How can I upload video, generate thumbnail and convert to different formats?

I haven’t used WP in a very, very long time so please bear with me.

I’m using v3.3.1
I’ve used get_children() to display images of a page in a custom template.
I then customized a template to turn the images into a JQuery carousel.

Now, I want to add videos to that gallery.

My question is, how can I:

1. Have thumbnails generated once I upload videos via media library.
2. Convert the videos into multiple formats (all or most of: mp4, webm/vp8, ogg/vorbis & swf) so that I can use them with MediaElement.js

I’d really appreciate some direction on this

Thanks.