regular freezes on c650 stock firmware

[agtr]

most probably. I had freezing problems when I was watching the mkv films with usb flash drive in the past, cos it was not able to transport the data to the tv sufficently, its bitrate was low. so the high bitrate movies did not play smootly. similarly, your cable must be the rootcause of the freezing problem as it may not handle the data to the tv as it should do.