Claus Witt - Claus Witt

One of those "I just needed to deploy"-days

It all began when I had to deploy a change, that needs to go live today. The software to build the docker image failed because of the ruby version not being supported... and so began the "let's update this outdated rails app with obscure dependencies"-dance that took an hour

Pretty Print json in vim

I hand edit json many times a week. For that reason the vim command for doing a quick pretty printing of json in current buffer usually is muscle memory for me; however I mistyped it twice today, and decided to make a command and a keybinding for it instead. (Even

transcoding

Our most simple transcoding service

At Fliva we had an issue; customers kept uploading iPhone footage in HDR formats with varying framerates, and our software could not handle it. The colors looked washed out, and just plain wrong. Our first stab at a solution was, of course, to use ffmpeg. However ffmpeg produced the same

glsl

Writing a Progress Bar Overlay Shader

Some of our customers in Fliva want to show a simple progress bar inside their video. You see this a lot nowadays in social media videos, where the progress of the video is embedded inside it so that you, as the consumer of the video, know how much more you

hubot

Writing a Hubot Adapter for Bitrix

Back in the day, we installed hubot on our Hipchat developer chat. When hipchat got sold to Atlassian we jumped ship and chose Slack instead. Years later the company chose to invest heavily in having a shared system across all division handling tasks and CRM primarily - but since this

corona

Corona Beats from Last Year

Last year I spent some time one afternoon making a short corona-beat. I never really shared it... Now it's here... clauswitt · Corona Beatz #1

ffmpeg

Decoding Video Frames with ffmpeg/libav

Opening the file AVFormatContext *formatContext; if (avformat_open_input(&formatContext, "path/to/file.ext", nullptr, nullptr) != 0) exit(1); // Couldn't open file /// Retrieve stream information if (avformat_find_stream_info(formatContext, nullptr) < 0) exit(2); // Couldn't find stream information Find the first video stream int videoStreamIdx = -1; for (int i

kubernetes

Install Datadog in Kubernetes

First of all, we use helm. So we start here: https://docs.datadoghq.com/agent/kubernetes/?tab=helm Add the repository helm repo add datadog https://helm.datadoghq.com helm repo add stable https://charts.helm.sh/stable helm repo update Install the chart helm install datadog -f values.yaml

database

Just Create a Relation

I recently read You might as well timestamp it and today I came across an equal truism Just create a relation. Many a time have i seen tables of a given object where the table has a status field and a status_changed timestamp. But guess what; knowing when a

game

Basic Breakout Game with Raylib

I have always wanted to write games. Back in the day that was the whole idea why I wanted to be a programmer. And I have worked myself into a new job at Fliva exactly because I wanted to become a game programmer. Only problem was that I found a

howto

Know your assumptions, and test them

In my day to day I very often stumble upon yet another issue in one of our software systems that needs fixing. And most often, the issue is rather apparent and easy to fix. This past couple of days (ok, almost a week) I have been stuck on a problem

music

Much more than ten albums that shaped my taste in music

My wife began this challenge on Facebook. Each day post an image of an album cover of music that shaped your taste in music... The rules states that you should say why, just post the image (and the rules) and tag someone new each day. (My wife as a good

audio programming

A ring buffer for audio samples

At Fliva we work with audio (we have a c++ library that essentially works as a audio sequencer), video (we have a rendering engine which basically works as a scriptable After Effects clone) and we do transcoding, muxing and all that jazz... When we began this journey we generated video

xml

Formatting Xml Files with xmllint

I am currently working on a project where I need to parse Open Xml files comming from the Office Suite. As you may already know this involves opening what is essentially a zip file full of xml files. When creating a parser though, having source files for referencing is very

tcpdump

Using tcpdump to Spy on Webservers

I recently had to debug an error where stuff that should have been returned through a server to server call did not work correctly. Both servers - in development mode at least - was on my local machine. But since I had to hack either an external dependency or the

family time

I Wrote a Pong Game with My Son using Cocos Creator

My son (Toke, 7 years old) and I have long talked about making our own computer game. I have four reasons for doing so. * I would like him to know a bit about what I do all day * I would like him to be interested in games from a makers

c++

How to create a plugin system in C++

To create a plugin system in C++ you need three things. * An interface for the plugin * A way for the plugin to inject itself into your program * A way for the program to load the plugins The interface The first two parts are handled together in this case. By having

movie

Watching the Social Network Lets Me Focus on Work

I love working to some kind of (controlable) background noise. Something I can mostly ignore while working, but that I can focus on when loosing my train of thought. Mostly I use music but lately I have found that (some) movies helps me as well. Why watching a movie while

c++

Printing C++ Objects to stderr/stdout

When your C++ projects grow a little, you may find yourself needing to log the state of objects. There are two ways of doing this (assuming that you'll want to log the data the same way each time). The wrong way is writing logging code that knows everything about your

cmake

Generate Source Files With CMake

Sometimes when writing c++ programs I have some textual data that I want to use in the program that I want to be part of the executable instead of in flat files next to the executable. However while developing it is far easier to have the textual data in separate

boost

Trim Strings in C++ with Boost

One of the biggest grievances with I had when I started writing a lot of c++ code was that a lot of things that we take for granted as built in things in other (primarily dynamic) languages are all a bit harder to do (right) in c++. This means that

c++

Split Strings in C++ With Boost

I just wrote about how to trim strings with boost. The code where I first needed to trim a string, was actually very simple naive parser where strings of key value pairs would be split, and then each part trimmed to ensure that both key and value was without leading

books

Where I Go To Learn

I try to learn a new thing every day. Sometimes it is a big thing sometimes something small. Blogs and news I read a lot of blog posts. Every day I go to Reddit and HackerNews and click approx 10-30 links on each site - after having scanned headlines and

git

So, you forgot to make a git branch?

It happens to me at least once a week. I meant to make a topic branch. But I dove into the code too quickly - and suddenly I am a couple of commits into what at the moment seems like an important feature or bug fix, and I realize -

emacs

Writing Intelligent Keyboard Shortcuts in Elisp

In my quest to get better aquainted with my new editor I decided to make some intelligent keyboard shortcuts for my blogging repository. I decided to have one keyboard shortcut that could publish the current draft (with jekyll publish) and one to create a new draft (with jekyll draft). How