Flamenco video analysis

I continue my testing of the new Musical Gestures Toolbox for Python. One thing is to use the toolbox on controlled recordings with stationary cameras and non-moving backgrounds (see examples of visualizations of AIST videos). But it is also interesting to explore “real world” videos (such as the Bergensbanen train journey). I came across a great video of flamenco dancer Selene Muñoz, and wondered how I could visualize what is going on there:...

December 17, 2021 · 3 min · 440 words · ARJ

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

Preparing video for Matlab analysis

Typical video files, such as MP4 files with H.264 compression, are usually small in size and with high visual quality. Such files are suitable for visual inspection but do not work well for video analysis. In most cases, computer vision software prefers to work with raw data or other compression formats. The Musical Gestures Toolbox for Matlab works best with these file types: Video: use.jpg (Motion.jpg) as the compression format. This compresses each frame individually....

November 17, 2021 · 2 min · 259 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

Rotate video using FFmpeg

Here is another FFmpeg-related blog post, this time to explain how to rotate a video using the command-line tool FFmpeg. There are two ways of doing this, and I will explain both in the following. Rotation in metadata The best first try could be to make the rotation by only modifying the metadata in the file. This does not work for all file types, but should work for some (including ....

October 27, 2021 · 2 min · 256 words · ARJ

Crop video files with FFmpeg

I have previously written about how to trim video files with FFmpeg. It is also easy to crop a video file. Here is a short how-to guide for myself and others. Cropping is not the same as trimming This may be basic, but I often see the concepts of cropping and trimming used interchangeably. So, to clarify, trimming a video file means making it shorter by removing frames in the beginning and/or end....

October 26, 2021 · 1 min · 190 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

Running a successful Zoom Webinar

I have been involved in running some Zoom Webinars over the last year, culminating with the Rhythm Production and Perception Workshop 2021 this week. I have written a general blog post about the production. Here I will write a little more about some lessons learned on running large Zoom Webinars. In previous Webinars, such as the RITMO Seminars by Rebecca Fiebrink and Sean Gallagher, I ran everything from my office. These were completely online events, based on each person sitting with their own laptop....

June 27, 2021 · 6 min · 1240 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

Making 100 video poster images programmatically

We are organizing the Rhythm Production and Perception Workshop 2021 at RITMO a week from now. Like many other conferences these days, this one will also be run online. Presentations have been pre-recorded (10 minutes each) and we also have short poster blitz videos (1 minute each). Pre-recorded videos People have sent us their videos in advance, but they all have different first “slides”. So, to create some consistency among the videos, we decided to make an introduction slide for each of them....

June 15, 2021 · 4 min · 644 words · ARJ