[mythtv-users] backend takes 100% CPU recording DVB-T

Stephen Williams stephen.gw at gmail.com
Thu Apr 13 08:35:28 UTC 2006

On 4/1/06, Chris Hubball <chris at hubball.org> wrote:
> Hello,
> I'm running 0.19 and I'm finding that the backend is taking 100% when
> recording DVB-T from my Nova-T card.
> This makes Live TV impossible because it has no CPU time left for playback.
> I would expect the backend to only take a small amount of CPU time
> because it's basically just saving the MPEG-2 stream to a file.
> I'm thinking that maybe there is some transcoding going on, however I
> think I've disabled all transcode options.
> Does anyone out there have a Nova-T running with a reasonable CPU usage?
> Thanks,
> Chris.

Ran into this problem last night also with a Nova-T (old 909 model).

Now the really interesting thing is that this only started happening
for me when testing kernel 2.6.15 (Debian testing branch). Running the
_same_ 0.19 install (from source against the fixes branch) and
configuration with a 2.6.8 kernel results in the normal (very low) CPU
usage. Switching to 2.6.15 results in 100% CPU usage and an unusable
system during recordings.

So it appears that the problem isn't exclusively linked to 0.19, maybe
this is an interaction between myth 0.19 and recent versions of the
Nova-T driver, or maybe it's only a driver issue.

My question to everybody else who is seeing this problem is what
version of the DVB drivers and kernel are you using?


More information about the mythtv-users mailing list