Sebastien Dumetz

Blog Posts

About this blog

After some years of entrepreneurship, I wanted to start sharing some things I learned. Some are just bits of data I extracted from a particular problem, others are more in-depth analysis of technical or business problems. There's a bit of everything, half for my later self to remember, and half for whomever may find it of use.

Welcome to my blog!

Sebastien DUMETZ

Plugins helpers for Jekyll

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I use Jekyll a lot at work for various static sites. Throughout it, I’ve developped some handy plugins. While Jekyll’s plugins system is easy and powerful to use, the doc lacks some info on helpers functions, right_way™ to parse arguments, etc… Here’s a short list, half for myself to remember, half for others to learn.

Handle linux signals in Unity3D

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Unity3D’s portable runtime based on Mono has become a great “write once run everywhere” tool for interactive apps or video games. However stable it is, there is always some edge cases to portability. The handling of SIGTERM, SIGINT, etc… linux (well, POSIX) signals are one of them.

JS CustomEvent efficiency

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CustomEvent in browser-JS is a rarely used feature, while it’s ubiquitous in it’s server-side counterpart. It looks like an elegant solution to dispatch state changes, redux-style.

Providing codecs informations on HTML5 video

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The HTML5 VideoElement allows for codecs informations in the type property. For once, even safari seems to happily support it. How is it important? Because browsers will choose the first input they can play solely depending on the type property (or file extension, if absent). Once they make the wrong choice (i.e. A too high level mp4 video for iOS/ a low end android), they’ll just hang there forever.

Encoding videos for the web in 2017

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I’ve fiddled a bit recently with self-made HTML5 video players. While it’s easy to use and now widely compatible, I’ve had some trouble encoding videos. So here is my cheat sheet for mobile-first video distribution in 2017, including an in-depth look into mp4/webm performance.

Using Webworkers with Webpack

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I started using web workers for real-worl loads a few weeks ago and like many before me, I found it to be quite easy to use, but a real pain to debug. I’ll gather my thought about them for later use.

A faster Leap Motion experience

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Like many, I was really enthousiast when the Leap motion was unveiled some years ago. At last, a company that emphasized on gesture recognition’s main problems : Speed and precision. Like most, I have been disappointed. Still not fast enough, still not precise enough. There is still not much to do in the land of gesture control. Or is there?

Read a video Backward (Part 2)

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In previous post, I stated how I made a video player capable of reading a file from back to front. However I’m quite a beginner in video encoding and I felt there was improvements to be made.

Writing a native evdev adapter

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I’ve recently found myself in need of a library to read evdev events. Usually, the X server will retrieve those events, parse them and send them to the concerned X client. In my case though, I needed xpad events from a gamepad. The only existing way to get them through X is the joystick driver, but it has been designed to control X server with a controller instead of a mouse.

How to read a video Backward (Part 1)

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I’ve recently faced an unexpected challenge in trying to read (decode & display) a video backward at normal speed. For someone who don’t know shit about video encoding, it looks like it should be as straightforward as calling video.previousFrame()… except it’s not. Let’s see why and how we worked around this to create a new generation of holographic applications.

Large capacitive wheel design

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I’ve found myself in need of a large sliding sensor. Many solutions exists for small sizes, inspired from ipod’s great capacitive wheel (DIY ones). However, when it comes to large size sensors, I found myself in lack of good references. Here is how I made a 15cm wide capacitive touch wheel.

Animate a SVG with motion-path

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One of the big wins of svg for the web is animation. It’s not as important now that we have canvas that works for nearly everything, but there is one thing really easy with SVGs and a real pain with canvas : Moving an object along a path.

Dev Projects
  • info Stingray
    A real time video player
  • info
    holusion's website
  • info node-thumbnail-manager
    A xdg compliant thumbnail manager
  • info node-evdev
    An evdev events parser on nodejs to be used in electron apps
  • info aptly web ui
    A web interface for aptly