If you embed a video in a web page, don’t set it to start up automatically. Ideally, don’t even have it downloading automatically.
When I come to your site, why should my data feed slow down because of content I might not want? Worse still, why should my music listening (or other video watching) be interrupted by some bod piping up out of nowhere, leaving me to scramble for the source of the problem?
If your media content gets classified as a problem, you’ve an extra obstacle to overcome in getting your message across.
Make it the user’s choice to download and launch the content. Use your words and layout to make them want to do it.