Add Imgur GIFV support for embed

[netuoso]

Issue

Currently gifv is not supported natively in condenser. This ends up with users pasting traditional GIF files which can be very large in comparison.

Summary

Since GIFV is not a real extension and merely just a friendly interpretation of a video link, rewrite the GIFV url to a MP4 source and include in HTML video tag.

Screenshot

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Files Changed

• utils/Links.js
• cards/MarkdownViewer.js
• shared/HtmlReady.js

[pkattera]

Thanks netuoso! I approve supporting gifv in condenser, pending a technical / security review of this implementation.

[roadscape]

I don't think we can merge this PR as-is because imgur blocks hotlinkers, and image/video media is better served through our secure proxy. (Btw the proxy will soon support webp images, but IIRC gifv is webm.)

[netuoso]

Could you elaborate on what you mean by imgur blocking hotlinks?

The terms of service allows users to serve content on websites that they upload, and indeed imgur has an embed feature directly available from their site. Imgur terms ask that website admins do not turn imgur into a content delivery network for storing their sites assets; however, user uploads that are "hotlinked" or embed are allowed.

Btw, GIFV isn't anything other than a proxy filetype to a video file. It can be MP4 or WEBM or whatever depending on browser/device compatibility.

[roadscape]

I'm not sure if it's documented but that's what happens.. they probably consider us a CDN.

We allow hotlinking on forums, but hotlinked images cannot be used as content for a website, including blog posts, avatars, site elements
https://twitter.com/imgur/status/879408405403664384

[netuoso]

Well instead of leaving it to interpretation from a social media comment I have reached out to Imgur directly.

[roadscape]

We have direct experience with this... comment just confirms it

[netuoso]

Their terms of service includes what we are discussing and says "we [Imgur] will be the judge".

It suggests reaching out and opening a line of communication instead of just assuming its good to go, so I have done that and will see what they say.

[KINGdotNET]

Are we expecting this change soon?

[roadscape]

I'm pretty certain hotlinking to imgur is a non-starter; pls bump if new information comes in.