Multiple USB webcams working at the same time

After working happily with FW-products for many years, the recent trend of disappearing FW-ports have made me look for USB-based solutions. For hard drives the switch has been easy, and I also recently got my first USB-based sound card. The hardest part has been to figure out how to handle video cameras.

I have been using various Unibrain cameras for years, and have gotten used to the simplicity of being able to hook up multiple cameras to one computer. Last year when I tried hooking up multiple USB-based webcams to a computer (Windows, since they didn’t work on OSX at all), only one could work at a time. I was therefore pleasantly surprised when I found that Logitech’s QuickCam Vision Pro for Mac actually works well on OSX, and you can even have several of them running at the same time (see screenshot)! Now the only problem is the auto-focus and auto-contrast which tend to cause problems in video analysis (particularly when doing background subtraction).

Music Information Retrieval

We organised a small workshop on Music Information Retrieval some weeks ago, and for that I carried out a small check for the most important MIR-topics using Google Scholar. I did this by first searching for the phrase “Music Information Retrieval”, which turned up 4670 hits. Then I started adding various other phrases, and the result was as follows:

“Music Information Retrieval” + “…”

  • 3730 – audio
  • 1990 – MIDI
  • 544 – action
  • 485 – motion
  • 328 – gesture
  • 85 – movement action gesture
  • 45 – “motion capture”
  • 21 – “body movement”

Quite clearly, audio-based methods seems to dominate the MIR literature, while symbolic representations (e.g. MIDI) is also quite high on the list. Words like action, motion and gesture turn up some hits, but these words are quite general, and may refer to many different things. It is interesting to notice how few hits there are for “body movement” and “motion capture”. Quite clearly there is room for a lot more MIR research from an embodied perspective.

Downgrade solved the WordPress problem

I just downgraded from WordPress 2.7 to 2.6.5 after living with an extremely slow web page for some weeks. There are lots of discussions about why WordPress 2.7 is so slow, and it boils down to some compatibility problems with the server it is running on. I don’t have time to investigate this further, so I decided to roll back instead and wait for next version of WordPress instead.