Recent content on Alastair Barber
--> --> --> Earlier I discovered how to get a block of IP addresses, announce them to the internet, and have the traffic piped to a router at home . Whilst this meant that devices connected to this router had real public IP(v6) addresses accessible to any other host on the internet (with IPv6) there were a couple of things that I felt were sub-optimal about this setup. Apart from it being IPv6…
Here’s the story of AS202858 . Recently I got curious as to where exactly IP addresses came from, and how does ’the internet’ know where packets addressed to one should actually end up. This article is a quick overview of what I discovered and how I got my hands on my own slice of the IPv6 address space, and how I used it practically. It’s a high-level overview, although…
The venerable Si5351 pops up in a lot of applications related to amateur radio as a convenient and flexible Direct Digital Synthesizer (DDS). It is a device primarily designed to replace crystals, oscillator circuits and PLLs used in digital systems to provide clocks used by, for example, ethernet, HDMI and USB controllers. In this article, I’ve collected some notes on understanding the…
The Weak Signal Propagation Reporting (WSPR) protocol is designed to allow for radio propagation conditions to be measured across different frequencies and times. It is a slow speed digital mode, and there exists a network of thousands of receiving stations worldwide reporting the identity of received stations, along with their locations, to a central server. Whilst there are applications of this…
Here is a very simple tool that can be used to simulate producing sine waves from PWM pulses and an appropriate filter in LTSpice. It can be downloaded and built or run online…
I decided to try and learn about WebAssembly from the ground up by building the (very simple) C++ PWL file generator for the web using WebAssembly. I spent some time learning about how WebAssembly is implemented and finding out what is needed to get the program to run. Here are some notes from this process. It is intended as a bird’s eye overview of the concepts, there are links here to much…
This is a fun website that I recently put together for a hackathon run by Amadeus. I’ve not created anything for the web in ages so this was good fun to put together, and try and figure out this modern JavaScript thing :) The backend is written in Python 3 using Flask and runs on a fun mix of Amazon Lambda, S3 and the excellent Python Anywhere . It’s something that I’m keen on…
Update : Check out the FxGuide DigiPro Report On the 23rd of July, I’ll be presenting a paper at the Digital Production Symposium (DigiPro) in Anaheim called Camera Tracking in Visual Effects, An Industry Perspective of Structure from Motion \(Free Download\) . The overall aim is to examine why, when there’s so much research being done in automatic camera tracking in the computer vision community,…
I did this work as an earlier part of my EngD and it’s written up in the Elsevier Computers And Graphics Journal ( free preprint version ) . The idea came about from an earlier work by Klein & Drummond who used motion blur to produce a single frame visual gryroscope. We had a go at extending this to see if you could accurately determine changes in focal length from motion blur.
2020 Update - Much of the code and recommendations in this post will be well out of date! But I’ve kept it up as inspiration. For Christmas, I decided to attempt to make magic as real as I could using the wonder that is electronics, programming and determination. I set out to make a ‘Weasley’ clock. For those who don’t know, this is a magical device that lives in the…
JASIOHost is based upon the observer model of software design. In order to successfully gather audio data from an Audio Input – one must write a class that is able to handle the data returned – in a similar fashion to how you may handle UI events
For my final year project, I had to design and code a digital audio mixing program, with an interface as a multi-touch table. Although I had access to some (very good) FTIR (Frustrated Total Internal Reflection) ones in the lab at my university, I thought it’d be cool to try and build one myself over the winter holiday. Here are some pointers from my experience…
Hello! I’m Alastair, a Software Engineer currently based in Helsinki. I have worked for several years in the Visual Effects industry, originally completing my Engineering Doctorate (EngD) at DNeg and the University of Bath. I have since worked at Foundry and Technicolor FEV (Mill Film) . I now work at IXI and was previously at ICEYE I’m interested in embedded electronics, visual…