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Chapter 3: Segmenting audio streams
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init 1380 4 5140.31407 1301.37098 3188.25760
merge C[1] C[2] 216.64228 4923.67179 976.02824 3459.62944 -271.37184
merge C[0] C[3] 314.79587 4608.87592 650.68549 3632.84769 -173.21825
merge C[0] C[1] 666.35578 3942.52014 325.34275 3454.50602 178.34166
The first lines are segment definitions where segments considered for clustering are used to
initialize a cluster. For instance, the first line define a segment in file ‘bic.1’ from instant
0.000 to 2.400 with label male, from which cluster C[0] is initialized with 240 frames and
a generalized log-likelihood of 2.9956. The second line shows a segment not considered
for clustering (because of the female label). The init line provide information regarding the initial partition where each segment is in a separate cluster: the total number of
frames (1380), the total number of clusters (4) followed by the generalized log-likelihood
(5140.31407), the BIC penalty term (1301.37098) and the BIC value obtained by combining the two previous terms (3188.25760 = (5140.31407) - 1.5 (1301.37098) in this
example). Each merge line following the init line describes the merge operated at each
step of the clustering algorithm. In the line
merge C[1] C[2] 216.64228 4923.67179 976.02824 3459.62944 -271.37184
clusters C[1] and C[2], at a distance of 216.64228, are merged, the resulting cluster being
identified as C[1]. After merging, the generalized log-likelihood is 4923.67179, the BIC
penalty 976.0282 and the BIC criterion 3459.62944. The last value reports the BIC
variation with previous step.
The log option is particularly usefull with option ‘--disable-bic’ which turns off the
BIC stopping criterion. Hence, the command
scluster --disable-bic --log=LOG foo.spf foo.seg /dev/null
will perform clustering until all segments are grouped, writing each step of the process to
LOG. Finding out what is the best way to stop the clustering algorithm can then be studied
directly from the log file thus saving a lot of useless computation.