As I hear it,
left hand mainly plays Octaves.
Right hand plays chords in different invertions (im not sure about some musical terms in english)
Sometimes it just sounds as he plays the tonic and the third in the chord to give it more substance, aswell as some bassliness.
For example. 'Cmaj7(C E G H) after you play the chord, you can basicly play any of the notes for a filler, or just Cmaj7 then C and E, again Cmaj7, in whatever chord he plays, I just took an example.
The second thing I would do, is learn what key signature this is in. And you play THAT scale, if you are a beginner this will be good for you later, but ferociously handy if you want to play a song where it would be cool to improvise, you learn the keysig scale. And when you learn the song and to play the chords. Just remember the scale you practiced, what notes was it you played, and press any of them lol, just land on the tonic of each chord when you change. It's that simple. Tonic being the Primary tone of each chord. Cmaj7 chord, C is the tonic.
The good thing with improv, if you learn the scale really good. It will never sound horrible, you can land on notes when you switch chord that dosnt fit at all, but you always know where to go.
Ahh right, the bass line it appears as if he just plays octaves, and then plays them like 1 - 3 -5 -8 or 1- 5- 8.
Take a Cmaj7 for example in right hand.
Left hand plays C G C(an octave up).
These are "simple" enough structures I think you can get down with a bit of practice.
Basically that's all I can give you. I'm sure you can find the chord theme he is playing somewhere. Since I've never really listened to Coldplay nor played anything by them. I may be totally misstaken.
Hope it helps.