Update UniPC to support 1D diffusion. (#5199)

* Update Unipc einsum to support 1D and 3D diffusion.

* Add unittest

* Update unittest & edge case

* Fix unittest

* Fix testing_utils.py

* Fix unittest file

---------
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

src/diffusers/schedulers/scheduling_unipc_multistep.py

@@ -282,13 +282,13 @@ class UniPCMultistepScheduler(SchedulerMixin, ConfigMixin):
         https://arxiv.org/abs/2205.11487
         """
         dtype = sample.dtype
-        batch_size, channels, height, width = sample.shape
+        batch_size, channels, *remaining_dims = sample.shape
 
         if dtype not in (torch.float32, torch.float64):
             sample = sample.float()  # upcast for quantile calculation, and clamp not implemented for cpu half
 
         # Flatten sample for doing quantile calculation along each image
-        sample = sample.reshape(batch_size, channels * height * width)
+        sample = sample.reshape(batch_size, channels * np.prod(remaining_dims))
 
         abs_sample = sample.abs()  # "a certain percentile absolute pixel value"
 
@@ -300,7 +300,7 @@ class UniPCMultistepScheduler(SchedulerMixin, ConfigMixin):
         s = s.unsqueeze(1)  # (batch_size, 1) because clamp will broadcast along dim=0
         sample = torch.clamp(sample, -s, s) / s  # "we threshold xt0 to the range [-s, s] and then divide by s"
 
-        sample = sample.reshape(batch_size, channels, height, width)
+        sample = sample.reshape(batch_size, channels, *remaining_dims)
         sample = sample.to(dtype)
 
         return sample
@@ -534,14 +534,14 @@ class UniPCMultistepScheduler(SchedulerMixin, ConfigMixin):
         if self.predict_x0:
             x_t_ = sigma_t / sigma_s0 * x - alpha_t * h_phi_1 * m0
             if D1s is not None:
-                pred_res = torch.einsum("k,bkchw->bchw", rhos_p, D1s)
+                pred_res = torch.einsum("k,bkc...->bc...", rhos_p, D1s)
             else:
                 pred_res = 0
             x_t = x_t_ - alpha_t * B_h * pred_res
         else:
             x_t_ = alpha_t / alpha_s0 * x - sigma_t * h_phi_1 * m0
             if D1s is not None:
-                pred_res = torch.einsum("k,bkchw->bchw", rhos_p, D1s)
+                pred_res = torch.einsum("k,bkc...->bc...", rhos_p, D1s)
             else:
                 pred_res = 0
             x_t = x_t_ - sigma_t * B_h * pred_res
@@ -670,7 +670,7 @@ class UniPCMultistepScheduler(SchedulerMixin, ConfigMixin):
         if self.predict_x0:
             x_t_ = sigma_t / sigma_s0 * x - alpha_t * h_phi_1 * m0
             if D1s is not None:
-                corr_res = torch.einsum("k,bkchw->bchw", rhos_c[:-1], D1s)
+                corr_res = torch.einsum("k,bkc...->bc...", rhos_c[:-1], D1s)
             else:
                 corr_res = 0
             D1_t = model_t - m0
@@ -678,7 +678,7 @@ class UniPCMultistepScheduler(SchedulerMixin, ConfigMixin):
         else:
             x_t_ = alpha_t / alpha_s0 * x - sigma_t * h_phi_1 * m0
             if D1s is not None:
-                corr_res = torch.einsum("k,bkchw->bchw", rhos_c[:-1], D1s)
+                corr_res = torch.einsum("k,bkc...->bc...", rhos_c[:-1], D1s)
             else:
                 corr_res = 0
             D1_t = model_t - m0

tests/schedulers/test_scheduler_unipc.py

@@ -269,3 +269,113 @@ class UniPCMultistepSchedulerTest(SchedulerCommonTest):
 
         assert abs(result_sum.item() - 315.5757) < 1e-2, f" expected result sum 315.5757, but get {result_sum}"
         assert abs(result_mean.item() - 0.4109) < 1e-3, f" expected result mean 0.4109, but get {result_mean}"
+
+
+class UniPCMultistepScheduler1DTest(UniPCMultistepSchedulerTest):
+    @property
+    def dummy_sample(self):
+        batch_size = 4
+        num_channels = 3
+        width = 8
+
+        sample = torch.rand((batch_size, num_channels, width))
+
+        return sample
+
+    @property
+    def dummy_noise_deter(self):
+        batch_size = 4
+        num_channels = 3
+        width = 8
+
+        num_elems = batch_size * num_channels * width
+        sample = torch.arange(num_elems).flip(-1)
+        sample = sample.reshape(num_channels, width, batch_size)
+        sample = sample / num_elems
+        sample = sample.permute(2, 0, 1)
+
+        return sample
+
+    @property
+    def dummy_sample_deter(self):
+        batch_size = 4
+        num_channels = 3
+        width = 8
+
+        num_elems = batch_size * num_channels * width
+        sample = torch.arange(num_elems)
+        sample = sample.reshape(num_channels, width, batch_size)
+        sample = sample / num_elems
+        sample = sample.permute(2, 0, 1)
+
+        return sample
+
+    def test_switch(self):
+        # make sure that iterating over schedulers with same config names gives same results
+        # for defaults
+        scheduler = UniPCMultistepScheduler(**self.get_scheduler_config())
+        sample = self.full_loop(scheduler=scheduler)
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_mean.item() - 0.2441) < 1e-3
+
+        scheduler = DPMSolverSinglestepScheduler.from_config(scheduler.config)
+        scheduler = DEISMultistepScheduler.from_config(scheduler.config)
+        scheduler = DPMSolverMultistepScheduler.from_config(scheduler.config)
+        scheduler = UniPCMultistepScheduler.from_config(scheduler.config)
+
+        sample = self.full_loop(scheduler=scheduler)
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_mean.item() - 0.2441) < 1e-3
+
+    def test_full_loop_no_noise(self):
+        sample = self.full_loop()
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_mean.item() - 0.2441) < 1e-3
+
+    def test_full_loop_with_karras(self):
+        sample = self.full_loop(use_karras_sigmas=True)
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_mean.item() - 0.2898) < 1e-3
+
+    def test_full_loop_with_v_prediction(self):
+        sample = self.full_loop(prediction_type="v_prediction")
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_mean.item() - 0.1014) < 1e-3
+
+    def test_full_loop_with_karras_and_v_prediction(self):
+        sample = self.full_loop(prediction_type="v_prediction", use_karras_sigmas=True)
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_mean.item() - 0.1944) < 1e-3
+
+    def test_full_loop_with_noise(self):
+        scheduler_class = self.scheduler_classes[0]
+        scheduler_config = self.get_scheduler_config()
+        scheduler = scheduler_class(**scheduler_config)
+
+        num_inference_steps = 10
+        t_start = 8
+
+        model = self.dummy_model()
+        sample = self.dummy_sample_deter
+        scheduler.set_timesteps(num_inference_steps)
+
+        # add noise
+        noise = self.dummy_noise_deter
+        timesteps = scheduler.timesteps[t_start * scheduler.order :]
+        sample = scheduler.add_noise(sample, noise, timesteps[:1])
+
+        for i, t in enumerate(timesteps):
+            residual = model(sample, t)
+            sample = scheduler.step(residual, t, sample).prev_sample
+
+        result_sum = torch.sum(torch.abs(sample))
+        result_mean = torch.mean(torch.abs(sample))
+
+        assert abs(result_sum.item() - 39.0870) < 1e-2, f" expected result sum 39.0870, but get {result_sum}"
+        assert abs(result_mean.item() - 0.4072) < 1e-3, f" expected result mean 0.4072, but get {result_mean}"