| 42 | | * Choose a preset. The default is `medium`. The preset determines compression efficiency and therefore affects encoding speed. Valid presets are `ultrafast`, `superfast`, `veryfast`, `faster`, `fast`, `medium`, `slow`, `slower`, `veryslow`, and `placebo`. Use the slowest preset you have patience for. Ignore `placebo` as it provides insignificant returns for a significant increase in encoding time. |
| | 42 | * Choose a preset. The default is `medium`. The preset determines compression options and efficiency and therefore affects encoding speed and size. Valid presets are `ultrafast`, `superfast`, `veryfast`, `faster`, `fast`, `medium`, `slow`, `slower`, `veryslow`, and `placebo`. Use the slowest preset you have patience for, with a crf that is acceptable, given that preset. Ignore `placebo` as it provides insignificant returns for a significant increase in encoding time. Note that CRF values are different based on which preset you select, a "slower" preset generates more compression/bit, but may increase filesize. If you compare "ultrafast" with "veryslow" at the same CRF value, "veryslow" may generate a larger file, with overall better compression. So for instance if -preset ultrafast with -crf 15 generates a file with comparable size to "veryslow" -crf 20, the veryslow preset file will have better quality for the same file size. You can also specify a bitrate for a preset (see below), instead of crf, for controlling file size with a certain compression level. |
