[FFmpeg-user] Difference between videos with libx264 and h264_nvenc

Carl Eugen Hoyos ceffmpeg at gmail.com
Mon Feb 24 23:13:30 EET 2020

Am Mo., 24. Feb. 2020 um 21:13 Uhr schrieb Totte Karlsson
<totte.karlsson at alleninstitute.org>:
> When using the libx264 encoder on 8bit raw input, the resulting video shows up slightly darker than the original. Using this command:

(Note that this is not x264-user)

> ffmpeg.exe -y -hide_banner -vcodec rawvideo -f rawvideo -r 60 -s 658x492 -i \\.\pipe\DEV_000F315B978C<file://./pipe/DEV_000F315B978C> -pix_fmt gray -c:v libx264 -crf 23 X:\Videos\One_2020T115817.avi

Complete, uncut console output missing, don't forget to remove "hide_banner".

> When running the compression using nvidias encoder, h264_nvenc, the darkening of the video does not occur. Using this command:
> ffmpeg.exe -y -hide_banner -vcodec rawvideo -f rawvideo -hwaccel nvdec -r 60 -s 658x492 -i \\.\pipe\DEV_000F315B978C -pix_fmt gray -c:v h264_nvenc -crf 23 X:\Videos\One_2020T120806.avi

nvenc does not support gray encoding.

Carl Eugen

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