DVD frames i or p ... still dont get it

J

Johny-115

Member
Here is my situation ... i have Canon HF100 ... so source is 1080@50i
and iam confused how to output it to get best result on dvd-video

on my PC, LCD TV .... 25p looks good and fluid (film-like), 50i looks too alive ... in case of pc it deinterlaces by making it 50p, and i suspect my LCD TV do do the same, it just looks ridiculously fluid, and that looks bad ... like home video

on old TV (i think) ... 25p stutters, and 50i looks normal i guess

so iam after this normal 25fps look ... not ridiculously fluid ... so iam thinking whether should i even render backups also to 50i ...

so i thought about this:
i read movies are 24p and re-interlaced for dvds .... so if iam right ??? 50i has in fact some extra movement information (i mean i can convert it to fluid 50p) in contrast of deinterlaced version 25p (i cant convert 25p to fluid 50p) .... so what if i did it same way as movies are done ... what if i exported my 50i footage to 25p video file ... and then re-interlaced it back to 50i (just for dvd, of course i will keep my 25p files as main ones)

i mean by that ... 25p>50i cant possibly reconstruct this extra fluidness ... so even having player deinterlacing it 50i>50p for playback ... it should still look like 25p right ? or not ?
 
i compared now interlaced encoded and progressive encoded dvd on my computer and then LCD TV

progressive: looks very good on PC (no artefacts), on tv it looks bit like interlaced (some lines artefacts)
interlaced: not so good on PC, looks like some deinterlace is going on (some artefacts), on tv interlace lines are visible (wtf)

i noticed mediainfo application reads dvd as progressive but there was stll part field order and it sed top field first .... is it possible nero encoded dvd as progressive but somehow gives tv dvd players info to read it as interlaced .. and is it possible for dvd player to somehow play progressive mpeg2 as interlaced ?
 
You seem to be considering your options purely on *preference* here, but at the same time aren't considering the reality of what interlace vs. progressive gives you.

On an LCD Television, interlaced video is usually handled "properly" (The quality depends on the set), via hardware deinterlacers, which bring it to a progressive framerate. The key to these deinterlacers though, is that they also preserve the fluidity of 50i by deinterlacing it to 50p, NOT 25p. The display is still progressive, but has additional hardware to convert interlaced video on-the-fly (Note: the exception usually being when the TV is used as a monitor)

On an LCD Monitor, interlaced video is not handled at all - the monitors are progressive, and lack any internal hardware to perform deinterlacing. They WILL present interlace artifacts ("combing"), unless handled by other hardware (a video card), or software. NLE programs usually deinterlace for preview purposes, but this is done, as I said, in software.

On a CRT Monitor, interlaced video is also not handled at all. CRT Computer monitors are progressive, and as such, do not natively handle interlaced video; the same rules from above apply.

On a CRT Television, interlaced video is natively handled; no processing is necessary, because the TV is essentially designed to handle it (or historically, the video was tailored to fit the TV).

Your first post questions the hyper-fluidity of the camera's native 50i. This is just how it is, unless you want to discard frames (and turn it into 25p). You will naturally sacrifice smoothness in the process. You're absolutely right about not being able to turn 25p back into smooth 50i, once you deinterlace, you lose the information, but it's important to understand the difference between pure interlacing, and telecined film. Pure interlaced video (50i or 60i) has that hyper fluid look you're describing; of course, it's intended for interlaced display devices, but it's essentially the same motion as 50p, but the key difference is that pure interlaced video has no whole frames; every frame is only a field, which blends in with the next frame (which itself is also only a field).

Telecined film on the other hand, is not interlaced the same way. Telecine is also not even performed for fluidity reasons - it's performed in order to match the native 29.97fps rate on NTSC televisions. For telecined film, the motion essentially remains the same (there's more stutter afterward actually), but for every three progressive frames, there are two interlaced frames, hence the frequently used term, 3:2 Pulldown. There are hundreds of websites describing the telecine process, but you shouldn't have to worry about it. Bottom line is, it's not a method of preserving motion, it's a method of matching framerates.

My ultimate suggestion is to just leave it at 50i...
 
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