Copyright Doubts

Hello, Greetings of the Day, I have established my media firm recently and is at the start up level. There are several copyright doubts which i would like to solve for avoiding an infringement quandary. We are creating a web-series which will be played predominantly on YouTube for the sole purpose of monetizing to earn profits. The show predominately is focused on sitcoms, films etc ... hence, we wish to use several video clippings, barely of 20 seconds in every episode. My query is, if we put a disclaimer stating, '' the clips or clippings used in the episode are not created or owned by us and we do not have the rights to them and thus there is not copyright intended ... " as well as in addition to the disclaimer which will be played in the starting seconds of every episode, if we provide credits to the copyright owner of the video clippings while the clippings are being displayed, do we still execute infringement? I would be very much pleased and happy if you can provide with the necessary information and knowledge. Regards, Raunak Kelekar