Skype and VLC cannot use v4l2loopback video device

I'm playing around with using DSLR cameras as webcams with gphoto (CLI to cameras over USB) and v4l2loopback (dummy video devices), which works with OBS but neither Skype nor VLC which will either show a black image or fail with an error message. Running VLC in verbose mode and digging a bit around showed that … Continue reading Skype and VLC cannot use v4l2loopback video device →

Function pointers in Java

Overview The last post about reactive programming introduced an experimental library which, among other things, implements method references (aka function pointers) for Java. If Java allowed for such a syntax, I could imagine a succinct example: class TestClass{ int add(int a, int b){ return a + b; } public void test(){ FunctionPointer fp = TestClass.add; … Continue reading Function pointers in Java →

AWS diaries: serving HTML from lambda

AWS lambda is a neat feature that runs code in response to requests and transforms the code's output into some response. Requests can be an event occurring in the AWS platform such as an S3 modification or an HTTP request. The response is an MVC-style model which needs to pass through some network component, like … Continue reading AWS diaries: serving HTML from lambda →

The Model-View-Presenter-Controller pattern

In this post I'll talk about the MVPC (Model-View-Presenter-Controller) design pattern I use in client applications such as progressive web apps and mobile clients. It can be best understood as an evolution of the MVC (model-view-controller) pattern past the MVP (model-view-presenter) pattern. The basics: MVC and MVP You might want to skip this section if … Continue reading The Model-View-Presenter-Controller pattern →

Book of dark arts: storing data in the view

Pentagram, source Wikipedia. Towards the end of the year I'll indulge in the dark arts, join the goblins and leave my white architect hat under the Christmas tree where it belongs. I'm helping a friend (a technically minded, non-programmer) write his first mobile app . We wanted to keep everything simple: use technologies which can … Continue reading Book of dark arts: storing data in the view →