fix vqgan-vae for latent diffusion

dalle2_pytorch/vqgan_vae.py

@@ -435,12 +435,12 @@ class VQGanVAE(nn.Module):
         return fmap
 
     def decode(self, fmap):
-        fmap = self.vq(fmap)
+        fmap, indices, commit_loss = self.vq(fmap)
 
         for dec in self.decoders:
             fmap = dec(fmap)
 
-        return fmap
+        return fmap, indices, commit_loss
 
     def forward(
         self,
@@ -453,9 +453,9 @@ class VQGanVAE(nn.Module):
         assert height == self.image_size and width == self.image_size, 'height and width of input image must be equal to {self.image_size}'
         assert channels == self.channels, 'number of channels on image or sketch is not equal to the channels set on this VQGanVAE'
 
-        fmap, indices, commit_loss = self.encode(img)
+        fmap = self.encode(img)
 
-        fmap = self.decode(fmap)
+        fmap, indices, commit_loss = self.decode(fmap)
 
         if not return_loss and not return_discr_loss:
             return fmap