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Video Playback Laggy

Posted: Sun Mar 15, 2020 2:26 pm
by jakesinn
Hi all,

I've created a DCP for a feature. I will attach the metadata and coversheet.

When I played back the DCP in DOM Player, most of it was fine - it was really only the end part that was playing back laggy. Will it play like this when ingested?

Cheers

Re: Video Playback Laggy

Posted: Sun Mar 15, 2020 2:50 pm
by Carsten
I don't think so. That DCP is pretty small for it's run time. Did you use the default data rate of 100MBit/s.? Check the playback resolution in player, and set it to quarter resolution. Are you doing this on a Mac?


- Carsten

Re: Video Playback Laggy

Posted: Sun Mar 15, 2020 3:08 pm
by jakesinn
Yes, I used the default data rate. Is that wrong? I don’t really know what that does to be honest.

I did set it to quarter resolution, and it still played back like that.

Yes, I am on Mac.

Re: Video Playback Laggy

Posted: Sun Mar 15, 2020 3:45 pm
by Carsten
The Mac has some special issues with playback currently.

For a long time, DCP-o-matic used a very conservative default data rate setting of 100MBit/s. Probably because initially, DCP-o-matic was DVD-o-matic and targeted DVD conversions, where 100MBit/s was more than enough. Recently, the default data rate for new installations has been changed to 150MBIt/s, but, existing installations still use the initial setting, even after updates. That's not a big thing, you will have a hard time noticing differences between 100 and 150MBit/s. And it has nothing to do with the playback performance issues. Set it to 150MBit/s and forget about it.

I am sure your DCP is okay. You can play with the window size in the player to see wether playback performance improves. Some settings give a better performance. On most current high-res Macs, full screen is impossible. To make sure everything is okay, you may stop somewhere around the end of your piece and give DCP-o-matic a few seconds to build a playback buffer - if you start playback then, the first seconds will play smoothly.

- Carsten

Re: Video Playback Laggy

Posted: Sun Mar 15, 2020 3:59 pm
by jakesinn
Thanks.

I'm going to re-make the DCP. I think it was actually a problem with the original MP4 file.

One thing I was wondering is also about the audio. I want it to play in 5.1. I'll attach the audio map. I don't think it's going to be 5.1 though.

Re: Video Playback Laggy

Posted: Sun Mar 15, 2020 5:01 pm
by Carsten
Is your source is stereo, how should the DCP become 5.1?
You may play a bit with the Upmixers under DCP->Audio, though. As far as I remember, you have an actual cinema to test the results? Because sometimes, these experimental Upmixers create strange results. If you use a recent DCP-o-matic version, you may need to enable the Upmixers first in advanced prefs before they show up.

- Carsten