[FFmpeg-user] libx264 very bad scaling with 4 real CPU cores (no HT)

D dcmhoybdpzkh at web.de
Fri Dec 4 12:06:24 CET 2015

On 03.12.2015 22:22, Lou wrote:
> On Thu, 3 Dec 2015 16:43:28 +0100
> D <dcmhoybdpzkh at web.de> wrote:
>> If someone is interested in porting these commands to x264 that would
>> be nice.
> Don't try to manually set a each option. That's a waste of time &
> effort. It usually results in contradictions and a less than optimal
> output. Just use the x264 encoding presets: they were designed so users
> wouldn't have to deal with dozens of options.
Thanks for mentioning this. I wasn't sure whether or not to do it 
because HandBrake utilizes the CPU very well (in $top: ~387%) and some 
presets like the ultrafast one wasn't scaling very well as all (4 cores, 
~210%) (029372.html). So I thought maybe it has something to do with the 
command, but you are right, if the presets are carefully done by the 
devs, they should scale.
Wanted to ask this in a x264 place -- 
https://www.videolan.org/developers/x264.html -- but I don't see a user 
mailing list or forum (they link to doom10 which doesn't exist, LOL) or 
something, there is only a x264-devel). Well I guess there is still "and 
IRC (#x264 at freenode" but it's for chat where a topic is not organized 
and basically also lost in the future.

The other thing I find weird with -preset is that one can use -crf 
setting with it. I thought a preset would cover this and no -crf setting 
would be needed/allowed. But because it is, the question is what other 
settings are allowed/needed? Confusing.
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