Adding movies or photos to a document
You can place photos and movies within a TextEdit document. The embedded graphics appear alongside the text in the document.
Drag a photo or movie from the Finder to the document window.
Movies and photos can only be embedded in Rich Text Format (RTF) documents and Word Format documents. To convert your document to an RTF file, choose Format > Make Rich Text. After you add a movie or photo, the next time you save the document, it is saved as an RTFD file.