[libdav1d @ 0x55a991124600] libdav1d 1.4.2
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'FLCL - 05 [BDRip 1440x1080 x264 FLAC]._hardsub.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomav01iso2mp41
    encoder         : Lavf60.16.100
  Duration: 00:23:36.42, start: 0.000000, bitrate: 695 kb/s
  Stream #0:0[0x1](und): Video: av1 (Main) (av01 / 0x31307661), yuv420p10le(tv, bt709, progressive), 960x720, 630 kb/s, SAR 1:1 DAR 4:3, 23.98 fps, 23.98 tbr, 24k tbn (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
      encoder         : Lavc60.31.102 libaom-av1
  Stream #0:1[0x2](und): Audio: opus (Opus / 0x7375704F), 48000 Hz, stereo, fltp, 59 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]

encoded with:

find \*mkv -print0 |sed 's/mkv//g'|xargs -0 -L1 -I@ ffmpeg -i 'ass/@ass' -i @mkv -pix\_fmt yuv420p10le -ac 2 -c:a libopus -b:a 64k -c:v libaom-av1 -row-mt 1 -tiles 4x2 -cpu-used 2 -lag-in-frames 48 -crf 30 -movflags +faststart -flags +global\_header -map\_metadata -1 -map\_chapters -1 -y -vf "scale=-2:720,ass='ass/@ass',hqdn3d=8" out/@\_hardsub.mp4