An application that is widely used is in the last stage
of the calculation of the MEL frequency cepstral coefficients (MFCC).
After computation of the log of the MEL band energies,
which are represented by the input data vector ,
the DCT is applied, and normally only about half
of the DCT coeffients are retained. This operation
(truncated DCT) can be represented by a single matrix
multiplication
.
For MaxEnt PDF projection, we also require the
total energy
For more details, see Chapter 10

Baggenstoss
2017-05-19