These attributes do not work when bicubic filtering is enabled.  Disable bicubic filtering to use the other xv attributes.  See the radeon man page for more info.

xvattr -a XV_BICUBIC -v 0

thanks a lot alex

How come XV_BICUBIC is enabled by default, when it makes all those settings useless?

Isn't it possible to disable the other settings when bicubic is enabled?

Reopening, as discussed with Jérôme.

Having bicubic filtering is nice, but it breaks all the user expectations when the brightness, contrast, etc. sliders offered by graphical applications fail to do anything.

Possible solutions include:
- Disabling bicubic filtering by default
- Only showing the colour correction values when bicubic scaling is disabled (I'm not sure whether that's possible with XVideo's interface, but my guess is not...)
- Implement colour correction even when bicubic filtering is selected.

The latter would obviously be the preferred way.

(In reply to comment #4)
> - Only showing the colour correction values when bicubic scaling is disabled
> (I'm not sure whether that's possible with XVideo's interface, but my guess is
> not...)

Indeed, I don't think so. However, it should be possible to disable bicubic filtering when the colour correction is not the identity.

> - Implement colour correction even when bicubic filtering is selected.
> 
> The latter would obviously be the preferred way.

Agreed, with the above alternative possibly being next in line, but certainly much easier to implement.

Might be worth disabling bicubic by default due to this bug and bug 28114.  I'm not sure how motivated people are to fix this stuff on old chips.

bicubic disabled by default.