CELLAR -- Mar 28 1800 UTC

Meetecho session

Agenda / Notes

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👥 Participants (please add yourself as you join)

• Spencer Dawkins
• Jérôme Martinez
• Dave Rice
• Steve Lhomme
• Michael Niedermayer
• Robert Sparks
• Charles Eckel

Regrets:

📣 Note Well

https://www.ietf.org/about/note-well/
Please be KIND to each other.

👀 Previous meeting minutes

• Are any corrections needed to the previous meeting minutes?
• Jerome said "fine for me", so approved.

Introducing Charles Eckel, our new Area Director

🗣️ Working Group Documents

See https://datatracker.ietf.org/group/cellar/documents/

draft-ietf-cellar-tags

• draft-ietf-cellar-tags-24 has Charles's Yes vote, so is formally
  ready for approval.
• Charles wanted to check with the new ADs, to see if anyone wanted to
  review it before sending it to the RFC Editor.
• Charles is finishing up discussion with IANA and will bring a
  possible resolution to the mailing list.

draft-ietf-cellar-codec

• Steve has submitted -18, which Charles is happy with.
• Charles had a question about a downref in the revised Shepherd
  writeup for -18. Spencer clarified what Spencer was saying in
  the writeup. :smile:
• Charles wants to take a look at IANA considerations before Last Call
• This should be going for IETF Last Call very soon.

Expired draft-ietf-cellar-chapter-codecs

• Any update?
• We do have one set of reference specifications that we might not be
  able to provide for review
• Can someone persuade the National Library of Japan to share this?
  Possibly the Library of Congress?

draft-ietf-cellar-ffv1-v4

• Any update?

• We have a new proposal for RGGB/Bayer support in FFMPEG under
  discussion for this specification

  • https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/22528
  • https://lists.ffmpeg.org/archives/list/ffmpeg-devel@ffmpeg.org/thread/KVWNFO5EFHAVJXUVZWA7Q3GA2YEZE4BA/

• There is also several proposals from Michael forstoring raw LSB that
  needs to be reviewed

• Floating point support is available in FFmpeg, but still need to
  update the spec
• When would the group be reviewing text for this draft? We hope this
  year, but 4Q26 at the earliest

🔥 Hot Topics

Recent Errata for our RFCs

Errata 8658

• Steve says this errata isn't correct - it's the presence of the
  attribute that describes the recurring aspects, not the value of the
  attribute itself
• Suggested Status (for our AD) is "Rejected"

Errata 8854

• Steve says this errata isn't wrong, but objects to the
  suggestion of "unbounded" values in XML or EBML specifications.
• The right way to say this, is by omitting the maxOccurs attribute,
  and the specification says that's equivalent to "unbounded".
• Suggested Status (for our AD) is "Rejected"

Errata 8810

• Martijn says this report is correct.
• Suggested Status (for our AD) is "Verified"

Starting on an Internet-Draft for Matroska v4 Additions

• Steve has submitted PR 1094, creating a new draft.
• The suggested name is "Matroska Media Container v4 Additions".
• Spencer's question - would we bundle additions into multiple
  documents, possibly published over time?
• We are deciding whether to checkpoint the additions as of a date, or
  as "update 1" to produce a document for each addition
• These really are new elements in Matroska
• Spencer's question - this looks like our answer to the question
  about how we move Matroska forward, over time. Do I have that right?
  Spencer thinks so
• Spencer's question - does Updates mean the base specification can be
  untouched?
• If we want to have Update relationships between Matroska and
  Matroska additions, we need to add that to -codec and -tag
• We can close on that in the next couple of weeks

"Added" and/or "Revision" attributes for EBML

• Steve has submitted PR 433, to allow implementations to
  distinguish between RFC 9559 elements and new elements in the EBML
  schema.

Any Other Business?

• None noted

Next meeting dates

| Meeting | Date |
|----------
| interim-2026-cellar-04 | 2026-05-26 |
| interim-2026-cellar-05 | 2026-06-23 |
| interim-2026-cellar-06 | 2026-08-25 |
| interim-2026-cellar-07 | 2026-09-22 |
| interim-2026-cellar-08 | 2026-10-27 |
| interim-2026-cellar-09 | 2026-12-08 |