How to accumulate data-sets?

Question

I have vector with values between 1 and N > 1. Some values COULD occur multiple times consecutively. Now I want to have a second row which counts the consecutively entries and remove all those consecutively occuring entries, e.g.:

A = [1 2 1 1 3 2 4 4 1 1 1 2]'

would lead to:

B = [1 1;
     2 1;
     1 2;
     3 1;
     2 1;
     4 2;
     1 3;
     2 1]

(you see, the second column contains the number of consecutively entries! I came across accumarray() in MATLAB recently but I can't find any solution with it for this task since it always regards the whole vector and not only consecutively entries.

Any idea?