

this is cause mencoder drops or duplicates frames to reach the desired framerate.

only motion interpolation techniques such as offered by mvtools are able to suppress major judder during a framerate conversion.
Thanks for quick answer. I wonder, is there any plugin or mod for mencoder that will allow it to use "motion interpolation" method?

with this method smooth results may only be achieved, if the ratio of source and destination framerate is integer.
Do you mean 30 > 15, 24 > 12, 25 > 12.5? I've tried that (I've tried 30000/1001 > 15000/1001), videos are still jerky. :(

[Dark Shikari]

Thanks for quick answer. I wonder, is there any plugin or mod for mencoder that will allow it to use "motion interpolation" method?The only open source motion interpolation framechanger is MVtools--see the Avisynth forums.

[AlexeyS]

The only open source motion interpolation framechanger is MVtools--see the Avisynth forums.
Thanks. But I can't use Avisynth, because I use Linux server (tried to install Avisynth 3 and Avisynth 2 for windows through emulation, but both didn't work).

How can I get smooth movies with 30 > 15 (24 > 12 etc) conversation then? Is there any special option for mencoder?

[scharfis_brain]

if 15fps with integral decimation still is yerky for your eyes, then you have to live with it. the framerate iss too low to be considered moving smoothly...
motion interpolation WON'T help!

[AlexeyS]

if 15fps with integral decimation still is yerky for your eyes, then you have to live with it. the framerate iss too low to be considered moving smoothly...
motion interpolation WON'T help!
15 fps (or even 10 fps) are ok for my eyes. :)

The thing is my video looks like it's 3 fps sometimes. For example, could you look at this movie please (camera movement at 21-23 seconds is really jerky):
http://www.roamearth.com/ff/30-to-15.flv

I do -ofps 15000/1001 for 30000/1001 movie here...

[scharfis_brain]

look at the source and make sure that it is completely fluent in this scene!
Ma this scene be shot with another camera that has another base framerate?

Also provide the source, please.

[AlexeyS]

look at the source and make sure that it is completely fluent in this scene!
Ma this scene be shot with another camera that has another base framerate?

Also provide the source, please.
Ok. Here's same movie, encoded with same settings, but with 30000/1001 fps:
http://www.roamearth.com/ff/30-to-30.flv

And this is original movie encoded with iMovie (the original was HDV NTSC):
http://www.roamearth.com/video/2/27temp

[scharfis_brain]

then I guess mencoder does something wrong, OR the program that added the white bars did something bad.

Could you upload a sample of the unprocessed HDV-File?

I want to try something to reduce jerkyness by adding motion blur.

[AlexeyS]

then I guess mencoder does something wrong, OR the program that added the white bars did something bad.

Could you upload a sample of the unprocessed HDV-File?
Sure, but original movie (27temp, link above) looks very good. It's really smooth.

Anyway, I will try to find cassette tomorrow and capture same video without recompression.

Also, white bars and grey artifacts are added by mencoder after I join two files (logo and 27temp movie). White bars are not the problem, because I will add one black frame to the logo later and bars will be black, but this grey artefact is really pain. I wonder, how can I remove it?

I want to try something to reduce jerkyness by adding motion blur.
The thing is mencoder will be re-encode uploaded videos automatically and I don't think users will prepare their movies (adding motion blur for example) before uploading.

Or you're saying about adding motion blur with mencoder?

[AlexeyS]

I'm not able to upload video, because my camcorder seems to be broken :( (it turns on, but touch screen and control through FireWire doesn't work). I will go to service and repait it and upload video in a few weeks or maybe later.

[microchip8]

you can try with the framestep filter, eg

-vf framestep=2 -ofps 15