I built a video player with this engine for Linux. It loads the processor two-three times more than VLC. Tried with and without OpenGL (FOLEYS_USE_OPENGL macro). Without OpenGL, it slows down if you expand the video to full screen.
Developer @daniel (Foleys Finest Audio)
sudo apt install libavcodec-dev \ libavfilter-dev \ libavformat-dev \ libavdevice-dev \ libavutil-dev \ libswresample-dev \ libpostproc-dev \ libswscale-dev \ libavresample-dev