GPU effects mode (experimental)_What are the benefits if I choose to try it?

It looks interesting to try GPU mode.
Just wondering why one might choose to use it.
Before I try it, just thought I’d ask around a bit to see
what the benefits may be.
Thanks for any ideas.

I think you mean GPU Processing (experimental)?
Depends what you mean by benefits and depends on the GPU hardware you have and which OS you are using.

Best bet is to run a trial project with GPU Processing enabled and see.

To give a touch of personal perspective, when I used GPU processing (experimental) on my AMD processor & GPU based Windows 10 system it was a disaster. Constant crashes and lags which made Shotcut very difficult to use. Without it, it works superbly and problems are rare but easy to recover from when they happen.
YMMV so try it out and it may be a boost to your productivity, but if it doesn’t work out for you, turn it off :slight_smile: It’s an experimental feature, so experiment !

It was renamed in 18.06.02

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Ah thanks. I’m not using the latest versions. Staying with 18.03 for the moment.

Bear in mind that if you create and save a project with GPU effects, you will not be able to open and edit the project in non GPU mode. The mlt will need to be edited to remove GPU elements before in can be used in regular mode.

Which is why a trial experiment is recommended.
Never wise to commit to an important lengthy project until you’re aware of pitfalls.

Thanks for the ideas.
I was also wondering if there may be any commonly known reasons for
experimenting with it that I may not be aware of.
Like maybe any particular things that can be done with Shotcut using
GPU Effects setting enabled that cannot be achieved without it enabled.
By the way,
Windows 10, Creators (1709)
Shotcut 18.06.02
Nvidia GT 730

I’m not quite sure either. I had it enabled for a while, and it may have helped with exporting, but there was an issue with “Open MLT XML as a Clip”. Issue being as I couldn’t put them into the playlist. This was several versions back, as I disabled the feature and never activated it again.

One way to experiment is by copying a current MLT file, then rename it with GPU in the file name. That way you’re not going to overwrite the good MLT file. With the GPU file, experiment with exporting, various filters, etc.

Before starting a new project you start, ensure GPU Effects is turned off.

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I didn’t find any advantage when I was using it but that’s not to say there isn’t one, I use lots of effects in my work and it seemed to trip up most often when I had layers of effects on the same item. Say size&position, transparency, crop and chroma-key all on the same image or clip, and this was before key-frames were introduced. My feeling is that it may be because some of the combinations included effects that were GPU reliant with ones that weren’t, but that’s just speculation. Doing the same project without GPU effects would work OK.
Hudson’s suggestion re how to experiment sounds good to me. I had to completely recreate a project at one point when it wasn’t working out, and you want to avoid that if you can.

One downside is that the TEXT filter is not available when you enable GPU processing.

Thanks all for the ideas.
So at this point I feel no inclination to experiment with
GPU Effects setting enabled
because I’m seeing no advantages to using it.
No problem. Shotcut seems to be great without it.
I was just curious about why the option is there.
Thanks again.

The advantages are:

  • faster when using only GPU video filters (not combining it with CPU filters)
  • does processing in 16-bit floating point per color component in linear light for better image quality

The idea is to eventually make it more stable and integrate with FFmpeg GPU decoding for even greater speed.


Okay, thank you for the clarification about the advantages.
That’s good to know.
And the plan you mention sounds like a good one.
Looking forward to it.
ShotCut is an amazing tool, and fun to work with!
Thanks again.

The advantages are:

faster when using only GPU video filters (not combining it with CPU filters)
does processing in 16-bit floating point per color component in linear light for better image quality

I had some bad experiences with GPU enabled (text filter and some transitions not working – but they seem to work now).
Quality matters more than speed but 16-bit floating point really improves color quality. In another thread, I reported that when I edited very bad clips of an anniversary taken with a poor photo camera with a terrible yellow color cast, and the color correction was much more accurate and efficient with GPU enabled. For instance, there was a pink stain in the middle of the candles lights without GPU whilst there was none with GPU processing.

Good to know.
Sounds like it’s useful for certain color correction situations then.
That’s what I was wondering, specifically where GPU enabled
has been useful in projects.