[mythtv] Mythtv 0.20 DVB-T 'Could not open demux device' messages

[Wolfgang Nothdurft]

On Di, Oktober 3, 2006 16:35, Daniel Kristjansson wrote:
> On Tue, 2006-10-03 at 14:55 +0100, John Pilkington wrote:
>> I posted this first to the atrpms list, and later started a new thread,
>> subject "Ticket #1970   (dvbrecorder: limit number of open pid filters)"
>> dvb-usb: will use the device's hardware PID filter (table count: 15)
>> I mentioned this earlier but it was in the heat of the upgrade.
>> I'm still getting these error messages every two seconds during
>> recording.
>>   DVBRec(0) Error: Could not open demux device.
>>                          eno: Too many open files (24)
>
> I believe this is normal with your device. MythTV doesn't know ahead
> of time that your card can't filter the number of streams needed, so
> it opens as many as possible until it gets that error. What happens
> then is that every couple seconds it closes a pid that it wants to
> listen to and opens another it wants to listen to, it does this in
> a round-robin fashion so that it has a relatively up to date view
> of the metadata in the stream. The fix referred to in the [10946]
> changeset makes sure that it gives the current audio and video
> streams priority over other streams, and attempts to always record
> them.
>
> The error message you are seeing should be suppressed, but doesn't
> indicate any real error in the recording. The worst that will
> happen with 24 streams is that channel changing will be a little
> slow and potentially you won't be able to record MHEG or other
> interactive television programs. Regular TV and DVB Radio should
> work fine.

I have the same issue with a DVB-C Technotrend C2300 (dvb_ttpci/ST STV0297
DVB-C).
I don't think that this error can be ignored, because after serveral
restarts of myth the card is unusable and I have to reload the kernel
module. I don't know if this is a driver issue or a myth issue. At the
moment I have hardcoded a pid limit for me, so everything is fine.

On my system I get first eno: Operation not permitted messages and later
eno: Too many open files. The kernel writes errors like
dvb-ttpci: StartHWFilter error  buf 0b07 0010 06e1 b96a  ret 0  handle ffff
to syslog and than later the card gets unusable.
I can't say how long it takes when the cards is unusable, if I let
mythbackend run, because I swap often between my stable and my develop
backend. I can only say that after four or five restarts the driver needs
a reload.

Wolfgang