OptionalBase64Inline base64 payload (no data-URL prefix). Prefer URL/storage refs for large media.
OptionalMimeIANA mime type, e.g. video/mp4. Used to gate provider capability checks.
OptionalObjectObject/blob key within the storage provider.
OptionalStorage@memberjunction/storage provider key, when the media lives in MJ file storage.
OptionalURLDirectly fetchable URL (http(s) or data URL).
A pointer to non-text content. Segmenters emit these for media segments instead of (or alongside)
Text.Exactly one of
URL,Base64Data, or (StorageProviderKey+ObjectKey) is expected to be populated; consumers resolve whichever is present.