I did some more tests with x265. The details can be found in the attached file, here I put a summary table where "Before" are the results of the previous test that used a build with ffmpeg-4.4 but without the latest patch. "Build" represents the test with ffmpeg-4.4 with the latest patch applied and "AppImage" represents the test done with appimage-multibit which has ffmpeg-4.3 with the latest patch. There are no big differences. Strange thing is that with "AppImage" we have correspondence of the project frames ("7500"), with the "Build" we still have the difference 7470 and 7500 that we had also in "Before". Shouldn't the "Build" with the "AppImage" be the same? Before Build AppImage x265-10-bit 27.5 fps 28.2 fps 27.8 fps x265-12-bit 25.5 fps 25.8 fps 25.35 fps x265-hi 10.6 fps 10.6 fps 10.9 fps If you have more specific tests to request, please let me know.