cx88 default contrast,volume,balance

[Mauro Carvalho Chehab <mchehab (at) infradead.org>]

Ian, Marcin and Michael,

We've postponed those patches for quite a long time! Due to lots of
other stuff, those silly fixes were just staying. To return this
subject, let me point the pending issues:

1) Saturation
   0xff seems to be oversaturated in most of the cases.

   Proposed solutions were:
a) Limit maximum saturation at half of maximum chipset scale

if we limit it to 0x7f, most softwares will show this as 50% and seems
ok, but we lose a hardware capability of improving saturation with bad
signals.

b) Creating a non-linear control

This breaks applications like tvtime that reads the value before
incrementing/decrementing it

I would add these two other alternatives:

c) App knows minimum, maximum and default values. So, application may
show default as 50% even when default is less than it, and do
interpolation at userspace

d) We can create a shadow register for it, ranging, let's say, from 0 to
512, where 0-0x3f is interpolated to 0-256 at writing the real register.
On reading, we can just return the sreg value.

I am more to (c)

2) Audio balancing

The way Marcin proposed the fix will produce real weird results if the
user changes balance and volume, then changes back. The better is also
to use shadow register for volume and balance and calculate db
attenuation when writing the real registers.

To be practical on that and not postponing those patches, I suggest to
threat (1) and (2) with separate patches. Maybe Marcin may propose such
patches.

Cheers,
Mauro. 


Cheers, 
Mauro.

--
video4linux-list mailing list
Unsubscribe mailto:video4linux-list-request (at) redhat.com?subject=unsubscribe
https://www.redhat.com/mailman/listinfo/video4linux-list