if isinstance(self.pretrained, str): self.apply(_init_weights) logger = get_root_logger() logger.info(f'load model from: {self.pretrained}') checkpoint = torch.load(self.pretrained, map_location='cpu') state_dict = checkpoint['model'] state_dict['patch_embed.proj.weight'] = state_dict['patch_embed.proj.weight'].unsqueeze(2).repeat(1,1,self.patch_size[0],1,1) / self.patch_size[0] ## Duplicate weights for temporal attention and temporal norm # new_state_dict = state_dict.copy() # for key in state_dict: # if 'blocks' in key and 'attn' in key and 'relative' not in key and 'mask' not in key: # new_key = key.replace('attn','temporal_attn') # if not new_key in state_dict: # new_state_dict[new_key] = state_dict[key] # else: # new_state_dict[new_key] = state_dict[new_key] # if 'blocks' in key and 'norm1' in key and 'relative' not in key and 'mask' not in key: # new_key = key.replace('norm1','temporal_norm') # if not new_key in state_dict: # new_state_dict[new_key] = state_dict[key] # else: # new_state_dict[new_key] = state_dict[new_key] # state_dict = new_state_dict msg = self.load_state_dict(state_dict, strict=False) logger.info('Missing keys: {}'.format(msg.missing_keys)) logger.info('Unexpected keys: {}'.format(msg.unexpected_keys)) logger.info(f"=> loaded successfully '{self.pretrained}'") del checkpoint torch.cuda.empty_cache() elif self.pretrained is None: self.apply(_init_weights) else: raise TypeError('pretrained must be a str or None')

这段代码主要是加载预训练模型的过程。如果传入的预训练模型是一个字符串，那么就会根据该字符串的路径加载模型。加载过程中会将模型的权重进行初始化，并将预训练模型的权重加载到新的模型中。如果预训练模型是 None，则会进行默认初始化。如果传入的预训练模型不是 str 或 None，则会抛出一个 TypeError。