[mythtv-users] reported runtimes are 4-5 minutes short for a single channel

[Mark Knecht]

On 4/20/07, Michael T. Dean <mtdean at thirdcontact.com> wrote:
> On 04/20/2007 07:03 PM, Mark Knecht wrote:
> > On 4/20/07, Michael T. Dean <mtdean at thirdcontact.com> wrote:
> >
> >> On 04/20/2007 05:09 PM, Seth Daniel wrote:
> >>
> >>> Recently, reported runtimes for one channel (CBS received OTA here in the
> >>> Los Angeles, CA area) have consistently been 4-6 minutes shorter than
> >>> the time it was set to record for.  So, if I have a rule that recorded
> >>> CBS for 1 hour the reported runtime would be 54-55 minutes.  The entire
> >>> show will have been recorded.
> >>>
> >>> I have seen where some people have recommended running 'mythcommflag
> >>> --rebuild' because they suspect the seek table is inaccurate.  I tried
> >>> this but the reported runtime remained the same.
> >>>
> >>> This problem happens on all recordings on this one channel.  All other
> >>> recordings on other channels have correct runtimes.
> >>>
> >>> I get CBS OTA using an HDHomerun.  Mythtv is compiled and is a very
> >>> recent SVN version.  HDHomerun firmware is 20070320.
> >>>
> >>> As far as I can tell nothing out of the ordinary is in the mythtv logs.
> >>>
> >> This is nothing to worry about.  You're getting the whole show.  The
> >> commercials in the show are encoded slightly differently from the show,
> >> so myth's "estimated" runtime is off a bit.  It will eventually be
> >> fixed, but it's low priority because it doesn't really break anything
> >> and requires some pretty substantial changes to fix properly.
> >>
> > I've had some problems with this also. I found it does break things a
> > bit. If I've gone past the reported runtime - say a 60 minute show
> > where the runtime is being reported as 36 minutes - and say I'm at 45
> > minutes and then save my position and exit the show intending to come
> > back later, then I find I cannot get back into the show at all. At
> > that point I've just had to delete the show completely and hope to
> > rerecord.
>
> That's a different issue.  With the issue the OP is experiencing, it's
> impossible to go beyond the reported runtime (since the reported runtime
> is exactly at the end of the show).  In other words, in his situation,
> Myth just thinks the show is 55 minutes long.  When Myth says he's at 53
> minutes into the show, he's actually just over 57 minutes into the show...
>
> Yours is the case that requires a seektable rebuild, as suggested by the
> OP.  However, mythcommflag is unlikely to work properly in that case,
> and you'll likely have to use "mythtranscode --buildindex".
>
> The consistently off by 4-5 minutes per 1 hour show doesn't hurt
> anything.  The runtime is double
>
> Mike

Thanks for the info Mike.

We've been seeing a lot of problems with ivtv giving up and dumping in
dmesg. To work through that I've built a new kernel and updated to
ivtv-0.10-X. I haven't had time to boot it yet. I'm waiting for some
down time over the weekend to try that.

If I still see the problems with program times then I'll look into
these rebuild commands.

thanks,
Mark