What that mean in gluoncv, when training yolo v3?

well, the code in training file is:

train_dataset = gluoncv.data.LstDetection(lst_file_path)
train_loader = gluon.data.DataLoader(train_dataset.transform(YOLO3DefaultTrainTransform(width, height, net, mixup=args.mixup)), batch_size, True, batchify_fn=batchify_fn, last_batch='rollover', num_workers=num_workers)

when I print the data shape, I find in class LstDetection(Dataset), the label shape is (1,6) which means (xmin, ymin, xmax, ymax, ids, difficult), but in class YOLO3DefaultTrainTransform(object), the label shape become (2, 7).

I was confused.

Have solved, It’s mixup.