What I learned at OggCamp 2018

I last attended OggCamp in Liverpool in 2015 and had a great time. There wasn’t one in 2016, and in 2017 it was in the wrong part of the UK for the gods of time & space to allow.

I did though make it to OggCamp 2018 in Sheffield, so here’s some of the things I took away:

Sheffield is Super

It’s been a long time since I was last in Sheffield, and an even longer time since I arrived by train on the Penistone line. The rolling stock is still the faithful old Pacer, that I’m sure they were going to replace when I was still in my teenage years…

Anyway, some lovely new buildings in amongst the old, and some nice ‘modern’ uses for re-purposed places too. One of which was where I had coffee and breakfast – Tamper Sellers Wheel on Arundel Street. Absolutely amazing food, coffee and service.

OggCamp

I got the feeling there were fewer attendees than at Liverpool, but I couldn’t be sure. The layout in Sheffield wasn’t ideal, with venues being split by five storeys, so it felt a bit disconnected. However, once the Welcome Talk was underway, there were plenty of familiar faces around and it soon felt like OggCamp again.

I went to a talk on The Things Network, as it’s always good to find out what other groups are doing, and if there are any ideas I can use to help with my own TTN projects on the Isle of Man. It seems the main thing we need to work on here in the island is a use case which builds a community around it, as that looks like the most successful way of involving enough people and getting access to some funds.

The next talk was about delivering images over the mobile web. Not something I’d specifically thought about but quite interesting nonetheless.

  1. You can wind up your JPEG compression without really noticing on small screens.  A nice tool called cjpeg-dssim, which looks at structural similarity, can help with this.
  2. File formats matter. SVGs are a kind of XML, and can even go inline with your HTTP code – BUT beware. If you create them in Adobe products, it seems about 98% of the resulting file size is cruft that you can remove! WebP seems to be the best format in terms of quality vs filesize, but is only supported in Chrome and Android browsers for now.
  3. Size matters. Most mobile browsers download loads of pixels, and then throw most of them away before displaying. This wastes mobile data, slows down load times, as well as making the processor in the mobile device work harder than it has to. Ideally create lots of versions of an image which differ by about 25 kB in size, and then use some responsive scripts to load the correct size image for the current viewport size. Speeds things up a lot.
  4. Lazy loading saves data, as most pages don’t get viewed in their entirety. Loading images just as they scroll up towards the viewport means that if the user doesn’t scroll, no data is wasted (and page loads quicker) but if they do scroll, they still see all the pictures.

The final talk before lunch was about hacking the O2 Joggler. This was great, as the presenter was clearly very passionate about re-using old kit that would otherwise have gone to waste. I’d never really considered hacking as a force for environmental good before. It seems that the Joggler is quite versatile with hacked firmware, and they’re available fairly cheaply at the moment.

Beer with Friends

As much as OggCamp is great (really, you should attend), I received a Twitter message from someone I’d never met in real life but who I’ve swapped messages with for years. They’d noted I was in Sheffield and wondered if I wanted to meet up. A very chilled afternoon of drinking in the sunshine and exploring various drinking venues and beers of Sheffield followed, before riding the train again.