[Question] Video Stream

[nor0x]

I'm pretty sure it's not the intended behavior of the newly added video features and IVideo, but would it be possible to retrieve a live video stream from a headless browser context, similar to continuous calls to page.ScreenshotAsync.

As far as I understood the new video feature, it's for recording and saving it afterwards?

[kblok]

Hey @nor0x can you share a use case for that?

[nor0x]

in my specific usecase i would want to display a (in the best case live) feed of browser pages. A headful browser is not an option in my case because the view is rendered manually on various platforms

[kblok]

cc @arjunattam

[arjunattam]

Thanks for this @nor0x. Yes, the video feature is built to record and save a file. We could consider providing it as a stream. Does your scenario require cross-browser support? If not, we could explore a Chromium-only workaround to support this scenario.

I will move this issue to the main playwright repo, since this is an upstream change. We could use this issue to collect more feedback on this request.

[nor0x]

thanks for the reply @arjunattam - currently Chromium-only would be very fine. Do you have a hint at what code to look at?

[atemiz]

I think eliminating the delays (currently min 100ms) between ScreencastFrame events might be useful.

https://chromedevtools.github.io/devtools-protocol/tot/Page/#event-screencastFrame

[nor0x]

@atemiz good idea, i didn't know that there are 100ms between ScreencastFrame events. Just to make sure i get this right - these 100ms are in Chromium or playwright?

[atemiz]

@nor0x Chromium;
https://chromium.googlesource.com/chromium/src/+/refs/heads/master/content/browser/devtools/devtools_video_consumer.cc

[pavelfeldman]

Note that non-Chromium do not have this limitation and stream into vp8.

[pavelfeldman]

@atemiz: thanks for the pointer, I removed the limitation upstream: https://chromium-review.googlesource.com/c/chromium/src/+/2546475, I believe that was a regression. We are still dropping frames based on the backpressure, but it should not be as bad as it used to be.

[nor0x]

thanks for the update @pavelfeldman i will see how i can use this

[nor0x]

Hey @pavelfeldman, another (maybe stupid) question. Chromium uses Skia for rendering, right?
If i wanted to get a snapshot or preview of the current browser content, do i always have to go through snapshotting - even if i use Skia for rendering the content on my side (currently as images)

[dgozman]

@nor0x In theory it is possible to expose some other format representing the content being drawn (DisplayList? Maybe even Skia commands list?), but that's not the usecase Playwright focuses on.

[nor0x]

@dgozman alright got it! thanks

[pavelfeldman]

Thank you for reporting this issue and providing comments to those that might be facing a similar problem. I am now closing this as a part of the triage, please feel free to file a new issue with additional details. Given the limited resource and a lot of requests, we need to fulfill most popular requests and at the same time keep our issue database manageable.

[jfloodnet]

@nor0x I have a similar use case, did you get something working?

[frmsaul]

I'm curious also. Any progress on this?