Note: This feature is available in Dedicated Web Workers.
The canConstructInDedicatedWorker static property of the MediaSource interface returns true if MediaSource worker support is implemented, providing a low-latency feature detection mechanism.
If this were not available, the alternative would be a much higher latency approach such as attempting the creation of a MediaSource object from a dedicated worker and transferring the result back to the main thread.
A boolean. Returns true if MediaSource worker support is implemented, or false otherwise.
if (MediaSource.canConstructInDedicatedWorker) {
// MSE is available in workers; let's do this
}