What are the limits of Luma and Chroma for broadcast and smartTV?

[giovannis6224513]

Hi men,

I'm trying to make some video files for smartTV in h264 and h265.

Can someone help me to configure the limits of luma and chroma?

What values ​​do I have to put in video limiter so that the image can be reproduced correctly?

For smartTV, do you have to use the legal limit?

Thank you very much

[R Neil Haugen]

Broadcast is broadcast ... unless you've got an actual HDR b-cast, which is still rather uncommon. I've got a couple things for you to try.

At Adobe MAX, colorist Robbie Carman noted that although the limiter in Resolve is better ... and just well, works period ... they do enough work in PrPro that he's worked that a lot also. (A lot of his stuff is like NPB programs for National Geo, adverts for major networks, nearly all broadcast stuff.)

He gave the setup that he and his minions use in PrPro:

Video Limiter effect, change type of effect to Luma & Chroma, set Luma to 1 and 99 (min/max), Chroma to -5 and 105(min/max).

Jarle Leirpoll, in a post I've seen, gave the following process for a simple 'hard limiter' ...

For now, a black Color Matte with Blend Mode set to Lighten and a white Color Matte set to Darken will clip anything above 100 and below 0. I use this on top of an Adjustment Layer with the Video Limiter as a "hard limiter" thingy.

Legal limit these days is 0-255, except for very few old-style places. Very uncommon.

Neil

[chrisw44157881 · Accepted solution]

for yours, couldn't you make a soft rolloff with curves? that's what I do. its subtle, but noticable.

you can also set levels effect output RGB 204 and transfer mode color to get chroma in limits as well. normalizes to the vectorscope 1st box no matter how much saturation you accidentally use.

premiere pro cc 2015.2 broadcast safe preset

CreativeCOW

[R Neil Haugen]

I've done soft rolloff with curves also. I've had colorists tell me that does not always get all the spiked bits, though. So they typically like a soft-limiter as the first part of a limiter action, then a hard limiter to make sure no 'leakers' get through.

But I think a key here ... is when using the Video Limiter or a Curves effect or something like that, if applied on the clip it needs to be 'below' any other color effects in the ECP. So it's the last thing touching color/brightness.

Neil

[giovannis6224513]

Thanl you, i try it

[giovannis6224513]

Hello neil, can you show mee the link of this post or explain better.

Thank you

[R Neil Haugen]

The video limiter settings that colorist Robbie Carman uses are shown as applied on a clip here ...

The other process ... a bit more work but interesting and Jarle is also experienced at creating deliverables for people with no sense of humor (b-cast station engineers, you see ... ), so it would have to work ...

It's a three-layer stack over your project.

First layer ... an Adjustment layer: New Item icon, select Adjustment Layer ... in the Project panel rename so you know what it is drag it over your clip, from the Effects panel drag the Video Limiter effect onto it, and set for something like .01% and 99.9%.

For the mattes, you use the "new item" icon bottom right of the Project panel, select "Color Matte" ... it pops up a dialog with your sequence frame-size/rate settings, you ok, then a dialog of a color picker. Make this one black ... make sure the selector is all the way upper left corner, and the data in the HSL or RGB stuff is 0-0-0. "Ok", and rename this one Black color matte (so you know what it is) and drag this from your project panel onto your clip. With this matte on the clip and selected in your timeline, go to the Effects Control Panel, Opacity section, set Blend Mode option to Lighten.

Make another Color Matte, drag the picker all the way to bottom right corner for white, make sure the HSL is showing 0-0-100 and RGB is 255-255-255. Rename this one to know what it is, drag atop the stack of layers on the timeline, go to ECP, and with this matte selected, in Opacity options, set blend mode to Darken.

This is a way of assuring that no stray pixels pop out from the Video Limiter, as with just the VL, you can at times get a leaker pixel ... with the two color mattes added, you won't.

Neil

[giovannis6224513]

I hope Adobe oferte a good and segure solution at this problem early ...

LIKE THAT I HAVE HEARD THERE OTHER VIDEO EDITORS HAVE EASY TO CHECK THAT ....

[R Neil Haugen]

Put in the ol' feature request form ... these get distributed to all managerial types. While the above offered suggestions work for nearly all things, they're not as slick as a really good video limiter.

Neil

https://www.adobe.com/cfusion/mmform/index.cfm?name=wishform

[Jim_Simon]

I've honestly never worried about it for TV playback.  I don't think it's really necessary.

[R Neil Haugen]

True. And much of my work isn't for commercial b-cast either. But some ... needs to be within specs. At that point, knowing how is rather necessary.

Neil

[Jim_Simon]

I think it's only "necessary" if the project needs it.  Mine never do.

"Helpful" to know, I might agree with.  "Can't hurt" to know, definitely agree.