Kayaking motion analysis

Like many others, I bought a kayak during the pandemic, and I have had many nice trips in the Oslo fiord over the last year. Working at RITMO, I think a lot about rhythm these days, and the rhythmic nature of kayaking made me curious to investigate the pattern a little more. Capturing kayaking motion My spontaneous investigations into kayak motion began with simply recording a short video of myself kayaking....

December 15, 2021 · 3 min · 547 words · ARJ

Releasing the Musical Gestures Toolbox for Python

After several years in the making, we finally “released” the Musical Gestures Toolbox for Python at the NordicSMC Conference this week. The toolbox is a collection of modules targeted at researchers working with video recordings. Below is a short video in which Bálint Laczkó and I briefly describe the toolbox: https://youtu.be/tZVX\_lDFrwc About MGT for Python The Musical Gestures Toolbox for Python includes video visualization techniques such as creating motion videos, motion history images, and motiongrams....

November 13, 2021 · 2 min · 246 words · ARJ

Converting a .WAV file to .AVI

Sometimes, there is a need to convert an audio file into a blank video file with an audio track. This can be useful if you are on a system that does not have a dedicated audio player but a video player (yes, rare, but I work with odd technologies…). Here is a quick recipe FFmpeg to the rescue When it comes to converting from one media format to another, I always turn to FFmpeg....

October 13, 2021 · 2 min · 235 words · ARJ

Normalize audio in video files

We are organizing the Rhythm Production and Perception Workshop at RITMO next week. As mentioned in another blog post, we have asked presenters to send us pre-recorded videos. They are all available on the workshop page. During the workshop, we will play sets of videos in sequence. When doing a test run today, we discovered that the sound levels differed wildly between files. There is clearly the need for normalizing the sound levels to create a good listener experience....

June 17, 2021 · 3 min · 510 words · ARJ

Combining audio and video files with FFmpeg

When working with various types of video analysis, I often end up with video files without audio. So I need to add the audio track by copying either from the source video file or from a separate audio file. There are many ways of doing this. Many people would probably reach for a video editor, but the problem is that you would most likely end up recompressing both the audio and video file....

May 11, 2021 · 2 min · 254 words · ARJ

Splitting audio files in the terminal

I have recently played with AudioStellar, a great tool for “sound object”-based exploration and musicking. It reminds me of CataRT, a great tool for concatenative synthesis. I used CataRT quite a lot previously, for example, in the piece Transformation. However, after I switched to Ubuntu and PD instead of OSX and Max, CataRT was no longer an option. So I got very excited when I discovered AudioStellar some weeks ago. It is lightweight and cross-platform and has some novel features that I would like to explore more in the coming weeks....

March 18, 2021 · 4 min · 795 words · ARJ

Some thoughts on microphones for streaming and recording

Many people have asked me about what types of microphones to use for streaming and recording. This is really a jungle, with lots of devices and things to think about. I have written some blog posts about such things previously, such as tips for doing Skype job interviews, testing simple camera/mic solutions, running a Hybrid Disputation, and how to work with plug-in-power microphones. Earlier today I held a short presentation about microphones at RITMO....

February 10, 2021 · 3 min · 445 words · ARJ

Convert between video containers with FFmpeg

In my ever-growing collection of smart FFmpeg tricks, here is a way of converting from one container format to another. Here I will convert from a QuickTime (.mov) file to a standard MPEG-4 (.mp4), but the recipe should work between other formats too. If you came here to just see the solution, here you go: ffmpeg -i infile.mov -acodec copy -vcodec copy outfile.mp4 In the following I will explain everything in a little more detail....

January 24, 2021 · 5 min · 992 words · ARJ

Convert MPEG-2 files to MPEG-4

{width=“300”} This is a note to self, and could potentially also be useful to others in need of converting “old-school” MPEG-2 files into more modern MPEG-4 files using FFmpeg. In the fourMs lab we have a bunch of Canon XF105 video cameras that record .MXF files with MPEG-2 compression. This is not a very useful format for other things we are doing, so I often have to recompress them to something else....

March 19, 2020 · 2 min · 267 words · ARJ

Simple tips for better video conferencing

Very many people are currently moving to video-based meetings. For that reason I have written up some quick advise on how to improve your setup. This is based on my interview advise, but grouped differently. Network {width=“200” height=“100”} The first important thing is to have as good a network as you can. Video conferencing requires a lot of bandwidth, so even though your e-mail and regular browsing works fine, it may still not be sufficient for good video transmission....

March 18, 2020 · 3 min · 623 words · ARJ