code: public String getLocalVideoUri(String assetname) {
          File f = new File(assetname);
          Log.d(TAG, "Video path "+f.getAbsolutePath());
          String uri = Uri.fromFile(f).toString();
          Log.d(TAG, "Uri "+uri);
          return uri;
  //        return "file:/"+assetname;
  //        return "asset:///"+assetname;
      }
docs: Gets a valid Uri of a local video file
  @param assetname The resource id of the video
  @return A Uri as a string