Levels Computer To Studio For Bluray?

Peter Riding wrote on 10/19/2014, 6:23 PM
Wondering whether I should do this for Bluray. Demand for Bluray among my clientèle is very low so I haven't explored it much but I have some coming up.

More background: The cams are usually a mix of AVCHD from Canon 5 series, Panasonic AC90, and Panasonic TM series.

My two standard outputs are as an MP4 file 1920x1080, and as a standard definition DVD. Everyone gets these two.

For the MP4 I do not perform any Levels conversion and the videos look great on computers, tablets etc, but too contrasty on TVs. As expected. For the DVD I do a Sony Levels Computer to Studio conversion on the video bus. Looks great on TVs but washed out on computers and tablets. Again as expected.

Tried both versions as Bluray n.b. without and with the Levels conversion. Did both Blurays within Vegas Pro, not going to DVD Architect Pro. Both look the same. Is that right? Is there something in the Bluray spec. that makes the conversion unnecessary.

The project I used for testing is not ideal as its an outdoor wedding in very bright contrasty conditions so harder to judge. But its a real shoot, not someones backyard cat, and its short so it renders quick without me having to pick shorter loops.

Thanks.

Pete

Comments

GlennChan wrote on 10/19/2014, 6:51 PM
For the MP4 I do not perform any Levels conversion and the videos look great on computers, tablets etc, but too contrasty on TVs. As expected.
I think you may have a misconception.

All you needed to do was to make a MP4 file with proper levels. That should play with correct levels on 99% of tablets, computers, TVs, etc.

There is only one standard set of levels for TVs (in any particular country) and one standard set of levels for formats that play back on computers, tablets, etc. You do not need to make a special version of TVs and a special version for computers. If your rendered video file has the right levels, it will play back correctly almost everywhere. Almost all software and hardware obeys standards and will correctly perform the right conversions. (Vegas does not.)

Tried both versions as Bluray n.b. without and with the Levels conversion. Did both Blurays within Vegas Pro, not going to DVD Architect Pro. Both look the same. Is that right? Is there something in the Bluray spec. that makes the conversion unnecessary.
That doesn't seem right to me. One (or both) of them should have the wrong levels and you should be able to see that.

If you play back the footage on a consumer TV then maybe the consumer TV has some weird type of levels adjustment or image enhancement going on.
GlennChan wrote on 10/19/2014, 7:01 PM
So here's what you can do.

1- Bring the footage into Vegas. Go into the properties for one of the events and see what codec Vegas uses to decode the footage.

If it's Quicktime, then it's probably decoding to computer RGB. But maybe not.
If it's some type of Sony MPEG4 or AVC HD codec, it's probably decoding to studio RGB.

You can do that for each camera and for each way in which footage comes into Vegas.

2- For simplicity's sake, don't use the 32-bit floating point mode under project settings.

I'll assume that all your footage is decoding to studio RGB. (This may or may not be the case.)

3- It may or may not have values from 235-255 on the histogram. If so, you can apply color correction to bring that down.

4- When rendering to MPEG4 or MPEG2, do not apply any levels conversion.
musicvid10 wrote on 10/19/2014, 8:52 PM
Bluray uses the same levels as DVD.
If your playback levels look different on different devices, something is set wrong.
Peter Riding wrote on 10/20/2014, 2:37 PM
Thanks guys, I'm trying to understand this I really am. Can I ask a follow-up.

The four cams I use most frequently are the Panasonic AC90, the Panasonic TM900, the GoPro Hero2, and the Canon 5DII, often several bodies of some.

I've checked the Properties in Vegas for each as in Glen's point 1. The easiest way to share all that data seems to be with a PDF:

http://www.ashtonlamont.co.uk/images/dvi/codec-info-vegas.pdf

I removed the folder locations only as they reveal client information.

I also inspected the info via VLC media player – Mediainfo didn't seem to get me any more that was useful. This time as a JPEG showing all 4 cams:

http://www.ashtonlamont.co.uk/images/dvi/codecs.jpg

I do have Quicktime Pro on my system but as far as I can understand Vegas is using an AVC HD codec.

I never use 32 bit. My videos are invariably shot in poor conditions and for an audience thats only interested in content not in technical chops so there's little point in trying to polish them over what 8 bit can do.

Now, when I inspect the Histogram I am seeing what appears to be a full range for all the cams e.g. an AC90:

http://www.ashtonlamont.co.uk/images/dvi/scope-ac90.jpg

and a TM900:

http://www.ashtonlamont.co.uk/images/dvi/scope-tm900.jpg

I've included the option window “Studio RGB tick untick” to illustrate that there is still data in both ends regardless of its setting.

I'm getting the playback features I described earlier on three different TVs (one plasma two LCD), two desktops, a laptop, an Ipad3 and a Galaxy S3. I just took it for granted that to get a video without crushed highlight and shadow areas on a TV you do need to apply the Sony Levels conversion Computer to Studio n.b. I don't do any conversion for non-TV devices.

If you can spot anything in my workflow thats not right I'd be very grateful but its a big ask and I'll just soldier on if needs be.

Pete
musicvid10 wrote on 10/20/2014, 3:43 PM
I can look at these later, but you set the levels for the codec, not the device.
Duncan H wrote on 10/20/2014, 5:35 PM
Peter,

You are not alone. I continually struggle to comprehend levels, after some years. I read the posts, think I get it, then realise that I do not! What you have stated is precisely how I understood things, but clearly, I'm not understanding the issue, so thank you for (again) raising this vexing issue. I shall (again) read all responses diligently, in the hope that one day I may gain enlightenment!
musicvid10 wrote on 10/20/2014, 6:29 PM
The video scope settings do no affect the histogram.
If that's what you're getting after the studio rgb filter, then you've not applied it LAST in the fx chain, and/or your preview is not set at Best/Full. Is your Project set to match media?
john_dennis wrote on 10/20/2014, 6:38 PM
I'll share what I do. The video from my camera appears in the Video Scopes / Waveforms like this:



Since the levels are greater than the 0-100 range expected, I apply the Computer to Studio RGB filter.

After applying the filter, the levels look like this:



When uploaded to youtube using the Sony AVC/MVC / Internet render template, the output looks like this:



[b]Without the Computer RGB to Studio RGB filter, the output looks like this:



Why do I care? Notice the loss of text in the white stickers behind Kevin in the video where no levels adjustment was done.

My main system:
Motherboard: Asus X99-AII
CPU: Intel i7-6850K
GPU: Sapphire Radeon RX480-8GB
RAM: Corsair Dominator (4 x 4 GB) DDR4 2400
Disk O/S & Programs: Intel SSD 750 (400 GB)
Disk Active Projects: 1TB & 2TB WD BLACK SN750 NVMe Internal PCI Express 3.0 x4 Solid State Drives
Disk Other: WD Ultrastar/Hitachi Hard Drives: WDBBUR0080BNC-WRSN, HGST HUH728080ALE600, 724040ALE640, HDS3020BLA642
Case: LIAN LI PC-90 Black Aluminum ATX Full Tower Case
CPU cooling: Corsair Hydro series H115i
Power supply: SeaSonic SS-750KM3 750W 80 PLUS GOLD Certified Full Modular Active PFC Power Supply
Drive Bay: Kingwin KF-256-BK 2.5" and 3.5" Trayless Hot Swap Rack with USB 3
Sound card: Crystal Sound 3 on motherboard. Recording done on another system.
Primary Monitor: Asus ProArt PA248q (24" 1920 x 1200)
O/S: Windows 10 Pro 22H2, Build 19045.2130

Camera: Sony RX10 Model IV

https://www.youtube.com/user/thedennischannel

Duncan H wrote on 10/20/2014, 11:28 PM
Thanks John,

Much appreciated and I've looked at both videos. It might just be me, but these seem surprisingly subtle differences. I've applied the levels filter in a similar manner to videos and seen quite substantial changes in the blacks, particularly upon uploading to Youtube.

Very helpful for my education, although on this one issue, I recognise that I continue to need further study and perhaps some remedial coaching, as I find it fiendishly challenging to understand, as I had similar approach / understanding to Peter Riding re levels for computers & TV's. Thanks
GlennChan wrote on 10/21/2014, 1:19 AM
Ok so all your footage is being decoded with Sony codecs for the mpeg-2 transport stream and AVC formats.

In 8-bit projects, those decode to studio RGB.
If you render to either DVD (MPEG-2) or Blu-Ray (MPEG4), both the Sony codecs for that expect studio RGB.
So you don't need to do any levels conversions.

see http://www.glennchan.info/articles/vegas/v8color/vegas-9-levels.htm for a long-winded explanation

*Oh yeah, the Video Preview window won't be accurate. My levels article should explain at least one of the workarounds.

--------------------
It looks like some of your cameras record superwhites, or illegal values above white level. Some systems will clip these values and others won't. If you want all your viewers to see the same thing, then you can apply color correction.

see http://www.glennchan.info/articles/vegas/color-correction/tutorial.htm

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VLC and Quicktime Pro behave differently than Vegas. Both of those programs generally convert levels correctly.

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In your Youtube videos, the "No Computer RGB to Studio RGB Filter " version has correct levels. Your camera records superwhites that are being clipped. This is arguably the "correct" behaviour and is what the camera designers wanted (which I think is stupid, but that's what almost all video camera manufacturers did and it causes a lot of problems).

You might like it better if color correction was applied to bring those highlights into legal range.
GlennChan wrote on 10/21/2014, 1:26 AM
Now, when I inspect the Histogram I am seeing what appears to be a full range for all the cams e.g. an AC90:
It's not a full range.

Yes, there are some values below 16. This can be due to:
- Borders on the image (not applicable in this case)
- The way the camera is designed. If you placed a lens cap on the camera, then the resulting image won't be totally black due to sensor noise. So, the camera might darken the image so that the resulting image will be pretty close to pitch black.
- Noise from compression. (This doesn't really explain it.)

If you just color correct the image to taste, then you can choose whatever blacks you want to have. Make sure that you are previewing the image correctly though. In your situation, the Video Preview window will be horribly inaccurate and misleading because that is NOT what your image will look like.
malowz wrote on 10/21/2014, 3:36 AM
i tested a few tv's with blu-ray players and a few blu-ray titles. all of them used "16-235" levels

all cameras i had and have record "16-255", but past 235 are almost always only reflections, highlights, etc, not any important part of the video itself.

so, no questions for me. everything has worked great.

also, i offer "free tv adjustments" when delivering events on blu-ray. a few tv/blu-rays sets are horribly adjusted by default (uber-saturated, all sharpness maxed, noise reduction, dynamic contrast, etc...). i made a "adjustment" blu-ray with patterns/levels/etc to quickly adjust tv's for optimal quality, on my blu-rays and blu-ray movies.

i do a very detailed adjustments on my videos, i like everything as "perfect" as i can. all of that worth nothing on a unadjusted tv/bd set.
musicvid10 wrote on 10/21/2014, 7:45 AM
It's safe to say that none of those cameras will shoot 16-235, without purposeful manual intervention (when possible).

16-255 for the Panny's (iirc), and 0-255 for the Canon and GoPro, are much more typical shooting values in full light.

We've been over this before, and anyone interested can dig up Nick's excellent 'camera levels' threads.

With the levels filter applied last, and the result previewed at Best/Full, a histogram will look something like this somewhat-conservative example:

Peter Riding wrote on 10/21/2014, 6:19 PM
Oh dear, it appears that your cam may shoot 0-255, 16-255, 16-235, 0-235 etc etc and how Vegas deals with this depends not only on the file type but the codec within. And just in case you thought you could inspect the Histogram to see whats going on ..... think again. Not necessarily so :- (

One then has to wonder how to deal with several cams in a multicam edit that have differing 0-255 values. Presumably render them to common denominator in an intermediate file type. Monster Cineform files perhaps. What a mess!!!

Its reassuring that at least one other contributor to this thread had formed the same opinion as me regarding doing a Levels conversion from Computer to Studio RGB for DVD.

Thanks everyone for your contributions. I'lll be back in a few days once I've had the chance to absorb the updated information. Meanwhile I'll get my Bluray orders out the door sans conversion, and continue my MP4 and DVD videos as before as it seems to be working.

Phew!

Musicvide10, can I ask one more favour? A link to a thread or two with reliable information such as you've referenced. Very much appreciated thanks.

Pete
Duncan H wrote on 10/21/2014, 6:38 PM
Peter,

I couldn't have said it better. I just produced a mulitlingual on-line video in Mandarin, English & Japanese and was then asked to produce 300 DVD's for distribution. The footage was a combination of three different cameras, at least 1 was 16-235, one was 16-255. But most DVD's distributed are likely to have been viewed on laptops (therefore, do they need sRGB to display or can they be left as cRGB?).
In the end, after grappling with exactly the issues that you are,I applied some levels at individual clip level (to try to manage super blacks) then I simply burned the DVD's & distributed. I'm forming the opinion people are quite oblivious / accepting of crushed blacks, superwhites etc, as on-line video viewing has become the norm and they view dodgy level videos constantly. Doesn't make producing video with wrong levels the right approach, but I am not bright enough to get to grips with the issue within Vegas. Thanks for your thread.
GlennChan wrote on 10/21/2014, 8:05 PM
Oh dear, it appears that your cam may shoot 0-255, 16-255, 16-235, 0-235 etc etc and how Vegas deals with this depends not only on the file type but the codec within. And just in case you thought you could inspect the Histogram to see whats going on ..... think again. Not necessarily so :- (

Your camera either records superwhites or it doesn't. That's issue #1.

Vegas needs to use a codec to decompress your camera's footage. Depending on how you bring the footage into Vegas, different codecs might be used. All the codecs that Vegas uses will either be studio RGB or computer RGB. That's issue #2- figuring out whether the footage is being decoded to studio or computer RGB.

Nick Hope's camera levels thread may be misleading in rare situations. It does not make a distinction between #1 and #2. It assumes that the *same* codec will always be used for footage from a particular camera.
If you import footage into Vegas in a weird way, then that assumption may not hold true. e.g. If somebody else captured the footage and sent you the files, then maybe Vegas will be using a different codec.

Here is the camera levels thread:
http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=795690

Its reassuring that at least one other contributor to this thread had formed the same opinion as me regarding doing a Levels conversion from Computer to Studio RGB for DVD.
I suspect that's wrong...?

For your circumstances, you don't need to apply any computer --> studio RGB conversions.

All your camera footage will be decoded with codecs that decode to studio RGB.
You are encoding your final product with either Sony Vegas's MPEG2 or MPEG4 codec. Both expect studio RGB.
So no conversion is necessary.
DVD is MPEG2
BluRay is MPEG4
GlennChan wrote on 10/21/2014, 8:20 PM
But most DVD's distributed are likely to have been viewed on laptops (therefore, do they need sRGB to display or can they be left as cRGB?).

You just need to make a DVD with standard video levels. They will play back correctly on TVs and laptops.

Video standards were created so that this is possible. In rare cases, some consumer equipment does not follow standards... but that's typically not something that you can control.

For some reason, some people on this forum have been saying that computers are "0-255" and that TVs are "16-235". This is very misleading; it isn't really true. All you really need to know is that there is only one set of correct levels for DVDs, Bluray, MPEG2 files, etc. etc. In Vegas, you create proper levels by giving the codec you are rendering to what it wants. This will either be:
-studio RGB
-computer RGB


---
What I'm saying should make sense. Suppose that you go to the store and buy a DVD. It will play back correctly on your TV (via your DVD player) and on your computer (through Windows Media Player or whatever).

The engineers who design this stuff aren't so dumb that you'd have one version for computers and another version for TVs. They created video standards for this reason.
musicvid10 wrote on 10/21/2014, 9:01 PM
But the engineers who make graphics cards are that dumb. They expose controls they shouldn't, and give them enticing names, so any curious kid can screw up the monitor video levels without knowing a thing. That's just one of the problems.
john_dennis wrote on 10/22/2014, 9:01 AM
@Glenn Chan

"[I]In your Youtube videos, the "No Computer RGB to Studio RGB Filter " version has correct levels. Your camera records superwhites that are being clipped. This is arguably the "correct" behaviour and is what the camera designers wanted (which I think is ****, but that's what almost all video camera manufacturers did and it causes a lot of problems).

You might like it better if color correction was applied to bring those highlights into legal range.[/I]"

I downloaded your color correction presets last night and applied them to a video. Then, my wife came home.

I've also used the Brightness and Contrast filter to contain my camera "super whites" to the "legal" range. I wouldn't be surprised if the Computer RGB to Studio RGB filter isn't just a special case application of the Brightness and Contrast filter.

Someone who understands this stuff correct me if I'm wrong.

I sense you're practicing relativism when you use "correct" when referring to anything over 100.

My main system:
Motherboard: Asus X99-AII
CPU: Intel i7-6850K
GPU: Sapphire Radeon RX480-8GB
RAM: Corsair Dominator (4 x 4 GB) DDR4 2400
Disk O/S & Programs: Intel SSD 750 (400 GB)
Disk Active Projects: 1TB & 2TB WD BLACK SN750 NVMe Internal PCI Express 3.0 x4 Solid State Drives
Disk Other: WD Ultrastar/Hitachi Hard Drives: WDBBUR0080BNC-WRSN, HGST HUH728080ALE600, 724040ALE640, HDS3020BLA642
Case: LIAN LI PC-90 Black Aluminum ATX Full Tower Case
CPU cooling: Corsair Hydro series H115i
Power supply: SeaSonic SS-750KM3 750W 80 PLUS GOLD Certified Full Modular Active PFC Power Supply
Drive Bay: Kingwin KF-256-BK 2.5" and 3.5" Trayless Hot Swap Rack with USB 3
Sound card: Crystal Sound 3 on motherboard. Recording done on another system.
Primary Monitor: Asus ProArt PA248q (24" 1920 x 1200)
O/S: Windows 10 Pro 22H2, Build 19045.2130

Camera: Sony RX10 Model IV

https://www.youtube.com/user/thedennischannel

GlennChan wrote on 10/22/2014, 11:50 AM
I've also used the Brightness and Contrast filter to contain my camera "super whites" to the "legal" range. I wouldn't be surprised if the Computer RGB to Studio RGB filter isn't just a special case application of the Brightness and Contrast filter.
You can get those filters to do the exact same thing.

I don't like the user interface on the Brightness and Contrast filter.

I find the user interface on the Curves filter the easiest (if I use the presets I made to deal with studio RGB levels). It also does useful things such as getting rid of illegal values.