[QLab] Audio dropout

[lindsay jones]

Hey everyone,

OK, I have this really weird problem, and I'm trying to figure out what to
do. Here's the situation:

We're using Qlab 2.3 build 1135 on a Mac Mini 2ghz core duo machine, with
4GB of RAM, and a Presonus Firestudio interface. The sound files are stored
on a external USB 30 GB drive.

We're running 3 shows in rep with a LOT of cues, and all the shows are
playing flawlessly, EXCEPT the curtain call of the third show, which keeps
having 1-2 second long dropouts in random places during playback. These
dropouts never occur in the same place.

Before you ask, you should know the following:

- all soundfiles in all 3 shows are 16 bit, 44.1k wavs.
- the file has been swapped out several times, the cue was actually
rerecorded to see if that helped (it didn't) and the cue event in Qlab was
completely rebuilt. (But it still happens).
- it ONLY happens on this one cue
- all Energy Saving/Screen Saving etc. preferences have been turned off

The ONLY thing that I have been able to figure out about this is that if I
actively click on the screen while the cue is playing, the cue will not cut
out. If I just let it play, it inevitably will cut out, although in a
different place every time.

PLEASE help me, I'm desperate. It's the freakin curtain call at the end of
three shows, where everyone wants to breathe a sigh of relief and they can't
because of this problem. Any help anyone can offer would be greatly
appreciated.

Thanks so much
Lindsay

-----------------------------
Lindsay Jones
Unique Music and Sound Design
www.lindsayjones.com
-----------------------------

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[Lindsay Jones]

Hey everyone,

Thanks so much
Lindsay

________________________________________________________

[Christopher Ashworth]

Hi Lindsay,

Any console log messages? (/Applications/Utilities/Console.app)

Does it happen at ANY time with the last cue, or only after a certain amount of time has passed?

When you say you solve it by clicking on the screen--where exactly are you clicking and at what time?

Is there nothing else running in the workspace at this point, and nothing else after this cue?

How long is the cue where this happens?

Are all three shows the same workspace? i.e. is this same workspace working correctly 2 times in a row, but always failing the third time?

If so, is the time it fails roughly the same time each night?

If so, is there something that could be scheduled to happen on this machine at the same time each night?

Best,
Chris

On Jul 6, 2010, at 1:53 PM, lindsay jones wrote:
>
> We're using Qlab 2.3 build 1135 on a Mac Mini 2ghz core duo machine, with
> 4GB of RAM, and a Presonus Firestudio interface. The sound files are stored
> on a external USB 30 GB drive.
>
> We're running 3 shows in rep with a LOT of cues, and all the shows are
> playing flawlessly, EXCEPT the curtain call of the third show, which keeps
> having 1-2 second long dropouts in random places during playback. These
> dropouts never occur in the same place.
>
> Before you ask, you should know the following:
>
> - all soundfiles in all 3 shows are 16 bit, 44.1k wavs.
> - the file has been swapped out several times, the cue was actually
> rerecorded to see if that helped (it didn't) and the cue event in Qlab was
> completely rebuilt. (But it still happens).
> - it ONLY happens on this one cue
> - all Energy Saving/Screen Saving etc. preferences have been turned off
>
>
> The ONLY thing that I have been able to figure out about this is that if I
> actively click on the screen while the cue is playing, the cue will not cut
> out. If I just let it play, it inevitably will cut out, although in a
> different place every time.

[Søren Knud]

Just a thought - have you tried to store the files on another harddrive?

If it is the same audiofile- it sounds to me like its something with that file rather than Qlab. Could it be that that part of the HD is damaged in some way?

Can you try to run the workspace on another computer (from the same harddrive) if the above does not work?

Just to figure out WHERE the problem is...

>> The sound files are stored
>> on a external USB 30 GB drive.

________________________________________________________

[Lindsay Jones]

Any console log messages?  (/Applications/Utilities/Console.app) 

I will see if we can generate that for you, I don’t currently have one.

Does it happen at ANY time with the last cue, or only after a certain amount of time has passed? 

The earliest it’s happened is 15 seconds into the cue, and the latest has been 2:30 in the cue

When you say you solve it by clicking on the screen--where exactly are you clicking and at what time? 

I’m clicking on Finder windows outside of Qlab. Not clicking on anything inside of Qlab. Doing this during the entire playing of the cue.

Is there nothing else running in the workspace at this point, and nothing else after this cue? 

Nothing else is running. Nothing else is after this cue. I should also say that it does it in context in the show, and if I wait for the show to end and the house to clear, it will do it again later as well. And of course, sometimes it happens, and sometimes it doesn’t.

How long is the cue where this happens? 

There are two versions of the cue, and it has happened with both, one is 2:30 long and the other is 5:00 approximately.

Are all three shows the same workspace?  i.e. is this same workspace working correctly 2 times in a row, but always failing the third time?

All 3 shows are in different workspaces, although they share the same settings. 

If so, is the time it fails roughly the same time each night?   If so, is there something that could be scheduled to happen on this machine at the same time each night? 

No, I’ve had the problem at different times as well.

Thanks so much, Chris!
Lindsay

[Steven Devino]

I am throwing out wild cards here but, is Time Machine trying to run on that external drive? Is spotlight off for that drive? Have you looked at activity monitor to see if some process kicks in when ever the drop out occurs?

BTW you should still have the console messages from any of the shows. You can search them by time of occurrence.

Steve

[Jason Knox]

I'd try Soren's idea and move the file to the system disk.  Good luck.

[Emery Roth III]

Last year I did something similar, we had 3 shows in rep, on certain
days all three would play. I found if I didn't restart the computer
in between shows then I was asking for a dropout to occur. Not sure
if that’s the problem you're seeing, but maybe it can help?

--Emery

On Jul 6, 2010, at 1:55 PM, Lindsay Jones wrote:

> We're running 3 shows in rep with a LOT of cues, and all the shows are
> playing flawlessly, EXCEPT the curtain call of the third show, which
> keeps
> having 1-2 second long dropouts in random places during playback.
> These
> dropouts never occur in the same place.

________________________________________________________

[Christopher Ashworth]

On Jul 6, 2010, at 2:22 PM, Lindsay Jones wrote:

> Any console log messages? (/Applications/Utilities/Console.app)
>
> I will see if we can generate that for you, I don’t currently have one.

Someone else mentioned this, but it bears making sure it's clear: the console logs are preserved for a pretty long time on any given machine, so the chances are your logs from the shows where this already happened still exist.

Best,
Chris

[*]

If you'll FTP your offending file somewhere that I can download it (even
if it's huge), I'll downloaded it & start looping it on my Qlab rig & see
if I have any issues.

*

On Tue, July 6, 2010 12:53 pm, lindsay jones wrote:
> PLEASE help me, I'm desperate. It's the freakin curtain call at the end of
> three shows, where everyone wants to breathe a sigh of relief and they
> can't
> because of this problem. Any help anyone can offer would be greatly
> appreciated.

[Jeremy Lee]

Any chance that this is a very long file? USB can get confused with other stuff on the buss. Try putting it on the internal drive (ran MANY a show off the internal drive on a Mini w/o problems) and see if it clears up.

USB = not that great a thing...

On Jul 6, 2010, at 10:53 AM, lindsay jones wrote:

> We're using Qlab 2.3 build 1135 on a Mac Mini 2ghz core duo machine, with
> 4GB of RAM, and a Presonus Firestudio interface. The sound files are stored
> on a external USB 30 GB drive.
>
> We're running 3 shows in rep with a LOT of cues, and all the shows are
> playing flawlessly, EXCEPT the curtain call of the third show, which keeps
> having 1-2 second long dropouts in random places during playback. These
> dropouts never occur in the same place.

--
Jeremy Lee
Sound Designer, NYC - USA 829
http://www.jjlee.com

[Projectile Objects]

I thought I would comment on this after having personal experience with QLab dropping audio 1 hour before a show premiere.  I know it is out of date, but I wanted to share what I've learned.  I used the console logs on mac to see that it was in fact QLab and not the computer doing this. The same thing happened with the built in 3.5mm jack as well as an external Roland USB Audio device.

 I believe the reason for this is when there's a CPU or memory overload, QLab will cut the audio before it cuts the video.  This may be Mac specific being that other audio engineers have reported, "CPU Overload / Audio drop-out detected" in separate applications.

Figuring out what is causing the overload is crucial for troubleshooting it:

 In our project, a projection mapped still image with a mask had a fade out, but not "Stop when target is done" check box.   This caused it to run in the background throughout the entire show. About 15-30mins in the audio would crash, forcing an entire computer restarted to get it back.    Luckily, I had an old (working) version of the project on a backup iMac and we were able to use that for our Premiere.  (IMHO, always have a backup!)

[Chris Ashworth]

Hi Projectile Objects,

FWIW this to me sounds like something more extreme than a typical audio dropout or CPU overload — if the system required a restart to function again it is likely something more concerning than a CPU overload, which is just the computer not being able to process fast enough to get audio to the driver in time for the delivery deadline. An overload will produce glitching or stuttering but I am not aware of a case where it has led to a crash.

It is not necessarily the case that QLab will “cut the audio before it cuts the video”; both audio and video engines are running on multiple dedicated background threads, and if the system is running into resource limits it does not pick one type of output to degrade over the other. 

Best,

Chris