DART: A Framework for Distributed Audio Analysis and Music Information Retrieval - Intelligent Music Information Systems: Tools and Methodologies - page 225

Figure 3. Audio is split and converted to a SampleSet data type, in order to subtract all music that is
panned down the middle of the stereo field. This conversion is then reversed and played back.

filters in order to create a Schreoder Reverberator
algorithm, which is then grouped, saved and reused
as if it were a single unit. This unit aggregation
gives the user more freedom to take advantage
of Triana's modularity.
One feature of interest resides in the Converters
folder; two units are available that allow the user
to convert from MultipleAudio to a SampleSet
Triana data type— and back again ( MAudioToSSet
and SSetToMAudio respectively). This opens up a
whole range of possibilities to the user, enabling
them to utilize many of the numerous math and
signal-processing units to process the audio, and
then convert data back to a MultipleAudio data
type for playback. One example of how this tech-
nique could be used is shown in Figure 3.
In Figure 3, a Stereo2Mono unit (also in the
converters folder) is used to split the stereo chan-
nels of an audio file or stream into two distinct
mono channels. Each side is then converted to a
SampleSet and fed into a Subtractor unit from
the Math folder. This subtracts the left from the

right stereo channel, which results in the removal
of sound that is contained in both that is, those
panned in the middle of the stereo field. This is a
simple way of removing vocals from many songs
and leaving the (majority) of the backing track (as
vocals in particular are normally panned down
the centre). This is just a simple example of how
a few of the converter units could help users cre-
ate their own algorithms. It must be remembered
that the user is encouraged to try create different
algorithms themselves, and experiment with dif-
ferent unit connection chains—and not only using
the presets given in Triana.
As mentioned previously, Triana also contains
hundreds of statistical, mathematical, and signal
processing units, which can be used in conjunction
to all of the MultipleAudio compatible units, open-
ing up an vast range of units to facilitate and aid
MIR and the creation of useful MIR algorithms.
Triana includes Fast Fourier Transform units, a
range of filters, graphs, and histogram viewers,
spectrum analyzers and more, meaning that algo-