[mythtv-users] Preview Errors caused by superfluous LiveTV zero length files?
Tom Dexter
digitalaudiorock at gmail.com
Fri Apr 18 13:29:25 UTC 2008
On Fri, Apr 18, 2008 at 2:35 AM, Michael T. Dean
<mtdean at thirdcontact.com> wrote:
> On 04/15/2008 03:07 PM, Tom Dexter wrote:
> > I frequently get these preview errors in my mythbackend.log.
> >
> > 2008-04-13 12:29:01.342 Preview Error: Previewer file
> > '/video/recordings/1051_20080413122857.mpg' is not valid.
> > 2008-04-13 12:29:01.343 Preview Error: Run() file not local:
> > '/video/recordings/1051_20080413122857.mpg'
> > 2008-04-13 12:29:01.349 Preview Error: Preview process not ok.
> >
> > fileinfo(/video/recordings/1051_20080413122857.mpg.png) exists: 0
> > readable: 0 size: 0
> >
> > I've been able to determine that they're occurring because, every time
> > I enter LiveTV or change channels in LiveTV, a zero length mpg file
> > gets created in addition to the valid file that gets streamed to the
> > frontend.
>
> Dummy video. It's required for some capture card types.
>
Aha...I didn't know there was actually a reason for those. Like I
said, they never appeared to cause any harm anyway.
>
> > It gets auto expired and disappears shortly after. I had
> > this issue in 0.20.2. It's never caused any problems, but I thought
> > for sure this would be fixed in 0.21.
>
> Patches welcome. :)
>
>
>
> > In 0.21 I've also been
> > occasionally getting these in the mythbackend.log:
> >
> > 2008-04-13 13:00:30.833 Preview Error: Encountered problems running
> > '/usr/bin/mythbackend --generate-preview 0x0 --chanid 1071 --starttime
> > 20080413124200 '
> >
> > I'm not sure what's trying to do that, but the '0x0' part certainly
> > looks suspect...maybe those are related to the bogus zero length
> > LiveTV files as well.
> >
> > Is anyone else seeing any of the above? Like I said...the extra zero
> > length LiveTV mpg files have been occurring ever since I first built
> > the system and they happen every time I enter LiveTV or change
> > channels without fail. For example, I just went into LiveTV and
> > surfed though a few channels and get this:
> >
> > /video/recordings $ find . -size 0
> > ./nfslockfile.lock
> > ./1021_20080415145909.mpg
> > ./1041_20080415145916.mpg
> > ./1051_20080415145926.mpg
> >
> > ...and here are some of the zero length files along with the valid
> > ones that get streamed to the frontend:
> >
> > /video/recordings $ ls -alt *.mpg
> > -rw-r--r-- 1 mythtv video 12806560 Apr 15 14:59 1051_20080415145928.mpg
> > -rw-r--r-- 1 mythtv video 12549188 Apr 15 14:59 1041_20080415145918.mpg
> > -rw-r--r-- 1 mythtv video 0 Apr 15 14:59
> > 1051_20080415145926.mpg
> > -rw-r--r-- 1 mythtv video 8618484 Apr 15 14:59 1021_20080415145910.mpg
> > -rw-r--r-- 1 mythtv video 0 Apr 15 14:59
> > 1041_20080415145916.mpg
> > -rw-r--r-- 1 mythtv video 0 Apr 15 14:59
> > 1021_20080415145909.mpg
> >
> > Also, I have "Display thumbnail preview images of recordings" turned
> > off for my frontend. Does the backend try to generate them for all
> > recordings anyway?
>
> Yep. The setting only affects whether they're displayed in the frontend.
>
>
> > I suppose in any case they'd be needed for mythweb
> > even if no frontends used them.
> >
>
> Ahem. (muttering)not really since mythweb uses custom-sized preview
> images... However, some other clients may use them.
>
> And if they haven't been generated ahead of time, enabling their display
> would make the Watch Recordings screen completely unusable. Since
> there's no harm in generating them, ...
>
>
> > I use the "Display live preview of recordings option"...speaking of
> > which (getting a little OT here)...where did the low cpu option for
> > the live preview go in the setup menus? I still have it set in the
> > settings table (PlaybackPreviewLowCPU),
>
> We don't remove old values from settings (as they don't hurt anything).
> Doing so would be dangerous.
>
>
> > but I don't see it anywhere in
> > the menus...it's definitely not on the same screen with the "Display
> > live preview" option.
>
> It was removed in development of the mythtv-vid branch (and was since
> merged to trunk before the 0.21 release). I'm not sure why Daniel took
> it out, but I trust there was good reason.
>
> Was it /really/ necessary for you?
>
> Mike
>
Thanks much for all the answers Mike.
The low cpu preview thing certainly wasn't a must...without it the
watch recordings screen tends to use as much CPU as watching shows, so
I feel like I have to make sure (and remind my wife) to not leave myth
on that screen overnight. The preview certainly look better at full
speed. If I was concerned enough of course, I'd just switch to
thumbnails.
Thanks again.
Tom
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