The full form of VMAF is Video Multimethod Assessment Fusion.

Video Multimethod Assessment Fusion (VMAF) is an objective full-reference video quality metric developed by Netflix in cooperation with the University of Southern California and the Laboratory for Image and Video Engineering (LIVE) at The University of Texas at Austin. It predicts subjective video quality based on a reference and distorted video sequence. The metric can be used to evaluate the quality of different video codecs, encoders, encoding settings, or transmission variants.

VMAF is a perceptual video quality assessment algorithm developed by Netflix. VMAF Development Kit (VDK) is a software package that contains the VMAF algorithm implementation, as well as a set of tools that allows a user to train and test a custom VMAF model. Read this techblog post for an overview, or this post for the latest updates and tips for best practices.

The metric is based on initial work from the group of Professor C.-C. Jay Kuo at the University of Southern California. Here, the applicability of fusion of different video quality metrics using support vector machines (SVM) has been investigated, leading to a “FVQA (Fusion-based Video Quality Assessment) Index” that has been shown to outperform existing image quality metrics on a subjective video quality database.

The method has been further developed in cooperation with Netflix, using different subjective video datasets, including a Netflix-owned dataset (“NFLX”). Subsequently renamed “Video Multimethod Assessment Fusion”, it was announced on the Netflix TechBlog in June 2016 and version 0.3.1 of the reference implementation was made available under a permissive open-source license.

In 2017, the metric was updated to support a custom model that includes an adaptation for cellular phone screen viewing, generating higher quality scores for the same input material. In 2018, a model that predicts the quality of up to 4K resolution content was released. The datasets on which these models were trained have not been made available to the public.