[linux-dvb] - DEC3000s -- dvbscan fails - build channel list with kaffeine fails -

Peter Beutner p.beutner at gmx.net
Wed Aug 10 13:56:34 CEST 2005

Johann DUPUIS schrieb:
 > [snip]
> Any idea?
> Any way to guess what is wrong? Some tests to done?
> For people who are (successfully) running DEC3000s with linux, could you
> give me some feedback [on stability, features (that are missing), or
> ...]? Especially, stability with TPS (since even in standalone mode I
> experience some troubles when changing channel (no image or no sound
> until shutdown/restart the DEC3000s)?
i can only speak of the dec2000t but as they use the same driver and 
about 90% the same code they should share most of the problems :/
There are some problems with section filters which dont work properly in 
some cases that might explain why the scan fails. (Although iirc 
scanning worked with dec2000t last time I tried.) But you might try to 
look for a channels.conf for your area in the internet instead.

About missing features:
- you wont get any status information(signal quality, signal lock etc.)
- no teletext
- pid filtering is somehow limited, as you cannot set the filter to any 
arbitrary pid, but you are limited to setting the video/audio/pcr pid 
filter. which might be a problem with some applications.
- no support for the CI of the dec2450t and the dec3000s, so no support 
for any encrypted channels.

about stability:
it works quite well if you just watch, but the box very much likes to 
hang if you are zapping around. This also happens under windows but not 
that often and reproducible as with the linux driver.
According to the linuxtv wiki it is at least partly a hardwary problem 
as the AV711x chip is a "quite sensitive beast and hangs often".
Although atleast with the dec2000t these hangups mostly vanished with 
newer firmware & software versions under windows.
So there are certainly some parts in the linux driver which are "wrong".

Some things you could try:
- if the box shares the usb bus with other devices try to remove them, 
so that the box is the only connected usb device.
- as said above try to get a pre-made channels.conf for your area and 
try if simply locking into a channel with szap and the viewing with 
mplayer works
- load the ttusb_dec module with debug=1 and then send the relevant 
dmesg output after you ran the szap/scan command which might give a clue 
what excactly doesnt work.


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