Taking advantage of the fact that I compiled a version that uses system (external) ffmpeg, I did some comparative testing with CinGG appimage which uses an internal ffmpeg instead. I report the results: Source: blender movie "Tears of steel" 1080p, webm (Used an interval of the first 1440 frames via In/Out Points) mp4; preset h264.mp4 ffmpeg internal --> render at 117.4 fps (25.4MB) ffmpeg external --> render at 175.3 fps (22.8MB) mxf; preset DNxHR 444 ffmpeg internal --> render at 92.9 fps (1.8GB) ffmpeg external --> render at 120.5 fps (1.8GB) I had already noticed that ffmpeg from the command line (external) was faster than ffmpeg inside CinGG; but now we see that even external ffmpeg called up inside CinGG is still faster than internal ffmpeg. What could be the cause of this difference?