All I can say about the videos you see is that they are a drop in the ocean compared to the number of encounters with police officers where upon a member of the public is treated fairly, politely and with dignity (even in the face of intense provocation)
This. I think in the vast majority of cases the police do a very difficult job very well. We really only hear about the "bad" cases, and I'm sure most of the police join us in condemning them. I'm pretty sure the culture of silence hardly exists any more.
Having said that, I think we need to remain vigilant that the police do not get extra powers (S44, thankfully now repealed) just because they or politicians ask for them.