Como cuento/pagino esta query?

[Genetix]

prueba de esta manera

Código sql:

SELECT COUNT(DISTINCT a.id_video ) AS total FROM categorizado AS a 
INNER JOIN videos AS r ON a.id_video = r.id 
INNER JOIN categorias AS c ON c.id = a.id_cat 
WHERE a.id_cat IN (6, 52, 78, 140, 141, 157)