[FFmpeg-user] Why ffmpeg libx265 generate way smaller files than cuda/nvidia based one?

[Reindl Harald]

Am 05.08.22 um 18:38 schrieb jatmvp ctf:
> Different implementation of same standard should not behave way different I
> assume, or not have same features or performance (at least).

says who?

H265 has tons of features, optimizations and options as H264 had and in 
both cases even with the same params two output files are not guaranteed 
binary identical

> Could you describe a little more or at least give source?

frankly you have lots of encoding params and the hardware implementation 
is a subset of them and from what i know usually has lower quality due 
reducing of complexity
> What are you suggesting by different implementation exactly then?

that you accept that each implementation choses other deatils within the 
specification as viedeo encoding is always a tradeoff between 
size/quailty/speed

if you want the best quality with the smallest files use x264/x265 - 
it's that easy - other than you hardware implementation this may get 
bugfixes and improvements over the years