Skip to main content

Decode Morse code from a wave file using SQLite

A recent programming puzzle from Wunderdog caught my interest for one simple reason: it had the word wave file in it. Music and audio-related technology is something close to my heart. Besides, I have not had a DIY project related to music in a while, so why not look into it.

The conundrum is straightforward. A wave file contains morse code, and one must decode it to dash and dot letters. The choice of technology is free.

A pragmatic developer would look into some popular audio processing library - in my case, something written in go - and write a simple program. I had something different in mind, though. I've recently read The Art of PostgreSQL book and done some exercises in more advanced Postgres features. Why not apply the lessons learned in morse code parsing?

The outcome is Endeavour, a no-frills Python wrapper + some exotic SQL window functions. It is neither fast nor pretty, but it proves that analyzing waveform files with SQLite is possible.

Comments

Popular posts from this blog

I'm not a passionate developer

A family friend of mine is an airlane pilot. A dream job for most, right? As a child, I certainly thought so. Now that I can have grown-up talks with him, I have discovered a more accurate description of his profession. He says that the truth about the job is that it is boring. To me, that is not that surprising. Airplanes are cool and all, but when you are in the middle of the Atlantic sitting next to the colleague you have been talking to past five years, how stimulating can that be? When he says the job is boring, it is not a bad kind of boring. It is a very specific boring. The "boring" you would want as a passenger. Uneventful.  Yet, he loves his job. According to him, an experienced pilot is most pleased when each and every tiny thing in the flight plan - goes according to plan. Passengers in the cabin of an expert pilot sit in the comfort of not even noticing who is flying. As someone employed in a field where being boring is not exactly in high demand, this sounds pro...

Canyon Precede:ON 7

I bought or technically leased a Canyon Precede:ON 7 (2022) electric bike last fall. This post is about my experiences with it after riding for about 2000 km this winter. The season was a bit colder than usual, and we had more snow than in years, so I properly put the bike through its paces. I've been cycling for almost 20 years. I've never owned a car nor used public transport regularly. I pedal all distances below 30km in all seasons. Besides commuting, I've mountain biked and raced BMX, and I still actively ride my road bike during the spring and summer months. I've owned a handful of bikes and kept them until their frames failed. Buying new bikes or gear has not been a major part of my hobby, and frankly, I'm quite sceptical about the benefits of updating bikes or gear frequently. I've never owned an E-bike before, but I've rented one a couple of times. The bike arrived in a hilariously large box. I suppose there's no need to worry about damage durin...

Extracting object properties from an IFC file with IfcOpenShell

Besides the object geometry information, IFC files may contain properties for the IFC objects. The properties can be, for example, some predefined dimension information such as an object volume or a choice of material. Some of the properties are predefined in the IFC standards, but custom ones can be added. IFC files can be massive and resource-intensive to process, so in some cases, it helps to separate the object properties from the geometry data. IfcOpenShell  is a toolset for processing IFC files. It is written mostly in C++ but also provides a Python interface. To read an IFC file >>> ifc_file = ifcopenshell.open("model.ifc") Fetch all objects of type IfcSlab >>> slab = ifc_file.by_type("IfcSlab")[1] Get the list of properties >>> slab.IsDefinedBy (#145075=IfcRelDefinesByType('2_fok0__fAcBZmMlQcYwie',#1,$,$,(#27,#59),#145074), #145140=IfcRelDefinesByProperties('3U2LyORgXC2f_hWf6I16C1',#1,$,$,(#27,#59),#145141), #145142...