Objective video quality assessment I'm trying to develop a tool that given a video (without a reference video), it can measure the quality. Basically given some thresholds, it assigns them a rating (I just need 4 classes 1-4). Since we don't have the original reference videos, I'm not looking for approaches using SSIM or PSNR or such. Possible options are using machine learning approaches.

Is there any available tool or package for that? If not, how can I implement one?
What you are looking for is called “no-reference quality assessment”. Google can give you specific examples.