Video plays in notebook but not in JupyterLab

When I run an example similar to what is in the ImageRecorder demo as a notebook, the video plays automatically. For example a cell containing:

video = VideoStream.from_url( "http://localhost:8000/video.mp4") video

In a Jupyter notebook runs as expected, showing the video. However in Lab it just shows the class string as output:

VideoStream(video=Video(value=b'http://localhost:8000/video.mp4"))

Is there some magic command that needs to run or some setting in Lab? I know Lab disables javascript to some degree, perhaps that has something to do with it?

[vhirtham]

For everybody who has trouble showing the widget in JupyterLab:

It is actually related to ipywidgets. What solved the problem for me was the answer from “adhg” in the following issue: https://github.com/jupyter-widgets/ipywidgets/issues/2083

I just quote it, so you don’t have to follow the link and search for it:

1. Install nodeJS (https://nodejs.org/en/)
2. pip install ipywidgets
3. jupyter nbextension enable --py widgetsnbextension
4. jupyter labextension install @jupyter-widgets/jupyterlab-manager 5 (may need to restart your lab)

For step 2, you can also use conda instead of pip. I hope that helps. Greetings

@maartenbreddels Maybe it is helpful to add this to the installation section of the documentation.

[maartenbreddels]

Error creating view for mediastream: Failed to execute 'captureStream' on 'HTMLMediaElement': Cannot capture from element with cross-origin data

If this is the case, than we can’t solve that. There are security issues with this, and actually ipywebrtc development led to security improvements in chrome that may be the cause of this.

Basically, why this is not allowed is the following. If I give you a html page, with a link to a video you can only access (your private videos somewhere in the cloud), there are ‘private pixels’ on the page. These private pixels should not be allowed to be read by any javascript on that page, because I could send those to my private server and steal your video. Before, chrome actually allowed too much, and Firefox was too strict. Is this maybe Firefox?