If your choice is only for video then go for bigger screen. But if you want to play games and want to use some apps in addition to movies and music then ipod touch is very good choice
Personally i suggest ipod touch because for 2 reasons
1, For 15k we are getting almost 90% features of iphone and 100% in apps and games
2, Front camera, for 15k i think now there is no android phone is coming with front camera with video chatting feature. But in ipod we can able to use facetime,skype and recently google+ also added
So, My vote is for ipod touch 4g. Don't buy or preorder white ipod touch which is bit costlier than black model. you can get 32gb black model for 14 to 15k in ebay but 8gb white model is in preorder for 13.5k in letsbuy