change in left right padding in feature_extractor.py

Author: prishajain1

src/maxdiffusion/models/ltx2/text_encoders/feature_extractor_ltx2.py

@@ -42,10 +42,15 @@ def _norm_and_concat_padded_batch(
   """
   b, t, d, l = encoded_text.shape
 
-  # [B, T, 1, 1]
-  mask = attention_mask[:, :, None, None]
-  
+  # Calculate left-aligned padding mask identical to Diffusers `_pack_text_embeds`
+  # Diffusers padding side is "left" for Gemma text encoders.
   sequence_lengths = jnp.sum(attention_mask, axis=-1)
+  token_indices = jnp.arange(t)[None, :]
+  start_indices = t - sequence_lengths[:, None]
+  mask = token_indices >= start_indices
+  
+  # Broadcast to [B, T, 1, 1]
+  mask = mask[:, :, None, None]
 
   eps = 1e-6