Why padding is applied before passing into STFT

[SI-Abid]

Why in this method,

demucs/demucs/htdemucs.py

Line 420 in e976d93

def _spec(self, x):

a specific amount of padding applied on the signal waveform? The padding used on both sides is not equal.

For the following params,
signal_length = 160000 n_fft = 4096 hop_len = 1024

the padding is (1536, 2304)

I found no proper documentation on this anywhere in the code or paper.