[linux-dvb] Twinhan DVB Cab/CI (2031) problems

Zoilo Gomez zoilo at xs4all.nl
Sun Aug 13 03:58:44 CEST 2006

I decided to do some tests using kernel, with following results:

1) locking problems occur using "dvbscan -v" (nut also ("vlc -v") in the 
following situations:
=> kernel with downloaded snapshot 20051202: locks fine, 
dvb-scan returns 0x1f and dumps PMT quickly
=> kernel with downloaded snapshot 20060115: locks fine, 
dvb-scan returns 0x1f and dumps PMT quickly
=> kernel with downloaded snapshot 20060715: no lock, dvb-scan 
returns 0x00 + timeout!
=> kernel with downloaded snapshot 20060717: no lock, dvb-scan 
returns 0x00 + timeout!
=> kernel with downloaded hg snapshot: no lock, dvb-scan 
returns 0x00 + timeout!

So it seems that something has gone wrong between snapshots from January 
and July, with these locking problems as a result.

The strange thing is that the locking problems do not prevent xine or 
vlc from coming up with streaming data (picture), however in between 
"vlc -v" prints 'no lock' every 15 seconds or so, but keeps going anyway 

Of course I would prefer to use the latest dvb-version, but I cannot get 
it to work for reasons mentioned above.

What could possibly be wrong?

Can someone tell me who has a more recent working combination (recent 
kernel + recent dvb-snapshot)?

2) in all dvb-snapshot versions that have I tested, I always need to 
remove the DST_TYPE_HAS_TS204 flag from the "DCT-CI" record in dst_list 
(dst.c), or I will not get a picture; only a long list of TS 
discontinuities. Aren't the necessary patches (Sept 2005) present in 
recent snapshots? I don't understand why I keep running into this 
problem ....

3) whenever I use a "working combination (eg. + snapshot 
20060115), I still have other tuning problems. When I change frequency, 
I need to start vlc 2 times: the first time there seems to be no lock. 
Ctrl-C, restart and ... locked ! If I pick another PID in the same TS, 
there works the first time, so it seems clearly tuner related.

Any help is very much appreciated!



Zoilo Gomez wrote:

> I still have some weird problems with the Twinhan Cab/CI (2031).
> In the mean time I have upgraded to kernel
> 1) When I compile the included drivers (no hg) then the 
> following happens:
> => dvbscan works fine, returning tuning status=0x1f and dumping PMT 
> tables
> => gxine displays garbage (green / purple squares etc)
> => vlc dumps lots of TS discontinuities
> 2) When I compile latest hg and install, the following happens:
> => dvbscan is no longer working, returning tuning status=0x00 and not 
> dumping any PMT tables
> => gxine and vlc more or less work, i.e. if you select the same freq 
> several times (maybe 5 times or so); however the signal is not stable 
> with CI, where vlc dumps a couple of dozen 'invalid header 
> [0x30:d2:c5:7c] (pid: 2001) lines every few minutes and lock seems lost.
> After some browsing in the archives (sept 2005), and comparing source 
> code for both versions, I found that removal of DST_TYPE_HAS_TS204 
> from dst_tlist[] seems to more or less fix 1):
> => dvbscan is working fine
> => vlc working too (!), but unfortunately not always: usually when I 
> change freq, vlc gets stuck after dumping some initial  'TS 
> discontinuities' .... If I stop vlc at this point and restart the same 
> command once more (ie. with same freq) it works immediately. If I 
> change freq+pid, the same problem repeats: first time it is wrong, but 
> second time it works.
> So it looks like there is one small tuning problem left.
> Any suggestions what is going on here? I do not understand very well 
> what is happening. How can I debug it? What do the macro's 
> DST_TYPE_HAS_FW_2 etc mean?
> Thank you and best regards,
> Z.
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> linux-dvb at linuxtv.org
> http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb

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