Reducing RAM usage during export

So I’ve been trying to export an absolutely massive project for about a week now (17 minutes with 8 layers of 4K60 video), and I have been getting failed exports at around the 3-minute mark (but never at the same spot). I’ve theorised about this being an issue with my machine running out of memory, since task manager shows it at 100% CPU and around 95% RAM for the majority of the rendering process. I can’t be certain of this since it renders for about 30 hours usually before this point is reached.

Interestingly, the first 3 minutes of the video file is viewable and looks completely normal up until about 5 seconds before the end, when things start to look a little choppy and some video layers disappear for individual frames.

As can be seen in the above screenshot, the RAM usage is about half Shotcut and half the actual rendering process. Is there a way that Shotcut’s RAM usage can be decreased while rendering is in process, possibly by unloading all of the clips for the duration of the render (since the computer will be too slow to do anything useful while it’s rendering anyway)? If not, consider this a feature request.

In the mean time, is there a way that I can manually run melt.exe from the command line and give it the required arguments to allow it to render properly with shotcut remaining closed? Do I need to pipe in the XML file for rendering or pass it as an argument or something?

Yes you could try rendering using the command-line interface (qmelt.exe). Basically:

  • start the export in Shotcut,
  • stop the export,
  • copy the XML to a file,
  • stop Shotcut,
  • restart your computer
  • then run melt.exe with the XML file before starting any other applications.

See here for more details:, or here for the Dan’s instructions: Command line rendering

If you are on a locale that uses commas for decimal point you must also set environment variable LC_ALL = C.

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