[linux-dvb] Re: a szap question

[Johannes Stezenbach <js@linuxtv.org>]

Ryan Mak wrote:
> 
> When I use szap with a channel.conf generated by
> dvbscan, does all the other outputs matter when the
> status is 03? For example:
...
> status 03 | signal 6d7c | snr 708f | ber 0000ff00 | unc 00000000 |

The status bits are defined in enum fe_status in
linux/include/linux/dvb/frontend.h.

I think SNR is undefined if there is no signal (FE_HAS_CARRIER)
(no signal, no signal to noise ratio). So if you want
to point your dish the signal level is the only thing
you have. BUT: Due to the zig-zag scan in the frontend driver
it is unstable unless you already have a full lock, and it
is also possible that the internal AFC of the demod makes
it less than ideal as a dish pointing indicator anyway.

I'm not sure about BER and UNC, but IMHO they are undefined
if there is no full lock (FE_HAS_LOCK).


Johannes