FCP broadcast safe not working.

[Colin Tse]

Thank you Rafael and frankly I learn so much from you.

I have my sequence set as ProRes422 HQ, render in high precision YUV, have cropped 1% of all edges, dropped in “RGB Limit” and “Broadcast Safe”, and under black still persist.

With curiosity I tried to crop further on the image and found that the under black have gone away when all black portion are cropped.

Further study I tried scaling up the picture and discovered that the underblack gradually raise up back to legal when I scale it heavily up say 300%. Sorry for my dumb would this because I blow the video signal up thus reducing the noise in the black?

I try to upload a sample of 1 sec and hope this can help the analysis.

[Colin Tse]

Sorry miss-press the button before I say thank you. By all means I don’t just look for a solution but also want to unveil the mysterious cause to enrich myself.

Much appreciated.

https://reels.creativecow.net/film/sample-for-underblack-video

[Rafael Amador]

Sorry, but I can’t do nothing with the clip you uploaded. I can’t download it. and even if I could, the clip will be Broadcast Safe if has been converted to h264 with QT. All the illegal values are clipped on compression.

[Colin Tse] ” Eventually, the only codec that can reserve most of the visual quality and can clip out the underblack after export is “Animation”.”
Answering to this: This is normal. When you set Animation as the sequence codec, FC forces render in 8b RGB. There there blacks are mapped to 0% (bit 0) and whites to 100% (bit 256). No room for under-blacks or super-whites. Under-blacks and supper-whites happens in YUV.

Questions:
– Which application is the cartoon coming from?
– Are they coming from AfterEffects?
If so, there is no way that there are under-blacks. AE clips everything under 0% and over100%.
– Which is the original codec of the animation?

[Colin Tse] “With curiosity I tried to crop further on the image and found that the under black have gone away when all black portion are cropped.”
As I mentioned, the issue may come from the “Aperture”: the way that QT present or open movies.
Another thing that could be causing troubles, is if the clip has been exported with an Alpha channel.

Can you send me “1 frame’ of the original footage?
Do like that:
– Open a clip in QT Player and put the play head wherever you want.
– Hit “I”, then hit “O”.
– Copy (Cmd-C).
– Open a new window (Cmd-N) and paste (Cmd-V).
You will have movie with just one frame. Then “Save as..”.
Save the new clip as self contained.
You can zip it and send it to me to nagavision at nagavideo dot com.
rafael

http://www.nagavideo.com

[Colin Tse]

Thanks Rafael I learn so much from you!

The original footage was created from Flash by an animation house , so difficult to go back and change the color. (Not sure what gadget they used by don’t think its AE). Then converted to “Animation” mov wrapped for FCP edit.

1 frame sample file has been created as instructed and sent to you through email.

Very much appreciate for your help!!

Colin

[Rafael Amador]

Hi Colin,
The first I have to tell you is that I know almost nothing about cartoons.
I see two issues with the picture:
– First the blacks and whites. That’s easy to appreciate as soon as you have a look to the scope. Blacks are too high (3%)and Whites are too low (90%). I don’t know if this is intentioned, but I don’t think so.
This can be due to the conversion RGB to YUV. If’ve saw different applications behaving in many different ways depending of the codecs they were dealing with.

– Second is that there is something wrong with most of the black line that conform the profile (outline) of the characters. The thin almost black line that separate them from the background, and most of all in the areas where the line is almost vertical, there are some pixels where the BLUE channel is screwed. There is no Blue information at all. Even rising the Saturation with the 3W-CC, the Blue channel value keeps = 0. and I’m almost sure that’s the origin of the noise we see as underblacks.

Is not difficult to detect it: Open the picture in the canvas at 100%, and with the Digital Color Meter (Utilities) set with “1 pixel aperture”, pass it very slowly by those borders. You will notice that before the picker reaching the inner Black area (R=G=B= 3.1), many times the Blue value is = 0.
And if you upscale the picture and you look at the FCs Parade you can easily tell that most illegal Blue values (underblues) are concentrated on those “borders” lines.
No idea about the reason of those pixels.

How to fix it?
If you just want to get rid of the under-blacks, running the movie through compressor with the “Broadcast Safe” ON, will do it. also, just running the clip through AE, should get rid of any illegal RGB value.
If you want to fix the movie, you have to fix two things:
– Levels: Rise the whites and crunch the Blacks.
– Fix the noise; There is noise on the Chroma channels on the lows. You will get rid of a lot of that by crunching the Blacks, and will help you also the “Desaturate Lows” filter (Set it; “Apply Below 5 or even below 10. Those color shouldn’t really have chroma. Softness: 5 to 10). This will clean all that spill on the underblacks.
I’ve also tried with the best denoiser available for FC (Neat-video) which is able to clean the noise on the Chroma channels, and also makes disappear all the spill on the underblacks.

I can see some times a single point on the under-blues. This shows up whenever I tweak some filters, but always disappear when I open a new Scope window. At this point, I’m not sure if that can be just a problem with the very scope.
I’ve done all the tests on a ProresHQ sequence and as you know, with just a single frame.
My opinion is that the reason of those issues may be the inconsistent conversion of the footage (color spaces, codecs, platform (?)), with no color managing.
rafael

http://www.nagavideo.com

[Colin Tse]

Thank you Rafael, you’ve done so much that I really appreciate and also real sorry to keep troubling you.

I’ve done the same and yes I can find the thin edge that may be the trouble source. The underwhite and overblack are the poor color correction from the offline editor which can be easily fixed. Our concentration is how to eliminate the illegal black (underblack).

I tried to replicate the same as you suggested but have some troubles:

1. I cannot find an option in Compressor to check broadcast safe on.

2. Applied all filters as suggested (even to a higher extend) can eliminate some underblack, but majority of them still persist. (As snapshot)

I don’t know if there is any wrong setting incorporated in my FCP machine that has different outcome from your test. Will go back and check again.

Also I will try to ask how the animation house create the file so to determine how these troublesome black thin lines are generated.

Thanks

Colin

[Rafael Amador]

[Colin Tse] “1. I cannot find an option in Compressor to check broadcast safe on.”
Sorry,
I meant Color, no Compressor.

I’ve rendered the file in Color with the “Broadcast Safe” filter ON and also in AE.
Imported back to FC, both files keep showing that spills on the underblacks.
In years I’ve never heard a single complain about legalizing with Color.
In the other hand, getting off-levels in AE is technically impossible, so the only conclusion I can reach is that FCs scope is faulty.
Rafael

http://www.nagavideo.com

[Colin Tse]

Very lovely. Thanks Rafael.