Spanish to English Other Other commercial / spot

I need help with this paragraph:

Realización de 56 segundos de animación para utilizarse en los armados de un comercial de 50 segundos y dos reducciones de 30 segundos aproximadamente (estas ultimas duraciones no incluyen el material en fílmico)

My draft translation is: Creation of a 56-second animation to be used for a 50-second commercial editing and two xx of approximately 30 seconds (the last durations include the film material)