Trim video file using FFMPEG

This is a note to self, and hopefully to others, about how to easily and quickly trim videos without recompression.

Often I end up with long video recordings that I want to split or trim. One a side note sometimes people call this “cropping”, but in my world cropping is to cut out parts of the image, that is, a spatial transformation. Splitting and trimming are temporal transformations.

You can of course both split and trim in most video editing software, but these will typically also recompress the file on export. This reduces the quality of the video, and it also takes a long time. A much better solution is to trim losslessly, and fortunately there is a way to do this with the wonder-tool FFMPEG. Being a command line utility (available on most platforms) it has a ton of different options, and I never remember these. So here it goes, this is what I use (on Ubuntu) to trim out parts of a long video file:

This will cut out the section from about 1h19min to 2h18min losslessly, and will only take a few seconds to run.

Nordic Sound and Music Computing Network up and running

I am super excited about our new Nordic Sound and Music Computing Network, which has just started up with funding from the Nordic Research Council.

This network brings together a group of internationally leading sound and music computing researchers from institutions in five Nordic countries: Aalborg University, Aalto University, KTH Royal Institute of Technology, University of Iceland, and University of Oslo. The network covers the field of sound and music from the “soft” to the “hard,” including the arts and humanities, and the social and natural sciences, as well as engineering, and involves a high level of technological competency.

At the University of Oslo we have one open PhD fellowship connected to the network, with application deadline 4 April 2018. We invite PhD proposals that focus on sound/music interaction with periodic/rhythmic human body motion (walking, running, training, etc.). The appointed candidate is expected to carry out observation studies of human body motion in real-life settings, using different types of mobile motion capture systems (full-body suit and individual trackers). Results from the analysis of these observation studies should form the basis for the development of prototype systems for using such periodic/rhythmic motion in musical interaction.

The appointed candidate will benefit from the combined expertise within the NordicSMC network, and is expected to carry out one or more short-term scientific missions to the other partners. At UiO, the candidate will be affiliated with RITMO Centre for Interdisciplinary Studies in Rhythm, Time and Motion. This interdisciplinary centre focuses on rhythm as a structuring mechanism for the temporal dimensions of human life. RITMO researchers span the fields of musicology, psychology and informatics, and have access to state-of-the-art facilities in sound/video recording, motion capture, eye tracking, physiological measurements, various types of brain imaging (EEG, fMRI), and rapid prototyping and robotics laboratories.

New Publication: Analyzing Free-Hand Sound-Tracings of Melodic Phrases

We have done several sound-tracing studies before at University of Oslo, and here is a new one focusing on free-hand sound-tracings of melodies. I am happy to say that this is a gold open access publication, and that all the data are also available. So it is both free and “free”!

Kelkar, Tesjaswinee; Jensenius, Alexander Refsum
Analyzing Free-Hand Sound-Tracings of Melodic Phrases
Applied Sciences 2018, 8, 135. (Special Issue Sound and Music Computing)
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In this paper, we report on a free-hand motion capture study in which 32 participants ‘traced’ 16 melodic vocal phrases with their hands in the air in two experimental conditions. Melodic contours are often thought of as correlated with vertical movement (up and down) in time, and this was also our initial expectation. We did find an arch shape for most of the tracings, although this did not correspond directly to the melodic contours. Furthermore, representation of pitch in the vertical dimension was but one of a diverse range of movement strategies used to trace the melodies. Six different mapping strategies were observed, and these strategies have been quantified and statistically tested. The conclusion is that metaphorical representation is much more common than a ‘graph-like’ rendering for such a melodic sound-tracing task. Other findings include a clear gender difference for some of the tracing strategies and an unexpected representation of melodies in terms of a small object for some of the Hindustani music examples. The data also show a tendency of participants moving within a shared ‘social box’.

Come work with me! Lots of new positions at University of Oslo

I recently mentioned that I have been busy setting up the new MCT master’s programme. But I have been even more busy with preparing the startup of our new Centre of Excellence RITMO Centre for Interdisciplinary Studies in Rhythm, Time and Motion. This is a large undertaking, and a collaboration between researchers from musicology, psychology and informatics. A visual “abstract” of the centre can be seen in the figure to the right.

Now we are recruiting lots of new people for the centre, so please apply or forward to people you think may be interested:

Come study with me! New master’s programme: Music, Communication and Technology

It has been fairly quiet here on the blog recently. One reason for this is that I am spending quite some time on setting up the new Music, Communication and Technology master’s programme. This is an exciting collaborative project with our colleagues at NTNU. The whole thing is focused around network-based communication, and the students will use, learn about, develop and evaluate technologies for musical communication between the two campuses in Oslo and Trondheim.

Interested, apply to become a student!