Its a wordpress blog where the client is writing their own articles but they know nothing about HTML/CSS - so it has to automatically center the embedded video for them.
Unfortunately, I dont know enough about PHP to re-configure how wordpress builds the page when they publish an article.
Thanks for the suggestions.
You might try posting on the wp forum for a way to customize the loop output based on the content in a post, but it's going to be tough to find a solution that doesn't require you to modify the php.
If the object is automatically placed in a p (or div), centring the object via the centre/center! align button on the WYSIWYG editor should do the trick. Objects themselves don't centre, so I understand the use of p. Some blogging platforms allow you to chose between p and div for new input. Both should work with the align buttons.
@ardav and @nizuya: guys, thanks a ton for the input. I actually figured out how to make it work and it was super-simple. I just needed to set the OBJECT to display:block and then the margin:auto worked. Don't know why I didn't think of that sooner.
Nice one. Although - had issues with margin:auto in order browsers. Still had to centre-align the outer tag.