Rendering 60i to 24P, 8-bit, 32-bit

i6pwr wrote on 6/12/2011, 8:53 PM
I've been doing some trial and error, rendering some HD footage from my XR500V to 24P.....using both 8-bit and 32-bit floating point.

Could be me, but I could see a difference with the 32-bit full range over the 8-bit in the shadow detail. Again, difference was subtle but I thought it was noticeable.

I tried numerous renders, clip was 1 minute in length...definately adds to the render time using 32-bit. Went from almost normal speed to 5-10 frames/sec, never crashed, but I don't mind long render times if the final project is noticeably better.

A few questions I have are:

1) Using an 8-bit camera, I believe mine is, saving onto a DVD or BD, with render time set aside...will 32-bit full range yield a better final result? I understand the 32-bit helps in the FX, but am I seeing things with the shadow detail being better? Also note, I did change the gamma to "Video" or 2.222.

2) Rendering to 24P....the custom tab when going to render the file, has a few options for framerate. The source is 1920x1080 60i, I would like to render as 24P. Without burning a disc and only viewing on my monitor from the HD, I can see a noticeable improvement when rendered in 24P than 23.976, with or without pulldown, when viewing the panning movements. Question is, if I use 24P, does my set or dvd player change it back to 23.976?

Should I use 23.976, 23.976+ 2-3 Pulldown, or 24? Which ones can't be used or will have no effect?

3) Does it make a difference (the framerate) if it's viewed from my PC onto an external monitor or my own, or from a disc, DVD-R or BD? Do the players only recognize one or the other?

It seems my rig is stable rendering using 32-bit Full, if it's just too much "useless" info for vegas and only hogs CPU, then naturally 8-bit is fine. I can only imagine 32-bit with multiple effects how long a 30 min render could be but not at that bridge yet.

Basically i'm after the smoothest, highest PQ, film-like render in 24P that I can achieve, from 60i footage..without using a dedicated 24P cam.

4) When I render HDV it seems to max at 1440 and not 1920, I assume I need to render to Blu-Ray for the 1920 Res?

5) Will changing the PQ slider from default 15 up to max change anything? I didn't seem to notice, if it does, what exactly does it target?

I did read the articles by Glenn Chan and Karl Soule as well...did clear some things up.

I'm sure I have more questions but i'll hear what you have to say for now.


craftech wrote on 6/13/2011, 5:09 AM
In general, less compression when rendering = more shadow detail because the blacks don't get crushed as much. When you shoot, if you can increase the black gamma setting in the camera that will also help a lot.

kairosmatt wrote on 6/13/2011, 7:07 AM
Since you are starting out at 29.97 it will probably be best to stick to 23.976 rather than 24 full frames per second. The computer should play it back fine, and it is a standard for TV/DVD, and it makes the math and processing simpler.

In my experience if you want to edit 24p and output 24p you should have all your material in 24p (24p=23.976). So convert before you edit. DVFilmaker does an amazing job of this, but its a 3rd party tool ($) and it takes a loooooooong time.
Cineform can do a reverse pulldown removal (even though you don't have pulldown) when converting and this can actually work well in a pinch to get that 24 motion.

Vegas can do it too, but you want to be careful. If you want to get the film like cadence, then Vegas has to combine fields into single frames and drop every 4th one to achieve this motion, but you HAVE to disable resample on every single event. Otherwise it will be doing some kind of blending and you won't get the results you are looking for.

DVD players remove the pulldown automatically. I always render to 23.976+pulldown for DVD, and just regular 23.976 for computers.

i6pwr wrote on 6/13/2011, 6:38 PM
I re-rendered a rew clips and when disabling the resample, it was much faster to render...however when I viewed the clip on my monitor, the pans were jerky and with the resample on, the pans were smooth.

Would this show on the final burn or just on the monitor?

When would you select 24 over 23.976? With or without pulldown.
musicvid10 wrote on 6/13/2011, 9:25 PM
If you want 24p, you should shoot 24p.
If you shoot 8-bit, you should edit with 8-bit.
The quality slider targets motion estimation. In most cases imperceptibly.

Less is more.
kairosmatt wrote on 6/14/2011, 4:51 AM
Definitely what musicvid said about shooting 24p to start with.

But you can still get useable results by converting 60i.

Pans are going to seem jerky in 24p. Unless they are super slow or whip pans. That's just the nature of it. When you don't disable resample, Vegas is blending frames so it helps smooth out the jerkiness, and that's fine if that's the feeling you want to go with. But in that case it may be better to stay in 60i, or if its for a computer, de-interlace to 30p.

Pulldown is for incorporating 24p into a 60i signal. You don't need it if you are staying on a computer.

i6pwr wrote on 6/14/2011, 8:19 PM
Well, one major issue is that I don't have a 24P cam....yet. :) Basically just experimenting in hopes to find the correct formula to make it work as best as I can hope for.

You are kinda losing me on the resample..if enabled smoothes some of the jerkiness, would that not be adventageous or does it take away fom the fluidity in another form?

I'm absorbing all this as much as I can, I definately have an understanding of what's going on, just trying to figure out all the settings. Kinda like sitting down in front of a mixer board for the first time, intimidating I guess but doable.

What about rendering 60i to 60P, then back to 24P? Would this be a waste of time or do nothing for my cause?

What about the 23.976 over 24P, why are there both of these?
musicvid10 wrote on 6/14/2011, 9:08 PM
"Well, one major issue is that I don't have a 24P cam....yet. :)"

I'm wondering what your preoccupation with 24p is?
Your 60i will look much better at its native frame rate or 30p than by cutting or blending frames to make it 24p. Is it a nostalgia look you're after?

What is commonly called "24p" (23.976 IVTC) is already becoming a legacy format (a bit like cassette audio), with major film producers already going for 48p and 60p for feature productions. Higher frame rates simply look better.
farss wrote on 6/14/2011, 9:25 PM
"What about the 23.976 over 24P, why are there both of these"

Film, the stuff made of plastic, is shot at 24.000 frames per second.
When it is broadcast in NTSC land it is run at 23.976 fps, in PAL land it is run at 25 fps. Visually pretty well no one will notice the difference but it can cause major technical problems with audio sync if a production gets those numbers mixed up.

The video equivalent of film is shot at 23.976 although some video cameras will run at 24.000 fps.

The reason why there are two numbers that can cause so much grief is purely technical. Even "30p" isn't 30.000 fps.

kairosmatt wrote on 6/15/2011, 9:35 AM
If you are still hellbent on 24p from 60i and your pans are too juddery for your taste, you could de-interlace, turn of resample, and set playback rate to 0.8. You will not lose any frames and it will playback a little slower and potentially smoother.

As for the quality of 24p, I much prefer this to higher framerates like 60p. Just my thing, I don't think you can say 48 and 60 are 'superior.' Just different. And honestly, its such a small part of the overall picture.

(yes, I have read what James Cameron and Peter Jackson are up to-will wait to see how it looks)

i6pwr wrote on 6/15/2011, 8:10 PM
"Film, the stuff made of plastic"....nice one, needed the chuckle. :)

I understand the part of broadcasting at 23.976, and shooting at 24P, what I was curious is why vegas has an option to render in 23.976 as well as 24P.

Under the "Custom" tab, there is a "Framerate" drop down and listed in the box are, (in conjunction with others) 23.976, 23.976 + 4-3 pulldown, 24.000, 25.000 etc.

If i'm rendering 60i footage to 24P, based on what you're saying...makes no difference if I choose 23.976 over 24.0. Of course if I need to add pulldown then that's obvious but for anything else, it's being viewed from a DVD player at 23.976.

Not all of my footage is in line to be rendered at 24P, just some of it I guess i'm after that "24P look" for lack of better terms. If I can't get it to work to my satisfaction then I will surely render at a higher framerate....just experimenting right now, not hellbent, just experimenting.