[FFmpeg-user] What parameters were set in preset?

[Qianliang Zhang]

Hi everyone,

You know, while doing x264 encode, -preset can do a good job. Current
presets in descending order of speed are: ultrafast, superfast, veryfast,
faster, fast, medium, slow, slower, veryslow, placebo. But what are these
values stand for? What parameters are used and set in these presets?

Could anybody explain? Appreciate.