Using existing work done by the development communities of Matroska, FFV1, and FLAC, the IETF Working Group on Codec for LossLess Archiving and Realtime Transmission (CELLAR) will formalise specifications for these open and lossless formats. In order to provide authoritative, standardised specifications for users and developers, the Working Group will seek consensus throughout the process of refining and formalising these standards.

This WG fills gaps in terms of standardising open, transparent, self-descriptive, lossless formats as an important mission to be undertaken by the open source community. Work addresses concerns about the sustainability and credibility of existing specifications for the long-term use of these formats through a broader review and formalisation encourage widespread adoption.

The Working Group will seek consensus and refinements for specifications for both FFV1 and Matroska in order to provide authoritative, standardized specifications for users and developers. Backward compatibility with existing versions 0-3 of the FFV1 and Matroska specifications will be an important goal, while also reviewing and refining the current version 4 under active development.