vf "format=yuv444p, unsharp=6:6:0.6:6:6:-0.3, hqdn3d=7:7:5:5"
とやってみたら
[hqdn3d @ 0x102052f20] ls:7.000000 cs:7.000000 lt:5.000000 ct:5.000000
[format @ 0x1020528e0] auto-inserting filter 'auto-inserted scale 0' between the filter 'src' and the filter 'Parsed_format_0'
[hqdn3d @ 0x102052f20] auto-inserting filter 'auto-inserted scale 1' between the filter 'Parsed_unsharp_1' and the filter 'Parsed_hqdn3d_2'
[scale @ 0x102053380] w:720 h:480 fmt:yuv420p sar:8/9 -> w:720 h:480 fmt:yuv444p sar:8/9 flags:0x4
[unsharp @ 0x102052ac0] effect:sharpen type:luma msize_x:6 msize_y:6 amount:0.60
[unsharp @ 0x102052ac0] effect:blur type:chroma msize_x:6 msize_y:6 amount:-0.30
[scale @ 0x102053260] w:720 h:480 fmt:yuv444p sar:8/9 -> w:720 h:480 fmt:yuv420p sar:8/9 flags:0x4

444でunsharpしてるっぽい。ますます、わからなくなった。