[mythtv-users] hdpvr latest firmware color saturation issue question

Devin Heitmueller dheitmueller at kernellabs.com
Mon Jul 23 01:15:42 UTC 2012


On Sun, Jul 22, 2012 at 7:14 PM, Gary Buhrmaster
<gary.buhrmaster at gmail.com> wrote:
> FD: I do not have a HD-PVR, so I have no standing in this debate.
>
> When the driver is actually wrong, such patches should
> be submitted/applied upstream (in the driver).  That means
> everyone is a winner.
>
> Rather than hardcoding a fixup, is not a better temporary patch
> (until you get the patch into the kernel) is to set the initial values
> at the device creation to be "more reasonable", and let the user
> decide for themselves what the correct values should be set to
> for their unique cases (the linux way is to allow one to shoot
> ones-self in the foot, or whatever exposed body part one wants
> to aim at).  I am in favor of good defaults.  I am not in favor of
> taking away my good judgement.

This is *not* a driver bug.  The assumption that 50% of the
operational range of any given control is a valid default is fatally
flawed.

For every control, the driver reports the minimum value, maximum,
step, and the default.  See here for more info:

http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-queryctrl.html

The application should read the default value out of the driver.  If
the application isn't using VIDIOC_QUERYCTRL to determine the default
value for the control, it is broken.

All that said, if the driver *is* returning a wonky default, then
*that* is a driver bug (but I doubt that is the case here).

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com


More information about the mythtv-users mailing list