[Kdenlive-devel] Cutting List Specification Version 0.04

[Rolf Dubitzky]

On Saturday 16 November 2002 05:57 pm, Christian Berger wrote:
> But NTSC doesn't have an integer fps. NTSC has 29.9something.

It's 29.97... well close enough to 30.

> This is
> already a serious problem at timecodes on normal video.
> And look at _real_ video. You don't expect your camera or VCR to run at an
> accuracy of better than 1% do you? And 1% equals about one frame every 4
> seconds. Or half a minute at a 1 hour video.

What's your point? Your argument just hardens the argument te 29.97 is pretty 
close to 30. Concidering the accuracy of camera and video it _is_ 30.

> BTW, try to calculate the timespan between
> 01:24:35:20 and
> 03:32:42:01 in your head

Err.. nobody want's to write the timeline XML in emacs, right? This is about 
communication between GUI and effect engine, is it? The GUI can have a 
display which could be toggled between mayby hh:mm:ss.mmm, hh:mm:ss.ff or 
just fffff (just the frame number), whatever.

> Besides without opening the files we could not even check their validy. Or
> imagines what happens when you have a draft edit on 10 fps files and later
> do the real edit on 25 fps files.

I don't understand. Where do 10fps files come from? Why should anybody have a 
10fps and a 25fps version of the same thing? Wouldn't you rather reduce 
resolution in your draft?

> Or what is if you want to do slo-mo. Then you would maybe have to work
> with fields. What would you do? Say it's 23,5 frames?

Video _is_ frame based. slo-mo is also framebased. even if every slo-mo frame 
is an alphablend between the previous and next real frame, still a PAL 
_target_ will have 25fps, no matter how slow the slo-mo is.

> Well you also have to keep in mind that computer video editing is not
> always done with 25 fps or  30fps. Many people prefer 12,5 fps or 15 fps
> or other wiered framerates.

Where is the problem with 30fps, 12.5fps, or 15fps and the hh:mm:ss.ff format?

> Besides, look into the future. With new codecs interpolating frames in a
> high quality might be trivial. Some codecs don't even have fixed
> framerates. Just think of realplayer's codecs. They only have a maximum
> framerate, but the actual framerate differs.

I still don't get the point. Are you talking about _editing_ video in 
realplayer format? Why would you want to do that? You edit a video in a decnt 
format, i.e. DV, or if you really want to insert some stolen stuff, for 
heaven's sake in mpeg. After the job is done. You can export to realplayer 
format. (can you actually do that on linux?) If you have the need to edit 
realplayer files it is trivial to use transcode to transcode it to a decent 
format.


Cheers,
Rolf

***************************************************************
 Rolf Dubitzky  
 e-mail: Rolf.Dubitzky at Physik.TU-Dresden.de
 s-mail see http://hep.phy.tu-dresden.de/~dubitzky/
***************************************************************