[MEncoder-users] Re: Thumbnail creation

[Jon Drukman]

131071 wrote:
> Hi,
> 
> let me explain what the application looks like. The whole thing is a webapp
> written in Java, mplayer/mencoder is called from within there using
> Runtime.getRuntime().exec(command). What I want to accomplish now is to
> create a sort of rough overview of the video file using thumbs. So I take
> the length of the file in seconds and calculate points I want to have a
> thumb from. So I need to be able to specify for example for a 50 sec. video
> to make thumbs at e.g. 10/25/40 sec. And since this does not work out with
> -ss, and only having the ability to make thumbs at the very begining of the
> file is not an option, I'm looking for a different solution.

first run mplayer -identify to find the length and fps.  multiply to get 
the total number of frames.  divide by the number of thumbs you want, 
then use -vf framestep=x to skip through the video.

i use that in combination with vf tile to create one output jpeg with 
multiple smaller thumbs inside it.

-jsd-