Nowadays, nobody doubts about the huge economical benefits the watermarking solutions will one day bring. The paper is devoted to the theoretical evaluation of the watermarking capacity, i.e. devoted to find out with mathematical rigour the maximum amount of information which can be inserted into the DWT of natural video, for prescribed constraints of transparency and robustness. The starting point is the accurate statistical model for the watermarking attacks the authors already reported. In this paper, in addition to the classical Shannon solutions, the capacity is evaluated by two approaches: (1) a method developed in order to increase speed and precision for watermarking evaluations and (2) the general Blahut Arimoto algorithm, adapted by Justin Dauwels for the discrete case. The experiments are run on a video corpus of 10 video sequences of about 25 minutes each