DNXHD Waveform Lumetri Scope missing data

Report · Mar 29, 2018

Hello,

I am looking into purchasing a field monitor that records via SDI out on my camera in 10 bit to DNXHD format. Upon doing some tests and transcoding my mp4 file to DNXHD the DNXHD files have missing data in the Waveform Scopes in Premeire Pro CC 2018. Example is the blacks in the DNXHD clip are at level 20 while the native mp4 clip is showing a black level of 10. I'm fearful if I buy a field monitor it will record via SDI output and have wrong Waveform data. Anyway to resolve this issue if the built in format from the field monitor does this? Maybe it's just a transcoding error and not an actual recording error.

the field monitor also allows for ProRes which I want to avoid since I'm on a Windows PC.

Report · Mar 29, 2018

I'm not sure I'm following your comments.

So ... it seems you transcoded a file in maybe Media Encoder or something from mp4 to some flavor of DNxHD/R, and then viewing that file in PrPro, the black-point of the DNxHD/R transcode was around 20 rather than the 10 of the mp4? In other words, the file has a higher black-point but all the data is there?

Or are you saying you transcoded, and the mp4 file had an uneven, clearly un-clipped bottom edge around 10, and after transcoding the output DNxHD/R file had a clearly shown harsh-line hard-clip at 20?

Screen grabs of this would be helpful, and also your transcode/export setting that created the DNxHD/R file. When I transcode into DNxHD/R, I don't ever see changes like this.

Neil

Report · Mar 29, 2018

hmmm. What I mean is the data changed. I know I said missing but that was the wrong word. The original .mp4 file shows a black shirt at 10 but transcoded using the DNX HQ 1080p 29.97 built in setting in media encoder shows the black shirt at 20. It's definitely the shirt because I have cropped in on the shirt on the same portion on both the native and transcoded clip.

Also someone told me in person to never color correct native footage as it messes up banding but I have never seen banding with native footage. Even when I transcoded to cineform I see no banding either when I change the color.

Premiere isn't changing the file it's just a reference to itself.

Report · Mar 29, 2018

I'd love a bit of this media to test. Original and transcoded, a second each would be fine ...

Neil

Report · Mar 29, 2018

well this is weird. I also have a section of my timeline I transcoded to cineform and if I turn the exposure all the way up the waveform monitor does not go above 100. Clamp is turned off and I'm on float. However the same media which is in .mts goes above 100 IRE with the waveform monitor when I'm halfway up on the exposure in the lumetri color panel. Why does Cineform refuse to go above 100 IRE?

Report · Mar 29, 2018

Lumetri is designed to keep you from hurting yourself or any pixels. In fact.

Many of us have asked for the ability to turn off the protective feature. We don't have it yet, however.

Neil

Report · Mar 29, 2018

Why does Cineform refuse to go above 100 IRE?

If I had to guess, I'd say that Cineform is in Full range (0-255), and the .mts file is in Video range (16-235).

Report · Mar 29, 2018

Is there a way to change the range display on my lumetri scopes?

Report · Mar 29, 2018

No. And it wouldn't really make any difference, as it isn't a limit on the scopes, it's a limit on Lumetri. If you have media with a wider data range, the scopes will show it. Even up through fairly wide HDR ... though you can't really set the scopes to HDR and work with regular media.

As noted in my post above, Lumetri is designed to only work within 0-100 on the left side scale. For the first couple iterations if your media had signal outside that, you had to use an effect prior to Lumetri in the ECP in order to get the signal within "bounds" so you could work it. Any controls in Lumetri just left that data sitting out there. You could get really bizarre effects that way! Bring your white point down to say 85 ... except, there's all those pixels still showing in the scopes and in the program monitor between 100-105. That ... was a mess.

So now, we can at least bring the signal back inside 0-100, but we cannot push it outside those bounds.

I've argued with the engineers at the last four NABs about this, and will again this time. The concern is that some of their users will "break" the media, so this is a 'safe' thing to do. Well, any other program I'd use allows me to do with it what I want to do with it. And I'd prefer that ability here also.

Neil

Report · Mar 29, 2018

Funny you should say that. As I moved the white slider up and not down all of the sudden the waveform started to go above 100 IRE. also it seems if I roll of the highlights in the curve section the waveform acts normal. Weird

Report · Mar 29, 2018

You moved data above 100 in Lumetri? Can we see a screen-grab of that, it's ... a miracle!

Yea, there's some weird things in how things respond to different controls, but my ... if you've got plus-100 action, I'm jealous!

Neil

Report · Mar 29, 2018

Report · Mar 30, 2018

I've argued with the engineers at the last four NABs about this... The concern is that some of their users will "break" the media

Further evidence that Premiere Pro has turned away from the Pro's.

I'm not a fan of this new direction. First we get Al Mooney turning Premiere Pro into Final Cut Pro, now this new guy is turning it into Premiere Hobbyist.

Frustrating.

Report · Mar 30, 2018

if you get the false color plugin it shows you all the data levels that don't show up on the waveform. I have it and it shows you all the blown spots. atomas setting in the false color plugin is the monitor setting on my field monitor. It's a little confusing at first because the false color plugin changes the waveform in the scopes but what it really does it show you 0-100. Once you get the false color the way you want turn off the false color and the waveform matches what you just saw in the false color.

Report · Mar 30, 2018

Patrick isn't the one who decided we shouldn't 'break' our media ... that was the old guy, Al.

Patrick took over during the time of NAB last year, with most everything up to that point, and realistically for a few months thereafter, already set on the path of the previous head. Considering that Patrick was one of the creators of a then revolutionary (and very pro level) grading apps ... I'm interested to see what he comes out with. Looking forward to what's shown at NAB.

Neil

Report · Mar 30, 2018

Well, perhaps there is hope for Adobe yet.

Report · Mar 30, 2018

I can never puzzle out the internal Adobe management planning ... and it certainly isn't shared with us peons! ... but at times, there are these glimmers of hope ...

Neil

Report · Mar 30, 2018

can you elaborate? are you talking about premiere's scopes or not at all in this post?

"turn off the false color and the waveform matches what you just saw in the false color."

Report · Mar 30, 2018

there is a plugin to display IRE levels in false color mode. Pink for example is 60IRE It shows colors over the image and the different colors represent IRE values. Field Monitors have this. Here is the plug in I bought for Premiere. https://timeinpixels.com/false-color-plugin/