DVD vid is jumpy

dannyoneill wrote on 10/7/2006, 12:38 PM
Hi, First the problem.

When I author a DVD in DVDA every second or so the video will have a slight stutter. Its ever so slight though.

Now, My situation.

I live in the UK so everything is 25fps PAL. My DV is 25fps as is my project. I have rendered the movie using the MPEG2 DVDA PAL spec but changed the framerate to the 23.9 movie one with pulldown, just for effect and to stop that awful video cam look.

The movie renders fine, plays back on the PC with perfect smoothness.

The problem seems to be when I author it to DVD (which is set to PAL mode for screen size reasons). It then plays back jumpy with this slight stutter every few seconds. I suspect its because the dvd project is in pal but there is no way to specify the framerate. Its also weird that when I do this it has to re-compress the movie, it doesnt do that if I stick to 25fps default template for the PAL rendering.

Anyone had this or know of a work around? I really would like to keep the movies in 24fps.

EDIT: The reason it needs recompressing in DVDA is it says the vid is not a compatible stream, despite the profile used to compress it being the normal PAL DV Widescreen but with the framerate changed :(

Comments

Steve Mann wrote on 10/7/2006, 11:23 PM
Where are you seeing the stutter? On the PC, on your set-top DVD player?
dannyoneill wrote on 10/8/2006, 1:08 AM
DVD player, the movie on the PC is perfect and in 24p, its only once its burnt to disk that it stutters.

I have done some tests, if I render the movie as PAL but change the framerate to 24p DVDA says its not a compatible movie and wants to re-compress it.

So I made it in NTSC 24p and also made my DVDA project NTSC and it works fine, no more stutters. So its only when DVDA re-compress's it that it goes wrong as DVDA re-compress's to 25p. I really want the resolution of PAL but the framerate I set it to.
marts wrote on 10/8/2006, 2:34 AM
The problem is that the PAL allows use of 50i only similarly as the NTSC 60i only.
The trick for publishing the 24p material in PAL is to speed it up to 25p and then to split the progressive frames to 2 fields to get the 50i (this way all the movies are published), when publishing 24p in NTSC the 3:2 pulldown is applied and there is no change in speed. So DVDA is able to use the 24p without any problem for NTSC, it must do the recompression however. For PAL the DVDA a does basically the same operation - it takes the 24p and does recompression in 50i but does not do any speeding up or frame interpolation so the resulting product will stutter since there will be 1 frame missing every second.
It is upon you to instruct the MPEG2 rendering application how to handle the different frame rates to be prepared for PAL authoring.
dannyoneill wrote on 10/10/2006, 7:50 AM
Pardon my ignorance but what must I do to get 24p in PAL format?