[linux-dvb] Re: Nexus CA Patches for analogue sound

[Johannes Stezenbach <js@linuxtv.org>]

Tim Kaiser wrote:
> The digital part runs quite good over months now, but there are a few
> limitations and bugs.
...
> Sound over analog is bad (I'm sure for Siemens DVB-C as well):

I use the analog part of the DVB-C regularly, and it works fine,
except that it fails to decode stereo sound. The implementation
of the analog support is of hack quality at best, though.
(vbi/teletext doesn't work, too, but that is due to a
bug in the saa7146 according to MiHu; or has anyone seen that
working under Windoze?)

> Problem:
> The MSP is configured strange on one register.
> 
> My Solution:
> The problem is, that the Chip is set to maximum amplification!!!!!!!
> The result is clipping and the automatic modes to
> prevent that are switched off!!!!

Not for the Siemens DVB-C. Indeed even with the current
setting, analog audio volume is considerably lower than
in DVB mode (with default av7110 volume settings).

> Actually I changed the address for the analog chip saa7114 just for me. It's
>  a different address compared with Siemens DVB-C card.
> (Address 0x42 for Nexus, but 0x48 for Siemens)
> I am able to communicate with the chip and try to find a valid
>  initialization. Analog tuning is broken: When i switch on the tuning i get
>  crashes or monitor flickering. Xawtv gives errors about invalid frequencies.
>  Actually i have no idea howto solve that. Will go on triing :-)
> I've started to try initializing the saa7114.

There's drivers/media/video/saa7114.c. Maybe we could find a way
to use that (and drivers/media/video/msp3400.c) instead of replicating
the code?

Johannes