# CELLAR -- Feb 24 1800 UTC {#cellar--feb-24-1800-utc} [Meetecho session][1] # Agenda / Notes {#agenda--notes} Please share video when possible. Remember that the session is being recorded and will appear at YouTube. Tip: press “Expand all” in the navigation menu ## 👥 Participants *(please add yourself as you join)* {#-participants-please-add-yourself-as-you-join} * Spencer Dawkins * Robert Sparks * Steve Lhomme * Jérôme Martinez * Dave Rice * Michael Niedermayer Regrets: * ## 📣 Note Well {#-note-well} https://www.ietf.org/about/note-well/ Please be KIND to each other. ## 👀 Previous meeting minutes {#-previous-meeting-minutes} * Are any corrections needed to [the previous meeting minutes][2]? * No objections on the call, so approved. # 🗣️ Working Group Documents {#️-working-group-documents} See https://datatracker.ietf.org/group/cellar/documents/ ## draft-ietf-cellar-tags {#draft-ietf-cellar-tags} * draft-ietf-cellar-tags-22 has been submitted * **Action:** Steve and Spencer will go through the IANA section looking at normative language. * **Action:** Spencer to close with ADs (and with IANA) to make sure we have addressed all DISCUSSes and COMMENTs, and then this draft will be approved ## draft-ietf-cellar-codec {#draft-ietf-cellar-codec} * We have our AD Evaluation for -16 [on the mailing list][3] * Steve has submitted -17, which Orie says addressed his AD Evaluation comments * * **Action:** Spencer will nudge Orie to move -17 forward before IETF 125, so Orie can schedule IETF Last Call while he is still our AD. * **Action:** Spencer to confirm with Stephan Wegner that the IESG and reviewers can get copies of specifications for references in this draft (ISO and ITU-T) ## draft-ietf-cellar-chapter-codecs {#draft-ietf-cellar-chapter-codecs} What we said at a previous meeting * draft-ietf-cellar-chapter-codecs-05 is Expired, but we said we were waiting to return to this draft * Still correct? Yes, we can return to this in 2026 ## draft-ietf-cellar-ffv1-v4 {#draft-ietf-cellar-ffv1-v4} What we said at a previous meeting * draft-ietf-cellar-ffv1-v4-22 is Expired - time to submit an update? * Jérôme has time to work on this in 2026 * Need to resynchronize with implementations * Need to address ffmpeg ffv1-v4 questions and work on performance improvements * We are working on hardware acceleration for ffv1-v3, and want to bring that forward # 🔥 Hot Topics {#-hot-topics} ## [Mailing list question][4] about [draft-swhited-ogg-stems/][5] {#mailing-list-question-about-draft-swhited-ogg-stems} * Is this draft/technology in scope for CELLAR? It's really a request for a Matroska profile * What standardization is actually needed? * We have already started mailing list discussion with Sam Whited (the [draft-swhited-ogg-stems/][5] author). We'll have more discussion, and will figure out whether anything needs to be updated in our working group specifications, and whether anything must be written down in order to achieve interoperability ## Starting on an Internet-Draft for matroska v5 {#starting-on-an-internet-draft-for-matroska-v5} What we said at a previous meeting * The Github version of what will become -00 is [here][6] * We do want to make it easier for newcomers to figure out what specification/version they need to look at in Github On this call * If we don't call this document v5, what DO we call it? (this would be both file name and title change) * Would we rather split the document out, for each new capability or group of capabilies? * The pace of changes is also relevant here. * We can say "Matroska extensions as of 2027", etc. but if there are obvious subsets, that would be better * We still need to think about the details here, but we think we can explain specific subsets ### Discussion about our charter to support v5 {#discussion-about-our-charter-to-support-v5} What we said at a previous meeting * Why does this need to be **v5**? We don't really use version numbers at the protocol level (Matroska does backwards compatibility) * Matroska does backwards-compatibility, so Matroska version numbers don't mean what version numbers mean in many protocols at the IETF * We haven't been using Matroska extension documents for very long - before, there was one big document that defined Matroska v2, etc. * v5 really is more of a feature set than a version number * We do need to make a decision about whether we would make changes that are NOT backward-compatible in v5. * Robert will look for similar uses of XML container versioning with other groups * Robert also needs a strong motivation for why IETF is the right place to do a Matroska v5 * Martijn pointed out that rechartering would also provide a home for any FLAC extensions On this call * We don't think we need to have a protocol identifier for Matroska, so we don't think we need to recharter in order to work on new capabilities in Matroska - at least not yet * We are going to have a new charter, the question is whether version numbers are part of that new charter * We (might) write extension documents, but leave the base Matroska specification alone * The only breaking change we've identified is a new timestamp format. It could be backward-compatible, and then we wouldn't need two versions (and otherwise, we do). * Is there specification work for us to do, on the new timestamp format? PR 422 * **Action:** Robert to socialize our understanding of versioning with the IESG at IETF 125 # Any Other Business? {#any-other-business} None noted on the call ### Next meeting dates {#next-meeting-dates} | Meeting | Date | |---------- | interim-2026-cellar-03 | 2026-04-28 | | 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 | [1]: https://meetings.conf.meetecho.com/interim/?session=35094 [2]: https://notes.ietf.org/notes-ietf-interim-2026-cellar-01-cellar [3]: https://mailarchive.ietf.org/arch/msg/cellar/_Ykn4tUnQRdZWCDXE_v4ngC75TI/ [4]: https://mailarchive.ietf.org/arch/msg/cellar/hmB6gyuWmExiUoVF3j9CmQJpsuw/ [5]: https://datatracker.ietf.org/doc/draft-swhited-ogg-stems/ [6]: https://github.com/ietf-wg-cellar/matroska-specification/actions/runs/20044018778/job/57485105914?pr=1026