Film-Tech Forum ARCHIVE: Playback Buffer Underrun Error

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Posted by Martin McCaffery (Member # 37) on 04-21-2014, 06:22 PM:

Christie Solaria One.

Anyone run across this before? About the last 8 mins of the show last night the lamp started flashing on and off (like a bad rectifier diode in 35mm). Fortunately, the end credits are 7mins so didn't have to lose the show.

Shut everything down and it started fine this morning. We've updated the software, and run the film again without problem. Any idea what caused it and how to prevent it in the future?

Posted by Marcel Birgelen (Member # 6801) on 04-21-2014, 06:38 PM:

This "Playback Buffer Underrun Error" you mention in the topic, that's the error you got?

You're sure your lamp was actually flickering off and on? Or was it just the screen going black?

A Buffer Underrun Error sounds like a problem with your storage not capable of providing sufficient throughput for sustained playback. That could explain the screen going dark, because the IMB went out of data to play.

Did you check your logs for any problem with your storage or maybe your NAS/storage server? Maybe you just encountered a disk failure during playback. In some cases, a faulty disk can temporarily hurt the performance of a RAID array, sometimes even beyond acceptable performance levels. Once the disk has been ejected, performance usually returns to acceptable levels.

Posted by Andrew Thomas (Member # 7000) on 04-21-2014, 06:46 PM:

I don't think there is anything to do to prevent it. The fix is to reboot the NAS.

Posted by Martin McCaffery (Member # 37) on 04-21-2014, 07:49 PM:

Yes, that was the error message.

I suspect it was just going projecting black, but didn't have the time to troubleshoot.
Have heard back from Christie and they say it is a known problem that the software update should resolve. We'll see.

Posted by Joe Redifer (Member # 3) on 04-21-2014, 09:31 PM:

Yes it was just projecting black. There would be no reason for the computer to shut off the actual xenon. When you run out of buffer there's nothing to show onscreen, hence the black. Your buffer of video data has emptied and the drive has to work hard to catch up.

All this talk off buffer underruns sure takes me back to the early 1990's when that was actually a thing you had to worry about when burning CDs.

Posted by Mike Blakesley (Member # 26) on 04-21-2014, 10:31 PM:

Ha, "buffer underrun." I knew I'd heard that term before but couldn't quite place it until seeing Joe's post.

Sheeze what are these projectors running on, old 80386 processors?

Posted by Randy Stankey (Member # 64) on 04-21-2014, 10:54 PM:

While I am sure that the software upgrade will cure the problem, it probably would not be a bad idea to check your hard drive array for bad sectors and other problems to be sure that it is running the way it should.

An ounce of prevention...

Posted by Jim Cassedy (Member # 4115) on 04-21-2014, 11:05 PM:

quote: Martin McCaffery
Anyone run across this before

Is your system using the Lenovo/Iomega E=MC NAS drives?

Several months ago, one Solaria 1 system that used that type of drive at one
of the theaters I take care of started getting occasional buffer/underrun
error messages before the NAS finially died, and had to be replaced.

It was still under warranty, so it didn't cost anything to swap out the
equipment, but they did loose day-&-a-half worth of shows.

In addition to the 'buffer underrun' message the staff also noticed that
the picture occasionally froze or jumped for a second or so. They described
it as much like the same effect you'd see when watching a 'bad' dvd disk.

Don't know if you've got the same problem potentially brewing, so you
might want to keep an eye on it!

Posted by Martin McCaffery (Member # 37) on 04-22-2014, 09:06 AM:

Using the Netgear ReadyNAS 2100.
Will do a sector check.

Posted by Marcel Birgelen (Member # 6801) on 04-22-2014, 04:20 PM:

quote: Mike Blakesley
Sheeze what are these projectors running on, old 80386 processors?

Big chance it wasn't the IMB after all. Sure, it could be some bug that's now fixed in the latest update, but it could also be a problem with the storage machine.

In an IMB setting, the storage is usually externally connected via e.g. Ethernet. The Solaria One allows you to use third party NAS hard/software via NFS to store your content. While this might sound like a very lucrative solution, the sustained transfer rates needed for flawless DCP playback might not always be totally trivial for lower end hardware. Many consumer NAS devices for example, will not perform well in a disk failure scenario and there might be other non-trivial compatibility issues that can cause troubles. If you use other devices, like switches, in between, those might also cause trouble and if you share your NAS with other clients/users, those clients might inadvertently cause traffic spikes that create problems for sustained playback.

Posted by Marco Giustini (Member # 4544) on 04-22-2014, 04:48 PM:

I'm assuming the ReadyNAS is a qualified NAS for Christie. I would definitely check it, with whatever tool Netgear is providing you.

Posted by System Notices (Member # 2357) on 08-14-2019, 08:32 PM:

It has been 1940 days since the last post.

Posted by Robert Jordan (Member # 10827) on 08-14-2019, 08:32 PM:

Playback buffer underrun error hit us about once a month since February. Thought it was failing drives, so we loaded our Netgear ReadyNAS 2100 with four WD Red 4TB drives. Problem persisted. We finally got our IMB software updated from 1.6 to 1.8.6 and have had no problems since. Shame on us for not getting software updates, but more interesting to others might be that the WD Red 4TB drives are working fine with Netgear ReadyNAS 2100.

Posted by Mark Gulbrandsen (Member # 72) on 08-15-2019, 07:00 AM:

quote: Mike Blakesley
Sheeze what are these projectors running on, old 80386 processors?

Nope, a much newer processor called the Intel Atom which is the modern day equivelent of the 80386 . [Eek!]

Posted by Marco Giustini (Member # 4544) on 08-15-2019, 07:41 AM:

in my home "legacy" ReadyNAS I have 6TB disks - Netgear stopped investing time on those units but there is no reason for a larger disk not to work as the working protocols are the same and the OS is really not limited to a specific size.

I am puzzled on why you should get buffer underrun errors out of the blue to be honest.

Posted by Mike Moreno (Member # 4887) on 11-07-2019, 11:29 AM:

I had the same problem in a christie 2220, it start on september, i replace 3 times and also the NAS, it suposed to be the IMB but yesterday it starts again.
im running on version 1.8.7(19). we can see the failure on screen because there is a gap betwen audio an image.
Today im loosig shows [uhoh]

Mike moreno
MExico

Posted by Brian Mendelssohn (Member # 9108) on 11-08-2019, 07:36 PM:

This was my nightmare for a year. We replace the NAS, IMB twice, updated software, etc.... We ended up getting a much fancier NAS that was much beefier than what came with out Christie Solara One+... and its been wonderful since.

Posted by Mike Moreno (Member # 4887) on 11-09-2019, 12:49 PM:

Yesterday I replaced Back plane, PIB, ICP,IMB,LVPS, and also the UPS [Big Grin]

.
Its working fine so far.

Mike moreno
Mexico

Posted by Mike Moreno (Member # 4887) on 11-14-2019, 12:01 PM:

Bad news (for me [Frown]

)

Playback Buffer Underrun error again after 5 days of replaced ICP,PIB,IMB,Back Plane ans LVPS.

Mike Moreno

Posted by Mark Gulbrandsen (Member # 72) on 11-14-2019, 12:13 PM:

Like almost all others have already done, I suspect you will be replacing the Christie IMS POS with a GDC in the very near future. Even the big chains that have those have already done that.

Mark

Posted by Steve Guttag (Member # 268) on 11-15-2019, 06:40 AM:

Note, the option is GDC or Dolby IMS

Posted by Mark Gulbrandsen (Member # 72) on 11-16-2019, 10:15 AM:

FWIW the chains are going with the GDC option.

Mark

Posted by Steve Guttag (Member # 268) on 11-17-2019, 11:10 AM:

I'm sure you've done the studies to prove that one [Roll Eyes]

I have seen both go in, depending on what the entity has elsewhere.

Posted by Brian Mendelssohn (Member # 9108) on 11-19-2019, 08:45 PM:

We did Dolby IMS and its been fine since.

Posted by Andrew Leist (Member # 8354) on 11-25-2019, 04:08 PM:

We had a "Buffer Underrun" error once because the NAS was connected to the Christie IMB with a CAT 5 cable (not 5e). Replaced it with a CAT 6 to fix the problem.

Posted by Mike Moreno (Member # 4887) on 11-25-2019, 07:58 PM:

last update on the issue, i replaced the NAS las week.
lets see... [beer]

Mike moreno