Looking for a C++ open source matrix storage library

Question

The library needs to:

1. record vector or matrices in "frames" (timestamped)
2. enable multiple streams and markers

It would be good if the library:

1. had a BSD licence
2. was well documented
3. was written in C++
4. enabled non-linear access

I have found a library that is very interesting and does points (1) and (2): SDIF. But the documentation is lacking and the license is LGPL.

Any recommendations ?