It's fairly easy if you know Ai. (Image trace is okay, but I'd recommend making your own (the right way), then use any Adobe pro video app to composite on your video, no need to export, just use the .Ai file)
But an easier way might be to use the .png by itself if it carries an alpha channel.
After Effects, PremierePro, and possibly AME will let you do this.
QT7 will also allow you to do it.
You could create a logo in Draw, then send it to Illustrator or Photoshop (it carries an alpha channel - bonus!)
In Illustrator there is always a white canvas behind your artwork.
Change to View > Show transparency grid in order to see what is transparent and what isn't.
Do you want to trace that logo? Or have you already?
Manual tracing will give you the best result as Ko already mentioned. But in case you want to autotrace, check the option "Ignore white"