In the Manual_20220228.pdf there are stupid errors at the pages 167 and 168 because I wrote wrong in the CinelerraGG Forum https://www.cinelerra-gg.org/forum/help-video/how-to-optimize-playback/?orderby=oldest
It should be "Rescaled to project size (FFMPEG only) = unchecked" instead of  "Rescaled to project size (FFMEG only) = unchecked".
Sorry for my mistake.

IgorBeg