The VMAF video quality metric is ubiquitous in the streaming world, and any discussion of video codec performance is seldom complete without poring over VMAFscores. But what is it? In this episode VMAF guru and leader of the Netflix Video Codecs and Quality team joins us to delve into the mysteries of the metric. How did it originate and why was it needed? How has VMAF been developed and what does the future hold for improvements? Along the way we talk about the work he and his team do at Netflix and where quality assessment and codec development is leading in a world of generative AI.