Thanks Igor for your answer. I do not know if that can help but the results of some encoding tests are as it follows : All tests achieved with the same project duration of 3'57s (30 photos between 9Mpx and 16Mpx  each of them) few vertical pans, and zoom effects with 3s solved transitions. (Informations given by Mediainfo app.) a= With hardware acceleration (HWA) and b = without 1 = Encoding with Quality mode (Q80) 1a)  4K / HWA / 60fps / Q80 result : encoding