applyConstraints method

The applyConstraints() method of the MediaStreamTrack interface applies a set of constraints to the track; these constraints let the website or app establish ideal values and acceptable ranges of values for the constrainable properties of the track, such as frame rate, dimensions, echo cancellation, and so forth.

Constraints can be used to ensure that the media meets certain guidelines you prefer. For example, you may prefer high-density video but require that the frame rate be a little low to help keep the data rate low enough not overtax the network. Constraints can also specify ideal and/or acceptable sizes or ranges of sizes. See Applying constraints in Capabilities, constraints, and settings for more information on how to apply your preferred constraints.