Session Date/Time: 29 Mar 2022 19:00

CELLAR

Summary

The CELLAR Working Group meeting discussed the status of several drafts, including FLAC, Matroska, and Codec and Tags. Key decisions were made regarding the standards track status of FLAC, the initiation of a Working Group Last Call (WGLC) for Matroska-09, and the publication of an update for Codec and Tags-08. Discussions also covered the process for adding codec IDs to the MP4 registry for FFV1 and FLAC, and plans for addressing new issues in the FLAC specification.

Key Discussion Points

Meeting Logistics & Audio Issues:
- Minor issues with Hedgedoc links were noted.
- A participant (Steve) experienced significant audio echo, which was eventually resolved for most attendees.
Previous Meeting Minutes & Document Status:
- Draft meeting minutes from February were approved without objection.
- Overall document status had not significantly changed since the last meeting, with several documents awaiting further discussion.
FLAC Document Status (draft-ietf-cellar-flac):
- Discussion centered on whether the FLAC document should be Standards Track or Informational.
- A sense of those present indicated a preference to maintain its status as Standards Track.
- It was noted that Pull Request 135, which incorporates necessary fixes for Standards Track publication, needs to be merged.
Matroska Draft (draft-ietf-cellar-matroska-09):
- The draft was deemed ready for publication of version 9, with the author having resolved outstanding issues and ensured compatibility.
- The process for submitting the draft to the data tracker was reviewed.
- The next step identified was to initiate a Working Group Last Call (WGLC).
- Due to the Matroska community's fan club outside the IETF, a suggestion was made to extend the WGLC duration and explicitly outreach to external communities (e.g., Matroska mailing list, FFmpeg developer list).
Codec and Tags Draft (draft-ietf-cellar-codec-and-tags-08):
- The primary concern was to publish an update (version 08) to ensure it's available for review concurrently with the Matroska WGLC.
- No significant updates were identified as pending, and the aim was to update before expiration, or soon after, to facilitate review.
FFV1 (RFC 9043) MP4 Registry & AVI Codec ID:
- Discussion on adding the MP4 codec ID for FFV1 (already registered externally) to RFC 9043 via errata.
- A similar process was suggested for the FFV1 codec ID used in AVI, which lacks an official registration list.
- The procedure for submitting errata via the RFC Editor website was outlined.
FLAC MP4 Registry:
- The need for FLAC to be in the MP4 registry was raised.
- The group discussed including a request for MP4 registration within the FLAC specification, similar to how FFV1 handled it for Matroska, and documenting existing container mappings (e.g., in Firefox, FFmpeg).
FFV1v4:
- No updates were available for the FFV1v4 draft. More time is needed to discuss its future direction.
FLAC New Issues:
- Two new technical issues were noted (145, 146) regarding shortcomings in the FLAC specification where implementations diverge. These will require future discussion to achieve working group consensus.

Decisions and Action Items

Decisions:

FLAC Document Status: The draft-ietf-cellar-flac document will remain Standards Track.
Matroska WGLC: draft-ietf-cellar-matroska-09 will proceed to a 4-week Working Group Last Call (WGLC).
Codec and Tags Publication: An update to draft-ietf-cellar-codec-and-tags-08 will be published soon to make it available for Matroska reviewers.
FFV1 (RFC 9043) Errata: MP4 and AVI codec IDs for FFV1 will be added to RFC 9043 via errata.
FLAC MP4 Registration: The FLAC specification will incorporate text requesting an MP4 registration for FLAC and document current container mappings.

Action Items:

Chairs: Initiate a 4-week Working Group Last Call for draft-ietf-cellar-matroska-09. This WGLC will include outreach to external communities such as the Matroska mailing list and FFmpeg developer list, with a reminder after two weeks.
Morgan: Merge Pull Request 135 into the FLAC draft.
Steve: Submit errata for RFC 9043 (FFV1) to include the MP4 codec ID and the widely used AVI codec ID, following acceptance of a pull request on the FFV1 GitHub repository.
FLAC Draft Maintainers: Incorporate language into the FLAC specification regarding MP4 registration and existing container mappings.
(Unspecified): Publish an update for draft-ietf-cellar-codec-and-tags-08.

Next Steps

Matroska: Monitor the 4-week Working Group Last Call and gather feedback.
Codec and Tags: Ensure publication of the updated draft.
FLAC: Address new technical issues (145, 146) in subsequent discussions, and complete updates related to MP4 registration.
FFV1v4: Further discussion needed to determine the direction of this draft.