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

[Tony Lill]

"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
http://svn.mythtv.org/trac/ticket/1660
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
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