Well, VLC et al seem to be able to decode and play videos without a problem, and one would think that the remaining 85% of CPU would be enough to copy the decod

Well, VLC et al seem to be able to decode and play videos without a problem, and one would think that the remaining 85% of CPU would be enough to copy the decoded image data into a buffer for the browser... But I haven't tried to do it myself, maybe it's harder than it seems.