black holes after msu smart deblocking

[cd090580]

Hi,

I have a big problem with the MUS Smart debocking filter. On the bright areas, all the bright/whites colors are replaces by black





The settings I use:


How can I fix the problem ? is it a bug of the filter ??

[jagabo]

You could work around it by reducing the brightness a bit.

[grannyGeek]

Take a look at this webpage, the section on "Overload" about 2/3 down the page.

http://www.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/sab/report.html

Another possible result is known as wrap-around. This is where all out of range values are converted to the lowest value i.e. black. This can result in poor quality video and should be avoided if at all possible. See figure 6.5.

The illustration looks a lot like cd090580 's problem.

jagabo, I'm wondering if this has something to do with colorspace conversion?
(just guessing, I am trying to learn more about color spaces, color ranges, and their limitations )

[jagabo]

jagabo, I'm wondering if this has something to do with colorspace conversion?
(just guessing, I am trying to learn more about color spaces, color ranges, and their limitations )

It probably is a colorspace conversion problem. When filtering VirtualDub converts any incoming YUV video into RGB. Then the filtering is normally done on that RGB data. Of course a particular filter can convert it back to YUV, work internally in YUV, then convert back to RGB. Given that MSU Smart Deblocking 0.5 has the option of deblocking Chroma as well as Luma, it must work internaly in YUV. I wasn't able to duplicate the problem with version 0.5 though. Since the input side of VirtualDub doesn't have the problem it must be in the filter. cd090580 should probably just look for a different version. I see they're up to 0.8 now. Or do as I suggested, decrease the brightness by a tiny bit to avoid the bug.

[Guiboche]

You can also first convert the file to lossless AVI, then apply the effect to your new AVI file. That should help....

[jagabo]

You can also first convert the file to lossless AVI, then apply the effect to your new AVI file. That should help....

That would make no difference if the problem is in the filter.

[Guiboche]

That would make no difference if the problem is in the filter.

Not at all, but I notice he's using a WMV file, so the problem could be from that format....

[jagabo]

That would make no difference if the problem is in the filter.

Not at all, but I notice he's using a WMV file, so the problem could be from that format....

But the input window of VirtualDub doesn't show any problems. That indicates it read the video and converted to RGB properly. I suppose it's worth a try though.

[huboss]

cd090580

Hello! Please, could you try out MSU Smart Deblocking 0.8, and if the problem repeats - write to the support email that can be found at the bottom of MSU Smart Deblocking homepage.

Please, report any bugs and\or suggestions - let's make the filter better!