I note on the Packman packaged ffmpeg that “ffmpeg -codecs” yields:
DEV.LS h264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (decoders: h264 h264_v4l2m2m h264_vdpau h264_cuvid ) (encoders: libx264 libx264rgb **h264_nvenc** h264_v4l2m2m h264_vaapi nvenc nvenc_h264 )
D.VIL. hap Vidvox Hap
DEV.L. hevc H.265 / HEVC (High Efficiency Video Coding) (decoders: hevc hevc_v4l2m2m hevc_cuvid ) (encoders: libx265 **nvenc_hevc** **hevc_nvenc** hevc_v4l2m2m hevc_vaapi )
but I don’t think that means nvenc is enabled.