Viterbi Training

When training the phone-loop model with the Variational algorithm, the statistics for updating the model parameters are computed on all possible paths. However, in certain situation we cannot afford to compute the probability of all possible sequence of units. A possible approximation is to re-estimate the model parameters on the supposed best sequence of units per utterance. This can be done by first generating the best path sequence for a set of utterances. Each sequence should be store in HTK label file format. The algorithm will not make use of the timing information this is not necessary to provide this information. Then the model can be retrained by running:

utils/phone_loop_train_1best.sh setup.sh parallel_opts keys_file model_in_dir labels_dir output_dir

For each entry key of the keys_file we expect the corresponding file to exists labels_dir/key.lab. Other arguments are defined as usual.