[mythtv-users] HD-PVR: Encoding Errors Running 0.22

Derek & Cindi Cass cass at casscoenterprises.com
Sun Dec 6 17:19:41 UTC 2009

>Tried another experiment.  I was wondering if maybe uneven performance on
>me disk drives were causing problems.  I have 2x1TB disk drives mirrored 
>using LVM.
>So,  I created a 2GB tmpfs filesystem to write the files to.  Everything
>in memory.  Never goes to disk, so is much faster.
>Tried to record ESPN News.  They have a lot of sports replays.  Same
>skipping problem.
>I opened a case with Hauppauge a week ago.  They claim 2 day response.
>Day 7 and I haven't heard back from them.
>My impression is its scenes that have a lot of motion in them.  Football
>Basketball I see jumps a couple of times per minute. Especially in
>which is constant motion.
>I also had the jump problem when recording Saturday Night Live.  They had
>Black Eyed Peas playing.  They dance/jump around a lot on stage.
>Maybe the HD-PVR just can't keep up.

I don't think this issue is motion based.  I have only once seen this issue
crop up during an NFL game, and I also record NHL games without issues.  I
record them in HD (720p) and I have great playback using the VDPAU High
Quality settings.  No tearing, no skipping.  I don't record anything at
1080i because I like to have mythcommflag be able to keep up with the

I get this issue recording Clifford the Big Red Dog or Blue's Clues fairly
often, at least once a week, so badly that it causes my MythTv box to
shutdown.  I record these shows at 480i.

I record all shows at the high quality bit rate settings.

I think this is related to the usb connection with the hdpvr, and that the
issue is on the hdpvr side.  I have a script that restarts both the frontend
and backend every night at 3am to help with stability issues.  Clifford will
come on at 6am and this issue may or may not crop up.  When it does, I
usually find my mythbox shutdown in the morning.  When I start the server, I
sometimes get usb related errors that cause the machine to fail to start, or
at least to force it to take over 5 minutes to start up.  If I powercycle
the hdpvr while I am getting these errors, fedora immediately recovers and
continues to startup successfully.

I am thinking of figuring out a way to powercycle the hdpvr nightly, or even
on demand via a user job that runs before starting a recording.  The hdpvr
power switch is a toggle switch that will stay toggled 'on' even if the
power goes out, so an X-10 electrical outlet (or equivalent) could be used
to power cycle the hdpvr.


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