[mythtv] Followup question on #6138 (HDHomeRun multirec)

Yeechang Lee ylee at pobox.com
Wed Feb 11 12:53:37 UTC 2009


Joel Means <means.joel at gmail.com> says:
> In minimal testing, it worked for me.  I have a single HDHR and was
> able to make four simultaneous recordings which appeared to be fine.

Six, here (two hardware = four virtual, plus two cable via
FireWire). Went well enough, as far as I could tell, with the caveats
below.

> I didn't really watch them through, as the channels I get with more
> than one feed on the multiplex are PBS, with one HD channel and one SD
> spanish channel and our local NBC, which has the regular HD feed and
> an all weather all the time feed.  So, not really things I want to
> watch.

Same here; I also use my HDHomeRun for OTA only and, other than the
occasional simultaneous recording from PBS HD and one of the PBS SD
stations, don't have any real day-to-day use for multirec other than
for more flexibility with soft padding (I use a global one minute
early and one minute late). I hadn't even thought about or known about
its much larger benefits for QAM users until it was mentioned
elsewhere.

Things I noticed during testing:

* A peculiarity with creating then deleting recording rules; see
  <URL:http://www.gossamer-threads.com/lists/mythtv/dev/369476#369476>.
  I've only run with multirec since applying the patch so don't know
  whether the issue exists with unpatched or not.
* A peculiarity with the scheduler. Let me illustrate:

- OTA channels KPIXDT, KTVUDT, KGODT, and KNTVDT. The last two have SD
  multiplexed channels. All are also available via cable, excluding
  the multiplexed.

LINEUP (*=Not available on cable)
KPIXDT
KTVUDT
KGODT
KGODT2*
KNTVDT
KNTVDT2*
KNTVDT3*

TUNERS
1 HDHomeRun physical tuner 1
2 HDHomeRun physical tuner 1
3 HDHomeRun physical tuner 2
4 HDHomeRun physical tuner 2
5 Cable tuner 1
6 Cable tuner 2


* I schedule simultaneous recordings on KPIXDT and KTVUDT.

1 KPIXDT
2
3 KTVUDT
4
5
6


* I schedule recordings on KGODT and KNTVDT.

1 KPIXDT
2
3 KTVUDT
4
5 KGODT
6 KNTVDT


* I schedule recordings on KGODT2 and KNTVDT3. The scheduler should
  reassign KPIXDT and KTVUDT to 5 and 6, like so:

1 KGODT
2 KGODT2
3 KNTVDT
4 KNTVDT3
5 KPIXDT
6 KTVUDT


Instead, I get the following:

1 KPIXDT
2
3 KTVUDT
4
5 KGODT
6 KNTVDT
KGODT2, KNTVDT3: Conflict warnings; no recordings scheduled


I know that the MythTV scheduler uses a one-pass model. I also know,
from the several threads on -users and -dev recently and from my own
experience, that there are certain peculiarities with how LiveTV works
with multirec tuner assignments. I do know, though, that the scheduler
is in my experience pretty smart about reassigning tuners based on
whether a recording needs a tuner that's already scheduled for use by
another. Is the above behavior due to your multirec patch, the
multirec functionality your patch extends, or the scheduler's existing
design?

-- 
Frontend/backend:	P4 3.0GHz, 1.5TB software RAID 5 array
Backend:		Quad-core Xeon 1.6GHz, 6.6TB sw RAID 6
Video inputs:		Four high-definition over FireWire/OTA
Accessories:		47" 1080p LCD, 5.1 digital, and MX-600


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