Render to video stream and interact with content.

[Horsetopus]

Hello,

I was just wondering about two things regarding CEF, if you guys could please enlighten me:
- Can CEF be renderer to a video stream?
- Is there a way to interact with the DOM from an external process? Otherwise I guess there is an in/out stream availlable? Worst case scenario I can use websockets for my usecase, but I would appreciate something more straightforward.

Thanks.

[magreenblatt]

What is your use case?

[Horsetopus]

Hi magreenblatt, thank you for answering.

Well... how to explain that.
I want to broadcast a video stream of some web content. Basically a slideshow. And I want to be able to control this slideshow not by interacting with the webpage but through some commands.
So ideally, here is how I with I would use CEF:

I have my program running.
Though my program, I launch CEF, ideally without even displaying it.
I get a video stream of the rendering from CEF, and broadcast it to every watchers.
And then I communicate with CEF in some ways to load the slide, and navigate through it.

For the communication, I could do this using websockets, or other web technologies. So I just ask if something else is available, but it is not my big issue.
What matters the most is the possibility of getting a video stream of the webpage rendering, if possible without even it being displayed on the desktop where it is running ( in order to not waste performances ).

If CEF doesn't support it, is it possible to use getUserMedia on the tab, without any UI prompt?

[magreenblatt]

If you don't want to display content on the source machine then you would need to use off-screen rendering. However, it will still take resources to render the web content. With off-screen rendering you get an OnPaint callback with a bitmap of the rendered contents. You would then need to turn that into a video yourself.

What you're trying to do sounds very similar to Chromecast. You might have an easier time using Google Chrome which already supports the Chromecast capability. The control that you're seeking should be easy enough to implement as a standard JavaScript application or Chrome extension.

[Horsetopus]

off-screen rendering, OnPaint callback.
I have the keywords, I'll get to work.
Thanks.

PS: As for chromecast, it doesn't match my needs. I need the stream available on the web, on multiple clients. But thanks.

[magreenblatt]

PS: As for chromecast, it doesn't match my needs. I need the stream available on the web, on multiple clients. But thanks.

Ah, OK. Missed the multiple clients part.