One of the limitations of Second Life is that the only video format supported for your avatars viewing
viewer pleasure are Quicktime or MPEG-4. Through the Mux API, you can use a little bit of javascript
to convert any video into an MPEG-4 stream, ready to watch wherever you might hangout on the grid.

doMuxPageRequest(string pageUrl, string mimeType)
{
   statusUrl = API_ENDPOINT_SIMPLE_XML;
   statusUrl += "transcodePageUrlRequest?";
   statusUrl += "clr=" + API_USER_ID + ":" + API_USER_KEY + "&";
   statusUrl += "url=" + llEscapeURL(pageUrl) + "&";
   statusUrl += "sot=" + llEscapeURL(mimeType) + "&";

  doRequest(statusUrl, "GET");

  llSetTimerEvent(DEFAULT_TIMER);

}

View the full Lindenscript sample