[FFmpeg-user] 2 pass encoding with hevc_nvenc

[Marco Diletti]

Hello,

i am trying to encode with a variable bitrate, 2 pass encoding, using
the codec
hevc_nvenv.

ffmpeg -i infile.mkv  -vcodec hevc_nvenc -preset slow -qmin 1 -qmax 50
-b:v 4000k -c:a copy -f matroska outfile.mkv

Theorically it shoulds use 2 pass encode, and it encodes with half
speed respect to preset medium.

My doubt is that ffmpeg do not iterate the encoding two times creating
a logfile.
##SELECTION_END##
If i use the option -pass 1, it creates a empty logfile.

How 2 pass encoding of nvenc works ? Someone know the exact or the best
command
syntax in order to do it ?

Sorry for the bad english. Thanks for your attention.
-- 
Marco Diletti <m.diletti at yahoo.com>