Track Fade to Color Bug.

farss wrote on 11/5/2003, 1:41 AM
I create a simple text title, set background to legal black and text color to legal white. Scopes report all is legal. Add one second fade in and out. Scopes report fade is to illegal black levels (0:0:0 or superblack).

Fine, change track fade to color to 16:16:16, makes no difference.
Apply Broadcast Colors filter to bus, makes no difference, still fade out to illegal color.

Insert another video track below with legal black in it problem fixed?

Now maybe I'm being a bit anal, I have a very dodgy monitor and these black levels are enough to throw it out of sync. None the less it's allowed to do that as I'm sending it illegal signals.

This is a fairly serious issue. I can fix it easily. I know a few of us are assuming that applying a Boadcast Colors filter will keep us legal, it would seem not so.

Maybe I'm misunderstanding how setting fades in and out work, I guess as they set composite level and underneath them is nothing but superblack then this makes sense, probably if I'd used a fade envelope results would have been better. Still cannot see why Broadcast Colors didn't fix it up.

Either way this is a significant trap

Comments

farss wrote on 11/5/2003, 7:21 AM
Bump,
I'm a bit surprised no one has picked this up. Either this is a bug or I'd bet a lot of us don't care or don't realise quite what we may be doing wrong.

Of course you may all know about it and I'm an idiot for not knowing in which case my humble apologies.
SonyEPM wrote on 11/5/2003, 8:43 AM
3 questions:

What system are you targeting (PAL? NTSC?)

Where are you applying the broadcast colors filter (media/event/track/output)?

What preset are you using?
farss wrote on 11/5/2003, 2:17 PM
SonyEPM,
Target is PAL.
Tried applying broadcast colors to track and video bus usining lenient preset.
It looks like the broadcast colors fx works fine correcting the portion of the title without the fades but the first and last sets of frames where it's faded down the levels drop to 0.

Placing black at 16:16:16 underneath the track fixes the problem.

Hope this gives you enough info to reproduce problem.


Bob Grant
farssAToptusnetDOTcomDOTau
TheHappyFriar wrote on 11/5/2003, 3:46 PM
I've reproduced it. I even tried the same thing in Premiere 6, and it doesn't give illegal black. But, premiere 6 gives you no option to use true black: It converts ALL black to legal.


farss have you had problems with illegal black? I've used Vegas for stuff in broadcast (with fades to black) and haven't had any problems.
farss wrote on 11/5/2003, 3:59 PM
I've got a really cheap TV that I use as a monitor and illegal black levelscan make it go real wobbly. Problem with too low black levels is the analogue values fall into the same region as the sync pulses, not good when it goes to transmission. You also get problems with hot whites, pushes the transmitter to have video that overlaps the audio causing nasty buzzes on reception, I'm sure you've heard that happen.

It really depends on the station, they've probably got a realtime legalizer so its not an issue. However our national broadcaster tech checks everything that comes in and they are real video nazis. Anything outside spec is just return to sender. A lot of indie film makers loose out because of this, even a lot of places that should know better fall into this trap.

That's the reason I keep waving my hands about these kind of issues. Even stuff coming straight out of some cameras is not legal, makes the images look a bit better, ie easier to sell the camera but....
SonyEPM wrote on 11/6/2003, 10:17 AM
There's no single black value that is right for all delivery scenarios, we do allow you to switch project formats at any time, and filters don't affect non-event areas of the timeline, so...

Your best bet is to create a video track at the bottom of all the other video tracks, and put a black solid color generator on that track at the level you need (you are doing this I think). You can use the broadcast colors filter on this track as well, your choice.
hugoharris wrote on 11/6/2003, 10:42 AM
Just so I have this straight - suppose I have a project with a single video track, and I fade out using an opacity curve at the end of the project (to black, because there are no tracks underneath). Even if I apply the broadcast colours filter to the master video bus, it will not catch the illegal black at the end (where there is no event)? I imagine I could insert a solid black event on a lower track that just covers the duration of the opacity change, yes?

Am I understanding this correctly?

Kevin.
Ron Lucas wrote on 11/6/2003, 2:18 PM
Good question, I would have thought the broadcast colors filter on the master video bus would catch this even without any events.

Ron
farss wrote on 11/7/2003, 4:32 AM
From my experience even applying the Broadcast Colors fx on the master video bus does NOT catch this problem. I first noticed it with an opening title, 1 sec fae up from black, 3 secs of title, 1 sec fade down, start video. The title uses legl white and legal black. The fades up and down fade to superblack which is illegal on a video signal.

Applying the fx to the bus corrects all video apart from this which seems strange.

The fix as EPM suggested (and as I am doing already) is to have an underlying track of 'safe' black. Of course at any point in your video if you fade to 0% you're expose the 'nothing' undrneath which is superblack so I guess you need to have a track underneath the whole timeline with safe black in it. Not really a big deal once you know. Really a worry though that you could easily think you've done the right thing applying the BC fx to the bus and you're still not legal.

It makes me wonder how many of us are sending out video that's not technically correct, maybe it's not a big deal, maybe I'm being anal about this kind of thing. Certainly EPM is correct that depending on what you are distributing for makes a difference in how significant these issues are and you can easily run into technical minefields.