[linux-dvb] What should scan files look like

[Alan Chandler]

I am a bit puzzled over exactly what scan files (ie the driving file for the 
scan program) should contain.

In particular, with my Freecom usb pen drive (14aa:0225 ids),  the scan file 
for the UK Crystal Palace that is distributed with scan does not work.  It 
has the single line

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

noting in particular the frequency of 505.83MHz, against the published 
frequency for JUST ONE of the multiplexes at Crystal Palace of 506MHz.

There was a post on this list that the Freecom device needed an exact 
frequency because of a firmware bug, so I did create a new file with 

T 506000000 8MHz 3/4 NONE QAM16 2k 1/32 NONE

And it appears to find the channels on one of the multiplexes.

But Crystal Palace has six multiplexes for digital terrestial TV, some with 
frequencies above and below the 506MHz

I had a poke around the code as to how it was finding frequencies to scan, but 
couldn't really understand it.  It appeared to be generating the next scan 
frequency once it had done the initial tune, but it was too hard without 
really getting down and understanding it.

I have created a file with the following in, and it works (in the sense that 
it scans the 6 frequencies mentioned and finds loads of channels, and then 
starts looking at others and fails most of the time but does seem to pick up 
some more)

T 506000000 8MHz 3/4 NONE QAM16 2k 1/32 NONE
T 482000000 8MHz 3/4 NONE QAM64 2k 1/32 NONE
T 562000000 8MHz 3/4 NONE QAM64 2k 1/32 NONE
T 530000000 8MHz 3/4 NONE QAM16 2k 1/32 NONE
T 578000000 8MHz 3/4 NONE QAM16 2k 1/32 NONE
T 538000000 8MHz 3/4 NONE QAM16 2k 1/32 NONE

So is this what the uk-CrystalPalace file _should_ look like, or have I 
totally misunderstood what should happen


-- 
Alan Chandler
http://www.chandlerfamily.org.uk