ffmpeg -y -i ~/input.mp4 -c:v h264_nvenc /tmp/output.mp4

ffmpeg-test-nvenc.txt

ffmpeg -y -i ~/input.mp4 -c:v h264_nvenc /tmp/output.mp4
ffmpeg version N-109033-g86157f5a25 Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 10 (Debian 10.2.1-6)
  configuration: --enable-nonfree --enable-cuda-nvcc --enable-libnpp --extra-cflags=-I/usr/local/cuda/include --extra-ldflags=-L/usr/local/cuda/lib64
  libavutil      57. 42.100 / 57. 42.100
  libavcodec     59. 52.100 / 59. 52.100
  libavformat    59. 34.101 / 59. 34.101
  libavdevice    59.  8.101 / 59.  8.101
  libavfilter     8. 50.100 /  8. 50.100
  libswscale      6.  8.112 /  6.  8.112
  libswresample   4.  9.100 /  4.  9.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/martins/input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    title           : Big Buck Bunny, Sunflower version
    artist          : Blender Foundation 2008, Janus Bager Kristensen 2013
    composer        : Sacha Goedegebure
    encoder         : Lavf57.63.100
    comment         : Creative Commons Attribution 3.0 - http://bbb3d.renderfarming.net
    genre           : Animation
  Duration: 00:00:10.00, start: 0.000000, bitrate: 24563 kb/s
  Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], 24559 kb/s, 30 fps, 30 tbr, 15360 tbn (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (h264_nvenc))
Press [q] to stop, [?] for help
Output #0, mp4, to '/tmp/output.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    title           : Big Buck Bunny, Sunflower version
    artist          : Blender Foundation 2008, Janus Bager Kristensen 2013
    composer        : Sacha Goedegebure
    genre           : Animation
    comment         : Creative Commons Attribution 3.0 - http://bbb3d.renderfarming.net
    encoder         : Lavf59.34.101
  Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 2000 kb/s, 30 fps, 15360 tbn (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
      encoder         : Lavc59.52.100 h264_nvenc
    Side data:
      cpb: bitrate max/min/avg: 0/0/2000000 buffer size: 4000000 vbv_delay: N/A
frame=  300 fps=0.0 q=28.0 Lsize=    2673kB time=00:00:09.86 bitrate=2219.6kbits/s speed=10.9x     
video:2669kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.175763%
martins@martins ~ % ffmpeg -y -i ~/input.mp4 -c:v h264_nvenc /tmp/output.mp4