qvbrQualityLevel property
Required when you use QVBR rate control mode. That is, when you specify qvbrSettings within av1Settings. Specify the general target quality level for this output, from 1 to 10. Use higher numbers for greater quality. Level 10 results in nearly lossless compression. The quality level for most broadcast-quality transcodes is between 6 and 9. Optionally, to specify a value between whole numbers, also provide a value for the setting qvbrQualityLevelFineTune. For example, if you want your QVBR quality level to be 7.33, set qvbrQualityLevel to 7 and set qvbrQualityLevelFineTune to .33.
Implementation
final int? qvbrQualityLevel;