Academy Software Foundation Technical Advisory Council (TAC) Meeting - April 16, 2025

Join the meeting at https://zoom-lfx.platform.linuxfoundation.org/meeting/97880950229?password=81d2940e-c055-43b9-9b5a-6cd7d7090feb

Voting Representative Attendees

Premier Member Representatives

Project Representatives

Carol Payne - Diversity & Inclusion WG / OCIO Representative
Cary Phillips - OpenEXR Representative
Chris Kulla - Open Shading Language Representative
Diego Tavares Da Silva - OpenCue Representative
Jonathan Stone - MaterialX Representative
Ken Museth - OpenVDB Representative

Industry Representatives

Jean-Francois Panisset - Visual Effects Society

Non-Voting Attendees

Non-Voting Project and Working Group Representatives

LF Staff

David Morin - Academy Software Foundation
Emily Olin - Academy Software Foundation
John Mertic - The Linux Foundation
Michelle Roth - The Linux Foundation
Yarille Ortiz - The Linux Foundation

Other

Lee Kerley - Apple
Bill Ballew - Dreamworks
Jim Helman - MovieLabs
Doug Walker - Autodesk / OCIO
Olga Avramenko - Sony Imageworks
Karen Ruggles
JT Nelson - Pasadena Open Source consortium / SoCal Blender group
Deke Kincaid, Digital Domain
Alyssa Alexis, SIGGRAPH

Antitrust Policy Notice

Linux Foundation meetings involve participation by industry competitors, and it is the intention of the Linux Foundation to conduct all of its activities in accordance with applicable antitrust and competition laws. It is therefore extremely important that attendees adhere to meeting agendas, and be aware of, and not participate in, any activities that are prohibited under applicable US state, federal or foreign antitrust and competition laws.

Examples of types of actions that are prohibited at Linux Foundation meetings and in connection with Linux Foundation activities are described in the Linux Foundation Antitrust Policy available at linuxfoundation.org/antitrust-policy. If you have questions about these matters, please contact your company counsel, or if you are a member of the Linux Foundation, feel free to contact Andrew Updegrove of the firm of Gesmer Updegrove LLP, which provides legal counsel to the Linux Foundation.

Agenda

General Updates
- Dev Days - May 15, 2025 #966
- OpenQMC #434
- SLP Volunteer Opportunities #992
- Rename project lifecycle stage ‘Adopted’ to ‘Graduated’ #999
- DigiPro CFP closes 5/16 #1003
- Open Source Days 2025 #1005
Annual Review: OpenEXR #483
Planning Session for TAC #972

Notes

General Updates
- Dev Days - May 15, 2025 #966
  - Olga: 2 events in 2025, first in May 15th, update posted to #tech-leads channel, Excel sheet to be filled to make sure all projects have coverage during the event to make sure participants can reach out to have questions asked.
  - Hosting Zoom info sessions, 4 of them. First on April 28th, with the other 3 following. Will post dates in #tech-leads and #geneal and #dev-days channel.
  - Larry: can it be added to ASWF meeting calendar? Olga: someone from LF team will create these events so they are. Michelle: yes, working on it.
  - Montana is helping with organization of Dev Days, will be reaching out to company leads. She’s organized the Animal Logic Dev Days, they will have lots of participants, she will share info with company leads if they want to organize in house to get the most participation possible.
- OpenQMC #434
  - Eric: no update
- SLP Volunteer Opportunities #992
  - Carol: we don’t have enough mentors, if you have 8 hours in the summer (1 hours a week for 8 weeks), please volunteer. A lot of you have already done this before, but please, we need this again. If you have any questions please message me, will repost link to #tac. We’ve hit the deadline for evaluating applications, but if you want to do this, let me know, we won’t turn you away. Even if you volunteer as guest mentor, that would be good as well. We need to get to at least 20 mentors to run this program. Final count is 80 people after we closed registration, we will accept 20.
  - Larry: not limited to people on this call, if you want to forward to other people in your company, that’s good as well.
  - Nick: there are quite a lot of detailed questions on the form… Carol: yes we got this feedback. You can use “Carol says its fine” in the form if you don’t have time.
  - Karen: Volunteer form for Mentors and/or Guest Mentors for SLP
- Rename project lifecycle stage ‘Adopted’ to ‘Graduated’ #999
- DigiPro CFP closes 5/16 #1003
  - You have a month if you want to submit!
- Open Source Days 2025 #1005
  - Emily: CFP is open, submit your talk by May 18th. For Virtual Town Halls, please pick your time. Can also indicate if you want to do a BoF.
Annual Review: OpenEXR #483
- Cary
- Presentation Slides
- Project Status depends on how you look at it!
- OpenEXR Project Mission
  - The goal is to keep the EXR format reliable and modern and to maintain its place as the preferred image format for content creation.
- Steering Committee
  - Same group in 8 years
- OpenEXR / Imath Releases
  - Trending down?
- Commits: TSC members vs others
  - Shows how much was done before ASWF was created
  - Normalize to remove before ASWF
  - Commits are light in 2025 so far
  - Consistent with past years
- Commits: TSC Members
  - Lion care is Kimball doing “real work”, Cary doing “plumbing and maintenance”, plus some others
- Roadmap: 2024
  - Core/Multithreading in the C++ API: Done! (mostly)
  - Rewrite OpenEXR python bindings in pybind11: Done!
  - Finish Imath port to Pybind11: meager progress
- 2024/2025: Improvements / New Functionality
  - New compression codec: HTJ2K (High-Throughput JPEG-2000)
    - Contribution from several people
    - Highlights a weakness: lack of effective performance benchmarks so we can judge the value. Internal testing at ILM, having figured out how to tune it for very good results. Jury still out. If it’s not very effective, we shouldn’t bother integrating it, but we will probably go ahead.
    - It’s been in beta, some DCC developers have done some integration, but not much real feedback.
  - New tools: exrmetrics
    - Reads and writes files, reports data about I/O speed, compression ratio, we can use to gather data.
    - Baseline performance metrics, can catch regressions in releases
    - A consistent tool to be used over time.
    - Larry: could this be used via CI? Or version tracking is on someone’s machine? Kimball: we would need a “steady machin” to have it be meaningful.
  - Miscellaneous build improvements
    - Better CI test, validation
      - Bugs and regressions came up, tried to expand the tests to account for that.
    - Gradual progress on pybind11 Imath bindings
  - OSTIF Security Audit
    - 4 vulnerabilities/bugs (via fuzzing)
      - Went over draft report
      - Met with handful of folks, presented what the library does, they took the code and documentation. Hooked up their fuzzers and found 4 vulns, we call them bugs. One they labelled as critical, Kimball fixed it right away.
    - Proposed better fuzzer
      - Service that uses Google Protobuffers to do a better job of constructing test cases, would be good for us to pursue and integrate
    - Was hoping audit would be broader than just looking at source code, we didn’t get a lot on the process of running a project, making releases… They looked at our GitHub workflows and didn’t report anything. They indicated that the human engineering aspect of threat actors is not their focus.
    - It was a good exercise, once we get final report, we can go back to the badge requirements and check that requirement and others. Haven’t looked at where we are yet, but it was one of the main outstanding requirements for Silver / Gold status.
  - OCIO Color Interchange Forum
    - Sitting in on that, ready to help in any way we can.
    - Our philosophy is that we’re the keepers of the low level format, not the policies and best practices about how to “do things”, but happy to have discussions on anything that might lead to changes in the format or metadata.
- Coming Soon
  - 2025 VFX Reference Platform: OpenEXR v3.4 (or v4.0? not sure)
  - Finish Imath port to Pybind11 (and pip install imath)
    - Took ownership of Imath PyPI project, it was dead, made request, took a year, but finally came through.
    - Now need a Python wheel workflow
  - Improved fuzzers
- Project Weaknesses / Needs
  - Windows support
  - Hardware-we-don’t-have support
  - Widening the contributor community
    - Over 8 years since ASWF, haven’t lost anyone, but a precarious situation where the only person who can do significant debugging of the core library is someone who is a senior exec at a studio!
  - Transition planning
    - Gave talk last year about “what it takes for OpenSource project to live 50 years”. Open Source Days 2024: Can Software Live for 50 Years or More? (Kimball & Cary) definitely worth the watch if you haven’t seen it yet, (~23 minutes) . Fundamental part of mission project is “do no harm”, a conservative approach. This was front of mind when we got submission for new codec, but for a project to continue, it needs to be open to activity. Maybe we should err on the side of being open to change to invigorate the project. If we introduce a codec and no one uses it, it may not be a mistake if it helps the project be active. We don’t want to turn away contributions not from Kimball.
    - Kimball: how do we get to having a sandbox version where people can try changes and don’t confuse the world when we try “experiments”.
    - Cary: who is going to carry on? I’m still enjoying this, but at some point we will need to hand this off, and the pipeline is thin. I struggle to identify things that people can contribute during Dev Days. I do the maintenance / plumbing / CI workflows, it’s a hard sell.
    - Gary (chat): We have the same issue with OpenFX as a pretty mature project.
- Questions
  - Eric: any further discussion on GPU accelerate compression / gdeflate
    - Kimball: after losing Steve that effort evaporated
    - Had some conversations with Foundry, but not recently.
    - Should be possible to swap in gdeflate
    - Larry: nobody is opposing it, and everyone wants it to land, but a developer bandwidth issue
  - Stephen Mackenzie: what aspects of Windows support requires help?
    - Kimball: recently people were still compiling i686 32 bit Windows binaries? It took 2 weeks to track down since I had to make a VM environment.
    - Cary: sometimes a combination of Windows + CMake. Someone called out a problem where we were pushing downstream Windows compilation options. A good patch was proposed, but I wouldn’t have known how to fix this.
    - In preparation for Imath bindings work, working on getting Boost and new Pybind11 bindings building on Windows, getting Boost::Python working in a GitHub workflow appears to be quite hard, especially if you don’t know much about Windows. May have some questions to pose to the wider group. In order to host the project on PyPI, we need need Windows builds.
  - David: the hard work is paying off, was at NAB last week, Foundry introduced Nuke Stage for Virtual Production, they have high resolution EXR playback as a feature. It’s on their website. https://foundry.com/products/nuke-stage They were also discussion OCIO, USD in their private demos.
  - Carol: is MaterialX in the same phase for the security audit?
    - Jonathan: our situation is similar, OpenEXR is ahead since they have finished all their issues. We’ve knocked out 4 of them ones reported to us, have 3 left. Related to how we interface with host applications. Kimball: 2 were in our testing framework, not the library itself.
    - Larry: an observer could get impression that “little was found” in security audit, but OpenEXR has been doing fuzz testing for years, so a lot of what an initial security audit would have initially found was already addressed. Jonathan: one thing we learned is the value of “grammar aware fuzz testing”. We have a basic fuzz tester in MaterialX, but a “grammar aware” fuzz tester was able to find issues we weren’t able to find with just random numbers.
    - Carol: we want to regroup, so we’ll put something on the agenda when we are “done”.
    - Cary: they gave us a draft, we met, action item is to finish the final report.
  - Cary: the people on the TSC Larry and Nick are committed to many other projects, it’s great to have you involve, but you have a lot of other responsibilities. None of the people who contribute to TSC have official company time budgeted to do this. I do this by finding spare hours, nights and weekends, it’s not paid for by the company, so it’s subject to the whims of my day job. Project is getting by with squeezing time from people with busy day jobs. Lucas Film is contributing their FTE between my time, Jonathan and others, but that’s different from an official budgeted time allocated to a project.
    - Eric: it is a mature project, we want stability from it. I hear wanting to get newer people involved, but the project is at a different stage?
    - Cary: it is no longer fair to say that OpenEXR is an old code base, it has been modernized thanks to Kimball. But for a project without a lot of turn, there is still a pretty stead churn of maintenance. GitHub Actions gets updated, have to rewrite your CI to deal with it.
  - Carol: it’s hard to find good first issues, things that new contributors can work at, but would encourage to try to introduce people to the project through CI maintenance. If they seem to fly with that, then they can start looking at the code. There’s lots of “non code” work to be done. Kimball: we talked about pointing people to Python bindings, but that work should really go into OIIO…
  - Eric R: if we’re going to add OCIO colorspace attribute to OpenEXR, if that gets done, could be a good first issue? Carol: depends on how we decide to add that!
  - Olga: make sure your good first issues are set up! Cary: haven’t updated those in a while, but have a note to update them. OpenEXR Good First Issues
  - Carol: this is why we want to do Dev Days twice a year, want docs, good first issues to be “always ready”. Nothing wrong to coming in as a new contributor and help with documentation, GitHub.
Planning Session for TAC #972