According to CTC loss documentation, the target sequence length must be <= to input sequence length. This allows the case where target sequence length == input length.

But what if your target is constant? Then CTC needs to predict interleaved blanks. In the pessimistic case where target is constant and let’s say equal to N, then model needs to predict N blanks. So really, target sequence length must be <= half input sequence length right?

Also, is there a better alternative to unaligned, unsegmented sequence prediction?