in utils.py [0:0]
def unpackbits(sample_bytes, seqlen):
x = np.zeros((len(sample_bytes), seqlen), dtype=np.int64)
for i in range(len(sample_bytes)):
b = np.frombuffer(sample_bytes[i], dtype=np.uint8)
x[i,:len(b)] = b
# 0 is reserved for padding -- return bytes in the range of 1-257
return x + 1