[TAG] frame rate of VCD and DVD

[Benjamin A. Okopnik]

On Fri, Oct 20, 2006 at 08:12:51PM +0200, Karl-Heinz Herrmann wrote:
> Mulyadi Santosa <mulyadi.santosa at gmail.com> wrote:
>  
> > My another problem is, suppose I have a video clip which has 30 fps. 
> > What should I do if I want to double the fps (i.e 60 fps)? Is there any 
> > tool available to do this?
> 
> None that I'm aware of, you would have to interpolate along the time axis. 

I don't know much about it, but that seems odd. One of the standard
tweaks in camera work, in the old days, used to be overcranking and
undercranking; ditto for playing the film. I'd have expected that
digitizing would make all of that seamless as well as extending the
range.

Looking at 'man mplayer', it seems like they've got several switches that are
applicable:

``
  -fps <float value>
         Override video framerate.  Useful if the original value is wrong or missing.
  -ofps <fps>
         Specify a frames per second (fps) value for the output file, which can be different from that of the source ma?
         terial.  Must be set for variable fps (ASF, some MOV) and progressive (30000/1001 fps telecined MPEG) files.
  io=<ifps>:<ofps>
       For each ifps input frames the filter will output ofps frames.  The ratio of ifps/ofps should match the
       -fps/-ofps ratio.  This could be used to filter movies that are broadcast on TV at a frame rate differ?
       ent from their original framerate.
''
 
> Linux tools I'm aware of are dvdrip (perl gui frontend) and transcode
> which does all the work (used heavily by dvdrip). The CLI of transcode
> is *horrible* so dvdrip is strongly recommended.

Oh, *brother*... no kidding. The last time I used 'transcode', I gave up
trying to construct the command line on my own and just googled for
someone else who had used it for the same thing. Mind you, it worked
great - but a camel would die of dehydration if it had to traverse the
length of that statement. I've taken months to write programs that were
shorter.
 

* Ben Okopnik * Editor-in-Chief, Linux Gazette * http://LinuxGazette.NET *