Recording Two shows using same channel

[Graham]

(this is why I stick around... so once or twice a year, I will strike down upon thee with great verbiage and furious typing those who fail to understand NRecord, and you will know my name is Johnsonx42 when I lay my explanation upon thee)

I have read your previous descriptions of NextPVR scheduling ... and this is the best yet.

NextPVR does what it needs to do. There is little point in making the scheduling more sophisticated because any attempt at more cleverness can be wrecked at recording time by someone doing one or two "Quick Records" (or watching Live TV) moments before a show is due to start recording.

[HollyCairns]

OK What do I have to do to make sure that a second show uses the same tuner as the first show so that the second turner is available for a show on a different channel. The shows recordings are done on the fly not preschedules as selecting All SHows on this channels doesn't always work or at least doesn't show in the client as to be recorded (shown as red) I'm willing to use padding or no padding or changing which shows are selected first or whatever. Just want to record show 1 on tuner 0, show 2 (same channel, a show which directly follows show 1) on the same tuner so that I can record another show at the same time as show 2 but on a different channel. I'm just confused which shows to select and in which order seems post padding is irrevelent. Any clues please.

[Graham]

... The shows recordings are done on the fly not preschedules as selecting All SHows on this channels doesn't always work or at least doesn't show in the client as to be recorded (shown as red)

Selecting All Shows should work and shows that are scheduled to be recorded should be highlighted in red. Please duplicate the problem(s) and attach NextPVR logs to a post listing the shows that should be recorded and are not highlighted.

NextPVR uses data in the EPG to decide if a show is "New" ... It might be that your EPG source is providing unreliable data regarding the "newness" of a show. Do you get different results if you schedule recording of "all" shows rather than "new" shows?

By default, NextPVR avoids recording episodes that have already been recorded (including episodes that have been recorded and then deleted). You can delete the recording history using the "-removehistory" command line option ... http://www.nextpvr.com/nwiki/pmwiki.php?...ineOptions

It should be possible to rely on NextPVR to make good decisions about the use of tuners.

[HollyCairns]

I think I've solved my problem. Thanks to all who replied.

[jcole998]

@HollyCairns...Would you care to share?

@johnsonx42...Many thanks for your (almost)thorough explanation of tuner use. You were SO CLOSE to explaining my situation but missed the mark. I'm making all this noise since there are occasions that my computer clock and the TV next work clock show have different time. Many times I have missed the beginning or the end of a show. Padding was the answer. When it works. I don't really care what tuner is selected for a given show, but indicating that a tuner needed for channel 2 is not available when there is already a tuner on channel 2 makes no sense. I was told it has to do with tuner sharing. I was told that tuner selection can be influenced by when and in what order shows are scheduled in addition to recurring show priority. I have been unable to combine these elements into the desired results.

Can you explain why NextPVR will not choose a tuner that is already tuned to the needed channel and share it? I can't seem to get an answer. Tuners were shared much more often in earlier versions.

[Graham]

Can you explain why NextPVR will not choose a tuner that is already tuned to the needed channel and share it? I can't seem to get an answer. Tuners were shared much more often in earlier versions.

I apologise if I have missed something.

What are the symptoms of the problem that you are trying to solve?
Do you have shows that are not being recorded even though a tuner is available?
Does NextPVR report "conflicts" even though a tuner is available?

[johnsonx42]

@johnsonx42...Many thanks for your (almost)thorough explanation of tuner use. You were SO CLOSE to explaining my situation but missed the mark. I'm making all this noise since there are occasions that my computer clock and the TV next work clock show have different time. Many times I have missed the beginning or the end of a show. Padding was the answer. When it works. I don't really care what tuner is selected for a given show, but indicating that a tuner needed for channel 2 is not available when there is already a tuner on channel 2 makes no sense. I was told it has to do with tuner sharing. I was told that tuner selection can be influenced by when and in what order shows are scheduled in addition to recurring show priority. I have been unable to combine these elements into the desired results.

Can you explain why NextPVR will not choose a tuner that is already tuned to the needed channel and share it? I can't seem to get an answer. Tuners were shared much more often in earlier versions.

It will, if it needs to. The answer will have to do with recurring recording priority, tuner allocation already done (i.e. single recordings), and the exact times of the shows in question (particularly, when you have shows that start a minute ahead of the hour, or finish a minute after the hour, this can lead to chaos).

It helps to remember that the scheduler schedules one show (recurring recording) at a time, and each individual recording is scheduled against the backdrop of everything ALREADY scheduled, but without regard nor even knowledge of what WILL be scheduled. So it will give you less than ideal arrangements. You can almost always analyze the schedule NextPVR has laid out and come up with a better arrangement. That's just the way it is.

Keep in mind also that cablecard tuners are multi-record capable in only the most limited sense - they can deliver data from the exact same channel to multiple recording streams, that's it. They can't deliver multiple TV channels carried on the same physical frequency like a regular digital tuner can. So their utility is limited to supporting padding on back-to-back recordings on the same channel if-and-only-if the scheduler happens to put the two recordings on the same tuner.

Consider this (assume 1 hour shows, and assume you have 3 tuners, 21, 22 & 23):

Show 1, Priority 1, Channel A, 8pm
Show 2, Priority 2, Channel B, 9pm
Show 3, Priority 3, Channel A, 9PM

The scheduler will schedule Show 1 on Tuner 21, Show 2 on Tuner 21, Show 3 on Tuner 22. Yes, I know that's not what you want. Now, let's add 1-minute pre-padding:

Show 1, Priority 1, Channel A, 8pm, 1-min pre-pad
Show 2, Priority 2, Channel B, 9pm, 1-min pre-pad
Show 3, Priority 3, Channel A, 9PM, 1-min pre-pad

The scheduler will STILL schedule Show 1 on Tuner 21, Show 2 on Tuner 21, Show 3 on Tuner 22. However at recording time, the recording engine will move Show 2 to tuner 23 to start pre-padding. Show 3 will stay on Tuner 22. I know, still not what you want, but you do get your padding on all 3 shows... but if there are more shows in the same timeslots, all may be ruined.

WHY WHY WHY WHY? Why can't it know to put Show 2 on Tuner 22 and Show 3 on Tuner 21, in order to keep Tuner 21 on Channel A the whole time? Because when the scheduler schedules Show 2 on Tuner 21, it has no idea Show 3 will come along later. It's not going to use a 2nd tuner when the 1st is available (because, for all it knows, the next two recordings to come along will be a 2 hour movie starting at 8, and a 9pm show that starts a minute early at 8:59; if it "burns" a tuner on Show 2, there will be a conflict).

Now reverse the priority of Show 2 & 3:

Show 1, Priority 1, Channel A, 8pm
Show 2, Priority 3, Channel B, 9pm
Show 3, Priority 2, Channel A, 9PM

Now the scheduler will schedule Show 1 on Tuner 21, Show 3 on Tuner 21, and Show 2 on Tuner 22. Now Tuner 21 stays on Channel A. That's what you want. YOU can do this after looking at the results of the scheduling... NextPVR can't.

[jcole998]

Thank you, johnsonx42. An excellent explanation! I appreciate your effort in helping me out.

It seems that I can't get it through my head that for the most part, padding is not a priority nor a factor in scheduling but only comes into play when the show is about to start at the pre-pad time. Unfortunate but padding appears to be sacrificial. Maybe some future update may include consideration for sharing tuners from the get-go.

As an exercise, or not, this next insert shows what is scheduled for Tuesday night. I'll post what NextPVR actually did.

Thanks, again.

[ATTACHMENT NOT FOUND]

[sub]

It seems that I can't get it through my head that for the most part, padding is not a priority nor a factor in scheduling but only comes into play when the show is about to start at the pre-pad time. Unfortunate but padding appears to be sacrificial.

NextPVR has always treated padding as "optional, but nice to have if possible". The reality is, the majority of users only have a single tuner, where you need to ignore padding to allow recordings in adjacent timeslots or you'll have all sorts of scheduling issues.

When things like multi-record came along later, it complicates those scheduling decisions. The app will try to take those possibilities into account to enable padding, but only in places where it wasn't going to make the scheduling engine horrendously complicated or hard to maintain (which would have been the case if I'd tried to make it perfectly suited to all scenarios).

[jcole998]

Thanks for that, sub. I used to be involved, software-wise, in scheduling when to play audio in various situations. Probably not comparable to what NextPVR does but I can appreciate what's involved.

I will try to see if I can come up with a scheduling process that works for me by using a combination of SQLite and Powershell. Hope you don't mind.

Thanks again to all who have contributed to helping me understand the scheduling process.