As part of my #StillStanding project I need to handle a lot of video files on a daily basis. Today, I wanted to check the duration and pixel dimensions of a bunch of files in different folders. As always, I turned to FFmpeg, or more specifically FFprobe, for help. However, figuring out all the details of how to get out the right information is tricky. So I decided to ask ChatGPT for help....
There is always a need to add fade-in and fade-out to audio tracks. Here is a way of doing it for a bunch of video files. It may come in handy with the audio normalization script I have shown previously. That script is based on continuously normalizing the audio, which may result in some noise in the beginning and end (because there is little/no sound in those parts, hence they are normalized more)....
After exploring some visualizations of kayaking, I was eager to see how a similar approach could work for walking. On a trip to the Norwegian mountains, specifically at Haugastøl, situated halfway between Oslo and Bergen, I strapped a GoPro Hero Black 10 on my chest and walked up and down a nearby hill called Storevarden. The walk was approximately 25 minutes up and down, and a fast-forward version of the video can be seen here:...
Last year, I wrote about video-based motion analysis of kayaking. Those videos were recorded with a GoPro Hero 8 and I tested some of the video visualization methods of the Musical Gestures Toolbox for Python. This summer I am testing out some 360 cameras for my upcoming AMBIENT project. I thought I should take one of these, a GoPro Max, out for some kayaking in the Oslo fjord. Here are some impressions of the trip (and recording)....
Today, I recorded Sound Action 194 - Rolling Dice as part of my year-long sound action project. The idea has been to do as little processing as possible to the recordings. That is because I want to capture sounds and actions as naturally as possible. The recorded files will also serve as source material for both scientific and artistic explorations later. For that reason, I only trim the recordings non-destructively using FFmpeg....
I have been doing several long recordings with GoPro cameras recently. The cameras automatically split the recordings into 4GB files, which leaves me with a myriad of files to work with. I have therefore made a script to help with the pre-processing of the files. This is somewhat similar to the script I made to convert MXF files to MP4, but with better handling of the temp file for storing information about the files to merge:...
I am recording a lot of short videos these days for my sound actions project. Sometimes the recordings end up being rotated, which is based on the orientation sensor (probably the gyroscope) of my mobile phone. This rotation is not part of the recorded video data, it is just information written into the header of the MPEG file. That also means that it is possible to change the rotation without recoding the file....
This week we started up our new online course, Motion Capture: The Art of Studying Human Activity, and we are also rerunning Music Moves: Why Does Music Make You Move? for the seventh time. Most of the material for these courses is premade, but we record a new wrap-up video at the end of each week. This makes it possible to answer questions that have been posed during the week and add some new and relevant material....
I often want to create motion videos, that is, videos that only show what changed between frames. Such videos are nice to look at, and so-called “frame differencing” is also the start point for many computer vision algorithms. We have made several tools for creating motion videos (and more) at the University of Oslo: the standalone VideoAnalysis app (Win/Mac) and the different versions of the Musical Gestures Toolbox. These are all great tools, but sometimes it would be nice also to create motion videos in the terminal using FFmpeg....
I have previously written about how it is possible to “flatten” a Ricoh Theta+ recording using FFmpeg. Now, I have spent some time exploring how to process some recordings from a Garmin VIRB camera. Some hours of recordings The starting point was a bunch of recordings from our recent MusicLab Copenhagen featuring the amazing Danish String Quartet. A team of RITMO researchers went to Copenhagen and captured the quartet in both rehearsal and performance....