I think , as err says,
model wants input of size
128, 3, 64, 64 # ( batch, channel, h, w )

but you are passing
64 1 4 4 # ( batch, channel, h, w ) 


please print those discriminator values and debug it , where is error coming from .
Also please use proper code formatting while posting.
Welcome Here .
If not solved, moderators will it , please calm.