This Audio Unit for Mac OS X combines computer vision head tracking with a low pass filter. For this simple example, the x-position of the head controls the cutoff frequency and the y-position controls filter resonance. I presented this work at HAID ‘09 (Haptic and Audio Interaction Design) in Dresden, Germany.
If you’d like to try this for yourself, click on the link below to download an installer. It works only on Intel macs with a built-in iSight camera. You can activate the plug-in through AU Lab, GarageBand, or Logic:
Forgotten Favorites was created by a company that I started with my two roommates in the summer of 2009. We had lofty ambitions of piggy-backing off of the success of Voice Record and the AppStore in general. We knew three things: we all loved music, we all loved technology, and therefore we all loved music information retrieval. Because we were trying to avoid needing an Internet connection during runtime, we settled on a lightweight form of MIR that just looks at the meta-data of the songs on the device. The idea of Forgotten Favorites is simple – everyone ends up neglecting music they love because they get distracted by new songs/albums. By parsing the meta-data of someone’s library, we were able to present “Forgotten Favorite” songs and albums. Items could be “banned” if someone never wants to hear it again, and a slider in the settings view sets the weighting between how favorite or how forgotten you like your results. It is localized in English, Spanish, French, German, and Japanese.
To quote my roommate’s website, “immediate commercial success did not ensue.” After a month of abysmal sales, we made the app free so that we would at least have more people using it. Regardless, I am very proud of our final product. It was fantastic working on a team with very competent people and I think we made a great app for what we set out to do. Some people love it and some people just don’t get it. The best part about all of this: I started the application with zero knowledge about Core Animation and finished with as much knowledge as you’d find in most books about it.
Abstract—This paper explores subband coding and the appli- cation of filter banks. First, the fundamentals of multirate systems will be reviewed. Next, the classic quadrature mirror filter bank is presented along with a discussion on how to eliminate all forms of distortion. An example of subband coding will be presented that utilizes two-dimensional quadrature mirror filter banks for image compression.
Abstract—Gain structures in digital filters are a source of product quantization noise due to finite wordlength. With certain assumptions, this gain structure’s noise can be modeled as a white noise source. This paper seeks to explore the effects of product quantization in the HVXC Decoder for the MPEG-4 Audio3 standard. The filter of interest is a fourth order high pass component in the post-processing stage of the decoder. Also, a scaling strategy will be employed to mitigate the effect of the quantization noise to reduce, if not completely eliminate, the chance of register overflow.
This Audio Unit for Mac OS X combines computer vision head tracking with a low pass filter. For this simple example, the x-position of the head controls the cutoff frequency and the y-position controls filter resonance. I presented this work at HAID ‘09 (Haptic and Audio Interaction Design) in Dresden, Germany.
