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

[Reindl Harald]

Am 06.08.22 um 20:11 schrieb jatmvp ctf:
> I thought quality goes in pair with size
there *may be* some correlation *but* you have speed/quality/size to 
assign and can only chose two as you can only have two of cheap/quick/good

you need a ton of cpu-usage to squeeze out the last bit of quality while 
a sloppy and fast run leads to a way larger output file with terrible 
quality

----------

take as example MP3 with VBR

it will have the same or even better quality with VBR than 320kbit - 
extreme example: why would you need 320kbit for 2 seconds of silence?

or take a mono record - with joint-stereo and VBR it takes less than 
half of the size of CBR with to difference - "play the same on both 
channels" don't need the information twice

and before someone cries: yes, VBR with maximum settings can sound 
better at complex parts where even 320kbit won't be enough because it's 
more evenly around the complex part which needs high bitrates and what 
your ear notices is un-evenly quality - headroom is the key - CBR don't 
have any