Recording Two shows using same channel

[HollyCairns]

I often record shows on the same channel one after the other. In both cases I have a 10 min buffer at the beginning and end of the shows. Usually these shows can use the same tuner during the period of overlapping . However sometimes they use two tuners preventing me recording another show at the same time. Is there some way I can force NextPVR to record the same show on the same tuner. For example:

5:00-5:30 Show1 it records on tuner 1 between 4:50 - 5:40
5:30-6:00 Show 2 (same show as Show 1 but a different episode) force it to record using tuner 1 5:20-6:10
5:30-6:00 Show 3 a different show on a different channel. Record on Tuner 2 5:20-6:10.


I hope I explained this OK.

HollyCairns, Toronto, Canada

[sub]

Yep, this can happen, and there isn't much you can do about it easily. It basically comes down to the order the shows were scheduled, and the priority assigned to any recurring recordings.

If you want show 1 and show 2 to schedule on the same tuner, and they're both recurring recordings, you can increase the priority on both of these, so that they're higher than show 3, causing their recordings to be scheduled first, and then they should record on the same tuner.

[HollyCairns]

Thanks. and how can you increase the priority? Do you do this in NextPVR or in its addon (I'm using Kodi).

[sub]

You can only do it in NextPVR itself. There is no equivalent in Kodi.

In NextPVR in the Recordings->Recurring screen, press the 'sort' button at the top of the screen a few times, to make sure you in 'priority order', then press the skip buttons (Ctrl-Left/Ctrl-Right) to move a show up or down the list.

[jcole998]

I've asked in the past how tuners are assigned for future recordings. From the above post, it seems that there is something that needs to be looked at.

I've re-prioritized my recurring recordings by grouping together all shows using the same channel, regardless of weekday. I'm trying this based on the hint given by sub that this will force back-to-back shows on the same channel on the same night to the same tuner. My test did not produce the results I expected.

I've inserted a screenshot of database entries from a "join" of Scheduled_Recordings, Recurring_Recordings, Capture_Source and Channel tables to produce the four lines for four shows on the same night and channel. I would expect the two back-to-back shows for each channel to be assigned the same tuner but they are not.

The following makes sense to me:
-the 2nd NBC show should have been assigned to the same tuner as the 1st NBC show
-the 1st CBS show should have been assigned to resource 22 and not conflict with the 1st NBC show
-the 2nd CBS show should have been assigned to same tuner as the 1st CBS show.

Can you please help me understand how these tuner assignments were made? Or is there a glitch somewhere? Pre-/post-padding suffers losses.

[ATTACHMENT NOT FOUND]

[pkscout]

I wonder if to get the desired result you have to group by time (with earliest time being higher priority). If I assume tuner 21 is a higher priority than tuner 22, then manually walk my idea of the logic for recordings here's what I get with your shows as they are shown:

Hawaii Five-0 is assigned to available tuner 21
Blue Bloods is assigned to tuner 21 because tuner 21 is already recording something in the previous time slot on that channel
The Blacklist is assigned to tuner 22 because tuner 21 is not available at that time
Blindspot is assigned to tuner 21 because it is available at the time and is the highest priority tuner

This logic works if NPVR is prioritizing using the highest tuner over keeping padding (or if NPVR is only looking at what tuners are in use at start time, not end time).

If you change the recording priority to Blindspot, Blacklist, Hawaii Five-0, Blue Bloods (which is 20:00, 21:00, 21:00, 22:00) then I think you might get the desired result (which is Blindspot on 21, then Blacklist on 21 and Hawaii Five-0 on 22, then Blue Bloods on 22). Then again, if NPVR is prioritizing tuner over padding, even that might not work (Blue Bloods could end up on 21). But it might be interesting to try.

Logic problems hurt my head.

[jcole998]

Hello, pkscout, and thanks for the suggestion on grouping by time. I tried something a little different and got non-intuitive results. Please check the screenshot:

[ATTACHMENT NOT FOUND]

This was created using only two programs. I scheduled Blindspot at 20:00 first and then Hawaii Five-0 at 21:00. I cannot understand why Five-0 was assigned the same tuner even though the channel is different and two other tuners are unused. It's been hinted that a tuner needs to be of the multi-record variety which the Hauppauge DCR-3250 allows.

Something is not right.

I'm hoping sub or Martin can help with this but, of course, all help is welcome.

sub? Martin? Anyone?

[BrettB]

This was created using only two programs. I scheduled Blindspot at 20:00 first and then Hawaii Five-0 at 21:00. I cannot understand why Five-0 was assigned the same tuner even though the channel is different and two other tuners are unused.

Your comment "I scheduled Blindspot ... first and then Hawaii Five-0..." leads me to think that you:

1. Deleted them (everything?) from recurring recordings
   
2. Added a new recurring recording for Blindspot
   
3. Added a new recurring recording for Hawaii Five-0
   
4. Used your query to look at the scheduling at that moment in time
   

Keep in mind that the way NextPVR tuner assignment works the tuner "assigned" in the Recordings table should really be considered only a guess/hint at the "expected" tuner which will ultimately be used. At the actual recording time less the pre-padding, if the "expected" tuner is in use for a channel not compatible with the channel needed for the recording (i.e. a channel not on the same frequency or if multi-record isn't available) then NextPVR will attempt to "move" the recording to a different tuner. So in your example, while it may seem that both recordings will be recorded on the same tuner (and recording 1 will lose post-padding and recording 2 won't get pre-padding), in actuality, at the recording time, Hawaii Five-0 should get moved to another free tuner and both recordings should have all pre- and post-padding.

[johnsonx42]

Hello, pkscout, and thanks for the suggestion on grouping by time. I tried something a little different and got non-intuitive results. Please check the screenshot:

[ATTACHMENT NOT FOUND]

This was created using only two programs. I scheduled Blindspot at 20:00 first and then Hawaii Five-0 at 21:00. I cannot understand why Five-0 was assigned the same tuner even though the channel is different and two other tuners are unused. It's been hinted that a tuner needs to be of the multi-record variety which the Hauppauge DCR-3250 allows.

Something is not right.

I'm hoping sub or Martin can help with this but, of course, all help is welcome.

sub? Martin? Anyone?

That is working exactly as designed (perhaps not what you wish, but there's no bug). The scheduler makes most efficient possible use of tuners as each recording is scheduled, without consideration of padding or what other programs may be recorded later. So you have a 1 hour program at 8pm, it schedules it on the highest priority tuner found to be available for the entire timeslot, which is tuner 21. Then you have a 1 hour program at 9pm, it schedules it on the highest priority tuner found to be available for the entire timeslot, which again is tuner 21. Yes, you may *want* it to use a different tuner, but it's always going to use the highest priority tuner available for the scheduled recording time. Even if <insert clever argument that it should do something different>? Yes, even if that.

What about Padding? Ah, the elusive padding... we could argue all day about what NextPVR *should* do about padding, but here's what it DOES do:

First, as I said above, (positive) padding is ONLY considered at recording time. The scheduler pays (positive) padding requests no regard at all, it's only the recording engine that attempts to do positive padding (for the rest of this, I'm talking about positive padding, that is, extra recording time before the program begins or after the program ends... negative padding is a whole different thing, I don't use it and I can't babble on for 10,000 characters about it - consider yourself lucky)

Post-padding: this one is easy. NextPVR doesn't give a crap about post-padding. If the tuner in use for the program isn't needed at all, you get post-padding. If that tuner is needed for ANYTHING else, even if there are 15 other tuners that could do the same thing, you don't get post-padding (or you get post-padding up until the tuner is needed). To my knowledge, there is nothing in the scheduler or recording engine that gives an ounce of consideration to your request for post-padding. The recording engine will stomp on your post-padding without apology, and in fact, last time I checked, doesn't even know that it did it. Post-padding is both figuratively and literally an after-thought.

Pre-padding: NRecord does it's best to make Pre-padding happen, with some constraints. At the time a recording is supposed to start WITH padding, the recording engine checks to see if the scheduled tuner is already available. If it is, great, it starts the recording with pre-padding. If not, it goes looking for another tuner that is available NOW and for the entire timeslot of the recording. If it finds one, it moves the recording to that tuner, and starts the recording. If it can't find any tuner that meets the criteria, it leaves the recording unstarted and tries again in about 0.000001 microseconds and repeats this roughly 100,000,000 times per second (perhaps I exaggerate, but it tries A LOT) until either a tuner becomes available OR it reaches the actual recording start time (when by definition, the original scheduled tuner is available).

In any case, when NRecord wants to start a recording, whether for pre-padding or the actual scheduled start time, it completely ignores the fact that a tuner might be recording post-padding. The only tuner status situation NRecord considers is a tuner in use for Live TV - it'll try to move a recording to keep Live TV going.

When moving a recording to try to get pre-padding, it considers moving ONLY that one, single recording. It will not look ahead and say "ok, I'll move this recording here, and then that recording there, and then swap tuners between those two recordings, and my user will be so very happy he'll give me an GaAs lollipop".

SO..... having said all that, given the recording schedule you've shown, assuming there are no other recordings, Blindspot will start recording at 19:59 on Tuner 21. At 20:59, NRecord will attempt to begin H5-0 on tuner 21, and finding it busy will move it to your next tuner (22?) and begin recording. Both programs will get both pre- and post-padding.

(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)

[Stanno]

(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)

Love it!!