o ݈ hK@s ddlZddlmZddZdS)N)V_NEGATIVE_NUMc Cs"|j\}}}|jd}||}||}||}||}ttj||df|d} tj|| fdd} ttj||f|d} tj| dddddfd|ddddfd| ddddf<dtj|||ftj|d } tj|ddd } || }d|ddddf<|dk}t d|D]}tj| dd|ddfd|d}||k}t tj d||d d| ddktj d||d d| ddk}t t| d|}||}tj| ddd }t|dddf<tj| ddd }t|ddddf<||ttj| d| d| dfdd}|| d}tj|dd\} }|| dd|ddf<qg}t |D]U}t||}t||}|dkrOd}ntt| ||d|f|d}|g}t |ddd D]}|t| |||f}|d|qm|d|}||q9|S) a) Do Viterbi decoding with an efficient algorithm (the only for-loop in the 'forward pass' is over the time dimension). Args: log_probs_batch: tensor of shape (B, T_max, V). The parts of log_probs_batch which are 'padding' are filled with 'V_NEGATIVE_NUM' - a large negative number which represents a very low probability. y_batch: tensor of shape (B, U_max) - contains token IDs including blanks in every other position. The parts of y_batch which are padding are filled with the number 'V'. V = the number of tokens in the vocabulary + 1 for the blank token. T_batch: tensor of shape (B, 1) - contains the durations of the log_probs_batch (so we can ignore the parts of log_probs_batch which are padding) U_batch: tensor of shape (B, 1) - contains the lengths of y_batch (so we can ignore the parts of y_batch which are padding). viterbi_device: the torch device on which Viterbi decoding will be done. Returns: alignments_batch: list of lists containing locations for the tokens we align to at each timestep. Looks like: [[0, 0, 1, 2, 2, 3, 3, ..., ], ..., [0, 1, 2, 2, 2, 3, 4, ....]]. Each list inside alignments_batch is of length T_batch[location of utt in batch]. )device)dimNr)inputrindexi)dtyper)shiftsdims)shapetortorchonescatgatherint8rollrange logical_orarange unsqueeze logical_not logical_andlong masked_fill_maxintargmaxinsertappend)log_probs_batchy_batchT_batchU_batchviterbi_deviceBT_max_U_maxpadding_for_log_probslog_probs_paddedv_prevbackpointers_rely_shifted_leftletter_repetition_maskt e_currentt_exceeded_T_batchU_can_be_finalmaskv_prev_shiftedv_prev_shifted2 v_prev_dupcandidates_v_current bp_relativealignments_batchbT_bU_b current_u alignment_brA_/var/www/eduai.edurigo.com/doc_train/edurigo_ai/Puru/tts/BhasaAnuvaad/utils/viterbi_decoding.pyviterbi_decodings       ( "        & rC)rutils.constantsrrCrArArArBs