NodeJs local Chrome Agent - Video 'Not available'

Hi all,

I’m currently setting up a WPT system for internal environment testing - all machines are running CentOs so I am using the nodeJs agent with a local version of Chrome running against Xvfb (With Fluxbox).

It’s all going ok so far, apart from the fact that no video seems to be recorded or passed back to the server for processing.

On the result page for test it simply has ‘not available’ in the video column.

Could anyone give me any info on how I can track down why video isn’t getting recorded?

Thanks in advance,


The node js agent doesn’t have any code for capturing video from desktop browsers which is why you’re not seeing it.

Ah, then that answers that Lol I should really have looked at the code before asking…

Well, as its a requirement for us, I’ll have a look into implementing it if at all possible. are there any notes or tips you could give me to point me in the right direction?


Not particularly. Most of the node agent video processing is expecting a mp4 recording of the browser window and if you can pull that off with xvfb you might be able to just plug it in (some of the viewport detection/trimming may need to be tweaked).

The regular desktop agents are somewhat more complicated and capture periodic screen shots (every 100ms initially but the frequency degrades over time) to RAM, de-dupes the frames and then writes them out as individual jpegs.