Thor (video codec)

Thor is a royalty-free video codec under development by Cisco Systems. The specifications of Thor were available in various Internet Drafts.^[1]

Thor

Developed by	Cisco Systems
Type of format	Video codec
Extended to	NETVC, AV1
Open format?	Yes
Free format?	Yes
Website	https://github.com/cisco/thor

On July 22, 2015, Thor was presented to the IETF as a candidate for their NETVC video standard.^[2] Thor uses some Cisco elements that are also used by HEVC.^[3] As part of the NETVC work, the Constrained Low-Pass Filter (CLPF) and motion compensation techniques used in Thor were tested in conjunction with the lapped transform coding techniques from the Daala codec.^[4]

On September 1, 2015, Cisco announced that the Alliance for Open Media would use elements of Thor to develop a royalty free video format, AOMedia Video 1.^[5][6][7]

According to Steinar Midtskogen, a principal Thor developer and AV1 contributor, Thor is in good shape for real-time CPU encoding (as of NETVC meeting 101, March 19, 2018), in strong contrast to AV1 at the same time.^[8] Thor development had stalled for the finalization of AV1, but Midtskogen envisaged further Thor development by merging the Daala entropy coder and adding more tools for screen content.^[9]