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Test out different fps
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Description

WebPageTest runs with 10 fps today. In some cases that means that a change in 100 ms is picked up by our alerts. Browsertime runs with 30 fps on desktop and 60 fps on mobile. We should try to do the same on WPT since the instance size is the same.

Event Timeline

I looked into the code and there is a hidden query fps parameter that you can use. There's two ways to do that:

  1. Add support to the WPT API (I can do a PR for that)
  2. Hack and set it to 30 fps per default (the same way we hacked setting Visual Elements on all runs.

I'll start with 2. so we can see the changes today.

/var/www/webpagetest/www/runtest.php

$test['fps'] = isset($req_fps) ? (int)$req_fps : null;

I've changed so default is 30 instead of null as a hack. If it works good I'll make a PR for the API.

We run 30 fps today, I think that is good enough. We can update the API later (we are still waiting on those security issues in the API :()