tensorplay.nn.functional.ctc_loss

tensorplay.nn.functional.ctc_loss(log_probs: Tensor, targets: Tensor, input_lengths, target_lengths, blank: int = 0, reduction: str = 'mean', zero_infinity: bool = False) → Tensor[source]

Compute the Connectionist Temporal Classification loss.

(alpha recurrence over the blank-extended target sequence); autograd flows through log_probs via the composed primitives.

Parameters:

• log_probs – $(T, N, C)$ or $(T, C)$ log-softmax outputs.

• targets – $(N, S)$ or concatenated $(\sum S_n,)$.

• target_lengths (input_lengths /) – $(N,)$ or scalars.

• blank – index of the blank label. Default: 0.

• reduction – 'none' | 'mean' | 'sum'.

• zero_infinity – zero out infinite losses (targets too long for T).