HEVC_NVENC: Add qmin and qmax

Hello,

when i used HEVC_NVENC with FFMPEG, i used the commandline from De-M-oN (i think you know which forum), which works very good and should be similar to crf from x264:

ffmpeg -i "<path to video> or avisynth script" -vcodec hevc_nvenc -pix_fmt p010le -preset slow -profile:v main10 -tier high -rc:v vbr_hq -b:v 0 -qmin 10 -qmax 19 -rc-lookahead 60 -spatial_aq 1 -aq-strength 7 -weighted_pred 1 "<output.mkv>"

The only things that are missing in Voukoder (Please correct me if im wrong) are these commands, that are important for this method:

-rc:v vbr_hq -b:v 0 -qmin 10 -qmax 19

Would be nice, if you could make it possible to use this "method".

Bump

Sorry to bother you again, but in order to use qmax and qmin without bitrate limitations, you need the parameter: -b:v 0

You can test that in ffmpeg with the following code:

ffmpeg -i "yourinput" -vcodec h264_nvenc -preset hp -profile:v main -rc:v vbr -b:v 0 -qmin 10 -qmax 16 Out.mkv

If you remove -b:v 0, ffmpeg will always use a constant qc value, but with -b:v 0 set ffmpeg/nvenc can use a lower value (qmin) for scenes that are more complex (more quality).

In ffmpeg you can see the current used value while encoding:

Instead of adding -b:v 0 a simpler "fix" would be to allow these values to be set to 0, what give me the correct result, when i'm testing in FFMPEG:

FFMPEG Example:

Ohh can you please try that with lower values like:

-qmin 0 -qmax 16?

Thank you, its working!