Hello,
I want to do this project for you. I had make a similar project before and it will be easy for me to add the features you require. I will make the multimedia playback core as a dll so that dll can be used by you to make a media player. The dll can be used under any programming language like .NET , C++, Pascal etc.
If you want to check some of my work you can look here: http://surodev.com.
Also if you have any questions don't hesitate to ask.
Best regards,
Ionut