[FFmpeg-user] Proper way to reverse PAL Speed up?

[Carl Eugen Hoyos]

Bernd Butscheidt <bbutscheidt <at> yahoo.de> writes:

> >>  The source is a German TV Recording (ZDF HD) 
> >>  broadcast in 50fps. I indeed want to speed down 
> >>  to double ntsc-frame rate (asetpts, setpts)
> 
> !!! and then drop every second frame to result 
> in standard ntsc film = 23.976  fps !!!!
> 
> > Why do you think that this is a good idea?
> 
> Cinema source is recorded at 24 fps

So why are you targeting a frame rate of 24000/1001 
instead of 24fps?

> to make it broadcast due to PAL standard the 
> television stations or all DVD releases of movies 
> are speed up to 25 fps. So films on DVD or 
> broadcasts of movies on PAL-television are
> about 4 percent shorter than the cinema version.

But are you sure that the pitch wasn't changed 
by 4% for tv transmission? Isn't it normally done 
(at least for non-B-movies) for DVD releases?
(I am not saying this is really the case, I am 
just wondering how you can be sure it isn't. If 
you don't hear the difference, I wonder if it is 
a good idea to change the playback speed with 
FFmpeg, especially since you can change it at 
playback time anyway.)

Carl Eugen