Vegas video levels - debate possible changes

NormanPCN wrote on 4/24/2014, 10:41 PM
Some SCS types have said they like reading about workflow topics and changes in these forums. I am starting this thread as just such a topic.

Vegas is fundamentally full range. Most all video, at least what I do, wants video levels. This means were as users have work to do to get video levels.

There is a common host of cameras out there outputting full range video. My Canon DSLR and GoPro for example. The AVC video stream actually has an optional flag to tell a decoder that the stream contains full range data. A lot of DSLRs and GoPros out there.

I cannot count how many times, I and others have posted answers to someone complaining about crushed blacks on file encodes. Almost to exclusion this comes from people using full range cameras. Vegas gets a bit of a black eye from this. People do not expect levels to change when they do not do anything in their edits.

Fade to black/nothing in Vegas is fundamentally 0,0,0 and there is nothing Levels fx or broadcast colors fx can do about this. One has to put a solid color track with legal black under all others. At a minimum even if a proposal like this is rejected Vegas should lets us declare in a project setting what the nothing black level should be.

The vegas video preview window is fundamentally full range and absolutely cannot display video levels properly. We have to add a levels effect and remember to take it off when rendering. The external preview device does have to ability to adjust. Why the preview window does not get the same option is beyond me. Especially as it is by definition on a computer display, which are always full range.

My Proposal:
Preview devices declare themselves as full range or video levels devices. Both the preview window and external preview device.

Project properties declares itself as full range or video levels. Note that 32-bit float levels already have something similar to this. If a project is video levels then fade to black/nothing will be a legal video level.

Render As templates, declare themselves as video levels or full range. The default for templates would be "same as project setting".

With this information Vegas now has all the info it needs to properly display full range or video levels data streams on full range or video levels device. It knows what adjustment needs to be done, it any. For example, a video levels project displaying on a video levels device needs no adjustment. Maybe a warning needs to be given when attempting to display full range on a video levels device. Only because data is being compressed. Other other direction I feel is not an issue. Expansion is going from less to more levels. Obviously "perfect" is the playback device uses the same levels are your video stream.

Render As can also make an adjustment as necessary. With the default I propose, nothing would ever happen here. However, I would suggest that "Internet" templates default to video levels and not to "same as project". We all know Youtube/Vimeo/Smugmug expect video levels.

Vegas has a long history of working a certain way and the existing user base is used to this. A lot of people don't like change. These proposed changes can easily default to the status quo of current Vegas. All items would default to declaring themselves as full range. With this Vegas never makes adjustments at any time and you make all adjustments manually as we do now.

New feature support/capability for declared full range cameras
With AVC streams that have the full range flag. Vegas can help users here. When importing into a video levels project, vegas can prompt it the user wants the data converted to video levels. No behind the scenes function should occur here (ie no user control). The prompt would simply add a levels effect as a media effect if the user selects to have the data normalized to video levels. That effect can be taken off should the user later decide that would be preferred.

Effects on current plug-ins
What should Media generators do in video levels projects. Currently all media generators default to color values outside the legal video levels range. In a declared video levels project they should probably be clamped to legal levels probably like the Broadcast colors effect does.


Marco. wrote on 4/25/2014, 4:23 AM
I second any desired added option if not the current mode is cut away.
farss wrote on 4/25/2014, 5:32 AM
I'd suggest reading documents such as this. I believe the latest couple of versions of Vegas support an ACES pipeline, no need to reinvent the wheel especially when an army of very capable people including Sony have worked on this wheel for several years.

I haven't looked at the ACES pipeline implementation in Vegas. How well it enables us to declare video from all the cameras we've used and will continue to use is a question I cannot answer. I fear SCS's implementation will be half baked but unless we embrace what they've already spent our money on and press them to make it a workable solution it'll remain as nothing more than a tick on the box.

paul_w wrote on 4/25/2014, 6:49 AM
This has been an ongoing discussion on this forum for years. And SCS are not taking a blind bit of notice. Its a serious issue that i and many others have had with Vegas for years.

Really simple: Give us proper VIDEO 16-235 levels at preview (including the internal preview monitor) and while rendering out. Never give us 0-15 illegal blacks or 236-255 super whites. Both will be rejected by a station, never mind looking crushed on playback. I wrote a plugin to do hard clamping 16-235 for this exact reason. Works perfectly and could so easily be part of Vegas internals. You do still have to adjust camera levels on the timeline, but you pretty much have to do this anyway depending on the camera. But graphics and fades to black where a real issue producing illegal blacks and super whites on text for example. Its crazy to have to use a 16 black track on every project!

Give us proper video legal levels - not the current 0-255 rgb nonsense. Other NLEs do this by default. And for good reason.

Its one of the most reported complaints about Vegas, second maybe to stability.
The only people who want 0-255 render out and previews are compositors. Well thats fine, so at least give us the option! Possibly a mode switch depending on your project.

Good luck with your proposals. Count me in for video levels changing for the better. (getting slightly tired of trying).

musicvid10 wrote on 4/25/2014, 9:11 AM
Staying out of this one. Acquisition levels are a moving target, not only "video" or "full range." Human interventions, with good tools like trained eyeballs, zebras and video scopes are still the most reliable approach because the outcome can be manipulated to represent the creator's intentions. Of course, that assumes some degree of knowledge and vision on the part of shooters and editors. Sunday picnic videographers aren't going to know the difference either way.

Hidden in these discussions are usually illusions of some kind of magical "scan pass," which would implicitly carry a huge time/patience price tag, and probably be no more effective than doing nothing. Presets are presets, and they are already present in the program. Although they could be defined or exposed in the project settings, they still require an informed level of intervention, and would be valid only under identical studio conditions.

The simple fact is that technology still cannot extract human intentions from the multitude of possible outcomes.

Discussions like this remind me of the clueless orchestra manager who wanted to retune the sitar so it would "sound right" with the piano!

Marc S wrote on 4/25/2014, 9:50 AM
I spoke to one of the main engineers about these issues at NAB. He was very open and interested but it seemed like it was the first time he heard about it. I also explained that people using Movie Studio who do not have scopes are being set-up to fail. I plan on doing a follow up with him but I'm also perplexed as to why this has been discussed for so many years in the forums with no movement on the part of Sony to solve it and adopt the standards that all other NLEs appear to use.

larry-peter wrote on 4/25/2014, 10:58 AM
I'm one of those who likes the control Vegas gives the user over levels. But I also have been guilty of forgetting to add the 16.16.16 black track when in a rush. I do think all monitors (internal and external) should be made easier to conform to whatever levels the user want to preview.

What about simply options on render to "limit video levels to 16-235" and "eliminate superblack." Just let Vegas do in the background what we've had to do manually? Would that satisfy Movie Studio users too?
ChrisDolan (SCS) wrote on 4/25/2014, 11:16 AM
The engineer Marc S is talking about is me, I think. :-) If I seemed underinformed on the topic at NAB it's simply that color and levels are not my area of expertise -- I have a reading-level knowledge of the topic, but not expert level. I assure you, it's not a deliberate attempt to ignore the problem!

I can't promise a fix of course, but I can say that I've been making an effort to learn more about IRE, setup, legal levels, etc. and I've been talking with experts on other teams in Sony.

Keep pushing us with informative, thoughtful posts like this I'll keep pushing to get this fixed, whether its me doing the work or another programmer.
robwood wrote on 4/25/2014, 4:28 PM
it's an sRGB editor. i'd prefer it stayed that way... if a colorspace flip-switch (rec709/sRGB) was added that'd be fine too.
NormanPCN wrote on 4/25/2014, 7:49 PM
Thanks for the replies guys.
@farss, I'll read the document you linked me to. Thanks.

At a minimum, regardless of anything I would hope SCS would give two options. They are pretty safe an innocuous and trivial to implement.

Giving the internal preview window the same option that the external preview device current has. Again, this is mind blowing that it does not currently have this option. I use Antares preview levels extension to work around this problem.

Letting us specify what black level "nothing" is. i.e. fade to black. Currently always 0,0,0 and levels fx can do nothing about this.
musicvid10 wrote on 4/25/2014, 9:13 PM
Think of black "nothing" as actually 100% alpha. Otherwise we could not have compositing.
NormanPCN wrote on 4/25/2014, 9:32 PM
Think of black "nothing" as actually 100% alpha. Otherwise we could not have compositing.

Yes, that is what it is on a specific track, and that is why levels fx cannot affect this. But, when you finish compositing and have your video stream and watch the video, it is a very real non transparent color.

We should have the option to specify what that "nothing" color is. One mans opinion.

As stated, right now we have to make sure there are no 100% transparent pixels, by putting a solid color media generator event, that covers the full timeline length, on a track underneath all other tracks. This is easy enough, but not obvious.
NormanPCN wrote on 4/25/2014, 9:36 PM
I thought of another simple change that can make our life easier if need need strict conformance to levels.

In the color picker dialog that the media generators, effects and such use, have a check box option in that dialog to restrict or otherwise clamp the colors we are allowed to select to a legal video levels range. Unchecked being the current full range.
musicvid10 wrote on 4/25/2014, 10:31 PM
When rendered to 24 bit codecs, of course that is correct, since an alpha channel is not rendered. Without the blocking track, an alpha codec renders those areas as transparent.
paul_w wrote on 4/26/2014, 7:49 AM
Hi Chris, really good to get some attention about this from SCS and thats much appreciated. Past attempts seem to have fallen on deaf ears so good on you for taking it on personally.
The issue seems to me to be quite simple as i stated earlier. I have spent an enormous amount of time trying to figure out what would be best for Vegas in terms of its video levels handling. The main issue seems to be that its not just a video NLE. That would have made life so much simpler and there would have been no argument about what rendered and preview levels we should have: 0-100 IRE (16-235). This is the world standard and anything outside that limit is classed as illegal. But Vegas is also a compositer tool, taking on a role similar to Adobe's After Effects. That means it needs to also handle 0-255 levels for computer generated media and transparency levels.
This is the real issue. Vegas needs to be both at the same time, but in real life, this is a real problem and making these two abilities (project modes if you like) difficult to co exist. On one hand, we want 16-235 workspace and rendering, on the the other we need 0-255 for compositor actions. Tricky. Currently Vegas is locked into Compositor mode as i see it. There is no IRE mode. All we have is a scope with an IRE tick box and the external monitor prefs can display as IRE. Buts thats it. Everything else requires work arounds which not everyone knows about (or can be bothered with). The shocking truth is - Vegas has been turning out illegal content for years! and this also effects playback levels causing blacks to be super black or 'crushed', and whites to go super white or 'burnt out'. Many posts on here about that have been reported.
So here's the thing. Lets keep both but be smart about it.
If we had a single project setting say 'project mode' for example, then we could decide if we want a compositor (full 0-255 with transparency =0) or video IRE mode for professional (legal) video level productions. Now since Veg projects can be nested, it seems logical to me this could work and allow say a nested compositor project, say with text and graphics, and then being placed in a final REC 709 project so the final rendering and previewing for grading would be correct. best of both worlds.
Thats one option.
Another way is the way i am using Vegas today. That is by setting the scope to iRE levels and using a hard clamp plugin (wrote my own here) to actively stop anything being rendered out as illegal (placed on the master out bus). This in combination with an external monitor in IRE preview mode seems to do the trick fine. But it also makes the Internal preview monitor useless for any serious grading. It never shows correctly.
So thats my setup here and it negates the need for work arounds with black tracks, special text back levels or graphics. Super blacks from those simply get clamped to 16. And at the same time super whites get clamped to 235. Easy.
As always, camera levels of ingested media are always going to need some kind of manual adjustment on the the timeline. That's a given, and its what we editors do as part of the job. We have to be able to correct levels and read scopes. So if say a camera like a DSLR outputs at 0-255, well, thats illegal so we immediately adjust the level of that media to fit in the IRE scale. Its very quick to do, yes if this was an automatic process life would be sweeter but is not a show stopper and quite expected really. There is a post somewhere on here where many cameras' output levels are listed. Its crazy, every combination you can think of. I think all of them at least produced a super white.
Using my own workflow with the clamp, i can still do any composite work. Transparency levels work, my 0 level (internally on the timeline) work fine, overlay text etc. But the final render is the key. Then its clamped and that is what is previewed and finally rendered. But as i said, this still leaves the Internal preview monitor pretty useless. Its showing 0-255 always. And thats very misleading. What you see is NOT what you get!

The idea of a project MODE to allow IRE or FULL range within a project. Which are then nestable.
Internal and external preview monitors need to be able to show IRE previews.
Output clamping works for me for IRE - but some brighter person than me may think of another way to achieve the same result. But no matter what goes on the timeline, we cannot have illegal levels out.

That was the long answer! I really hope this help in making positive changes to Vegas. Its one of the best NLEs out there for single users. Thats why i feel so passionate about getting it right. We need IRE! We edit video, Vegas is not just a compositor.

[late edit] as pointed out, i make reference to IRE when really we are talking here about REC709 (BT.709) levels. However, Vegas scopes are shown as IRE and that is why IRE was mentioned. But for the sake of clarity, we should stick to talking about REC709.

musicvid10 wrote on 4/26/2014, 9:25 AM
IRE (BT.1700) is an obsolete analog luminance standard, and has no current or practical relevance to digital production or transmission, or this discussion for that matter.
I know of no one who knowingly produces digital video for analog transmission, which went the way of the dodo some time ago.

Although IRE white and blanking voltage levels ([0,100] IRE) correspond to [16,235] RGB luminance (Y'), peak, which would be unacceptable to most digital broadcasters. PBS, as one example, allows for no chroma slop whatsoever in its submission criteria. The clipping level for digital video is 255 (108 IRE).

The proper controls for digital video production are already available in Vegas. Agreed, better GUI accessibility in the Project and Preview panes would be welcome, and that is likely all the hyperlexic contributors to this thread really want or need.

paul_w wrote on 4/26/2014, 10:37 AM
MV, was BT.1700 mentioned in this thread? We were talking BT.709 Which includes provision for digital broadcasting including 1080 HD.

BT.709 clear states using 16-235 legal levels and this is the whole point of this debate. Its a current digital format for HD and its why Vegas is failing badly with its 0-255 defaults. [insert confused users] And unless a user is aware and does know the work arounds, they most certainly will produce illegal levels. Which is of course the cause of posts like 'why are my levels looking crushed on playback?'.. you know the drill.

musicvid10 wrote on 4/26/2014, 10:41 AM
Paul, you are absolutely correct, and proved my point 100%.

IRE is ITU-R BT.1700
It is not a standard for digital video production or delivery.
If you went through your post and changed every reference to IRE to BT.709, you would be a lot closer to making sense. Best.
paul_w wrote on 4/26/2014, 10:44 AM
And yet BT.709 ie 16-235 is.. interesting.

musicvid10 wrote on 4/26/2014, 10:49 AM
Paul, for god's sake.

IRE [0,100] corresponds to 16-235 RGB luminance (Y'). Oh, I said that.
That's where any similarity ends. Done.
paul_w wrote on 4/26/2014, 11:04 AM
Why on earth are you getting upset? We are both talking about the same thing! Its 16-235!!! put whatever label you want on it. This seems to have caused confusion. Not intended. We are all really talking 709 if anyone wants to wiki it. There is no confusion. Now stop getting upset, its just a debate, calm down and lets see if anyone else would like to contribute to the OPs thread. If you want to take this outside, feel free to email me.

larry-peter wrote on 4/26/2014, 11:21 AM
Responsibility for broadcast levels has always fallen into human hands - from camera shaders with CCUs to post production engineers - and it required learning the standards, learning the scopes and knowing how to get the best out your equipment. I don't understand why one would want to give any of that up to software.

I'm fine with SCS adding a project template that does this automatically, but I would never use it. I use color curves for limiting levels rather than the Levels plugin because I want as much control as possible over how the <16 and >235 levels are brought into a 16 -235 workflow. Especially in an 8 bit project, the levels compressed automatically would quickly become useless in the color correction stage. I want the access to full-range levels until time to render.

To me, the post process is all about maintaining as much control as possible with the images. I don't know why one would want to let the software limit their options.

But, as I stated before, if there was an option on render to "remove superblack" I would use that to prevent my occasional forgetfulness in adding the 16 black track.
musicvid10 wrote on 4/26/2014, 11:26 AM
Ok I'm better now. Here's the edited version of my post above, which I left as-is.

Luminance, chroma, and analog composite levels are three entire entirely different things.

The corresponding luminance scales between analog and digital standards are by definition. BT.709 goes on to define it's own color primaries, matrices, transfer points, chroma subsampling, and a whole bunch of other stuff you or I will never understand fully. Broadcasters, in particular, go beyond that to define the amount of chroma slop they will allow in submitted material, in line with best practices. Internet and home delivery can be more forgiving, but anything in the source outside 16-235 gets summarily clipped on playback, meaning it never gets seen. Thus, any source containing full [-20,120] IRE peak levels, left untouched, runs the risk of looking truly horrible once encoded.

IRE chroma / composite levels can far exceed anything a broadcaster could or would dump on a digital stream. Those broadcasters who still run analog tape decks clamp the excess to conform.

My frustration was a result of watching you beat a dead horse; from your last generalized response I can see it is really an issue of education and not understanding that it is about a lot more than luminance. I am probably not the best teacher in that respect. The internet, however, contains all the resources necessary to understand the differences between analog voltage standards and digital video levels.
musicvid10 wrote on 4/26/2014, 11:33 AM
atom 12,


Again, we agree 100% on your two major points:
1. Informed human intervention is always necessary; and,
2. I want the full range of available levels exposed during preview and editing.

Adding a GUI "switch" to change between editing and playback levels would be the silver bullet, I suspect, that would satisfy folks on both sides of this "here we go again" discussion.

It's really a lot simpler than all the confabulation here would suggest. Best.

paul_w wrote on 4/26/2014, 11:48 AM
yes Atom, i agree with needed human intervention completely, i doubt whether this could be or should be an automated process. Absolutely. Like i said before in an earlier post, we pretty much have to adjust media anyway and will change from source to source.

But how is the full range edit or grade being compromised if we only limit the final render? I know you are an audio guy too, so thinking of this like working with a DAW at 96k 24bit and exporting to 44.1 16bit with limiting or compression added on the final mix. This is how i see a clamp of types being applied to the output at render time. Preview screens, well they just get adjusted to view the signal as it would be once rendered to 709. So i dont see anything bad happening to the Timeline or media during a grade. So i see it as an aid, not a hindrance.