Fades stutter - sometimes

[simon.b...@gmail.com]

Hy

I still use the 3.2.1 Version, because we are in the middle of a show. But we have a strange problem.

Sometimes (and really only sometimes), transitions between 2 videos stutter. If I start the same queue again, most times the problem is solved, but sometimes it's still there.

Then I close the presentation window or close QLab, start again. Then the stuttering is maybe gone, but not always. So I start the queue again, restart…until its working fluently. If it's once working fluent it usually stays like this. But I never know...so right now I don't like the situation.

Does anyone know this issue? Is it solved with the new version? Because I don't want to update, but if this is solved, it may be the only solution…

Thank you.

[Chris Ashworth]

Hi Simon,

On October 10, 2014 at 11:49:23 PM, simon.b...@gmail.com (simon.b...@gmail.com) wrote:

Hy

I still use the 3.2.1 Version,

Do you mean 3.1.2?

 because we are in the middle of a show. But we have a strange problem.

Sometimes (and really only sometimes), transitions between 2 videos stutter. 

A few things to try:

First, check to see if auto-loading cues can be used to help.  If a video is starting but is not yet loaded, it can take extra time to get going and slow things down.

Next, it’s possible that the most recent version (3.1.4) will help. I’d recommend trying it, even though you are running a show. You can test it, and always downgrade again if you want:

http://figure53.com/qlab/download/archive/

Best,

Chris

[simon.b...@gmail.com]

Unfortunately updating to 3.1.4 didn't help to solve the issue.

I am also already using auto load, and it does help - but just not every time. It's very random, I just can't figure out, what triggers the problem. I open QLab, fire the queue and it's ok, but next time it's not ok. Really strange. If I knew exactly when the problem appears, I could avoid it, but I can't. And as is it working as it should from time to time, it shouldn't be an issue that the computer is too slow. :-/

Thank you for any input.

PS: Using 10.9.4 with the newest, fastest macbook pro retina out there. Using the internal display at 1680x1050, two 1980x1080p60 and one 720x480p60 displays. QLab Version 3.1.2 ad 3.1.4.

[micpool]

How are your displays connected?

What codec, frame rate, and size are your videos.?

Mic

[Christopher Ashworth]

(mobile)

> On Oct 11, 2014, at 1:59 PM, simon.b...@gmail.com wrote:
>
> Unfortunately updating to 3.1.4 didn't help to solve the issue.
>
> I am also already using auto load, and it does help - but just not every time. It's very random, I just can't figure out, what triggers the problem. I open QLab, fire the queue and it's ok, but next time it's not ok. Really strange. If I knew exactly when the problem appears, I could avoid it, but I can't. And as is it working as it should from time to time, it shouldn't be an issue that the computer is too slow. :-/
>
> Thank you for any input.
>
> PS: Using 10.9.4 with the newest, fastest macbook pro retina out there. Using the internal display at 1680x1050, two 1980x1080p60 and one 720x480p60 displays. QLab Version 3.1.2 ad 3.1.4.

Hm, that's four displays off one machine, with an unspecified number of videos composited to the three display screens at any one time, at unspecified file resolutions and codecs.

It's entirely possible this is not enough computing power for what you're doing. Video takes a lot of computing.

Does the problem go away if you're playing back to only one screen?

Also, I do not recommend using 3.1.2 at all. It will definitely stutter with fades. Only 3.1.4 has a fix for that.

C

[simon.b...@gmail.com]

Yes it's a lot of displays! But I think I can't be the computer speed itself, as it runs very smooth from time to time. And if it's once running smooth, it stays that way, until you start again. 

I am using Full HD Proress 422 LT with 30fps and when the problem appears, there are usually 2 videos playing and 2 fading over. But there is also a part where 3 videos are playing and there is the same issue - and it's not worse.

The displays are connected by the HDMI-Port and the 2 Tunderbold-Ports.

[Pierre-Luc Brunet]

Have you tried going over Sam's list of computer performance tweaks to make sure no background computer activities are happening?

Here is the link:

http://figure53.com/notes/2013-10-29-prepare-execute-troubleshoot/

----------

Make sure spotlight is disabled. You can do it three different ways. The first one is in Sam's list (though on 2 different occasions I saw spotlight running even after running that terminal command)

Method 2: Run this in the terminal.

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist

Details here: http://osxdaily.com/2011/12/10/disable-or-enable-spotlight-in-mac-os-x-lion/

Method 3: Go to System Preference - Spotlight - Privary - And add the Macintosh HD to the privacy list. It will stop spotlight from searching this disk.

Give it a shot.

[Christopher Ashworth]

Does the problem happen if you have only one external screen attached?

(mobile)

[simon.b...@gmail.com]

I can't test it with only one Display right now, because I had to change the whole installation…and I would not be much use, as I can't see all the videos ;-)

But thank you for all the tips, I will test tomorrow the mavericks-hack and deactivate spotlight, I'll see.

[Christopher Ashworth]

Hi Simon,

(mobile)

> On Oct 12, 2014, at 11:17 AM, simon.b...@gmail.com wrote:
>
> I can't test it with only one Display right now, because I had to change the whole installation…and I would not be much use, as I can't see all the videos ;-)
>

The point is not to see all the videos but to see of the stutter still happens when doing less video processing.

[Christopher Ashworth]

To clarify: you sound sure that the problem is not that there is too much for the computer to do. But I am not sure of that.

The other thing to keep in mind is that loading from disk can be both A) a common source of stutter/slowdown, and B) relatively unpredictable when operating at the edge of the computer's limits. Drives can be accessed at different times and in different ways on different runs of a workspace, etc.

It's worth taking time to be especially thoughtful about how videos are preloaded, and trying different approaches. Sometimes it is helpful to add a load cue to preload a sequence explicitly, whereas sometimes using auto load on specific cues is a good approach. Experimenting with different approaches can be fruitful.

Best,
C

(mobile)

[fishmonkey]

yep, it's very easy to make incorrect assumptions about what is going on under the hood.

the key problem is that OS X is a multitasking operating system, with no hard real-time constraints. in practice this means that time critical processes are never guaranteed to get the system resources required for glitch-free operation.

therefore having some system headroom, and disabling unnecessary background processes, are really important if you want a reliable system...

[simon.b...@gmail.com]

Hi all

I think I figured it out now; the problem was on the first hand version 3.1.2, which gave in some cases really bad stuttering on fades. Starting the cues again solved this issue most f the time. BUT: After I started the same queues with many, many times to test, for example 3 Full-HD-Videos playing at the same time and then make a transition to another 3 videos, the Macbook Pro was getting really hot and probably the GPU started to trottle, which again let to stuttering. (my assumption)

It was really hard to figure it out, because it was two not connected issues, but after upgrading to 3.1.4 and the "initial" stuttering gone, it was easier to figure out.

So, not too bad after all, in normal shows, the computer doesn't get too hot and it doesn't stutter anymore. But I still got some issues with QLab, but the are hard to reproduce. But for example a still image was flickering after standing still for several minutes, with no touching of the computer, only 2 still images showing (and the other image wasn't affected. The problem has to come from QLab, because after the output of the computer we make a softedge in arkaos media master, and the blackout was on both screens (but not on other screens going through the same media master pc). Also I got the strange "blocks"-problem… But it's hard to reproduce, got it only once on a 6h show…But I'm not so sure if I consider QLab again as my media program, as there were just too many bugs and workarounds at this state. Maybe this will change in future version, but right now I can't recommend it fully - although it's a great program. But for very important applications, I prefer something more…developed. Maybe I try version 4 again ;-)

[Chris Ashworth]

Hi Simon,

On October 14, 2014 at 10:24:18 PM, simon.b...@gmail.com (simon.b...@gmail.com) wrote:

Hi all

I think I figured it out now; the problem was on the first hand version 3.1.2, which gave in some cases really bad stuttering on fades.

Yes; this is what was fixed in the recent update, when I noticed that fades on video properties were performed on the main thread and therefore could be interrupted by work happening on the main thread.

 Starting the cues again solved this issue most f the time. 

It would not really solve the issue fundamentally, but if the cue sequence was not, for example, pre-loaded properly then running it a second time could require less work on the main thread which would help on the second run.

BUT: After I started the same queues with many, many times to test, for example 3 Full-HD-Videos playing at the same time and then make a transition to another 3 videos, the Macbook Pro was getting really hot and probably the GPU started to trottle, which again let to stuttering. (my assumption)

Sounds possible, certainly.  That is a lot of video processing. I would expect the machine to get hot.  

I don’t know what “GPU throttle” is, that’s not a concept I’m familiar with.  

It was really hard to figure it out, because it was two not connected issues, but after upgrading to 3.1.4 and the "initial" stuttering gone, it was easier to figure out.

So, not too bad after all, in normal shows, the computer doesn't get too hot and it doesn't stutter anymore.

Cool, glad to hear that the fix in the update was helpful.

 But I still got some issues with QLab, but the are hard to reproduce. But for example a still image was flickering after standing still for several minutes, with no touching of the computer, only 2 still images showing (and the other image wasn't affected. The problem has to come from QLab, because after the output of the computer we make a softedge in arkaos media master, and the blackout was on both screens (but not on other screens going through the same media master pc). 

I don’t understand what your setup is, so I’m not sure how Arkaos would indicate that is a problem in QLab.

Based on my understanding of the rendering path, I don’t know a way it would be possible for this to be a problem in QLab.  If the buffer of a still image was ever lost for some reason, it would not be possible for QLab to render it again, it would be gone permanently.  Once a frame is rendering it will continue to render until the cue is stopped.  In particular with a still image there is very little happening except drawing the same image every time.  There is no where for it to “disappear” to.

It sounds like you have QLab output going to additional equipment, either via Syphon or some other mechanism.  My guess is the flicker came somewhere “downstream” from QLab.

Also I got the strange "blocks"-problem… 

I think I have missed what the blocks problem is.

But it's hard to reproduce, got it only once on a 6h show…But I'm not so sure if I consider QLab again as my media program, as there were just too many bugs and workarounds at this state. Maybe this will change in future version, but right now I can't recommend it fully - although it's a great program. But for very important applications, I prefer something more…developed. 

Please write in to support and we can arrange to refund your purchase, after all the licenses have been removed from your machines.

Maybe I try version 4 again ;-)

That may be a long wait. Feel free to write in and we can refund.

Thanks,

Chris

[simon.b...@gmail.com]

Hi

Sorry for the late reply, I had a lot of work to do.

I don't ask for a refund, so better take the money and improve QLab more ;-) Basically I really like this tool, 

Just for this Project, it was maybe a little bit too much, but also the newer version helped a lot. :-)

PS: Your support is really good and fast!

Thanks, Simon