Friday, 24 April 2009

back to playlisting

After a brief tangent into the wide world of mixing (of which I'll post some more in a bit from my proposed SMC paper in a bit) I'm back into playlist generation and related topics.  Along those lines it occurs to me that readers of my little blog may be interested in perusing my recently completed (Dec 2008 actually) M.Phil to PhD upgrade document.  For those of you unfamiliar with the British PhD system, PhD students start as a Master's of Philosophy by research student, then after about 24 months of independent research go through a process of summarizing and defending their work so far and what they intend to accomplish in the coming 18 - 24 months.  The outcome of this process is one of three things:
  1. Your work is deemed interesting, rigorous and sufficiently likely to succeed in the next couple of years.  As a result, you upgrade to a PhD student and continue on with your research (this is what happened in my case)
  2. You graduate at that point with a M.Phil.
  3. You completely fail your upgrade process.
So that happened back in mid december.  Here's the abstract from my upgrade:
A framework is described to consider various real world playlist use cases.  Automatic playlist generation is introduced as a means to improve music recommendation.  Literature in related topics is discussed.

A sample of the Myspace artist network is examined to investigate the relationship between social connectivity and audio-based similarity.  Audio data from the Myspace artist pages is analyzed using well-established signal-based music information retrieval techniques.  In addition to showing that the Myspace artist network exhibits many of the properties common to social networks, it is seen that there is an ambiguous relationship between audio-based similarity and the social connectivity. Further the Myspace sample is examined with the pairwise relational connectivity measure Minimum cut/Maximum flow.  These values are then compared to a pairwise acoustic Earth Mover's Distance measure and the relationship is discussed.  A means of constructing playlists using the maximum flow value to exploit both the social and acoustic distances is realized.

Two playlist generation methods are proposed for development and experimentation.  The first is a direct extension of the myspace dataset analysis into a robust playlist system for interactive internet radio broadcast.  The second is content based system which uses expert constructed playlists to construct transition models which can then be used on new material.  This is followed by a discussion of evaluation needs and strategies. 
 If you're interested in reading the whole thing (comments welcome and encouraged) download the pdf.

On an unrelated note, I'll be a Yahoo Open Hackday 09 in Covent Garden in a couple weekends.  It's free and I believe there are still some tickets if anyone is interested.  It should be rad.

Thursday, 16 April 2009

Conference alterations...

So this paper I'm trying to put together on mixing algorithms just didn't quite come together in time for DAFx. Or more exactly, the actual research wasn't quite done till like yesterday. But it's not all bad. I'm submitting to Sound and Music Computing 2009 instead, which looks like it'll be an interesting conference. This also gives me a couple more much need days to hash out a few more thoughts on things.
Here's a teaser from the paper:

For the purpose of this discussion we will be dealing with various types of song transitions in order of temporal complexity, from the simplest to describe in time to the most complex.

    Song to song transition types

  • Arbitrary Length Fixed Time Crossfade

  • Phrase-Aligned Start No Tempo Adjust

  • Phrase-Aligned Start, Running Beat Alignment

  • Phrase-Aligned Start, Phrase-Aligned Finish

Once I've got this draft done I'll post some more bits. In the meantime, anyone have any further ideas on core subdivisions of song to song transitions, from the perspective of time alignment?