The performance of GOP-DNN should be much better than GOP-GMM.
How to build
./build.sh
Run the example
cd egs/gop-compute
./run.sh
Theory
In the conventional GMM-HMM based system, GOP was first proposed in (Witt et al., 2000). It was defined as the duration normalised log of the posterior:
$$ GOP(p)=frac{1}{t_e-t_s+1} log p(p|mathbf o) $$
where $mathbf o$ is the input observations, $p$ is the canonical phone, $t_s, t_e$ are the start and end frame indexes.
Assuming $p(q_i)approx p(q_j)$ for any $q_i, q_j$, we have:
The numerator of the equation is calculated from forced alignment result and the denominator is calculated from a Viterbi decoding with an unconstrained phone loop.