[PixArt] fix small nits in pixart sigma (#7767)

fix small nits in pixart sigma

src/diffusers/pipelines/pixart_alpha/pipeline_pixart_alpha.py

@@ -273,15 +273,6 @@ class PixArtAlphaPipeline(DiffusionPipeline):
         self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1)
         self.image_processor = PixArtImageProcessor(vae_scale_factor=self.vae_scale_factor)
 
-    # Adapted from https://github.com/PixArt-alpha/PixArt-alpha/blob/master/diffusion/model/utils.py
-    def mask_text_embeddings(self, emb, mask):
-        if emb.shape[0] == 1:
-            keep_index = mask.sum().item()
-            return emb[:, :, :keep_index, :], keep_index
-        else:
-            masked_feature = emb * mask[:, None, :, None]
-            return masked_feature, emb.shape[2]
-
     # Adapted from diffusers.pipelines.deepfloyd_if.pipeline_if.encode_prompt
     def encode_prompt(
         self,

src/diffusers/pipelines/pixart_alpha/pipeline_pixart_sigma.py

@@ -199,16 +199,7 @@ class PixArtSigmaPipeline(DiffusionPipeline):
         self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1)
         self.image_processor = PixArtImageProcessor(vae_scale_factor=self.vae_scale_factor)
 
-    # copied from diffusers.pipelines.pixart_alpha.pipeline_pixart_alpha.py
-    def mask_text_embeddings(self, emb, mask):
-        if emb.shape[0] == 1:
-            keep_index = mask.sum().item()
-            return emb[:, :, :keep_index, :], keep_index
-        else:
-            masked_feature = emb * mask[:, None, :, None]
-            return masked_feature, emb.shape[2]
-
-    # Adapted from diffusers.pipelines.deepfloyd_if.pipeline_if.encode_prompt
+    # Copied from diffusers.pipelines.pixart_alpha.pipeline_pixart_alpha.PixArtAlphaPipeline.encode_prompt
     def encode_prompt(
         self,
         prompt: Union[str, List[str]],
@@ -369,7 +360,7 @@ class PixArtSigmaPipeline(DiffusionPipeline):
             extra_step_kwargs["generator"] = generator
         return extra_step_kwargs
 
-    # copied from diffusers.pipelines.pixart_alpha.pipeline_pixart_alpha.py
+    # Copied from diffusers.pipelines.pixart_alpha.pipeline_pixart_alpha.PixArtAlphaPipeline.check_inputs
     def check_inputs(
         self,
         prompt,
@@ -462,7 +453,7 @@ class PixArtSigmaPipeline(DiffusionPipeline):
 
         return [process(t) for t in text]
 
-    # Copied from diffusers.pipelines.pixart_alpha.pipeline_pixart_alpha.PixArtAlphaPipeline._clean_caption
+    # Copied from diffusers.pipelines.deepfloyd_if.pipeline_if.IFPipeline._clean_caption
     def _clean_caption(self, caption):
         caption = str(caption)
         caption = ul.unquote_plus(caption)