Version 1.8 was released in December. Version 1.5 in portage does not work very well, I recompressed a x264 video and it got much bigger, while the current git sources do what I expect instead and create a much smaller video. Also, they heavily optimized speed (50%) and quality in version 1.6, 1.7 and 1.8. Please update the ebuild. Reproducible: Always