I am using Blob for hide URL of the video. But unable to find exact Video Codec information

var mimeCodec = 'video/mp4; codecs="avc1.4d002a, mp4a.40.2"';

here is the code. which i am trying to use.

https://github.com/nickdesaulniers/netfix/blob/gh-pages/demo/bufferAll.html

How can i find my video codec.

Thanks