HTML5 Video not working in IE 11

Question

I have a video archive that I have working in everything except IE 11. I get the error \"Error: Unsupported video type or invalid file path\" when loaded in IE 11. Below is

Answer 1

I used MP4Box to decode the atom tags in the mp4. (MP4Box -v myfile.mp4) I also used ffmpeg to convert the mp41 to mp42. After comparing the differences and experimenting, I found that IE11 did not like that my original mp4 had two avC1 atoms inside stsd.

After deleting the duplicate avC1 in my original mp41 mp4, IE11 would play the mp4.