[MEncoder-users] Convert webm to any other format

[Reimar Döffinger]

On 23 Oct 2012, at 00:24, Paul Brauner <polux2001 at gmail.com> wrote:

> Hello,
> 
> I've used cheese (http://projects.gnome.org/cheese/) to record a small
> video with my webcam. I shouldn't have in retrospect but that's too
> late, I can shoot it again :) So it outputs webm files by default.
> When I try to use this video in kdenlive I get very weird behaviours
> (like, the video jumps to random frames). So naturally I've tried to
> convert it to another format. That's where trouble begins.
> 
>  - When I read the video with mplayer it displays
> http://pastebin.com/cuZRpkHn (notice the 1000fps). The video plays
> just fine, at the right framerate. When I press "o" I see that it
> lasts 2:50 min.
> 
>  - If I execute "mencoder -oac copy -ovc copy  myvideo.webm -o
> myvideo.2.web" I get a lot of "duplicate frames" messages
> (http://pastebin.com/dA7TR2rZ. The resulting video plays fine although
> now "o" says it lasts 2:49 min. kdenlive is still not happy with it.
> Mplayer still displays 1000fps.
> 
>  - Same exact thing if I execute the same command with "-idx".
> 
>  - If I execute the command with "-fps 12", I get a duration of
> 2:52min and the video features mostly artifacts (it looks like a
> mosaic).

I'm not sure you are looking at the right place for the issue, but -fps s for speeding up/slowing down video, -ofps is for selecting the output frame rate.

> At this point I'm a bit desperate: mplayer plays it just fine but I
> can't convert it into a file that plays the same way (and even less to
> a file that kdenlive likes). Is there a way to say "dump what mplayer
> displays in a raw file"? (I don't care for sound). If not, do you have
> an idea what to look for?

MPlayer -vo yuv4mpeg is intended for that. -vo png might work as well, if you do not mind losing the exact timing information.