Some questions about data loading

[ZHE-SAPI]

Hi,
This is a very enlightening work!!! @xing0047 @Dayan-Guan
I want to ask a question~

When I use./TPS/tps/scripts/train.py to read SynthiaSeq or ViperSeq data, I debug the code and find the following phenomena:

I tried to print some variables of __ getitem__ () ,

When the shuffle of source_loader = data.DataLoader() is set to False, and the batch_size=cfg.TRAIN.BATCH_SIZE_SOURCE is set to 1,

1. It is found that although the batch_ Size=1, but 4 pictures and the first frame corresponding to them are loaded at one time,
   Instead of 1 picture and the previous frame.

2. At the same time, it is found that 4 loaded pictures are disordered, such as 2-1-3-4, rather than 1-2-3-4, it seems to violate the settings of shuffle.

Could you please kindly explain my doubt? Thank you very much!!

The print code are as follows:

The print results are as follows，which the order of each run of print is different:

---index--- 1
---index--- 0
---index--- 2
img_file tps/data/SynthiaSeq/SEQS-04-DAWN/rgb/000002.png
label_file tps/data/SynthiaSeq/SEQS-04-DAWN/label/000002.png
---index--- 3
img_file tps/data/SynthiaSeq/SEQS-04-DAWN/rgb/000001.png
label_file tps/data/SynthiaSeq/SEQS-04-DAWN/label/000001.png
img_file tps/data/SynthiaSeq/SEQS-04-DAWN/rgb/000003.png
label_file tps/data/SynthiaSeq/SEQS-04-DAWN/label/000003.png
img_file tps/data/SynthiaSeq/SEQS-04-DAWN/rgb/000004.png
label_file tps/data/SynthiaSeq/SEQS-04-DAWN/label/000004.png
image_kf tps/data/SynthiaSeq/SEQS-04-DAWN/rgb/000003.png
image_kf tps/data/SynthiaSeq/SEQS-04-DAWN/rgb/000002.png
image_kf tps/data/SynthiaSeq/SEQS-04-DAWN/rgb/000001.png
image_kf tps/data/SynthiaSeq/SEQS-04-DAWN/rgb/000000.png
label_kf tps/data/SynthiaSeq/SEQS-04-DAWN/label/000003.png
label_kf tps/data/SynthiaSeq/SEQS-04-DAWN/label/000002.png
label_kf tps/data/SynthiaSeq/SEQS-04-DAWN/label/000001.png
label_kf tps/data/SynthiaSeq/SEQS-04-DAWN/label/000000.png