f=flv acodec=libfdk_aac ab=256k ac=2 vcodec=h264_nvenc vb=5M threads=0 vpre=medium keyint_min=50 g=50 preset:v=medium level:v=41 #top_field_first=1 progressive=1 meta.preset.extension=flv meta.preset.name=H264 (CPU) 5M / FLV