Video format not supported in some content types


I'm not sure if this is the proper forum for that, but I've encountered a problem using external mp4 video in some content types:

I'm trying to use an externally hosted .mp4 video in branching scenario, course presentation or interactive video. However, I always encounter the error message "video format not supported". The video does work, however, when I add a "video" in the column content type. The video also works just fine when I embed it in normal html5 web pages...

I'm not sure where the root of the problem is: Does H5P require some special codec inside the mp4 container to work reliably or is there some other kind of problem or bug even?

Here is a video where the problem occurs:

I've tested in Chrome and Firefox, running WP 5.1 and the latest H5P update.

What can I do?

Best regards,


BV52's picture

Hi Christian,

Accessibility is very important for H5P, and in order to allow subtitles for external videos we're currently requiring that the servers they are hosted on has an Access-Control-Allow-Origin header set that allow / or whatever site you're using access to the video in a cross origin resource sharing manner. We see that many servers used by community members unfortunately does not have this set, and that they are not controlled by the community member either, so we're considering a solution where you can decide to allow such servers, sacrificing accessibility.(i.e. sacrificing subtitles support to use these servers). In your case I think you or your administration has control over the servers so setting the CORS header should be achievable.