fix transformerLM inference recipe

lzr265946

2023-09-07 9b4e0969f29dccdfa78a55219f8107e549c96e45

 funasr/models/frontend/abs_frontend.py

New file
@@ -0,0 +1,17 @@
from abc import ABC
from abc import abstractmethod
from typing import Tuple

import torch


class AbsFrontend(torch.nn.Module, ABC):
    @abstractmethod
    def output_size(self) -> int:
        raise NotImplementedError

    @abstractmethod
    def forward(
        self, input: torch.Tensor, input_lengths: torch.Tensor
    ) -> Tuple[torch.Tensor, torch.Tensor]:
        raise NotImplementedError