Video Presenter Stuttering over time in the recording

[mliradelc]

Using Galicaster 2.0.0 I have a video stuttering over time, this can observe in this video: Video

The recording is affected by this, please view this video over the time (It has no sound): Video 2

Only the presenter stream is affected by this, and the cpu usage is about 30% all the time.

The strange is that the stuttering stops when you focus another window in the UI (Like using alt-tab), as you can see in the first video

The machine is:
Galicaster 2.0.0
Ubuntu 16.04

Hardware:
SDI camera @ 1080p30
BM Decklink Mini recorder
Datapath vision RGB E1S
Intel core i7 - 7400
8 GB Ram
MSI Z270 Motherboard
Nvidia GT730 Video Card

The profiles using actually are this:
Conf-dist.ini and conf.ini
profile lecture.ini

[sinhote]

We have the same problem in almost all our Galicasters here at the University of Cologne. It also affected the Galicaster 1.x in both Community and Pro versions.

Based on our experience, the issue manifests iff:

• Galicaster runs fullscreen.
• The recording window is the top-most window in the screen.
• The active profile has two streams (profiles with only one track do not suffer from this bug).

That means that the bug does NOT manifest (i.e. no stuttering) when:

• There's a window above the main screen of Galicaster (including the "No Audio" dialog)
• Galicaster runs in a window that does not cover the whole screen.

We suspect it must have something to do with the hardware characteristics of the computer; for instance, the issue does not affect our older Dell Optiplex 7010, but it does appear in the newer Dell Optiplex XE2. It happens in other models we currently use in production, too, but, strangely enough, it does not affect a laptop we are currently testing to use as mobile capture agent.

However, it is not a matter of processing power or performance (in other words, running the exact same pipeline as Galicaster from the command line --using gst-launch-- displays the two videos fluently and records them to disk without problems).

Also, it does not have anything to do with the recording devices: it manifests equally with Blackmagic, Datapath and Magewell, with PCIe or USB connections (always according to our experience).

I contacted Teltek informally about this issue a couple times (more than a year ago) but they could never reproduce this issue, which therefore makes it very difficult to debug. Therefore, we are running all our Galicaster in window mode (setting the resolution parameter of the [basic] section in the config.ini file to a value lower than the desktop's resolution) to workaround the problem.

It is kind of a relief to know that we are not the only ones seeing these issues. I hope that, at least, the workaround will help you to move forward despite of the bug.

[mliradelc]

I think this problem is more from the UI aspect than the others.

Ruben in your tests have you tried with the compiz configuration off?

I don't have another machine to test it with another enviroment, but it will interesting to test this in Linux mint using Gnome rather than Unity. If someone can make this test will be very useful.

Update: Ruben, your workaround works, now, Do you have the commands to disable the top bar and the side bar in ubuntu?

[sinhote]

I think this problem is more from the UI aspect than the others.

I don't have another machine to test it with another enviroment, but it will interesting to test this in Linux mint using Gnome rather than Unity. If someone can make this test will be very useful.

It may have to do with the desktop environment, too, I don't know... We did try to use Lubuntu instead of Ubuntu in order to lower the footprint of the OS and get rid of unnecessary dependencies (e.g. Libreoffice), but the issue there manifested no matter what (Galicaster fullscreen or not). So we went back to Ubuntu because we are already familiar with the system.

Ruben in your tests have you tried with the compiz configuration off?

I don't know what you mean by that, sorry

Do you have the commands to disable the top bar and the side bar in ubuntu?

Well, this is bug report and the question is completely unrelated... but anyway, the top bar and side bar (I guess you mean the Unity launcher) are handled in a complete different way.

• You can hide the launcher in "System Preferences > Appearance > Behavior > Hide launcher automatically". In order to make it even more difficult for the launcher to show, I reduce the sensitivity to the minimum and select the top-left corner as the trigger are (because it's smaller than the whole left side).
• I don't think you can hide the top bar at all when an app is in window mode. I haven't even tried, though. Anyway, it does not show any menus for Galicaster, so it's not a big problem IMHO.

I'd be happy to try and help you with any further questions, but if they are unrelated to this issues, we should perhaps bring them to the mailing list because they are off the topic here.

[smarquard]

Not sure if it will help or not, but you can drop the framerate of the previews using caps-preview in the profile, e.g. [track3] name = presentation device = blackmagic location = /dev/blackmagic/io0 file = presentation.avi flavor = presentation audio-input = none subdevice = 0 input = hdmi input-mode = 720p60 framerate = 25/1 caps-preview = video/x-raw,framerate=1/1 active = True This profile has framerate= as well, so the blackmagic is capturing at 60fps, recording at 25fps and previewing at 1fps. Regards Stephen

…

________________________________ From: Rubén Pérez <notifications@github.com> Sent: 11 May 2017 10:28 AM To: teltek/Galicaster Cc: Subscribed Subject: Re: [teltek/Galicaster] Video Presenter Stuttering over time in the recording (#522) I think this problem is more from the UI aspect than the others. I don't have another machine to test it with another enviroment, but it will interesting to test this in Linux mint using Gnome rather than Unity. If someone can make this test will be very useful. It may have to do with the desktop environment, too, I don't know... We did try to use Lubuntu instead of Ubuntu in order to lower the footprint of the OS and get rid of unnecessary dependencies (e.g. Libreoffice), but the issue there manifested no matter what (Galicaster fullscreen or not). So we went back to Ubuntu because we are already familiar with the system. Ruben in your tests have you tried with the compiz configuration off? I don't know what you mean by that, sorry Do you have the commands to disable the top bar and the side bar in ubuntu? Well, this is bug report and the question is completely unrelated... but anyway, the top bar and side bar (I guess you mean the Unity launcher) are handled in a complete different way. * You can hide the launcher in "System Preferences > Appearance > Behavior > Hide launcher automatically". In order to make it even more difficult for the launcher to show, I reduce the sensitivity to the minimum and select the top-left corner as the trigger are (because it's smaller than the whole left side). * I don't think you can hide the top bar at all when an app is in window mode. I haven't even tried, though. Anyway, it does not show any menus for Galicaster, so it's not a big problem IMHO. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<https://protect-za.mimecast.com/s/ZO8RBQCkl65Oux>, or mute the thread<https://protect-za.mimecast.com/s/meJRBXHqJw6MI6>. Disclaimer - University of Cape Town This e-mail is subject to UCT policies and e-mail disclaimer published on our website at http://www.uct.ac.za/about/policies/emaildisclaimer/ or obtainable from +27 21 650 9111. If this e-mail is not related to the business of UCT, it is sent by the sender in an individual capacity. Please report security incidents or abuse via csirt@uct.ac.za

[sinhote]

Hi @smarquard ,

That may certainly help, but the root cause cannot be a high framerate in the preview, because if I run a pipeline which is exactly the same as the one used by Galicaster (with preview + recording), with the exact same components, only with gst-launch instead of python, the preview(s) run fluently and without problems.

I should try and reproduce the bug with a test python program, in order to discard GTK's python bindings as the root cause.