[linux-dvb] Cam Menu?

Andrew Lyon andrew.lyon at gmail.com
Tue Oct 31 00:36:24 CET 2006

On 10/30/06, David Härdeman <david at hardeman.nu> wrote:
> On Mon, Oct 30, 2006 at 07:07:05PM +0000, Andrew Lyon wrote:
> >>On Mon, Oct 30, 2006 at 04:19:09PM +0000, Andrew Lyon wrote:
> >>Also make sure you use recent drivers from the dvb repo, a patch I wrote
> >>was committed a day or two ago, and without it, my CAM would lock up by
> >>simply using a remote control (which would in turn produce lots of
> >>interesting error messages).
> >
> >I am using a Technotrend S-1500 + CI + CAM, Ive not had errors when
> >using the remote, but I do get problems with my card/cam if I change
> >channels too quickly, and sometimes if i just leave myth running in
> >the main menu, when I watch tv it always gets lock, but I get a blank
> >screen for a long time and eventually a video error or I have to kill
> >mythfrontend, stopping the backend, removing and reloading budget_ci
> >and restarting the backend usually cures it, I ended up adding a menu
> >item for that but its not a nice solution :(.
> I have more or less the same problems. I spent some time last week
> debugging it but I didn't get that far.
> >Really not sure what is wrong, I can leave it playing a encrypted
> >channel for days at a time, but if I change channels a few times it
> >stops working, I have a feeling perhaps the cam is not responding
> >quickly enough to commands, are there any timeout values I could try
> >changing?
> If you're feeling adventurous, you might try recompiling MythTV. In
> mythtv/libs/libmythtv/dvbcam.cpp, function DVBCam::CiHandlerLoop(),
> there is a usleep(250) which I suspect is way to low. The CI
> specification (EN50221) says it's fine to poll every 100ms, so try
> setting it to 90000 or so (this ain't 100% correct because MythTV might
> still want the shorter timeout to read replies etc...but it's a start if
> you want to spend some effort debugging).

Wow!, changing usleep to 90000 seems to have completely fixed the
problem :), Ive changed channel over and over again and even by
entering channel numbers really quickly I cannot make it fail.

The channel change time seems the same too, I will see how it goes in
the next few days and report back again.

Thanks for your suggestion, didnt it work as well for you?


> Additionally, you might want to change
> mythtv/libs/libmythtv/dvbdev/dvbci.cpp, find the line in the beginning
> that says:
> static bool DebugProtocol = false;
> and change it to
> static bool DebugProtocol = true;
> which will give you much more debug info if/when the card acts up.
> >My dvb-s card (Avermedia 777) and Freeview channels do not have the
> >same problem.
> It seems very dependent on the CAM that you're using. I'm using an
> AlphaCrypt with 3.09 firmware, which seems extremely picky. For
> instance, I was earlier using an extra long cable to connect the CI
> board with the C-1500 board, and that caused constant lockups and errors
> (within seconds, cammenu was barely useable) and things improved when I
> used the original (shorter) cable again.
> I'm going to spend more time debugging my C-1500 when I have some more
> time to spend :)
> --
> David Härdeman

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