Question

Does HTML5/JavaScript provide a function to check whether videos like .mp4 can be checked. Then I could use a fallback to webm or even if the check for webm compatibility fails, another alternative could be pushed.

Are there features for checking compatibility implemented?

Answer 1

I use the following snippet:

/**
 * http://diveintohtml5.org/detect.html#video-formats
 */
function hasNativeMPEG4() {
      var v = document.createElement("video");

      if(!v.canPlayType) {
          return false;
      }
      // video/mp4; codecs="avc1.42E01E, mp4a.40.2"
      var result = v.canPlayType('video/mp4; codecs="avc1.42E01E, mp4a.40.2"');

      if(result == "no" || result === "") {
          return false;
      } else {
          // "maybe", "probably"
          return true;
      }
}

… if it doesn’t support MPEG4, then try to feed Flash fallback or WebM.