    def criterion_cfg(self):
        """cfg for the multitask criterion"""
        if self.decoder_type == "ctc":
            from fairseq.criterions.ctc import CtcCriterionConfig

            cfg = CtcCriterionConfig
            cfg.zero_infinity = self.config.get("zero_infinity", True)
        else:
            from fairseq.criterions.label_smoothed_cross_entropy import (
                LabelSmoothedCrossEntropyCriterionConfig,
            )

            cfg = LabelSmoothedCrossEntropyCriterionConfig
            cfg.label_smoothing = self.config.get("label_smoothing", 0.2)
        return cfg
cfg for the multitask criterion
fairseq/data/audio/data_cfg.py