Adjust encoder settings to trade off compression efficiency against encoding speed. This estabilishes your default encoder settings. Tunes, profiles, levels and advances option string will be applied to this. You should generally set this option to the slowest you can bear since slower settings will result in better quality or smaller files. Tune settings to optimize for common scenarios. This can improve efficiency for particular source characteristics or set characteristics of the output file. Changes will be applied after the preset but before all other parameters. Sets and ensures compliance with the specified profile. Overrides all other settings. Reduce decoder CPU usage. Set this if your device is struggling to play the output (dropped frames).