Diffusers, txt2img (and img2img when supported), make sure guidance scale defaults to 0 when num steps <=4

Signed-off-by: Raphael Glon <[email protected]>

Author: oOraph

src/huggingface_inference_toolkit/diffusers_utils.py

@@ -65,7 +65,14 @@ def __call__(
             logger.warning("Sending num_images_per_prompt > 1 to pipeline is not supported. Using default value 1.")
 
         if "num_inference_steps" not in kwargs:
-            kwargs["num_inference_steps"] = int(os.environ.get("DEFAULT_NUM_INFERENCE_STEPS", 50))
+            default_num_steps = os.environ.get("DEFAULT_NUM_INFERENCE_STEPS")
+            if default_num_steps:
+                kwargs["num_inference_steps"] = int(default_num_steps)
+
+        if "guidance_scale" not in kwargs:
+            guidance_scale = os.environ.get("DEFAULT_GUIDANCE_SCALE")
+            if guidance_scale is not None:
+                kwargs["guidance_scale"] = float(guidance_scale)
 
         if "target_size" in kwargs:
             kwargs["height"] = kwargs["target_size"].pop("height", None)