WebUI & website communication

[JackDesBwa]

Are you opened to contributions? What is the preferred way to submit such a contribution?
I plan to modify the WebUI part to allow communications with a website.

Context: Some users of https://stereopix.net/ use a very old browser version that supports sview plugin in order to have support for their displaying device that could not be controlled from inside the browser otherwise. It would be better if they could use up-to-date software.

Feasibility: Communication with the current server is tricky because of the security model of modern browsers, especially because the webUI server exposes a regular HTTP interface without encryption. Direct communication is therefore blocked. However initial tests show that the postMessage API, designed to safely enable cross-origin communication, can be used. It allows bidirectional communication between the website and the WebUI page when opened from the website. The WebUI page can then communicate with mongoose server as it does currently and act as relay.

Plan: The modification is not very trivial, so several intermediary steps could help. The initial plan would be to:

• Redraw the interface with modern html/css
• Transform the structure to separate UI code and API service, and use postMessage inside the page itself to communicate between the two
• Allow cross-origin communication to the API, without restriction, so that a website can use it
• Add access control restrictions, with interface for the user to accept connections
• Add a way to control the playlist and source type, so that the website can change the displayed medium dynamically

What do you think about this addition? Are there some features for the webUI that you thought about that I could possibly integrate at the same time?

Visual idea for the new UI: (light and dark themes)

[gkv311]

The current WebUI implementation is more like a proof of concept rather than a final solution. It relies on a legacy version of mongoose as the simplest yet functional embeddable HTTP server with compatible license, and doesn't implement any features for secure connection/authorization - basically should be fine for a home/restricted network, but not that good idea to use it in more open environment.

It would be nice bumping WebUI into something better, or at least more nice-looking, but does it really fits your needs? I'm not sure I understand the idea behind cross-origin communication...

[JackDesBwa]

does it really fits your needs?

It is not the perfect solution for my application, but it is a good fallback.

Anyway, it’s the only solution I found that is compatible with the security restrictions of the browsers, at least without introducing certificate management, which would pose significant practical difficulties for users.

I'm not sure I understand the idea behind cross-origin communication...

"Origin", the specialized name given to a string analog to the server address of a page (e.g. "http://localhost:8080")

Communication between tabs (or more specifically between scripts executed in pages located in different tabs/windows) is in the trusted zone if the origin of the two pages is the same. If the origin is different (cross-origin), the communication is very restricted. However, the postMessage API allows to pass messages (~serializable objects) between the pages, which is safe in the sense that the receiving page can/should check the origin of the message to decide to use it or not, and that the messages themselves are restricted to data only, that the receiver can process.

Zero data is sent to the servers, everything happens in the scripts inside the browser. Of course one of the script can decide to dialog with its server, but it is controlled independently each side of the "origin" boundary. If the tab is closed, the communication is cut.

In practice, the path is as follows: the web page opens a tab which loads webUI. It sends message to the webUI page which choose to answer, ignore, pass request to the server of sview or whatever is needed for handling this message. The webUI page can also send messages to the opener, for example to notify that a data changed or that the communication with sview is lost. That way, there is no deep change: all the actions that the current page can do is available to the distant page, with possible user validation in between, provided that a special message is handled to do it.

I hope this helps to clarify.

It would be nice bumping WebUI into something better, or at least more nice-looking

Ok, so I will try to propose something then.

[gkv311]

Communication between tabs (or more specifically between scripts executed in pages located in different tabs/windows)

Thanks for clarification. But was is a complete scenario? How sView+WebUI could be used by another web application/for which purpose?

Or the idea is to rely on HTTP loading interface inside sView (which is implemented by FFmpeg) and pass through remote URLs to open files in it (this would work only for URLs that don't require authorization)?

[JackDesBwa]

Or the idea is to rely on HTTP loading interface inside sView (which is implemented by FFmpeg) and pass through remote URLs to open files in it (this would work only for URLs that don't require authorization)?

Yes, I forgot to talk about this part, but it was indeed the idea.

[ThreeDeeJay]

@JackDesBwa Nice site. I have NVIDIA 3D Vision set up with Firefox 32 and just a few questions:

• This is probably a tall ask, but any plans to support the original 3D Vision NPAPI plugins?. It'd allow to display 3D even windowed like in certain sites.

• I installed the last version of sView before the NPAPI plugin was removed and disabled the 3DV ones but even though other modes seem to work, the viewer is empty with the sView mode, even in fullscreen:

By the way, there's a similar site called Phereo, which has a 3DV option, but images don't seem to (down?)load in the old Firefox version. Maybe something to do with certificates or some other outdated/broken feature. 🤔

also @gkv311 any chance we could get a standalone NPAPI plugin installer to use it with the newer versions of sView, or are they not compatible?

[JackDesBwa]

@ThreeDeeJay, your comment is mostly off topic. I did not find how to contact you directly, so I reply here, but if you want more details or continue the discussion, please contact me by email (preferably with the contact address of the website Stereopix).

Answers:

Nice site.

Thanks.

This is probably a tall ask, but any plans to support the original 3D Vision NPAPI plugins?. It'd allow to display 3D even windowed like in certain sites.

No plans.
One big reason it was not implemented when I coded the viewer is that 3D Vision NPAPI plugin is closed by a key which is computed depending on the domain name of the website. It was probably added so that websites had to pay nvidia to use it, and they discontinued the technology far before I created Stereopix. The plugin from sView was an open alternative, which provided similar display (e.g. windowed) but with more options. If the nvidia plugin is detected, but not sview, the viewer displays the message you saw.
Also NPAPI has been deprecated for ages now and finally abandoned about a decade ago for good reasons.

the viewer is empty with the sView mode, even in fullscreen

Not sure why. My work on it is too old now and I am not a Windows user. I have no way to test anymore. Maybe ask to people who have experience with the whole ecosystem to make it work and who actually use it, some of them are on this mailing group: https://photo-3d.groups.io/
By the way, there is no need to disable nvidia's plugin to make it work.

By the way, there's a similar site called Phereo, which has a 3DV option, but images don't seem to (down?)load in the old Firefox version. Maybe something to do with certificates or some other outdated/broken feature. 🤔

I know about this website. The company that was running it failed a long while ago, then it was kept online by nvidia without much maintenance for probably about a decade. A few years ago nvidia decided to give up after AmazonWebServices deprecated the servers it was running on. Someone from the modding community decided to pay to keep it online and I helped him to migrate to new servers, to reduce costs, to fix a bug that destroyed many images, to clean the public list of images by hiding the destroyed ones, and so on.

The browsers versions that support NPAPI are very old. I remember that the site did not work on modern browsers at some point because the encryption methods available in the previous server were all considered insecure, so I would not be surprised that we updated the server with new ciphers that were not known at the time those Firefox versions were released. I added an old cipher in the list, in hope it would help, but I cannot test myself.