UPDATE Both myself and @rcpalacio have been unable to find any licensed test files. As we have some open issues in portal that this may fix I have discussed with Vanja that we would be ok to add this fix without specific test files and add these later if we find any.
The new sub formats (brands?) showed up in some of our use cases.
For now I have been unable to find test files with a license of the correct sub format of mp4 to be able to test these and validate my change works.
I added webrick as a dev dependency due to this causing errors in the ruby 3.1 build. I found a related issue that suggests webrick is no longer bundled in ruby 3.x and fixing it by adding it as a dependency. As we only use it in a test file I only added it as a dev dependency to keep the changes minimal. I'm not sure how this built successfully previously 🤔
UPDATE Both myself and @rcpalacio have been unable to find any licensed test files. As we have some open issues in portal that this may fix I have discussed with Vanja that we would be ok to add this fix without specific test files and add these later if we find any.