[FFmpeg-user] libx265 a lot slower

Carl Zwanzig cpz at tuunq.com
Sun Aug 16 20:14:01 EEST 2020

Reindl is known for acerbic and unhelpful answers, AFAICT most readers 
ignore them.

On 8/16/2020 10:02 AM, Cecil Westerhof wrote:

> For the moment I will keep with 264. Especially because these files
> are only played once. Just wanted to make sure I was not overlooking
> something.

Probably not; for a one-use file, I'd take whichever one is easier to deal 
with (which might mean quickest to encode). And depending on the source 
material, and well, everything in the chain, you might use another codec 
anyway, there's nothing mystical/magical about x264 (and a few decidedly 
unfriendly things- ref "moov atom location").

> By the way: when searching on the internet, I saw often said that 265
> would be half as big as 264, but I see 'only' a third less space
> taken. Are the people saying 50% overly optimistic, or do I just have
> 'strange' videos?

"Never generalize."

I'd take any size estimate as a guess since your content and encoding 
parameters are probably different. If my own tests of x265 showed 30% 
smaller but 2x the encode time, I wouldn't bother.



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