Grey background on videos


G

Guest

Hey there guys. I have an issue when playing videos on Windows Vista that has
been annoying me. I watch a lot of videos on my computer so I decided to ask
for help.

When I play videos in fullscreen on Windows Media Player it fills the area
that does not have video (such as a 16:9 video on a 4:3 monitor) with a grey
color. I have taken a screenshot from a full black frame on a 16:9 video I
have.
http://rash.apanela.com/images/wmp_grey_back.jpg

Now, I have changed the color correction settings on my video card's display
driver (that would be a GeForce 6800 GT with ForceWare 158.18). The default
settings produce a "grey black" as well, just like WMP background above. I
know this is due to the TV YUV color range (16 - 235) that some videos are
encoded with. The problem is that the PC allows for full YUV range (0 - 255),
also called extended range. On Windows XP this problem was related to the
video card's driver that was supposed to detect when a video was encoded with
TV range and scale it to PC automatically. I believe NVIDIA's driver doesn't
support that yet on Windows Vista, hence I changed the video color settings
on ForceWare in order to "emulate" the PC range. 14% more contrast and 3%
lower brightness (to make blacks black).

Now, I believe WMP is detecting the video is in this TV color range and is
creating these grey bars in order to match the "grey blacks" from the video.
Here is a screenshot that shows the exact opposite effect from the first one
in this post.
http://rash.apanela.com/images/nv_color.png (this is a 2.35:1 video, so note
the grey bars from the video and the black bars from the player's fill in the
top and in the bottom - this screenshot was taken from PowerDVD and PureVideo
and is meant simply to show a video encoded in the TV range I mentioned).
Well, in fact, if I don't change ForceWare color settings then I'd see a full
grey screen on the first screenshot. That's why I believe WMP is producing a
grey background to match the exact 16 black from the TV range.

Since I don't think NVIDIA is supporting the range detection and scale any
soon on their drivers (and I believe it is their fault, not Microsoft's) I
ask: is there a way to make WMP produce a real black background (see first
screenshot) so it wouldn't contrast with my compensation? Moreover, I would
like to strongly suggest Microsoft to only sign WHQL drivers that detect the
PC/TV YUV color range and scale accordingly. Specially now that we have a
brand new renderer on Vista (Enhanced Video Renderer) it would be nice if
Microsoft pushed video card makers to deliver the best possible video
experience.

I would like to thank the reader who reached this far. Thank you. And I
really appreciate any help.

Andre

PS.: I posted this same question on the Pictures and Video discussion board.
I am posting it here again because I believe this group has more readers and
I would really like to have a solution. Thank you for understanding.
 
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G

Guest

I've got exactly the same problem with an ATI Radeon 1650.
I've not had it since the beginning with Vista, but I can't remember exactly
when it changed. VLC is perfectly fine in DirectX mode as is Media Player
Classic, so I think all the filters are working correctly. There just seems
to be something fundamentally wrong with WMP.

I tried playing with the multitude of video settings in VLC to try and
replicate the problem, and the closest I can get is by stopping the video
card from doing the rendering and getting it to use system memory instead of
video memory. That makes it look as bad as WMP.
Unfortunately I don't have my old graphics card so I can't swap them back
and see if it makes a difference.

Even though everything has the grey border, the picture quality of XVIDs
seems to suffer much more the MPGs.

The only thing I can possibly guess at is that Vista is not using the
hardware acceleration of the cards properly.

There have only been a few mentions of this on the web, so I'm guessing it's
not widespread (or new Vista users simply haven't noticed).
 
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G

Guest

Interesting. Well, I think WMP is trying to compensate for the YUV TV color
range, that's why it adds gray borders (and so you can't see the video's
limits).

Anyway, I've solved my problem (including the proper video scaling) by
installing Haali's Renderer. It has great quality and is 100% offloaded to
the GPU.

I thought Microsoft claimed EVR was focused on quality. :( Sad.

Andre
 

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