[MPlayer-users] play specified frame range?

[Nick Rout]

On Mon, 20 Mar 2006 20:39:53 -0600
Kichigai Mentat wrote:

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> On Mar 20, 2006, at 20.21, Nick Rout wrote:
> 
> > How can i get mplayer to play a specified frame range, eg from  
> > frame 500
> > to frame 2500?
> >
> > I can see -ss (seek to time) and -sb (seek to byte) but no seek to  
> > frame. Also can't see anywhere to specify how long to play for.
> Well, the "how long to play for" IS in the documentation, it's just  
> not listed as duration in frame. I believe what you were looking for  
> is -endpos
> 
> As far as figuring out frames, just do the math. If your footage is  
> 29.97 frames per second, then one frame is 0.033 seconds long. If  
> it's 23.97 frames, then it's 0.042 seconds. Otherwise, no, the  
> feature you want doesn't exist.
> 

Thank you.  As most of my stuff is PAL, the framerate is 25, and the
calulation is a lot easier :-)

Oh and -endpos seems to only relate to mencoder. I have an acquaintance
who wishes to play specific bits of a file, frame or time accurate (he
prefers frame but he can use a calculator!). For teaching purposes he
wants to be able to set up a system where he can play a specified chunk,
then discuss with the class, then play some more, etc.



-- 
Nick Rout <nick at rout.co.nz>