Media players: Black is almost never actually black. Why?

[Colmino]

Doesn't matter what I use. Media Player Classic, Winamp, Zoom Player.. When I watch a video, the luminance range is squashed. Whites are whites, but blacks are now dark gray. Like the players are arbitrarily forcing some sort of half-baked YUV compliance.

And how do I know it's not just a problem with the videos themselves? Because when I view them with VirtualDub, blacks are *gasp* black!

I'd love to know what I should be doing to fix this. Different media player? None of the ones I've mentioned cut it. Even Zoom Player, in addition to failing to acknowledge that it is artificially reducing the contrast ratio, lacks any adjustment tool for correcting the issue. I tried watching the videos in VirtualDub, but I suppose it goes without saying that those attempts met with failure.

Thanks.

[guns1inger]

Open the same video in MPC twice and compare them side by side. If one of off and the other is OK then you need to adjust your overlay settings.

[Colmino]

Hadn't heard about that test. Anyway, I tried it, and the result is that both iterations were identical (with blacks being dark gray).

[Baldrick]

Have you tried adjust the display video overlay settings? Like Avivo Video in the ATI Catalyst Center. Any difference when you change it?
Are you using ffdshow with some filters?

[jagabo]

VirtualDub uses the standard rec.601 matrix to convert from YUV (colorspace used by most codecs) to RGB. The rec.601 matrix expands the YUV luminance range from 16-235 to RGB 0-255.

Video overlay should be doing the same but in the graphics card's hardware. But the overlay proc amp settings can override this. This is why you were asked to compare two instances of MPC side-by-side. Only one program at a time can use video overlay so one of them would be writing RGB directly to the desktop.

The other possibility is that you have some colorspace converter or decoder that is putting out RGB without the rec.601 contrast expansion or with some brightness/contrast adjustments. You could use GraphEdit to view the filter graph that DirectShow builds. That may give you a hint about what's wrong.

[poisondeathray]

Just to add to the comments above, it may be the selection of the renderer.

If you are using VRM9 (renderless) or any other renderer other than overlay mixer, colors will looked washed out. However, if you use overlay mixer, you cannot use subtitles or take screenshots in MPC. Some other players (e.g. SMPlayer) do not have this limitation (i.e. have full capability while using overlay mixer)

Another option is to force RGB output (if you are using ffdshow to decode); just uncheck the YUV options in the output section - this will make it look exactly like vdub's preview. But beware, if you are ever using avisynth and DirectShowSource() - all these "changes" will be passed on to your encode so don't forget to reset everything

[jagabo]

If you use ffdshow to force RGB output you should set the Overlay -> Output -> RGB Conversion -> Contrast to "Standard (Y:16-235, chroma: 16-240)".

[Colmino]

Well, thanks for all the tips, folks. I expect that if I'd had a bit more time, I could have followed them to some sort of solution. Instead I took the lazy way out and grabbed SMPlayer, mentioned above. To my slight surprise, it plays the videos with correct contrast without any adjustments needed. That fits my criteria for a satisfactory fix. ;p Thanks again.