Shameless plug: I wrote a project to generate source proto files from binaries called protodump [1] - it regenerates all the message/field definitions (including the original names). It would just require pulling the binary off the AppleTV box
Hey, that’s really cool! Upvoted! ¿What binary formats are supported? - I couldn’t see that in the README and I’m guessing it isn’t universal (though I could be wrong!).
As for this specific context, presumably at least the bulk of the fields are shared between YouTube clients across architectures and platforms - it might be easier to just run the dump against binaries extracted from the YouTube apk than getting the specific Apple TV YouTube app binary. (For iPhone, you can just make a full iTunes backup but for Apple TV I imagine you’re going to need to do some forensic binary spelunking.)
It looks like it is in fact universal. Just glancing at the code here, it looks like the tool searches any arbitrary file for bytes that look like encoded protobuf descriptors, specifically looking for bytes that are plausibly the beginning of a FileDescriptorProto message defined here:
This takes advantage of the fact that such descriptors are commonly compiled into programs that use protobuf. The descriptors are usually embedded as constant byte arrays. That said, not all protobuf implementations embed the descriptors and those that do often have an option to inhibit such embedding (at the expense of losing some dynamic introspection features).
Shameless plug: I wrote a project to generate source proto files from binaries called protodump [1] - it regenerates all the message/field definitions (including the original names). It would just require pulling the binary off the AppleTV box
[1]: https://github.com/arkadiyt/protodump