Již bylo v prvním příspěvku
ffmpeg -i ... -preset X -crf 30 -c:a aac -movflags -c:v libx264 -pix_fmt yuv420p faststart output.mp4X jsou varianty : { slower, medium}
Výpis z ffmpeg (shrnutí po konci konverze - zjiného videa, z každého řádku smazáno [libx264 @ 00000073a2691680] )
SLOWER
profile Progressive High, level 5.0, 4:2:0, 8-bit
frame I:1     Avg QP:22.33  size: 28281
frame P:31    Avg QP:23.16  size:  4042
frame B:58    Avg QP:27.17  size:   562
consecutive B-frames: 12.2%  2.2% 10.0% 75.6%
mb I  I16..4: 23.2% 11.1% 65.8%
mb P  I16..4:  1.5%  0.9%  0.4%  P16..4: 33.1% 12.8%  9.7%  0.5%  0.2%    skip:41.0%
mb B  I16..4:  0.1%  0.0%  0.0%  B16..8: 39.3%  4.2%  0.5%  direct: 0.3%  skip:55.6%  L0:54.8% L1:40.0% BI: 5.2%
8x8 transform intra:21.4% inter:38.1%
direct mvs  spatial:93.1% temporal:6.9%
coded y,uvDC,uvAC intra: 45.1% 80.3% 53.7% inter: 6.5% 9.3% 1.1%
i16 v,h,dc,p: 62% 23% 13%  3%
i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 16%  8% 54%  3%  2%  3%  2%  4%  6%
i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 29% 14%  9%  7%  7%  7%  8%  6% 12%
i8c dc,h,v,p: 37% 30% 27%  7%
Weighted P-Frames: Y:0.0% UV:0.0%
ref P L0: 74.2%  6.9% 10.1%  4.2%  1.5%  1.3%  1.2%  0.5%  0.2%
ref B L0: 92.8%  4.5%  1.8%  0.4%  0.2%  0.2%  0.1%
ref B L1: 97.1%  2.9%
MEDIUM
profile Progressive High, level 4.0, 4:2:0, 8-bit
frame I:1     Avg QP:22.44  size: 27713
frame P:30    Avg QP:23.73  size:  4276
frame B:59    Avg QP:27.71  size:   480
consecutive B-frames:  7.8% 11.1% 10.0% 71.1%
mb I  I16..4: 24.0% 11.2% 64.8%
mb P  I16..4:  1.7%  1.1%  0.4%  P16..4: 36.5% 17.8% 10.1%  0.0%  0.0%    skip:32.3%
mb B  I16..4:  0.1%  0.0%  0.0%  B16..8: 33.7%  3.3%  0.3%  direct: 0.3%  skip:62.3%  L0:55.7% L1:39.9% BI: 4.4%
8x8 transform intra:22.6% inter:46.7%
coded y,uvDC,uvAC intra: 43.3% 79.0% 52.5% inter: 7.3% 9.7% 1.1%
i16 v,h,dc,p: 55% 28% 14%  3%
i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 20% 10% 57%  2%  2%  2%  1%  2%  3%
i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 32% 19% 11%  7%  6%  7%  7%  4%  8%
i8c dc,h,v,p: 39% 28% 26%  6%
Weighted P-Frames: Y:3.3% UV:0.0%
ref P L0: 79.6%  6.3% 11.3%  2.7%  0.1%
ref B L0: 94.0%  5.5%  0.5%
ref B L1: 98.5%  1.5%
Toto je pro oba výstup stejné. Jen řádek u SLOWER JE Weighted P-Frames: Y:0.0% UV:0.0% a má řádek navíc (mvs asi zkratka pro motion vectors):
direct mvs  spatial:32.7% temporal:67.3%
Něco jako mediainfo:
SLOWER / MEDIUM:
Format profile: High@L5 / High@L4
Format settings                : CABAC, 8 /4  Ref Frames 
ReFrames      : 8/4 frames
Encoding settings:
ref=8 / 3
analyse=0x3:0x133 / 0x113
me=umh / hex
direct=3 / 1
subme=9 / 7
trellis=2  / 1
b_adapt=2 / 1
rc_lookahead=60 / 40