[linux-dvb] DiB3000MC : autosearch doesn't work

Mario Rossi mariofutire at googlemail.com
Tue Oct 24 23:25:58 CEST 2006


Thank for the explanation. I misunderstood the meaning of NONE and AUTO.

I tried more to understand the behaviour of scan.

Reading the code of scan it seems that any of the 2 FECs, when they
are NONE, they are converted in AUTO before scanning.

The initial scan file for uk-CrystalPalace is

T 505833333 8MHz 3/4 NONE QAM16 2k 1/32 NONE

I've tried to change them to AUTO and apparently this is the maximum I
could change:

T 505833333 AUTO 3/4 AUTO QAM16 2k 1/32 AUTO

So the question is: what is special about the ones I cannot set to AUTO?


I'm trying to understand why Kaffeine is not able to scan properly:
kaffeine tries with the following settings

inv:2 bw:0 fecH:9 fecL:9 mod:6 tm:2 gi:4 hier:4

which in the scan language is

T frequency 8MHz AUTO AUTO AUTO AUTO AUTO AUTO

This is good for the HDTV channels (it works for scan as well) but for
the "standard" I need to specify (at least)
T 505833333 AUTO 3/4 AUTO QAM16 2k 1/32 AUTO
as I said before.

As a reference this is one of the stardard channels:

BBC ONE:505833330:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_3_4:FEC_3_4:QAM_16:TRANSMISSION_MODE_2K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:600:601:4164

while this is one working with AUTO

ITV HD Trialb:522000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_2_3:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_32:HIERARCHY_NONE:161:162:41029

Is there any substantial difference?

Thanks


On 10/22/06, Patrick Boettcher <patrick.boettcher at desy.de> wrote:
> The original problem was not to set all parameters to wrong values (this
> is what you are doing NONE is wrong in this field, AUTO, 1/2, 2/3, 3/4 5/6
> and 7/8 are valid) and then let the demod guess what might be correct, but
> to see if parameters set to AUTO are then really autosearched.
>
> > So it seems that one has to specify 3/4 for the standard channels
> > (QAM16 2k), while for HDTV channels (QAM64 8k) NONE is good enough.
>
> "Good enough" is not the correct term. This is not a tuneable parameter
> but a fixed one telling you which FEC is used by the boardcaster.



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