$ ffmpeg -v verbose -f v4l2 -input_format mjpeg -framerate 60 -video_size 1920x1080 -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -hwaccel_output_format vaapi -i /dev/video0 -vf 'scale_vaapi=format=nv12,hwupload' -c:v hevc_vaapi -map 0:a? -map 0:s? -c:s copy -rc_mode 1 -qp 25 -map_chapters 0 output.mp4 -y


ffmpeg version n5.0.1 Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 12.1.0 (GCC)
  configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nvdec --enable-nvenc --enable-shared --enable-version3
  libavutil      57. 17.100 / 57. 17.100
  libavcodec     59. 18.100 / 59. 18.100
  libavformat    59. 16.100 / 59. 16.100
  libavdevice    59.  4.100 / 59.  4.100
  libavfilter     8. 24.100 /  8. 24.100
  libswscale      6.  4.100 /  6.  4.100
  libswresample   4.  3.100 /  4.  3.100
  libpostproc    56.  3.100 / 56.  3.100
[video4linux2,v4l2 @ 0x5580ca087a80] fd:3 capabilities:84a00001
Input #0, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 778.047186, bitrate: N/A
  Stream #0:0: Video: mjpeg (Baseline), 1 reference frame, yuvj422p(pc, bt470bg/unknown/unknown, center), 1920x1080 [SAR 1:1 DAR 16:9], 60 fps, 60 tbr, 1000k tbn
Stream map '0:a?' matches no streams; ignoring.
Stream map '0:s?' matches no streams; ignoring.
[AVHWDeviceContext @ 0x5580ca08ff80] libva: VA-API version 1.15.0
[AVHWDeviceContext @ 0x5580ca08ff80] libva: Trying to open /usr/lib/dri/radeonsi_drv_video.so
[AVHWDeviceContext @ 0x5580ca08ff80] libva: Found init function __vaDriverInit_1_15
[AVHWDeviceContext @ 0x5580ca08ff80] libva: va_openDriver() returns 0
[AVHWDeviceContext @ 0x5580ca08ff80] Initialised VAAPI connection: version 1.15
[AVHWDeviceContext @ 0x5580ca08ff80] VAAPI driver: Mesa Gallium driver 22.1.3 for AMD Radeon Pro WX 2100 (polaris12, LLVM 14.0.6, DRM 3.46, 5.18.12-arch1-1).
[AVHWDeviceContext @ 0x5580ca08ff80] Driver not found in known nonstandard list, using standard behaviour.
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> hevc (hevc_vaapi))
Press [q] to stop, [?] for help
[graph 0 input from stream 0:0 @ 0x5580ca2d3f00] w:1920 h:1080 pixfmt:vaapi tb:1/1000000 fr:60/1 sar:1/1
[hevc_vaapi @ 0x5580ca08d600] Using input frames context (format vaapi) with hevc_vaapi encoder.
[hevc_vaapi @ 0x5580ca08d600] Input surface format is nv12.
[hevc_vaapi @ 0x5580ca08d600] Using VAAPI profile VAProfileHEVCMain (17).
[hevc_vaapi @ 0x5580ca08d600] Using VAAPI entrypoint VAEntrypointEncSlice (6).
[hevc_vaapi @ 0x5580ca08d600] Using VAAPI render target format YUV420 (0x1).
[hevc_vaapi @ 0x5580ca08d600] RC mode: CQP.
[hevc_vaapi @ 0x5580ca08d600] RC quality: 25.
[hevc_vaapi @ 0x5580ca08d600] RC framerate: 60/1 (60.00 fps).
[hevc_vaapi @ 0x5580ca08d600] Using intra and P-frames (supported references: 1 / 0).
[hevc_vaapi @ 0x5580ca08d600] Driver does not support some wanted packed headers (wanted 0xd, found 0x1).
[hevc_vaapi @ 0x5580ca08d600] Using level 4.
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf59.16.100
  Stream #0:0: Video: hevc (Main), 1 reference frame (hev1 / 0x31766568), vaapi(pc, bt470bg/bt470bg/smpte170m, progressive, center), 1920x1080 (0x0) [SAR 1:1 DAR 16:9], q=2-31, 60 fps, 15360 tbn
    Metadata:
      encoder         : Lavc59.18.100 hevc_vaapi
frame=  598 fps= 60 q=-0.0 Lsize=    4192kB time=00:00:09.95 bitrate=3451.7kbits/s speed=   1x
video:4189kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.079307%
Input file #0 (/dev/video0):
  Input stream #0:0 (video): 598 packets read (77541249 bytes); 598 frames decoded;
  Total: 598 packets (77541249 bytes) demuxed
Output file #0 (output.mp4):
  Output stream #0:0 (video): 598 frames encoded; 598 packets muxed (4289680 bytes);
  Total: 598 packets (4289680 bytes) muxed
[AVIOContext @ 0x5580ca08e4c0] Statistics: 4293086 bytes written, 2 seeks, 20 writeouts
Exiting normally, received signal 2.