[FFmpeg-user] Strange results with -preset

[Dave]

On Sunday 28 January 2018 18:38:48 Cecil Westerhof wrote:
> So it looks like I should always use superfast. (But probably a good
> idea to test it with a few other videos.)
> 
> Anyone an idea what could be happening here?

Some good answers already but something I read while researching
similar effects using x265 encoding told me that preset is just a
shorthand for a specific set of encoding options, some affect speed,
some affect quality.  Said combinations are defined by whoever set
up the preset keywords and there is no specific relationship between
size, speed and the key word chosen because the source material
may affect how the pre-selected options work, although in general
the fast presets will, in fact, give a faster encoding time.

If you really want to optimise sped and quality, you need to manually
choose your options to match the source materiel, eg lots of action,
cartoon animation, black and white etc.  I think there's a way (or some
website somewhere) which documents the full command line settings
that are enacted when choosing a preset.

Good luck!