The return values are definitely terrible, but the information I’m inferring is: - Maybe: the mime type is likely a container, and there are a wide range of po

The return values are definitely terrible, but the information I’m inferring is: - Maybe: the mime type is likely a container, and there are a wide range of possible contained formats… some supported, some not. As in the example, mp4 is such a container. - Probably: this is either a known format that’s definitely supported (boolean true) or a container format with a narrower range of contained formats, all of which are likely to be supported if any are. Newer or more obscure containers will more likely fall in this category. I hate to imagine the bikeshedding that must have gone into this API.