ACTIVEX for playing mkv and mp4 files

I'm a C# developer who needs ACTIVEX to play .MKV and .MP4 only, nothing else.I want only
people whom I intend to be able to watch videos. I have following requirements

1. A encryptor to encrypt the video with a KEY
2. The player (ActiveX) to play the encrypted video file when pass the KEY with which it was
encrypted
3. only .MKV and .MP4 support is needed
4. i will do only one time payment and not pay any royalty for all my projects that use your
ACTIVEX, so tell me final cost {Affordable please}