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Accuracy of Show Player?


EmmienLightFan

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I need a sequence to reach a certain point on New Years Eve at an exact time (You can guess what time this will be).

 

 

It must not be a second out.

 

 

I know I can just work out the time it needs to start using maths, but the show player has to load sequences and comm ports and all that. How shall I make sure that the seqeucne plays at the correct time?

 

Edited by EmmienLightFan
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Problem is the OP wants the sequence to play a "specific" part of the song at midnight on New Years Eve, if musical, the music file would need to be split, first half starts playing and ends right at midnight, so if the 1st half were 1 minute long, it would start at 11:59:00 in the Schedule Editor, then at Midnight 12:00:00am the second half of the musical sequence would start.  So he needs two sequences, one for the first part, one for the second he wants to start exactly at midnight and play until the end.  If he knows the exact end time, he can schedule any additiona full sequences at tat time to have lights or anything else they want playing animated or just use silent animation files after the midnight one ends.

 

Not all difficult, but will require some additional work to have a sequence fire exactly at the moment he wants it to start, unfortunately this will/may also put a short pause into the song between the two sequences.

 

Other than that, I don't know of an easier way to accomplish this.

Edited by Orville
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The point that I want to play at midnight is 29.3 seconds into the song.

 

If I start it at 11:59:30:700 will it work? Won't the show take a second or two to start?

 

 

Thanks very much.

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I would suggest this.

 

Change the time on your computer to read one hour "later" than current time. (edited the time frame here)

Schedule that sequence to run one hour earlier.

Now you can run your sequence without having an issue of your sequence ending at midnight and starting again at midnight in the middle of the sequence.

 

Did I loose you on this?

 

Just change the computer time one hour later and start sequence time on hour earlier.

Edited by Santas Helper
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Yep, you lost me.

Why will the computer have a problem with midnight?

Oh.. Are you saying that the PC will get confused because midnight is a new day?

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That's what I was wondering, why does it need to be two sequences.  No problem with a sequence crossing midnight - WITH ONE EXCEPTION!  A Show on Demand won't cross midnight, but a regular scheduled show will do it just fine - I do it every night year round.

 

The show scheduler will allow setting the start time to the second, but not a fraction of a second.  Yes,. there will be a little delay starting a show, so what I would do is to test it a few times until you know exactly how long the delay will be.  Test it as real-world as you can.  In other words, if the show computer will be idle waiting for a show to start 29 seconds before midnight, test it that way.  Then you can adjust the start time to get the "midnight" time to be as close as possible.  Once you know when to start it, you can schedule the actual performance.

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Yep, you lost me.

Why will the computer have a problem with midnight?

Oh.. Are you saying that the PC will get confused because midnight is a new day?

 

Jim has a good point. Try testing and see what happens.

 

I suggested bumping the time to keep from rolling into another day that may cause a delay if you are looking for precise timing once the sequence starts.

If you change the computer time one hour earlier, when the real time is midnight, the computer will read 11pm. So you can start the sequence at 10:??.?? so when it runs thru 11pm (real time is midnight) the computer will run without any delay because it is still in the same evening before midnight.

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Can I suggest something much easier?

 

What clock are you using to ensure it is EXACTLY midnight?  I mean, are you using an atomic clock pegged to the NIST clock that is going to be within sub-nano second precision?  Do you believe that even your computer is going to be exactly correct when it comes to Midnight?  Or are you using the same old clocks that you have had in the house or on the computer?

 

My point is this.  Midnight is what YOU say is midnight.  Are people REALLY going to be watching an atomic clock to ensure that it is EXACTLY midnight when your sequence does its thing?  Is there some kind of special thing that absolutely requires accuracy to the SECOND or even multi-second level?  

 

Take a page from the King Julian Netflix video.  Midnight is what YOU say is midnight.  Close is probably good enough.  https://pr.netflix.com/WebClient/getNewsSummary.do?newsId=1801

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Good helpful input DevMike. :)

 

But that didn't make the OPs concerns or options "much easier".

Edited by Santas Helper
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Jim has a good point. Try testing and see what happens.

 

I suggested bumping the time to keep from rolling into another day that may cause a delay if you are looking for precise timing once the sequence starts.

If you change the computer time one hour earlier, when the real time is midnight, the computer will read 11pm. So you can start the sequence at 10:??.?? so when it runs thru 11pm (real time is midnight) the computer will run without any delay because it is still in the same evening before midnight.

 

Wait... I wasn't thinking right.

Change the computer time one hour "ahead" local time and then schedule the sequence one hour behind local time.

This way you stay in the same day without it going into another day and possibly causing delay when going into the next day on the schedule.

Edited by Santas Helper
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Good helpful input DevMike. :)

 

But that didn't make the OPs concerns or options "much easier".

 

I think it does.  If the OP is the decider of Midnight, he can schedule a show so that his thing comes at midnight.  That's because midnight is whatever time the sequence hits that particular part he wants.  With no need for sub-second accuracy, then it becomes as simple as scheduling any other show.

 

No one who is watching his show is going to be simultaneously looking at an atomic clock to make sure this thing happens on some absolute SECOND perfectly.  Or even close to the correct second. Those that have their own time sources (watches) can not be expected to have sub-second accuracy references either.  

 

I'm all for being exact, but sometimes close enough is good enough.  The OP could even proclaim that his computer is perfectly set to midnight (it will be close and does periodically sync itself with the NIST if it is connected to the internet) and everyone else's clocks are off by a second or two.  

 

For every source someone could offer up as the 'REAL' midnight, I can find a couple of reasons why it wouldn't be.  Let's say for example that you believe that the broadcast from times square and the clock they show are EXACTLY midnight.  Doubtful.  First, that signal is going to need to be encoded at the source, transmitted to an uplink center (probably via Microwave) and decoded.  That's going to take a few hundred milliseconds.  Then that will need to be re-encoded and sent up to a satellite.  Figure 100 ms for the encoding and then 250 ms round trip to/from a geosynchronous satellite.  Now that needs to be decoded at the head end of either your cable company or sat provider and re-encoded.  Another 100 ms.  Are you using Direct TV or Dish Net?  Add another 250 ms for another round trip into the sky and back.  Using a DVR?  Even watching live you are still going to be introducing a delay of a few hundred ms - it takes time to buffer the video so you can do a replay (lets say 200).   A Dish/DTV viewer with a DVR is now over 1 second away from 'true' real-time.

 

So in that case, which is the actual midnight?  Is it the one that physically happened in Times Square, or is it the one you saw on your TV that was a 'live' TV broadcast of TImes Square?  Or is it the watch you are wearing that says 11:59:50?  Or is the exact spot of the ops sequence?  

 

Just get it close and don't sweat it.  That is a lot easier than going through gyrations to hit an exact time - which no one is going to appreciate anyway since they themselves don't have an absolute time reference.  

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Again, very helpful information, for someone who doesn't care about "Attention to Detail". But you have a customer that CARES!!!

 

Why not be a Help Desk assistant that you are and provide what would be helpful to the LOR situation and not the actual time of day??? :)

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Again, very helpful information, for someone who doesn't care about "Attention to Detail". But you have a customer that CARES!!!

 

Why not be a Help Desk assistant that you are and provide what would be helpful to the LOR situation and not the actual time of day??? :)

See, now I thought you were serious and I took the time to explain what I said.  What you were actually doing was making a backhanded jab?  Or am I missing the point?

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What I'm saying is, the OP is wanting to be assured that a certain point of the sequence will happen at a certain point of time. It's not for us to judge that OP's timing.

 

What would you suggest, when scheduling the show, that would work to keep that time of the sequence to the time the OP wants it to happen when it overlaps to the next day?

Let's not care about atomic clocks and Time Square. Lets focus on the OPs concern about the timing during and going into another day (after 12:00am).

 

What you said did not give the OP advice on scheduling in the LOR software. If the OP wants precise timing, we should be able to provide the answer of how the LOR software/scheduler can do that.

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The OP is asking for something impossible, and I am offering a suggestion that can make things work.  

 

It's impossible to sync externally because you do not have an absolute reference to time.  If however you call whatever your reference is (in this case the sequence itself) the absolute reference, it all works flawlessly.  I tried to offer some external non software/computer reasons why, which you won't accept.  Here are some technical reasons why.

 

Firstly there is no time code running in the LOR software.  By time code I mean SMPTE time code which could sync the software to an external clock.  The only reference we have to time is either the position of a media file (which allows us to stay in sync with media with ms precision), or to a tick counter that updates whenever it can - which also is not tied to an actual time clock, but counts how may cpu ticks have elapsed (which we can use to extract time differences but not actual clock time)

 

Second, assuming there was some external sync, the clock running on the computer also can not be relied upon as it too has no absolute reference to time.  In other words, if the clock is off by 1 second on the computer even with SMPTE time code (or whatever that would sync us directly to the clock on the computer) the sequence is going to be off by 1 second.  Is it possible for the computer to be off 1 second?  Not only possible, I say it is probable.  

 

Third, you do not control every aspect of the hardware that is running the software.  Windows is not a preemptive multitasking system.  Should something (or some THINGS) start up at midnight, those can very well consume an entire second of processing without releasing control back to the Show Player. A lot of things in windows kick off at midnight, so this is not just probable but likely.  The idea of setting the time ahead/behind the actual clock could help with stuff that runs at midnight so it is a good idea - at first.  However setting the clock yourself completely destroys the accuracy.  Are you absolutely sure the reference you used is the true reference?  Are you absolutely sure you hit the OK button (or enter or whatever) at the exact second so you are EXACTLY X Hours ahead/behind and not +/- a few seconds?

 

So, those 3 things alone will prevent you from ever syncing something exactly to any clock time.  Nothing you do can ever guarantee that you hit a particular point in a sequence, media, WHATEVER at exactly the CLOCK time you want.  No trigger, no scheduling trick, NOTHING will ENSURE that you hit on the exact clock second, even if you try to take all these variables into account.  Can you get close?  Yes.  Could you get lucky?  Sure.  But you will never be closer than a few seconds +/-, which is beyond the OPs threshold as you point out.

 

Now on the other hand what I am saying is that in this case there is enough 'slop' in the world that close and exact are the same thing.  What you and the OP are trying to do is create a solution for a problem that really doesn't exist.

 

So for the sake of argument, assume that those three problems don't exist.  Let's assume that there is time code available, that it is synced with the clock on the computer, that the computer clock is 100% accurate and that you control every aspect of the computer so that with 100% certainty it WILL hit exactly at the time you want.  Basically this thing is guaranteed to hit at the exact time without fail.

 

Now ask this:  What is the reward of being 100% on time, vs the cost of being 100% on time?  In other words, will anyone care that it is exactly at time X this thing goes off?  Go even further: will anyone even notice that it actually happened at exactly time X?  One step even father still:  Will even the OP even notice?  You will have a VERY hard time convincing me that even the OP is going to be watching a clock so intently that they are going to notice that they were a second off.  Or two.  Or even 3.  

 

If no one observing knows what exact clock time it is with any certainty, does it even matter if the computer does?  Is it even possible for someone to know exactly what time it is and to observe the show at the same exact same instant?  No.

 

Ok, so to this point I've shown that no one has an absolute correct clock time reference.  In other words, no observer is going to know exactly when it is time X, which makes this entire thing moot, but let's continue.  Even if we take the computer's clock as the absolute reference, it is impossible to ensure this sequence hits at exactly X because of the limitations of the computer, operating system, and software.  I have also shown that even if we can be assured that we have an absolute correct clock time reference (to the second), that even if everyone (the people watching and the OP) has access to that reference, that the observer can not notice that the sequence hit precisely at correctly at the exact instant of time X, since they simply can't do 2 things at once.

 

Can we think outside of the box and find a solution? Absolutely.  Rather than rely on an external time clock as our reference point, we use this point in the sequence as the absolute time reference point.  Tail wags dog instead of dog wagging tail.  If we are close (and that you can be), and then proclaim that part of the sequence as clock time X, it will become time X in everyone's mind.  No one can simultaneously observe the exact time X and observe the sequence at the same time - since you can't do two things at once.  Add a voice over into the sequence with a countdown and now the show becomes the absolute clock time reference and that you CAN control to the millisecond.

 

It is possible that observers may get external cues to when clock time X is approaching.  We do not control those external cues and therefore they can be grossly out of sync with our time X.  If someone shoots off a firework at 11:59 on your clock (12:00 on theirs) and screams happy new year a street over, who is right?  Obviously you need to at least be in the ball-park time wise since there are these external cues.  But can you really stop the world until your sequence runs to point X?  No, things around you are going to continue and you can't stop someone else from proclaiming it's time X when on your clock it is not.

 

So, here is the crux of my suggestion by my super powers of programming and help desking combined:  Don't sweat it.  You are going to have a difficult if not impossible task of getting everything synced to time X with the technology you have.  The payoff is minimal even if you could pull it off.  No one will have a hyper accurate time reference with them and so they will not know one way or another what is the absolute time.  No one (outside of maybe the OP, and even then I doubt it) will know if it exactly hits at the exact second since no one can observe the time reference and the show at the same time.  

 

On the other hand....  Spend just a small amount of time scheduling and getting it to within a few seconds of actual time X AND NO ONE (including the OP) is going to know if you hit exactly at midnight or were off a few seconds.  Your sequence itself becomes the correct absolute time, especially if you add time announcements and a countdown.  You are the hero and everything is great.

 

If the OP wants to continue exploring options to be exactly on time with some external clock, please do. I absolutely do not know the importance of this to the op vs my opinion of how important I think it is.  My professional programmer, help desker, and representative of the company roles all say the same thing: I am afraid that what you want to do is impossible.  If you continue down this road you will spend a lot of time to in the end come out with the same result - hope that luck is on your side and it works.  I think that you need to adjust your parameters just a little bit and you will be successful and happy.  I have offered a solution that will satisfy 99% of the real requirements - those being a great time on a New Years eve by ALL in attendance and have tried to provide enough examples to back that up.

 

I am happy to clarify any point I made with anyone.  If you are in disagreement, please present something with examples of why I am wrong.

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Ok, so now lets discuss the technical limitations of changing over to a new day on the clock.  We will assume that we have solved the above problem of hitting at exactly clock time X by whatever means.

 

YES it is a good idea to test whatever you come up with first.  The same care should be taken in testing what you come up with as you would with doing a sequence.

 

I am not sure how well the Schedule Editor/Show Player deals with running across midnight since I am not familiar with that code.  It would be Bob who knows/wrote that code, so I will test and let you know tomorrow when I am back in the office.  If I were to guess: Bob is fastidious when it comes to things like this and I would bet that it will work Just fine.

 

Otherwise, YES the idea about moving the computer clock back a few hours (as well as scheduling the show back a few hours) is an excellent idea.  We know that there is no issue with the hour changing.  Adjusting the clock on the computer so it says 10 PM when it is actually midnight is a fine idea.  Make sure that the computer is NOT connected to the internet during that show.  Windows will periodically automatically update your clock with the MS or Gov time servers.  If you leave it connected, it is possible that at your computer could go out, update the time to the correct time, and screw up your planning

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Now let's tackle the issue of 'Getting close'.  Let's assume that you have moved the clock back so midnight real time shows as 10PM on your computer.

 

It is possible to add up all the times of all your sequences.  However remember that we show things in CS resolution, including sequence length.  Each time a sequence plays there is a possibility of your computation going off by 1 CS.  It is VERY possible to be off by a second if you run a sequence that is actually +/- .4 CS enough times.   (We round, so being off .4 is the worst case.  That takes 15 times? 16?)

 

Be sure to actually let a show run for however long and see exactly what clock time it gets to when you want it to stop and your special sequence to start.  This could be tricky.  Once you know the absolute length of a show, you can schedule it to end just before that time.  Schedule your special show to start at exactly the clock time you need it to start.  Like others have said try to keep the sequence small to minimize load/etc time.  You'll go dark for a few seconds, and then back up.  You'll also be within a few seconds of clock time.

 

If you want even more control: Get close and use a button.

 

Pick a time that is close to the time you want your special sequence to start.  Say 9:45.  Now schedule your show such that it ends before 9:45 minus the LONGEST sequence you run, and then pad it by a minute or two to be safe.  If your longest sequence is 3:30, schedule that show to END at say 9:40 or 9:41.

 

Create a simple animation.  Now (and here is where testing is REALLY going to pay off for you), schedule that sequence to run normally and the special sequence to run on a trigger signal.  The simple animation should be set that it can be interrupted by the trigger.  By doing this, the show player should have already loaded both sequences and have them cached before you actually need the special sequence.  Now watch the clock and hit that button exactly when you need the special sequence to start.  You will go dark between the real show ending and this background/trigger sequence combination loading, but you will (as long as you hit the button at the right time) be closer than a couple of seconds out.  There may still be a delay between hitting the button and the special sequence starting, but it will be much shorter than the one above.

 

With all of my suggestions, this is the closest you are going to come without making yourself crazy.

 

(Edit: Sorry, I should have explained that you will need to create a button and connect it to the header of a controller.  Take a look at the doc for your controller to see where to hook up/etc).

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No matter what you do, you'll want to get the PC clock as close as possible if it is responsible for controlling the timing. There are various programs out there to do that. I used to use a program called Dimension 4 on XP. I've played around with Meinberg NTP in WIN7. But since the Windows time service does it for you once a day I haven't really worried about it that much.
 
http://www.meinbergglobal.com/english/sw/ntp.htm#ntp_nt_stable

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