[fix] FreeInit step index out of bounds (#8969)

* fix step index out of bounds

* add test for free_init with different schedulers

* add test to vid2vid and pia

src/diffusers/pipelines/free_init_utils.py

@@ -180,6 +180,8 @@ def _apply_free_init(
             num_inference_steps = max(
                 1, int(num_inference_steps / self._free_init_num_iters * (free_init_iteration + 1))
             )
+
+        if num_inference_steps > 0:
             self.scheduler.set_timesteps(num_inference_steps, device=device)
 
         return latents, self.scheduler.timesteps

tests/pipelines/animatediff/test_animatediff.py

@@ -10,6 +10,8 @@
     AnimateDiffPipeline,
     AutoencoderKL,
     DDIMScheduler,
+    DPMSolverMultistepScheduler,
+    LCMScheduler,
     MotionAdapter,
     StableDiffusionPipeline,
     UNet2DConditionModel,
@@ -353,6 +355,52 @@ def test_free_init(self):
             "Disabling of FreeInit should lead to results similar to the default pipeline results",
         )
 
+    def test_free_init_with_schedulers(self):
+        components = self.get_dummy_components()
+        pipe: AnimateDiffPipeline = self.pipeline_class(**components)
+        pipe.set_progress_bar_config(disable=None)
+        pipe.to(torch_device)
+
+        inputs_normal = self.get_dummy_inputs(torch_device)
+        frames_normal = pipe(**inputs_normal).frames[0]
+
+        schedulers_to_test = [
+            DPMSolverMultistepScheduler.from_config(
+                components["scheduler"].config,
+                timestep_spacing="linspace",
+                beta_schedule="linear",
+                algorithm_type="dpmsolver++",
+                steps_offset=1,
+                clip_sample=False,
+            ),
+            LCMScheduler.from_config(
+                components["scheduler"].config,
+                timestep_spacing="linspace",
+                beta_schedule="linear",
+                steps_offset=1,
+                clip_sample=False,
+            ),
+        ]
+        components.pop("scheduler")
+
+        for scheduler in schedulers_to_test:
+            components["scheduler"] = scheduler
+            pipe: AnimateDiffPipeline = self.pipeline_class(**components)
+            pipe.set_progress_bar_config(disable=None)
+            pipe.to(torch_device)
+
+            pipe.enable_free_init(num_iters=2, use_fast_sampling=False)
+
+            inputs = self.get_dummy_inputs(torch_device)
+            frames_enable_free_init = pipe(**inputs).frames[0]
+            sum_enabled = np.abs(to_np(frames_normal) - to_np(frames_enable_free_init)).sum()
+
+            self.assertGreater(
+                sum_enabled,
+                1e1,
+                "Enabling of FreeInit should lead to results different from the default pipeline results",
+            )
+
     @unittest.skipIf(
         torch_device != "cuda" or not is_xformers_available(),
         reason="XFormers attention is only available with CUDA and `xformers` installed",

tests/pipelines/animatediff/test_animatediff_video2video.py

@@ -10,6 +10,8 @@
     AnimateDiffVideoToVideoPipeline,
     AutoencoderKL,
     DDIMScheduler,
+    DPMSolverMultistepScheduler,
+    LCMScheduler,
     MotionAdapter,
     StableDiffusionPipeline,
     UNet2DConditionModel,
@@ -380,3 +382,49 @@ def test_free_init(self):
             1e-4,
             "Disabling of FreeInit should lead to results similar to the default pipeline results",
         )
+
+    def test_free_init_with_schedulers(self):
+        components = self.get_dummy_components()
+        pipe: AnimateDiffVideoToVideoPipeline = self.pipeline_class(**components)
+        pipe.set_progress_bar_config(disable=None)
+        pipe.to(torch_device)
+
+        inputs_normal = self.get_dummy_inputs(torch_device)
+        frames_normal = pipe(**inputs_normal).frames[0]
+
+        schedulers_to_test = [
+            DPMSolverMultistepScheduler.from_config(
+                components["scheduler"].config,
+                timestep_spacing="linspace",
+                beta_schedule="linear",
+                algorithm_type="dpmsolver++",
+                steps_offset=1,
+                clip_sample=False,
+            ),
+            LCMScheduler.from_config(
+                components["scheduler"].config,
+                timestep_spacing="linspace",
+                beta_schedule="linear",
+                steps_offset=1,
+                clip_sample=False,
+            ),
+        ]
+        components.pop("scheduler")
+
+        for scheduler in schedulers_to_test:
+            components["scheduler"] = scheduler
+            pipe: AnimateDiffVideoToVideoPipeline = self.pipeline_class(**components)
+            pipe.set_progress_bar_config(disable=None)
+            pipe.to(torch_device)
+
+            pipe.enable_free_init(num_iters=2, use_fast_sampling=False)
+
+            inputs = self.get_dummy_inputs(torch_device)
+            frames_enable_free_init = pipe(**inputs).frames[0]
+            sum_enabled = np.abs(to_np(frames_normal) - to_np(frames_enable_free_init)).sum()
+
+            self.assertGreater(
+                sum_enabled,
+                1e1,
+                "Enabling of FreeInit should lead to results different from the default pipeline results",
+            )

tests/pipelines/pia/test_pia.py

@@ -9,6 +9,8 @@
 from diffusers import (
     AutoencoderKL,
     DDIMScheduler,
+    DPMSolverMultistepScheduler,
+    LCMScheduler,
     MotionAdapter,
     PIAPipeline,
     StableDiffusionPipeline,
@@ -360,6 +362,52 @@ def test_free_init(self):
             "Disabling of FreeInit should lead to results similar to the default pipeline results",
         )
 
+    def test_free_init_with_schedulers(self):
+        components = self.get_dummy_components()
+        pipe: PIAPipeline = self.pipeline_class(**components)
+        pipe.set_progress_bar_config(disable=None)
+        pipe.to(torch_device)
+
+        inputs_normal = self.get_dummy_inputs(torch_device)
+        frames_normal = pipe(**inputs_normal).frames[0]
+
+        schedulers_to_test = [
+            DPMSolverMultistepScheduler.from_config(
+                components["scheduler"].config,
+                timestep_spacing="linspace",
+                beta_schedule="linear",
+                algorithm_type="dpmsolver++",
+                steps_offset=1,
+                clip_sample=False,
+            ),
+            LCMScheduler.from_config(
+                components["scheduler"].config,
+                timestep_spacing="linspace",
+                beta_schedule="linear",
+                steps_offset=1,
+                clip_sample=False,
+            ),
+        ]
+        components.pop("scheduler")
+
+        for scheduler in schedulers_to_test:
+            components["scheduler"] = scheduler
+            pipe: PIAPipeline = self.pipeline_class(**components)
+            pipe.set_progress_bar_config(disable=None)
+            pipe.to(torch_device)
+
+            pipe.enable_free_init(num_iters=2, use_fast_sampling=False)
+
+            inputs = self.get_dummy_inputs(torch_device)
+            frames_enable_free_init = pipe(**inputs).frames[0]
+            sum_enabled = np.abs(to_np(frames_normal) - to_np(frames_enable_free_init)).sum()
+
+            self.assertGreater(
+                sum_enabled,
+                1e1,
+                "Enabling of FreeInit should lead to results different from the default pipeline results",
+            )
+
     @unittest.skipIf(
         torch_device != "cuda" or not is_xformers_available(),
         reason="XFormers attention is only available with CUDA and `xformers` installed",