60 frames to 30 - how?

MarkGrigsby · 24th April 2005, 13:06

I'm hoping some kind expert could maybe answer this for me. Which is 'better':

a) 30 progressive frames per sec, converted by CCE to DVD format and therefore showing on TV as 60 interlaced fields per sec

b) 60 interlaced fields per sec, constructed from 60 genuinely progressive frames, converted via CCE and showing as 60 interlaced frames per sec.

Hope this makes sense....

Fishman0919 · 24th April 2005, 16:37

Forum rules

Quote:

12) How NOT to post on this forum:

Do not ask "what's best" because this question cannot be answered objectively. Each and everyone has their own view about what's best in a certain area. The best is what works best for you!

Guest · 24th April 2005, 16:59

That's like saying what is better, film or video? How is it possible to answer that?

You encode based on the nature of your source material. If it's video you would use interlaced encoding; if it's progressive, you don't. Where does "better" come in?

You can take video and deinterlace it to progressive to try to get a "film look". Is that "better". It's all esthetics.

MarkGrigsby · 24th April 2005, 17:23

I'm not sure I agree with what's been said above... Either that, or I don't understand it properly! I totally agree that the question of 'best' is often subjective, but there are also some scientific arguments that hold true. I just thought this might be one of those cases...

Quote:

If it's video you would use interlaced encoding; if it's progressive, you don't.

Well, in this case it IS video, but the framerate of that video is 60 progressive frames per second. This of course is not DVD compliant, so somehow I have to end up with 30 frames per second. What I'm asking is, is there some preferred way to construct those 30 frames? I can either just use half of the 60, or I can make 30 interlaced ones using all of the original 60 (selecting even and odd lines in turn).

I did try it both ways, and the overall 'look' is pretty much the same. That's why I'm asking if there is maybe a scientific reason why one of them should be preferred.

Sorry if I annoyed anyone before - totally not my intention!

PS I edited the title to make it less contentious!!

fccHandler · 24th April 2005, 20:00

Now that you've explained it, that's a really interesting question! I guess it depends on what device you will use to watch the video. On a regular old TV, I imagine the interlaced version might look more natural, because the motion is being updated 60 times per second rather than 30.

I would try encoding some high-motion stuff (sports, for instance) using both methods, and view them on different TVs.

Guest · 25th April 2005, 04:09

Quote:

Originally posted by MarkGrigsby
What I'm asking is, is there some preferred way to construct those 30 frames? I can either just use half of the 60, or I can make 30 interlaced ones using all of the original 60 (selecting even and odd lines in turn).

If you're going to an interlaced display device, which is suggested by you wanting to make a DVD, then your method b will have better temporal resolution, while your method a will have better vertical resolution. I would assume that the preferred choice would depend on the content.

Often, however, people like to get back to progressive frames so they have the option to play them on PC monitors, progressive TVs, etc.

24th April 2005, 13:06	#1 \| Link
MarkGrigsby Registered User Join Date: Jan 2003 Posts: 28	60 frames to 30 - how? I'm hoping some kind expert could maybe answer this for me. Which is 'better': a) 30 progressive frames per sec, converted by CCE to DVD format and therefore showing on TV as 60 interlaced fields per sec b) 60 interlaced fields per sec, constructed from 60 genuinely progressive frames, converted via CCE and showing as 60 interlaced frames per sec. Hope this makes sense.... Last edited by MarkGrigsby; 24th April 2005 at 17:37.

24th April 2005, 20:00	#5 \| Link
fccHandler Registered Jedi Join Date: Jan 2003 Location: Georgia, U.S.A. Posts: 733	Now that you've explained it, that's a really interesting question! I guess it depends on what device you will use to watch the video. On a regular old TV, I imagine the interlaced version might look more natural, because the motion is being updated 60 times per second rather than 30. I would try encoding some high-motion stuff (sports, for instance) using both methods, and view them on different TVs. __________________ May the FOURCC be with you...

24th April 2005, 16:59	#3 \| Link
Guest Guest Join Date: Jan 2002 Posts: 21,901	That's like saying what is better, film or video? How is it possible to answer that? You encode based on the nature of your source material. If it's video you would use interlaced encoding; if it's progressive, you don't. Where does "better" come in? You can take video and deinterlace it to progressive to try to get a "film look". Is that "better". It's all esthetics.