Qlab v3 weird video playback lag!

Fabio Rinaldo

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Jul 31, 2016, 8:09:23 PM7/31/16

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Hello gents,

hope you are well! I’m running into some pretty weird Qlab v3 (latest beta) video lagging.

Here’s the setup:

Mac Pro (Mid 2012)

OSX 10.10.5

CPU 3.2 GHz Quad-Core Intel Xeon

RAM 12 GB 1066 MHz DDR3 ECC

HD 2TB 7200rpm (same HD for content and OS)

GPU 2x ATI Radeon HD 5770 1024 MB

VIdeo outs:

4x monitors 1920x1080p50Hz (lets call them FRONT REAR LEFT RIGHT)

1x monitor 1024x768p60Hz (control)

I am playing 2 videos, to be played respectively on FRONT&REAR and LEFT&RIGHT. They are 40sec long, H264, 1920x1080@25. About 60MB each.

Content is programmed via 2 cues, that play on 2 surfaces that mirror the 2 pairs (FRONT&REAR and LEFT&RIGHT).

The videos stay synced but visibly skip some frames. Had a look on Activity Monitor, and nothing seems particularly overtaxed to me.

CPU during playback

HD during playback

Anybody has some wise hints for me??

Thanks a lot!

Fabio

Andy Lang

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Jul 31, 2016, 8:11:05 PM7/31/16

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On Sun, Jul 31, 2016 at 8:09 PM Fabio Rinaldo fabio....@gmail.com wrote:

Hello gents,
hope you are well! I’m running into some pretty weird Qlab v3 (latest beta) video lagging.

Just a note for the rest of the folks that Fabio’s also been in touch with us directly since he sent this, and we’re looking into this with him to see what’s going on with his configuration that might be causing these problems.

Thanks!

-Andy

—
Andy Lang
@SoundGuyAndy
sup...@figure53.com

Jack Crombie

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Aug 6, 2016, 11:42:08 PM8/6/16

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Great that you guys are on to it.

I'll just add that I had a similar problem that related to h.264 files. They'd been sent to me via Dropbox or wetransfer and I think there were some corrupt frames. The sections that played well and didn't depended each individual copy paste in finder from one drive to the next, so to fix it I transcoded the files to ProRes 422. If you can do an export of the original files from Premiere or Final Cut or Avid as ProRes 422, you might see the issues go away.

I know even transcoding the files that were sent to us, and seemingly corrupt, to ProRes fixed any playback issues we had.