Library to edit and watermarkin videos

[J_Zanetti]

Hello everybody,

Im working on an application that should manage some videos (in .flv
and .wmv format).

I would need to execute some operation on this video like adding few
frames at the beggining and at the end of the movie or apply
watermark. I would like to have a feedback from the application
telling me whether the operation was succesful or not.

Does anyone any know any library that could help me making such
operations with flv or wmv?
Thanks so much!