[linux-dvb] cx24116 & roll-off factor = auto

[linux-dvb] cx24116 & roll-off factor = auto

[Goga777]

Hi

does support cx24116  the roll-off factor = auto ?

Goga

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Re: [linux-dvb] cx24116 & roll-off factor = auto

[Christophe Thommeret]

Le vendredi 23 janvier 2009 18:58:54 Goga777, vous avez écrit :
> Hi
>
> does support cx24116  the roll-off factor = auto ?

no

-- 
Christophe Thommeret

Re: [linux-dvb] cx24116 & roll-off factor = auto

[Goga777]

> > does support cx24116  the roll-off factor = auto ?
> 
> no

who should be care about of corrected roll-off factor which have to send to cx24116 - the drivers or user software ? does
roll-off factor = 0,35 good for 99% dvb-s2 channels ?

Goga

 

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Re: [linux-dvb] cx24116 & roll-off factor = auto

[Alex Betis]

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On Fri, Jan 23, 2009 at 9:49 PM, Goga777 <goga777@bk.ru> wrote:

> > > does support cx24116  the roll-off factor = auto ?
> >
> > no
>
> who should be care about of corrected roll-off factor which have to send to
> cx24116 - the drivers or user software ? does
> roll-off factor = 0,35 good for 99% dvb-s2 channels ?

Driver interface allows specifying AUTO value for most of the parameters.
User application has no idea what card is used and what driver is running.
Since there are other drivers/chipsets that can handle AUTO setting, I don't
see any reason why application should not use it.

For example, DVB-S uses only rolloff = 0.35, so if the driver knows that the
chip can't accept auto value, it should use 0.35 value by default in that
case.

Beside all that, there is a bigger problem that pops up with cx24116 chips
using S2API.
When specifying AUTO value for any of the parameters the driver fails the
tuning, but the application knows nothing about it, so it thinks that
current received stream is from the new channel, while its not true.



>
> Goga
>
>
>
> _______________________________________________
> linux-dvb users mailing list
> For V4L/DVB development, please use instead linux-media@vger.kernel.org
> linux-dvb@linuxtv.org
> http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
>

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_______________________________________________
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For V4L/DVB development, please use instead linux-media@vger.kernel.org
linux-dvb@linuxtv.org
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Re: [linux-dvb] cx24116 & roll-off factor = auto

[Goga777]

> For example, DVB-S uses only rolloff = 0.35, so if the driver knows that the
> chip can't accept auto value, it should use 0.35 value by default in that
> case.

good idea. Anybody against ? 

Goga

Re: [linux-dvb] cx24116 & roll-off factor = auto

[Christophe Thommeret]

Le vendredi 23 janvier 2009 22:44:35 Goga777, vous avez écrit :
> > For example, DVB-S uses only rolloff = 0.35, so if the driver knows that
> > the chip can't accept auto value, it should use 0.35 value by default in
> > that case.
>
> good idea. Anybody against ?

That's already the case with cx24116, 0.35 is used for dvb-s

-- 
Christophe Thommeret

Re[2]: [linux-dvb] cx24116 & roll-off factor = auto

[Goga777]

> Le vendredi 23 janvier 2009 22:44:35 Goga777, vous avez Иcrit :
> > > For example, DVB-S uses only rolloff = 0.35, so if the driver knows that
> > > the chip can't accept auto value, it should use 0.35 value by default in
> > > that case.
> >
> > good idea. Anybody against ?
> 
> That's already the case with cx24116, 0.35 is used for dvb-s


already has been done with cx24116 ? It's strange because I can see in cx24116 debug logs the messages like this

unsupported rolloff selected (3) 

for dvb-s


Goga

Re: [linux-dvb] cx24116 & roll-off factor = auto

[Christophe Thommeret]

Le vendredi 23 janvier 2009 20:49:24 Goga777, vous avez écrit :
> > > does support cx24116  the roll-off factor = auto ?
> >
> > no
>
> who should be care about of corrected roll-off factor which have to send to
> cx24116 - the drivers or user software ? does roll-off factor = 0,35 good
> for 99% dvb-s2 channels ?

The scanning app should get the rolloff factor.
Yes, 0.35 is most likely.

-- 
Christophe Thommeret