wp-calypso/client/lib/media-serialization/constants.js

export const Formats = {
	DOM: 'DOM',
	STRING: 'STRING',
	SHORTCODE: 'SHORTCODE',
	OBJECT: 'OBJECT',
	API: 'API',
	UNKNOWN: 'UNKNOWN',
};

export const MediaTypes = {
	IMAGE: 'IMAGE',
	VIDEO: 'VIDEO',
	AUDIO: 'AUDIO',
	UNKNOWN: 'UNKNOWN',
};