Well you posted in Time Capsule area.. and clearly you don't want or need a TC. You would be better posting in the itunes area.
If you want to stream itunes you need an itunes running server.. ie a computer.
And you need some player that plugs into the home threatre, like apple TV.. this is what it does well.
This has nothing then to do with the title of your thread.. dlna.. no more. The problem then is you will need software on the computer that can recognise or convert your existing material into a format that itunes or atv can understand.