Ffmpeg how modify the contrast with nvidia “hevc_nvenc” codec

Hi,

I need to adjust to contrast of some mkv file I have tried this code:

ffmpeg -y -vsync 0 -hwaccel cuda -hwaccel_output_format cuda -i title00.mkv -c:v hevc_nvenc -b:v 5M -vf eq=contrast=1.0 output.mkv

but I get this error:

Impossible to convert between the formats supported by the filter 'graph 0 input from stream 0:0' and the filter 'auto_scaler_0'
Error reinitializing filters!
Failed to inject frame into filter network: Function not implemented
Error while processing the decoded data for stream #0:0

If I run the some line without “-vf eq=contrast=1.0”:

ffmpeg -y -vsync 0 -hwaccel cuda -hwaccel_output_format cuda -i title00.mkv -c:v hevc_nvenc -b:v 5M output.mkv

the command work and don’t show any error message but don’t allow me to adjust the contrast.

There is a way to modify the contrast with nvidia hevc_nvenc codec ?

Thanks !