Add unit test for LTX-2 upsampler pipeline

Author: mbohlool

src/maxdiffusion/tests/ltx2/test_latent_upsampler_ltx2.py

@@ -0,0 +1,171 @@
+"""
+Copyright 2026 Google LLC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+"""
+
+import unittest
+from unittest.mock import MagicMock, patch
+import jax
+import jax.numpy as jnp
+import numpy as np
+
+from maxdiffusion.models.ltx2.ltx2_utils import adain_filter_latent, tone_map_latents
+from maxdiffusion.models.ltx2.latent_upsampler_ltx2 import LTX2LatentUpsamplerModel
+from maxdiffusion.pipelines.ltx2.pipeline_ltx2_latent_upsample import FlaxLTX2LatentUpsamplePipeline
+
+
+class LTX2LatentUpsamplerTest(unittest.TestCase):
+  """Tests for LTX2 Latent Upsampler components and pipeline."""
+
+  def test_adain_filter_latent(self):
+    """Test ADAIN filtering matches global statistics."""
+    # Create latents and reference latents with different statistics
+    key = jax.random.PRNGKey(0)
+    key1, key2 = jax.random.split(key)
+    
+    # Target (High-res) latents: mean ~ 0, std ~ 1
+    latents = jax.random.normal(key1, (1, 4, 16, 16, 8)) 
+    
+    # Reference (Low-res) latents: mean ~ 5, std ~ 2
+    reference_latents = jax.random.normal(key2, (1, 4, 16, 16, 8)) * 2.0 + 5.0
+
+    # Apply AdaIN with factor=1.0 (full replacement of style)
+    filtered = adain_filter_latent(latents, reference_latents, factor=1.0)
+    
+    # Validate shapes
+    self.assertEqual(filtered.shape, latents.shape)
+    
+    # Validate statistics: output should now roughly match reference stats
+    axes = (1, 2, 3)
+    ref_mean = jnp.mean(reference_latents, axis=axes, keepdims=True)
+    ref_std = jnp.std(reference_latents, axis=axes, keepdims=True)
+    
+    out_mean = jnp.mean(filtered, axis=axes, keepdims=True)
+    out_std = jnp.std(filtered, axis=axes, keepdims=True)
+    
+    np.testing.assert_allclose(out_mean, ref_mean, rtol=1e-4, atol=1e-4)
+    np.testing.assert_allclose(out_std, ref_std, rtol=1e-4, atol=1e-4)
+
+    # Test factor = 0.0 (no change)
+    unfiltered = adain_filter_latent(latents, reference_latents, factor=0.0)
+    np.testing.assert_allclose(unfiltered, latents, rtol=1e-5)
+
+  def test_tone_map_latents(self):
+    """Test tone mapping compression scale logic."""
+    latents = jnp.ones((1, 4, 16, 16, 8)) * 2.0
+    
+    # Compress with 0 ratio should do nothing when properly scaled, 
+    # but based on the code: scale_factor = compression * 0.75
+    # If compression = 0.0, scale_factor = 0, scales = 1.0
+    mapped_0 = tone_map_latents(latents, compression=0.0)
+    np.testing.assert_allclose(mapped_0, latents, rtol=1e-5)
+
+    # Compress with > 0 ratio should reduce the magnitude
+    mapped_compressed = tone_map_latents(latents, compression=1.0)
+    self.assertTrue(jnp.all(jnp.abs(mapped_compressed) < jnp.abs(latents)))
+    self.assertEqual(mapped_compressed.shape, latents.shape)
+
+  def test_upsampler_model_forward(self):
+    """Test the neural network component of the upsampler for shape validity."""
+    b, f, h, w, c = 2, 3, 16, 16, 8
+    key = jax.random.PRNGKey(0)
+    
+    # Instantiate the module with small channels/blocks to keep test fast.
+    # mid_channels MUST be a multiple of 32 because GroupNorm uses num_groups=32 natively.
+    model = LTX2LatentUpsamplerModel(
+        in_channels=c,
+        mid_channels=32,  # Fixed: Changed from 16 to 32 to satisfy GroupNorm requirements
+        num_blocks_per_stage=1,
+        dims=3,
+        spatial_upsample=True,
+        temporal_upsample=False,
+        rational_spatial_scale=2.0 # Maps to 2x upscaling
+    )
+    
+    dummy_input = jax.random.normal(key, (b, f, h, w, c))
+    
+    # Initialize variables
+    variables = model.init(key, dummy_input)
+    
+    # Forward pass
+    output = model.apply(variables, dummy_input)
+    
+    # Assert temporal unchanged, spatial doubled, channels restored to `in_channels`
+    self.assertEqual(output.shape, (b, f, h * 2, w * 2, c))
+
+  def test_pipeline_latent_upsample_logic(self):
+    """Test FlaxLTX2LatentUpsamplePipeline call pipeline properties."""
+    mock_vae = MagicMock()
+    # Need to simulate the config behavior where parameters might be attached to VAE directly
+    mock_vae.config = {"spatial_compression_ratio": 32, "temporal_compression_ratio": 8}
+    mock_vae.latents_mean = [0.0] * 8
+    mock_vae.latents_std = [1.0] * 8
+    mock_vae.dtype = jnp.float32
+
+    # Dummy decode output logic (tuple with a video array)
+    dummy_video = jnp.zeros((1, 1, 32, 32, 3))
+    mock_vae.decode.return_value = (dummy_video,)
+
+    mock_upsampler = MagicMock()
+    # Upsampler .apply() should just return identically shaped / scaled latents for testing logic
+    mock_upsampler.apply = MagicMock(return_value=jnp.ones((1, 4, 16, 16, 8)))
+
+    pipeline = FlaxLTX2LatentUpsamplePipeline(
+        vae=mock_vae,
+        latent_upsampler=mock_upsampler,
+    )
+    
+    # Bypass VideoProcessor dependency for test isolation
+    pipeline.video_processor.postprocess_video = MagicMock(return_value=np.zeros((1, 3, 1, 32, 32)))
+
+    # Dummy params
+    params = {"latent_upsampler": {}}
+    prng_seed = jax.random.PRNGKey(0)
+    latents = jnp.zeros((1, 4, 16, 16, 8))
+
+    # Test returning latents directly
+    out_latents = pipeline(
+        params=params,
+        prng_seed=prng_seed,
+        latents=latents,
+        latents_normalized=False,
+        adain_factor=1.0,
+        tone_map_compression_ratio=0.5,
+        output_type="latent",
+        return_dict=True
+    )
+    
+    self.assertIn("frames", out_latents)
+    self.assertEqual(out_latents["frames"].shape, (1, 4, 16, 16, 8))
+    
+    # Ensure upsampler was called
+    mock_upsampler.apply.assert_called_once()
+    
+    # Test decoding flow
+    out_decoded = pipeline(
+        params=params,
+        prng_seed=prng_seed,
+        latents=latents,
+        latents_normalized=False,
+        output_type="pil",
+        return_dict=True
+    )
+    
+    # Check if vae.decode was called 
+    mock_vae.decode.assert_called_once()
+    self.assertIn("frames", out_decoded)
+
+
+if __name__ == "__main__":
+  unittest.main()