[vdr] Re: error channel switching

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

Andreas Hoelscher wrote:
> 
>                                          Roetgen, Sa 22.09.01 09:29
> 
> Hi,
> since dvb driver snapshot 20.09.01 I can't switch channels anymore.
> Snapshot 18.09.01 works fine (didn't test 19.09.01).
> 
> - Kernel 2.4.7
> - new Haupauge card
> - only dvb driver directory compiled
> - channel switching with vdr 0.95 (no patches)
> 
> error messages :
> 
> Sep 20 19:59:16 andreas2 vdr[1935]: ERROR (dvbapi.c,3280): Invalid
> argument
> Sep 20 19:59:21 andreas2 vdr[1935]: ERROR: timeout while tuning
> Sep 20 19:59:21 andreas2 vdr[1935]: ERROR: channel 1 not sync'ed on DVB card 1!
> Sep 20 19:59:21 andreas2 vdr[1935]: panic level: 0
> Sep 20 19:59:21 andreas2 vdr[1935]: retrying
> Sep 20 19:59:21 andreas2 vdr[1935]: ERROR (dvbapi.c,3280): Invalid argument
> Sep 20 19:59:26 andreas2 vdr[1935]: ERROR: timeout while tuning
> Sep 20 19:59:26 andreas2 vdr[1935]: ERROR: channel 1 not sync'ed on DVB card 1!
> Sep 20 19:59:26 andreas2 vdr[1935]: panic level: 0
> Sep 20 19:59:26 andreas2 vdr[1935]: retrying

I did some testing with the new "Inversion" frontend parameter Ralph has
announced yesterday, but I don't think that this could be responsible for
the errors you are observing.

The current VDR version doesn't know about this new parameter, so the struct
member in FrontendParameters may have some random value. However, the driver
developers were smart enough to make the 'default' case in SetInversion() result
to INVERSION_AUTO for the VES1893, and to INVERSION_OFF for the STV0299. In both
cases all channels on Astra (as far as I have observed) should be receivable, because
they all have INVERSION_OFF.

For the moment I will do the following change to VDR's dvbapi.c, just to
have the Inversion parameter initialized:

--- dvbapi.c    2001/09/21 14:14:28 
+++ dvbapi.c    2001/09/22 09:08:05
@@ -3252,6 +3252,7 @@
 
         FrontendParameters Frontend;
         Frontend.Frequency = freq * 1000UL;
+        Frontend.Inversion = INVERSION_AUTO;
         Frontend.u.qpsk.SymbolRate = Srate * 1000UL;
         Frontend.u.qpsk.FEC_inner = FEC_AUTO;
 
@@ -3298,6 +3299,7 @@
 
         FrontendParameters Frontend;
         Frontend.Frequency = FrequencyMHz * 1000000UL;
+        Frontend.Inversion = INVERSION_AUTO;
         Frontend.u.qam.SymbolRate = Srate * 1000UL;
         Frontend.u.qam.FEC_inner = FEC_AUTO;
         Frontend.u.qam.QAM = QAM_64;

What I don't yet know is: where can the information about the usage of
"spectral inversion" be found? I don't see it in, e.g., the channel listing
that comes with the Infosat magazine. Can it be determined automatically?

Well, I guess this is not such a pressing matter, since everything appears to
work fine on Astra.

Klaus
-- 
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Klaus Schmidinger                       Phone: +49-8635-6989-10
CadSoft Computer GmbH                   Fax:   +49-8635-6989-40
Hofmark 2                               Email:   kls@cadsoft.de
D-84568 Pleiskirchen, Germany           URL:     www.cadsoft.de
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