ATI, your help is needed - color space conversion under new CCC options

[HiThere]

It would seem that for newer Radeon cards under the newer CCC versions, there are a lot of options with regard to pixel format for output, black level expansion for video, etc....the problem is, consistent behavior across applications and various video sources is still elusive. It's not just me, there are plenty of threads over at avsforum concerning this issue.

Being as these settings are specifically there to enable output to a television under various conditions, I would like to see ATI clarify in some way the changes to the processing of video sources, including the Windows desktop, under various settings in the Catalyst Control Center...After experiencing what it's like to try and get consistent behavior from a Radeon-equipped PC connected to a television, specifically with regard to color space conversion or levels expansion from 16-235 sources (DVD, Bluray, basically all commercial video), I'd really like someone, anyone, at ATI to clarify the following:

1. For each of the "pixel format" settings under the CCC, what does each selection do with the desktop with regard to conversion to/from the card's "native" RGB?

2. For each of the "pixel format" settings under the CCC, what does each selection do to video sources with regard to conversions from YV12 or other format to/from the selected format, and any intermediaries (like the card's "native" RGB), and does this take place for all possible video renderers, or only some, and what should I, as a user, expect to see from my various video software players? If I am connected to a tv expecting black at 16, what do I need to set my software player up to do, generally, to enjoy video on the tv at "proper" black levels/color space, for each of the pixel format selections?

3. I understand there is a dynamic range setting under the new CCC for 5xxx series cards...what does this do, with regards to levels expansion, in conjunction with each of the above pixel format settings? Does it work for all video renderers for all sources, or just some? Where does the expansion or lack thereof occur in the signal chain?

In other words, I (and many, many other users as evidenced by the size and frequency of posts about black levels on ATI cards over at avsforums) want to know, mechanically, what each of these settings does. I want to know how many conversions are happening with regard to color space for each setting, and where in the processing chain they occur under various output conditions.

In other words, we need a white paper with a chart or diagram showing, at a driver/processing chain level, what is happening between the media and the output of our cards. These settings are there to enable the best possible experience when outputting to something other than a PC monitor, and I shouldn't, as a user, have to guess at what they do, how it is done, and where in the processing chain the action occurs. I understand that there is a myriad of third-party video playback software out there, and that each can throw its own set of wrenches in the mix....but I don't think ATI is holding up their end of the bargain with regard to specifying what their own settings are designed to do. So far as I can tell, there are no hover-over pop-up hints, no explanation in the help file beyond that which is already self-evident in CCC, and no information on the limitations/benefits of each setting and where it occurs in the chain. This is inexcusable...there can be no doubt that some engineer somewhere had to justify the presence of each new setting in CCC, no doubt that their utility and logical place in the processing chain had to be explained to someone, somewhere, no doubt there are some logical scenarios under which one would want to use those settings...so explain!

By way of example: If I select pixel format "YCbCr 4:2:2" in CCC, does the card pass blu-ray source video unmolested from disc to hdmi output, or does the card convert to/from native RGB in an intermediate step? Do I have to specify "no levels expansion" to my video player software when this setting is engaged? Do I still have to specify black level under Avivo settings when this format is engaged, or is it assumed that selecting the format indicates that no level expansion is desired? Does the pixel format conversion take place before or after other processing by the software player? Which pixel format setting gives me the most accurate output for bluray sources when connected to a television? I have no way of knowing the answers to these simple questions from the info provided by ATI.

[kn00tcn]

well, the hard way is to manually test the diff combos of options...

[mikiem]

FWIW I think a lot of stuff under the Avivo umbrella falls short of being omnipotent... If you've got video source that's already full range vs partial, or worse, with the US broadcast black level makes a difference. Whatever decodes the video, & how it interacts with Avivo, if at all, makes a difference. If in the process of decoding/displaying the video there's transcoding going on (i.e. a lot of streaming solutions), that makes a difference. What CCC settings are enabled in the registry (& which ones work with your card), & what they're set to can make a difference. Add to that ATI is evolving Avivo, where some settings that used to be available & appeared to work (at least somewhat in my experience) like Dynamic Range don't with 10.1. [I normally check Avivo separately with each driver version so I can go back somewhat by simply replacing a couple (or 4) files (...Common Files\ATI Technologies\Multimedia), though it's not foolproof.]

"If I select pixel format "YCbCr 4:2:2" in CCC, does the card pass blu-ray source video unmolested from disc to hdmi output, or does the card convert to/from native RGB in an intermediate step?"

That's not really the card's job. Whatever player app has to read the BD & get thru the DRM, then software has to decode the vid, & optionally audio. Then your graphics card has the job of putting on-screen whatever that software tells it to. If/When you use HDMI rather than DVI it's *mostly* irrelevant, with the addition of DRM measures & some often optional display settings. With Avivo an ATI card's drivers & related software can try to inject themselves into the process, as with Cyberlink's PowerDVD, hardware acceleration assisting decoding etc, but the results are far from guaranteed -- it all depends on whether all the software involved is agreeable to your ATI card/software butting in. At any rate, to directly address your question, encoded audio can be *passed through* your PC/laptop to an *external decoder*, which means whatever's on the other end of the cabling has to possess a decoder. Video pass through is called *file transfer*, i.e. copying file content to an external decoder like any one of dozens of stand-a-lone boxes available, using hard drives, USB sticks, network connections etc... Otherwise, if/when the graphics card is involved it's real *job* is putting the already decoded video it's given on screen.

"I have no way of knowing the answers to these simple questions from the info provided by ATI."

And... ATI has no way of knowing what software you have installed, how anything's configured in the registry, how the software you have installed conflicts with other software you've installed, what hardware you're using, what you have at the other end of the HDMI cable (or how it behaves), how you've set up Windows etc... It would be wonderful if the topic wasn't complicated, but for better or worse, what is, is. I'd suggest checking out any info & forums re: Media Player Classic home theater [MPC_HC], discussions on Direct Show filter merit, if in Vista/7 check out the greenbutton site, browse the forums at doom9.org & videohelp.com, check out GB-PVR, and of course the avsforums aren't bad at all. Remember Windows wasn't designed primarily for any home theater PC, & when it's used that way, satisfied users often don't use it for much else, i.e. don't have a lot of conflicting apps & DS filters installed. Also, HD is often designed around HDMI, which was designed primarily for DRM, Not function... there's a reason transcoding content to xvid etc is so popular, a part of many (most?) home theater/streaming setups, & using a stand-a-lone media player box is so popular (& perhaps why there are so many of them).

[HiThere]

First, thanks for all the info, I'm glad someone decided to chime in on it, and grateful for the help...

Originally Posted by mikiem

FWIW I think a lot of stuff under the Avivo umbrella falls short of being omnipotent... If you've got video source that's already full range vs partial, or worse, with the US broadcast black level makes a difference. Whatever decodes the video, & how it interacts with Avivo, if at all, makes a difference. If in the process of decoding/displaying the video there's transcoding going on (i.e. a lot of streaming solutions), that makes a difference. What CCC settings are enabled in the registry (& which ones work with your card), & what they're set to can make a difference. Add to that ATI is evolving Avivo, where some settings that used to be available & appeared to work (at least somewhat in my experience) like Dynamic Range don't with 10.1. [I normally check Avivo separately with each driver version so I can go back somewhat by simply replacing a couple (or 4) files (...Common Files\ATI Technologies\Multimedia), though it's not foolproof.]

I'm aware that there are a myriad of variables available to the user in terms of installed software and configuration...I just want to know where, logically, the various check boxes concerning pixel format, levels expansion, etc. in ATI's own drivers fall in the chain between input and output. I think it's the onus of the software providers to tell you about settings made available to the user, but c'mon...you mean to say ATI can't relate settings on their graphics card to common renderers such as EVR under Vista/Win7? Or to the Windows desktop? You know, using terms like "may be called by" or "processes the output of", or "doesn't effect the output of", or even putting the setting in a block on a flow chart? I'm not asking them to play "guess the output when I do this", I'm just asking where, logically, the setting applies it's effect and under what circumstances. If it just sits there until an application calls it, then I want to know. If it processes the frame buffer without regard to what's in it, I want to know...

The way I see it, somewhere along the line, an engineer had to explain the inclusion of these settings in CCC to a manager's manager, and perform testing of the settings under various scenarios, or he wouldn't have been authorized to charge time to the project, or add the check box to CCC...

Originally Posted by mikiem

That's not really the card's job. Whatever player app has to read the BD & get thru the DRM, then software has to decode the vid, & optionally audio. Then your graphics card has the job of putting on-screen whatever that software tells it to.

Sorry about the "pass through" term, if it's confusing...I just want to know if the selection of a pixel format under catalyst affects the output of bluray playback software in general....under what circumstances those settings perform their function...Again, simply knowing where it occurs in the process chain is enough, and if there are scenarios where it is ignored...I don't need to know the specifics about what effects it has based on the myriad other things I can do that change the color of a pixel.

Originally Posted by mikiem

I'd suggest checking out any info & forums re: Media Player Classic home theater [MPC_HC], discussions on Direct Show filter merit, if in Vista/7 check out the greenbutton site, browse the forums at doom9.org & videohelp.com, check out GB-PVR, and of course the avsforums aren't bad at all.

Those forums are where I'm coming from...and they're all asking the same set of questions.