FCP broadcast safe not working.

[Colin Tse]

The super black only on parade, not on luma waveform.

[Michael Gissing]

Then you shouldn’t get pinged by a broadcast tech check. I think the parade display is before broadcast limiting of blacks. I have seen sub black in parade before but not on final luma output.

[Colin Tse]

The sub black also on output when checking on an external tektronix WFM.

[Colin Tse]

Very much appreciate all the good thoughts and input.

I couldn’t find a good way to eliminate the sub black so guess just stick into “Animation” codec by now. Will do more experiment and research to see if better achievement can be made.

Thanks

[Rafael Amador]

The Animation codec will do it because is 8bRGB and will clip below bit 16 and over b239, but may cause few color issues.

For me this sounds to some kind of FC misfunction.
I would trash the “Constant Frame” folder and the “Waveform cache” files, and refresh FC Preferences and repair Permissions.
As I mentioned on my system the “RGB Limit” works perfectly.
rafael

http://www.nagavideo.com

[Colin Tse]

Thanks Rafael and I’ll try your suggestion and see if it gives any better result.

However I’ve tried three FCP stations with same configuration and hardware spec, all have the same result. Could this possibly be any config or hardware related issue?

[Colin Tse]

I did the trial and it looks the same. However I discovered that the color is perfectly legal in RGB space, however bleach out in YUV space. May be this is the reason why RGB limit not works since it clips all illegal color only according to RGB color space.

The trouble is I need to make the video also legal within YUV space for broadcast.

[Rafael Amador]

[Colin Tse] ” I discovered that the color is perfectly legal in RGB space, however bleach out in YUV space.”
I think your picture may have some very shiny and saturated areas.
I don’t know the picture you are working with, but for what you say, I think you need to make a proper Color Correction before trying to legalize it.
Broadcast safe is OK to get rid of some peaks that pass the levels after CC, but if your picture is very out of range and you just clip things, the picture can look very bad.
You need to correct first Luma and Saturation and you may need to make some secondary CC, otherwise if you just drop an RGB Limit filter, color may just disappear from bright saturated areas.
rafael

http://www.nagavideo.com

[Colin Tse]

Very much appreciate for your help Rafael. I starts to suspect if the video itself has some strange color coding.

The picture originally looking like this:

and the RGB parade like this (1):

When I switch the seq codec to animation, the RGB parade looks like this (2):

The strange thing is, if I have the seq codec as ProRes422 (HQ), the parade looks like (1). However if change any parameter in the scope display (e.g. from parade to waveform back to parade, or change the current frame to previous then back to current, or scope display to “All Lines” or other), the parade looks just as good as (2)! But once I move to another frame, the parade back to the bad one (1).

Any change in scope display makes the parade look good and any move on timeline makes it look bad.

I guess I may have to go back to original animator for primary color grading as suggested, but curious why I couldn’t eliminate the underblack by all means within FCP. The best I can do is to raise up the black level, making everything greyish.

Thanks very much for your kind assistance.

[Rafael Amador]

I don’t see nothing wrong on your original picture. Nothing too bright or too saturated.
BUT for the two gray bands that I see in the Parade snapshots (up and down), I can see that you have set “Render always in 8b RGB” in your Sequence settings.
Set “Render in high Precision YUV” in your Prores sequence. Don’t use the Animation codec.

What I can see as well is that the original picture has a 1 pixel wide frame all around the image. Is almost black but has different tonalities (it can be just because the Aperture). This might be causing the super-blacks. You can see that with the Digital Color meter (utilities).
Another thing is that the blacks are too high, so blacks are no real blacks (like the guy head). But this can be a designer decision.

So try what I told you with Prores HQ and “Render in high Precision YUV”. Then drop the RGB Limit filter on top to clip the super-blacks. I don’t think you have any super-white.
rafael

http://www.nagavideo.com