Codec Encoding for LossLess Archiving and Realtime transmission
charter-ietf-cellar-01

Document Charter Codec Encoding for LossLess Archiving and Realtime transmission WG (cellar)
Title Codec Encoding for LossLess Archiving and Realtime transmission
Last updated 2015-11-20
State Approved
WG State Active
IESG Responsible AD Ben Campbell
Charter Edit AD Ben Campbell
Send notices to (None)

Charter
charter-ietf-cellar-01

The preservation of audiovisual materials faces challenges from
technological obsolescence, analog media deterioration, and the use of
proprietary  formats that lack formal open standards. While obsolescence and
material degradation are widely addressed, the standardization of open,
transparent, self-descriptive, lossless formats remains an important mission to
be undertaken by the open source community.
 
FFV1 is a lossless video codec and Matroska is an extensible media container
based on EBML (Extensible Binary Meta Language), a binary XML format. There are
open source implementations of both formats, and an increasing interest in and
support for use of FFV1 and Matroska. However, there are concerns about the
sustainability and credibility of existing specifications for the long-term use
of these formats. These existing specifications require broader review and
formalization in order to encourage widespread adoption.
 
There is also a need for a lossless audio format to complement the lossless
video codec and container format. FLAC is a lossless audio codec that has seen
widespread adoption in a number of different applications including archival
applications. While there are open source implementations of the codec, no
formal standards for either the codec itself or its use in container formats
currently exist. Review and formalization of the FLAC codec standard and its use
in Matroska container formats is needed for wider adoption.
 
Using existing work done by the development communities of Matroska, FFV1, and
FLAC, the Working Group will formalize specifications for these open and
lossless formats. In order to provide authoritative, standardized specifications
for users and developers, the Working Group will seek consensus throughout the
process of refining and formalizing these standards. Initial specifications can
be accessed here:
 
Specifications:
- FFV1: https://mediaarea.net/temp/ffv1.html
- Matroska: http://matroska.org/technical/specs/index.html
- EBML: http://matroska-org.github.io/libebml/specs.html
- FLAC: https://xiph.org/flac/format.html

Development Versions:
- FFV1: https://github.com/ffmpeg/ffv1
- Matroska:
https://github.com/Matroska-Org/foundation-source/blob/master/spectool/specdata.xml
-  EBML: https://github.com/Matroska-Org/ebml-specification
 
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. Although not encouraged, non-backwards-compatible changes to the
input specifications will be acceptable if the Working Group determines that the
modifications are required to meet the group's technical objectives, provided
that the reasons for these changes are clearly documented. 
 
Deliverables:
- Informational specification for Matroska container format versions 1, 2 and 3
to IESG for publication
- Standards Track specification for Matroska container format version 4 to IESG
for publication
- Informational specification for FFV1 video codec versions 0, 1 and 3 to IESG
for publication
- Standards Track specification for FFV1 video codec version 4 to IESG for
publication
- Standards Track specification for FLAC audio codec to IESG for publication