It is a meditation video of sorts. The person is singing the mantra found in the Buddha's Heart Sutra, which is a very brief recitation of
phenomena both material and mental, that he asserts to be devoid of "own being". The phenomena include everything. Everything is asserted to be the
result of "interdependant origination". In other words, nothing exists on it's own, not even consciousness. This is the most important insight in
Buddhism. It is impossible to over estimate it's importance. The wisdom that flows from a realization of this truth is completely staggering.
The Heart Sutra is part of the Prajnaparamita literature of Buddhism. Prajnaparamita means Perfection of Wisdom.
The Heart Sutra is a very simple assertion of what to Buddhists is an established fact. There are no arguments or discussions or debates in the sutra.
Longer versions of the sutra are more discursive. The version referred to by the OP is just a simple statement of the basic position of the Buddha on
this subject, plus the mantra, which is the only part of the sutra sung in the video.
A nice musical rendition of a more complete version of the Heart Sutra follows: