This tool shows the capabilities of IPTC's Video Metadata Hub standard. VMHub can be expressed in JSON (as well as other formats). As you enter video metadata into the form, you can see the corresponding VMHub JSON appear.
Please note that this tool demonstrates only a small subset of the available fields in IPTC video Metadata Hub. The full VMHub spec includes many more fields such as Episode/Season/Series, fields for People, Products and Events shown, model release and rights information, transcripts, and much more.