Encoding with WebM can heavily strain older server hardware. If your processor is spiking, add the -speed parameter (values 1 to 5) to your execution command to sacrifice a small amount of file compression in exchange for significantly faster rendering times.
A common issue encountered during an unmanaged upgrade is a system package conflict. For instance, on rolling-release operating systems, upgrading the package tree might yield the following error: error: installation of libvpx breaks dependency 'libvpx.so' required by ffmpeg . vera s05 libvpx upd