[BUG] NVenc (FFmpeg) x265 output is scrambled

[Selur]

1st Handbrake does not use FFmpeg, it uses libav which is part of the FFmpeg project.
2nd what FFmpeg calls 'slow' is sometimes called 'hq 2 passes' what you get when you use 'variable bitrate (HQ)' in Hybrid. (+ may be encoder preset->quality)
NVEnc SDK does not offer real 2pass encoding (where you run two separated passes, 1st pass creating a statistic file and the second pass using that statistic file to make better decisions).
The '2pass' encoding NVEnc offers is an encoding where each frame gets encoded 2 times, where tries to optimize the encoding. This is similar to the 'real' 2pass encoding, but only similar. During 'real' 2pass encoding the decisions can be based on the data of all frames of the clip, wheres NVEncs decisions can only be based a previous encode of the current single frame (+ lookahead).
Since lots of folks don't like that NVEnc calls it's method 2pass encoding folks usually call it 'XY hq' or similar.

-> There is no real 2pass encoding like x264 and x265 offers when using NVEnc, doesn't matter if you use Handbrake, FFmpeg or whatever tool you like.

The only thing i am interested in, is to get the best quality option that is available to optimize the result for lower bitrate.

For lower bit rates better use software encoding, last I checked x264/x265 were noticeable better (but slower) there.


Cu Selur