Allow videos to play in Observable Desktop

[shadoof]

First, I love what you are doing with Notebooks 2.0!
Add I appreciate that the (mac) Desktop is likely not a sharply focused subproject atm. But it is an extraordinarily useful development and ideas-development environment! It has a simple look and feel and it is a good one and for quick review of most static content in markdown/html it would be even better if the Desktop was allowed to play videos ... rather then having to fire up the npm run preview server.

[mbostock]

Hmm, it should work, but I think the problem is the MIME type isn’t being set by Desktop’s built-in file server? You can work around by loading a blob and setting the MIME type yourself…

const videoBlob = await FileAttachment("Test recording.mp4").blob();
const videoUrl = URL.createObjectURL(new Blob([videoBlob], {type: "video/mp4"}));
display(html`<video src=${videoUrl} controls style="max-width:100%"></video>`);

Oh, and thanks for the appreciation! Glad you are enjoying Desktop & Notebooks 2.0.

[mbostock]

The MIME type problem is tracked by #27 if you want to upvote.

[shadoof]

Thanks for looking at that so quickly. This is just to report that the blob workaround works for me. Having the Desktop app display videos in cells that interpret html would still be nice.