From fca6fb3aa110650d4b0b4522a0d6706ea6ab04bb Mon Sep 17 00:00:00 2001
From: SolitaryThinker <wlsaidhi@gmail.com>
Date: Sun, 5 Jul 2026 16:12:20 -0700
Subject: [PATCH] [test]: add reduced-size Kandinsky-5 T2V SSIM test

---
 .../tests/ssim/test_kandinsky5_similarity.py  | 100 ++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 fastvideo/tests/ssim/test_kandinsky5_similarity.py

diff --git a/fastvideo/tests/ssim/test_kandinsky5_similarity.py b/fastvideo/tests/ssim/test_kandinsky5_similarity.py
new file mode 100644
index 000000000..b23d07f68
--- /dev/null
+++ b/fastvideo/tests/ssim/test_kandinsky5_similarity.py
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: Apache-2.0
+"""SSIM regression test for Kandinsky-5.0 Lite text-to-video.
+
+Runs a reduced-size generation (256x384, 21 frames) with a fixed seed and
+compares against a device-specific reference video via MS-SSIM. The preset
+default is 512x768 x 121 frames; the reduced size keeps CI cheap while the
+patch (1, 2, 2) and VAE temporal-4 / spatial-8 constraints stay satisfied
+(dims divisible by 16, num_frames % 4 == 1).
+"""
+import os
+
+import pytest
+
+from fastvideo.logger import init_logger
+from fastvideo.pipelines.basic.kandinsky5.presets import KANDINSKY5_T2V_LITE_5S
+from fastvideo.tests.ssim.inference_similarity_utils import (
+    resolve_inference_device_reference_folder,
+    run_text_to_video_similarity_test,
+)
+
+logger = init_logger(__name__)
+
+# The SSIM lane image bakes FASTVIDEO_FA4=1, but on L40S (sm89) the CLIP
+# encoder's dense MHA inference call routes into the FA4 CuTeDSL JIT, which
+# fails to compile there (nvvm.fmax signature mismatch vs the image's
+# nvidia_cutlass_dsl). Pin FA4 off so reference seeding and CI runs both use
+# the FA2 path with identical numerics.
+os.environ["FASTVIDEO_FA4"] = "0"
+
+REQUIRED_GPUS = 1
+
+device_reference_folder = resolve_inference_device_reference_folder(logger)
+
+_PRESET_DEFAULTS = KANDINSKY5_T2V_LITE_5S.defaults
+
+KANDINSKY5_T2V_PARAMS = {
+    "num_gpus": 1,
+    "model_path": "kandinskylab/Kandinsky-5.0-T2V-Lite-sft-5s-Diffusers",
+    "height": 256,
+    "width": 384,
+    "num_frames": 21,
+    "num_inference_steps": _PRESET_DEFAULTS["num_inference_steps"],
+    "guidance_scale": _PRESET_DEFAULTS["guidance_scale"],
+    "seed": 1024,
+    "sp_size": 1,
+    "tp_size": 1,
+    "fps": _PRESET_DEFAULTS["fps"],
+    "neg_prompt": _PRESET_DEFAULTS["negative_prompt"],
+}
+
+KANDINSKY5_T2V_FULL_QUALITY_PARAMS = {
+    **KANDINSKY5_T2V_PARAMS,
+    "height": _PRESET_DEFAULTS["height"],
+    "width": _PRESET_DEFAULTS["width"],
+    # Keep the reduced frame count even at full quality (preset default: 121).
+    "num_frames": KANDINSKY5_T2V_PARAMS["num_frames"],
+}
+
+KANDINSKY5_T2V_MODEL_TO_PARAMS = {
+    "Kandinsky-5.0-T2V-Lite-sft-5s-Diffusers": KANDINSKY5_T2V_PARAMS,
+}
+FULL_QUALITY_KANDINSKY5_T2V_MODEL_TO_PARAMS = {
+    "Kandinsky-5.0-T2V-Lite-sft-5s-Diffusers": KANDINSKY5_T2V_FULL_QUALITY_PARAMS,
+}
+
+KANDINSKY5_T2V_TEST_PROMPTS = [
+    "A curious raccoon peers through a vibrant field of yellow sunflowers, its "
+    "eyes wide with interest. The playful yet serene atmosphere is complemented "
+    "by soft natural light filtering through the petals. Mid-shot, warm and "
+    "cheerful tones.",
+]
+
+
+@pytest.mark.parametrize("prompt", KANDINSKY5_T2V_TEST_PROMPTS)
+@pytest.mark.parametrize("attention_backend_name", ["FLASH_ATTN"])
+@pytest.mark.parametrize("model_id", list(KANDINSKY5_T2V_MODEL_TO_PARAMS.keys()))
+def test_kandinsky5_t2v_inference_similarity(
+    prompt: str,
+    attention_backend_name: str,
+    model_id: str,
+) -> None:
+    run_text_to_video_similarity_test(
+        logger=logger,
+        script_dir=os.path.dirname(os.path.abspath(__file__)),
+        device_reference_folder=device_reference_folder,
+        prompt=prompt,
+        attention_backend_name=attention_backend_name,
+        model_id=model_id,
+        default_params_map=KANDINSKY5_T2V_MODEL_TO_PARAMS,
+        full_quality_params_map=FULL_QUALITY_KANDINSKY5_T2V_MODEL_TO_PARAMS,
+        min_acceptable_ssim=0.93,
+        # Match examples/inference/basic/basic_kandinsky5_t2v.py: FSDP inference
+        # is not used for Kandinsky-5, and the Qwen2.5-VL text encoder stays on
+        # CPU between encodes.
+        init_kwargs_override={
+            "use_fsdp_inference": False,
+            "text_encoder_cpu_offload": True,
+            "pin_cpu_memory": True,
+        },
+    )