Bug 249982 – WebM unsupported in open source builds

• Status: NEW
• Component: Media

[Vladimir Prelovac]

WebKit trunk can not play WebM media, althorugh it appears that latest Safari can.

Test:
https://www.webmproject.org/detect/

[Alexey Proskuryakov]

My understanding is that WebM support in underlying Apple frameworks requires having a restricted entitlement which open source builds cannot use, see Source/WebKit/Scripts/process-entitlements.sh. CC'ing folks who can comment with more expertise if necessary.

[Eric Carlson]

(In reply to Alexey Proskuryakov from comment #1)
> My understanding is that WebM support in underlying Apple frameworks
> requires having a restricted entitlement which open source builds cannot
> use, see Source/WebKit/Scripts/process-entitlements.sh. CC'ing folks who can
> comment with more expertise if necessary.

Alexey is correct - unfortunately the CoreMedia feature WebKit uses to add WebM support is disabled unless the framework is signed with an entitlement we can't use in open source builds.

[Vladimir Prelovac]

What is the reason Apple is not allowing this for open-source WebKit?

[Radar WebKit Bug Importer]

<rdar://problem/104004154>

[Vladimir Prelovac]

(In reply to Eric Carlson from comment #2)
> (In reply to Alexey Proskuryakov from comment #1)

> Alexey is correct - unfortunately the CoreMedia feature WebKit uses to add
> WebM support is disabled unless the framework is signed with an entitlement
> we can't use in open source builds.


Eric, I understand that the CoreMedia feature WebKit uses to add WebM support is currently disabled unless the framework is signed with an entitlement that cannot be used in open source builds. 

I would greatly appreciate it if you could provide more information about this limitation and the thought process behind it. A

dditionally, if there are any future plans to address this limitation, that would be greatly beneficial for the transparency and understanding of the project for those who are looking to contribute to WebKit. 

I thank you in advance for your time and effort in helping to clarify this matter.

[Alexey Proskuryakov]

The WebKit open source project cannot speak for Apple.

The options for contacting Apple as a developer are at https://wwdr.apple.com.

[Alexey Proskuryakov]

Sorry, wrong URL, should be https://developer.apple.com

[Vladimir Prelovac]

(In reply to Alexey Proskuryakov from comment #6)
> The WebKit open source project cannot speak for Apple.
> 
> The options for contacting Apple as a developer are at
> https://wwdr.apple.com.

But Eric is both a WebKit contributor and an Apple empployee and presumeably he would be much more viable to shed some light on this. 

(I do not see a clear path for asking about this specific issue from developer.apple.com to be honest)

[Alexey Proskuryakov]

A couple ideas that come to mind:
- File a feedback assistant enhancement request to expose WebM decoding to 3rd party developers, if this is what you ultimately need.
- Use one of the opportunities to interact with Apple engineers who work on Core Media, such as WWDC labs. I believe there are more options of this kind now.

[Vladimir Prelovac]

Alexey I appreciate what you are trying to do. I hope you can appreciate my perspective too.

> The WebKit open source project cannot speak for Apple.

I would also prefer that there was indeed a clear separation between Apple and WebKit. However that is not the reality.

Today there is this article on WebKit's blog:

https://webkit.org/blog/13686/release-notes-for-safari-technology-preview-161/

Or this post few weeks ago:

https://webkit.org/blog/13591/webkit-features-in-safari-16-2/

If "WebKit open source project cannot speak for Apple", it is odd that this news is posted on WebKit site, and not on Apple's site.

Also today, WebKit twiiter account has tweeted this:

https://twitter.com/webkit/status/1613679412746256389

Why does not WebKit project speak for any other WebKit based browser (and there are over 20 WebKit-based browsers out there)?

Fact is that WebKit does it only for Apple's Safari, so we can agree that WebKit is indeed speaking for Apple. And I can understand why, Apple being the biggest contributor to the project.

So when community asks a question like why is a certain feature only allowed in Safari's version of WebKit, we are really looking for a simple and transparent answer. Maybe the support is experimental and Safari is the testing ground? 

It is not this particular feature that is point of my interest but I am concerned that there are many more features like this contributed to WebKit, but being limited to only Safari, and even worse without proving any explainations or guidance, and that would be concerning from a standpoint of WebKit's reputation and eco-system of developers willing to contribute to it.

If you would like the kind of independence for WebKit that we I think we both do, a bit of transparency from Apple developers reading this will go a long way.

Thank you.