[mythtv-users] Backend drops frames at start of recording; add RAM?

Tony Lill ajlill at ajlc.waterloo.on.ca
Fri May 12 23:49:03 EDT 2006

"kanetse at gmail.com" <kane.tse at gmail.com> writes:

> I have noticed that when my master backend is starting to record 3
> programs simultaneously, it tends to drop frames at the beginning of
> the recordings.  By my estimate, it probably drop around 30s to 1min.
> I have confirmed that it's not a frontend issue, because the
> recordings always skip at the beginning, and regardless of which
> remote frontend I use to view the show, the exact same frames are
> skipped.
> I think it has something to do with the 3 tuners being set to record,
> and then stopping the recordings that were previously going, as well
> as starting up and queuing all the new and old transcoding/commercial
> flagging jobs.  I allow the machine to run 2 comm-flag/transcode jobs
> simultaneously.
> My machine only has 512MB RAM it (but it's a dedicated backend).
> Would topping this machine up to 1GB help this problem?
> My dedicated backend specs:
> MythTV-0.19-127
> 1xPVR-250
> 1xPVR-500
> 512 MB RAM
> Celeron D 2.93 GHz
> Fedora Core 4

No, the problem is probably the database activity. The same thread
that reads from the device also updates the database. On my system I got
dropped frames in the first minute of every recording. That was with
1G memory and only allowing 1 job to run at the same time. I bet you're
getting those lovely ivtv messages abount your application being too
slow. Check out
There's two patches there, mine, which should apply to 0.19 clean and
works great, and an alternate against the head that I couln't get to
work right.
Tony Lill,                         Tony.Lill at AJLC.Waterloo.ON.CA
President, A. J. Lill Consultants        fax/data (519) 650 3571
539 Grand Valley Dr., Cambridge, Ont. N3H 2S2     (519) 241 2461
--------------- http://www.ajlc.waterloo.on.ca/ ----------------
"Welcome to All Things UNIX, where if it's not UNIX, it's CRAP!"

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