Color correction for HD TV

Laurence wrote on 10/1/2009, 9:57 AM
When I shoot HDV and color correct so that it looks good on my pc screen, after uploading it to Facebook / Youtube / Vimeo it looks really good. The way I edited it is the way it still looks. However when I render to either Bluray or to a media file that I can play back on my HD TV, the color is way to saturated and intense. Some of the colors are way off as well. Is there any way to put a color correction filter just on renders that will make it look the same on an HD TV as it does on the Vegas preview? I really don't want to mess with a complicated preview system when I put a lot more HD videos online than I do Bluray.

Comments

ingvarai wrote on 10/1/2009, 10:18 AM
> play back on my HD TV, the color is way to saturated and intense
9 months ago I bought myself a real super TV, a Pioneer plasma TV. It has several settings, but I ended up with the "cinema" setting (if I remember correct). This settings means very natural colors, and when I play DVD's I have rendered using Vegas - the look is very close to the setting I have on my PC.

When I visit others, however, my DVD looks just like you describe, over saturated colors, high contrast, loss of details. But - this is the way people like it! Go to a TV shop ans watch how they over-saturate and over-contrast the images, just to sell TVs.

The simplest answer is to adjust your own TV. But this is not a good answer. And I don't have the answer. As a matter of fact, I am interested in this topic myself, and would like to know if there is a way to color correct my productions so that they will look ok on most TV sets.

ingvarai
musicvid10 wrote on 10/1/2009, 10:19 AM
I'd bet it's a setting on your player or TV that's causing a problem. The default color profile is often fake, like "Cinema" or "Vivid" or "Home Theater" which alters the throughput. Why is it the default? Because in stores the "gee whiz" color saturation is what sells sets.

Here is an almost identical complaint over on the DVDA forum:
http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=22&MessageID=674868
JJKizak wrote on 10/1/2009, 10:31 AM
The newer tv's have settings for each input and on mine had to adjust the contrast, color saturation for the bluray and HD-DVD player inputs. Never had to with just DVD players. I also noticed I think it was part 1 or part 2 of the National Parks on PBS the same thing occurred (torquoise skys) but they later corrected it.
JJK
bsuratt wrote on 10/1/2009, 11:44 AM
<< "after uploading it to Facebook / Youtube / Vimeo it looks really good" >>

Since there are no standards for color or anything else on the internet how do you know it looks anywhere close to what you see on other people's PCs. With the hugely variable number of factors involved in internet delivery, notwithstanding the variation and setup of monitors, video cards, etc you can never tell how it will look on another web display. Few people are looking at the web with expensive calibrated displays... more likely the cheapest display they can get. Laptop displays are in a world of their own quality wise!

I am currently testing a video on a private Vimeo account and asking for feedback among club members viewing it on their web connections. I have been invited to come and see for myself on several member's web. The amount of difference between web displays is enormous... yes many could be improved by adjusting the local display... but then the user would immediately balk at what no longer looks right to them and what they are used to on the web. There's no way to win here!

Make it correct for Blu-ray/HDTV if you have to. At least there are fewer variables and some degree of standardization. Then put that on the web and
accept the fact that no two web displays will show it as you would like anyway so don't waste your time!

Most of the HDV I do requires no color correction to go to Blu-ray and look excellent. In fact, in order to color correct High Def you will have to accept lower resolution because a full render is required.


prairiedogpics wrote on 10/1/2009, 1:15 PM
I have a Pioneer PDP-5020 plasma. You should be using "Movie" and not "Cinema" if it's a newer model. Search for your Pioneer model on AVS Forum and you will find the recommended "calibration" settings for your TV. No adjustment should be necessary from the Blu-Ray/DVD player.

This thread is for my TV. See post #2 as an example of recommended settings:

http://www.avsforum.com/avs-vb/showthread.php?t=1053444



Laurence wrote on 10/1/2009, 2:24 PM
I know a lot of the issues I'm struggling with are covered in http://www.glennchan.info/articles/vegas/v8color/vegas-9-levels.htmthis[/link] Glenn Chan article. I've just got to somehow get my head around these color space issues.
GlennChan wrote on 10/1/2009, 2:30 PM
What about the article is confusing?

Does the example workflows at the bottom clarify things?
Laurence wrote on 10/1/2009, 2:54 PM
What about the article is confusing?

My puny brain. The article is fine.

Actually, renders with 32 bit color seem to take days and often crash half way in. Add the extra rendering time that 32 bit color takes to the extra rendering that a plugin like Neat Video noise reduction adds and you can literally be looking at a week long render!

My problem (as I'm figuring it out) is that Youtube /Facebook / Vimeo renders are in a different color space and format than Bluray and HD TV media files. Color correcting for one looks terrible in the other. This video looks pretty good on Youtube:



The same media file copied to a thumb drive and played back on my WD media player on an LCD HD TV via HDMI looks terrible. Going to Bluray, the situation is exactly the same color wise. I just did a media file that is playing in the preshow ads at a local movie theater. The color on that looks great. It's just HD TV stuff that is driving me nuts.

As far as Vegas goes, I can now see that my HDV footage is in a different color space than any photos or graphics I add. I can see that I have to convert one or the other. I'm figuring it out. It just takes me a while.

When I used to work with SD, I used a Canopus firewire to DV video box for previewing. Everything was exactly the same color on my previews and final renders. Now with HDV, I have to preview on my PC monitor. The colors are accurate for PC playback but not for HD TV playback. That is the main thing I am struggling with I suppose.
Laurence wrote on 10/1/2009, 3:25 PM
How's this for a simplification:

If I am doing an HDV project with some stills and graphics, and I want to make an HD Vimeo or Youtube video, I should put a color corrector with the "Studio RGB to Computer RGB" preset on all the HDV tracks. Any extra color correction will be added after that.

If however I want to make a Bluray of this same project I should go and disable the color corrector with the "Studio RGB to Computer RGB" presets and instead color correctors to all the pictures and graphics tracks using the "Computer RGB to Studio RGB" preset.

That way I could do renders for both formats from the same HD project. Is that correct? If so, why isn't everybody talking about this stuff all the time?
Laurence wrote on 10/2/2009, 11:40 AM
Whoo Hoo! That Glenn Chan article rocks! Now I've got exactly what I want: perfect HD TV and computer renders for sites like Vimeo and Youtube!

Here's the simplification:

1/ Keep generated media and HDV video on separate tracks.
2/ Put color correctors on all tracks.
3/ Use media generator to create a broadcast legal black with RGB colors set to 16,16,16 and put this track below all the others. Stretch this media the entire length of the project. Once this track is in place, mute it.
4/ Set all track color correctors on HDV tracks to the "Studio RGB to Computer RGB" preset.
5/ Set all track color correctors on media generator tracks (including photo animated tracks) to the "Computer RGB to Studio RGB" preset then deselect this effect.

Now you can work away while looking at everything in the correct "Computer RGB" color space that looks great in the preview box and renders exactly right for Youtube and Vimeo.

6/ When you want to render an HD TV version, unmute the bottom 16,16,16 black media generator track.
7/ Unselect all the color correctors on the HDV tracks with the "Studio RGB to Computer RGB" preset.
8/ Go to the media generator tracks and enable all the deselected color correctors with the
"Computer RGB to Studio RGB presets).
9/ Render your HD TV version for Bluray or HD TV media playback.

If you want any further color correction, just add it to the clips while everything is in "Computer RGB" mode and leave it in place when you go through the other steps.

I just ran some test renders and both the HD TV and computer playback versions look equally good when I follow these steps.
LoTN wrote on 10/2/2009, 12:09 PM
Yep, Glenn's article is very good but I must warn newbies like me that they will have to carefully read it two times for real understanding. If two isn't enough, then try four and so on ;)

Laurence, there is something I don't catch for HDTV render. You say you remove the cRGB to sRGB FX, so generated media color becomes cRGB, right ? So, if I am not wrong, it is possible you face again color issues.

If my understanding is correct, how about keeping generated media with cRGB to sRGB FX and only use a global FX for sRGB on the video bus ? It would save you adding FX to all your HDV tracks during edit and let you enable cRGB to sRGB on the bus for HDTV render.

I learn every day and actually don't have a way to check this, I would be happy if you could shed some light.

BTW, thanks for the black track trick. I do not really understand what it does when rendering but I will have a try with it.
Laurence wrote on 10/2/2009, 12:23 PM
The http://www.glennchan.info/articles/vegas/v8color/vegas-9-levels.htmGlenn Chan link[/link] explains it all. Generated media is computer RGB, so when you render it without color correction, it is more saturated then the studio RGB level of the HDV video. The color correction on the generated media is only used when rendering for HD TV.

The reason for the 16,16,16 black is that otherwise Vegas will go to 0,0,0 black any time the video goes to black. Most of the time this doesn't matter, but it can screw with sync on older TV sets. I experienced this first-hand not too long ago. What happened is that I had a component TV input switcher that had some active electronics in it so that it could automatically select the proper live input. What I found was that my own renders would make the sync go crazy ever time the screen went to black. At the time I didn't know why and I ended up getting rid of the switcher, but in retrospect, I now realize that what was happening is that my videos had 0,0,0 black that was causing the problem. The 16,16,16 black looks the same as the black on commercial DVDs. Now my renders match commercial releases much more closely.

Sure you can set up a TV so that it looks good with renders that don't pay attention to correct color space. The problem is, that I want my projects to look good anywhere they play. I don't want to have to have a special calibration just for me. Most people will end up looking at it wrong if I do it that way.
LoTN wrote on 10/2/2009, 12:54 PM
Laurence,

Thanks for your reply. I already read Glenn Chan's documents about colors in Vegas. That's ok, oh well i believe it is. My english is improving slowly, I think there may be some misunderstanting.

To make it short: why did you choose to apply sRGB to cRGB on each HDV track instead of just on the video bus ?

If I am not wrong, doing this way would let you to just disable the cRGB to sRGB fx on the video bus when rendering for youtube and siblings. Leaving cRGB to sRGB on generated media would have nasty effects ?

Just wanting to understand. Thanks
Laurence wrote on 10/2/2009, 1:35 PM
>To make it short: why did you choose to apply sRGB to cRGB on each HDV track instead of just on the video bus ?

Because I also have titles and generated media like animated stills that are already in cRGB space. What I need is two master renders: one sRGB and one cRGB. For the sRGB render (for HD TV), the HDV is already in the correct color space, the generated media is not. For the cRGB render (Youtube HD, Vimeo & Facebook) the generated media is already in the correct color space, the HDV video is not. What I want to do is color correct just the HDV video for the cRGB render and just the generated media for the sRGB. The 16,16,16 black is only needed on the sRGB render.

What you may be getting at is that at first it would seem that you could just convert the HDV video to cRGB and put a cRGB to sRGB corrector on the master bus when you wanted to render an HD TV version. The problem with that is that you are doing a double conversion on the HDV video and in addition to the extra render time, there is the issue that both these conversions will be done at 8 bits and, when I've tried it this way, the double conversion leads to errors which show up as blockiness on solid colors and rich greens and blues being oversaturated.

The real solution is to leave the generated media in cRGB space and just do the sRGB to cRGB conversion on the HDV video when you need a cRGB render (Youtube) and leave the HDV video in sRGB space and just convert the generated media when you need a sRGB render (HD TV). Also ad the 16,16,16 black underneath for the sRGB (HD TV) render.

If there is an easier way, I'd love to know it. For now at least, this process is finally giving me the color in both formats that I've been longing for.
Laurence wrote on 10/2/2009, 1:38 PM
Another note: The double conversion from sRGB to cRGB back to sRGB on the HDV video would probably look just fine if you used 32 color (rather than the stock 8 bit) on your render. The problem is that 32 bit color adds days to your rendering time on even a short project and on top of that is really crash prone. There is nothing like a crash after 32 hours of rendering to make your blood boil! Anyway, I've given up entirely on 32 bit color.

Another note: I get pretty good color while I'm shooting. My HVR-Z7U has profiles settings that really allow you to customize the look you get while you shoot. The EX1 and EX3 have this as well and it really lets you get video that needs next to no color correction once you get your settings right. The only real color correction I need is for the sRGB to cRGB color correction for Youtube/Vimeo/Facebook/computer media playback. Once in a while you still need to color correct for field mistakes or to get a certain look. By separating the sRGB to cRGB correction from the look color correction, you can go back and forth between sRGB and cRGB by merely turning on and off the colorspace conversion filters.
LoTN wrote on 10/2/2009, 10:16 PM
Many thanks for your comprehensive answer Laurence. I got all your points.
Laurence wrote on 10/3/2009, 1:59 PM
Only a couple of us paying attention to this thread. Funny because at this point I'm pretty sure that most of us who are working with HDV are having colorspace issues without even being aware of it. I've been working with HDV for a few years now. All this time I've been getting what I now realize are quite inferior results because or my lack of understanding of colorspace which led to my skipping these important steps in my workflow.
morroni wrote on 10/3/2009, 5:28 PM
It could very well be the setting on your TV, but if the colors are shifting as well as oversaturating I suggest you use the color correction filter and use the Computer RGB to Studio RGB preset, or maybe it's the reverse, Studio RGB to Computer RGB. I'm getting old and I forget which worked. Also, Find the preset that sets the black at 7.5, it helps keep the video play backs from going squirrelly.
Laurence wrote on 10/3/2009, 7:23 PM
You're missing the point: that HDV projects have elements in two different color spaces: sRGB and cRGB. The HDV footage is in sRGB and the generated media is in cRGB.

With that in mind there are two common ways that end users look at HD video: online and on Bluray disc. Online (Youtube, Vimeo etc.) is in cRGB and Bluray is sRGB.

Thus when you render for Youtube or Vimeo, you want to put color sRGB to cRGB color correction on all the HDV parts and leave the generated parts like titles and animated photos in their native cRGB mode.

On the other hand, when you render for Bluray (which is sRGB), you want to put cRGB to sRGB color correction on all the generated parts and leave the HDV parts in their native sRGB mode. In addition to this, you want your blacks to be 16,16,16 black rather than 0,0,0 black. That is why you put the track of media generator 16,16,16 black on the bottom video track underneath all the others. This will make your fades to black stop at 16,16,16 instead of going all the way to 0,0,0.

When I do this my bluray renders and my online video renders both look equally good. HD TV stuff looks right with my TV set up to look good with any other bluray title. This is what I've been after, and how I've realized I can achieve it.
Erik Olson wrote on 10/3/2009, 11:39 PM
Is there a reference anywhere that says source for YouTube or other online videos must be in Computer RGB? Maybe something in the Flash Player SDK (if such a thing exists), as it's really the Flash Player that handles the playback on web pages.

Laurence wrote on 10/4/2009, 5:18 AM
As far as I know, there's no reference that says what color space a Youtube or Vimeo video should be in. You can certainly see a lot of Youtube video that are in sRGB space and that look really washed out because of it. There is no question in my mind that cRGB looks a heck of a lot better on Youtube, Vimeo or Facebook.
GlennChan wrote on 10/4/2009, 9:54 AM
Youtube accepts various formats for upload. I believe you just have to encode for that format correctly. And then Youtube converts that file/format into its own thing.

Remember that for the standards out there like MPEG-2, there is only one way to do it right in terms of levels. So if you make a MPEG-2 which you upload to Youtube, then you want to get the MPEG-2 levels right.
Laurence wrote on 10/4/2009, 10:12 AM
I've been using the Sony AVC codec and color correcting so that the image looks right in the Vegas preview window. Color wise, the image ends up looking the same on Youtube/Vimeo/Facebook as it does in the Vegas preview window. The same mp4 video file that looks great uploaded on Youtube looks way oversaturated when played back on an HD TV via a http://www.amazon.com/Western-Digital-WD-Media-Player/dp/B001JZFQU4WD media player[/link].
Laurence wrote on 10/4/2009, 3:32 PM
How's this for a workflow that will let you render both sRGB and cRGB versions (Bluray and Youtube HD)?

Set everything up for sRGB except put an sRGB to cRGB color corrector on the main video bus. Render sRGB video with this final color corrector disabled. Render cRGB version with it enabled.

In other words:

1/ No color correction on HDV tracks.
2/ cRGB to sRGB color correction on animated photos.
3/ On text set black level to 16,16,16 and white level to 235,235,235.
4/ Put a track of media generator 16,16,16 black under entire length of project.
5/ On the main video bus, put a broadcast colors filter for safety and a sRGB to cRGB corrector after that.
6/ For Youtube mp4 render leave main video bus sRGB to cRGB corrector enabled.
7/ For Bluray render, disable main video bus sRGB to cRGB corrector.