If a video doesn't have source code, then it can't be open source. Likewise, if you feel that an LLM doesn't have source code because of some property of what it is -- as you claim it isn't software and somehow that means that it abstractly removes it from consideration for this concept (an idea I think is ridiculous, FWIW: an LLM is clearly software that runs in a particularly interesting virtual machine defined by the model architecture) -- then; somewhat trivially, it also can't be open source. It is, as the person you are responding to says, at best "open weights".
If a video somehow does have source code which can "generate it", then the question of what it means for the source code to the video to be open even if the only program which can read it and generate the video is closed source is equivalent to asking if a program written in Visual Basic can ever be open source given that the Visual Basic compiler is closed source. Personally, I can see arguments either way on this issue, though most people seem to agree that the program is still open source in such a situation.
However, we need not care too much about the answer to that specific conundrum, as the moral equivalent of both the compiler and the runtime virtual machine are almost always open source. What is then important is much easier: if you don't provide the source code to the project, even if the compiler is open source and even if it runs on an open source machine, clearly the project -- whatever it is that we might try to be discussing, including video files -- cannot be open source. The idea that a video can be open source when what you mean is the video is unencrypted and redistributanle but was merely intended to be played in an open source video player is absurd.
If a video somehow does have source code which can "generate it", then the question of what it means for the source code to the video to be open even if the only program which can read it and generate the video is closed source is equivalent to asking if a program written in Visual Basic can ever be open source given that the Visual Basic compiler is closed source. Personally, I can see arguments either way on this issue, though most people seem to agree that the program is still open source in such a situation.
However, we need not care too much about the answer to that specific conundrum, as the moral equivalent of both the compiler and the runtime virtual machine are almost always open source. What is then important is much easier: if you don't provide the source code to the project, even if the compiler is open source and even if it runs on an open source machine, clearly the project -- whatever it is that we might try to be discussing, including video files -- cannot be open source. The idea that a video can be open source when what you mean is the video is unencrypted and redistributanle but was merely intended to be played in an open source video player is absurd.