[Model] Add native MAGI-2 Preview diffusion support (#5918)

Signed-off-by: Hongsheng Liu <liuhongsheng4@huawei.com>
Signed-off-by: hsliuustc0106 <liuhongsheng4@huawei.com>

tests/examples/offline_inference/test_magi2_shared_defaults.py

@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM-Omni project
+
+from __future__ import annotations
+
+import importlib.util
+from pathlib import Path
+from types import ModuleType
+
+import pytest
+
+pytestmark = [pytest.mark.diffusion, pytest.mark.cpu, pytest.mark.core_model]
+
+REPO_ROOT = Path(__file__).parents[3]
+
+
+def _load_example(name: str, relative_path: str) -> ModuleType:
+    path = REPO_ROOT / relative_path
+    spec = importlib.util.spec_from_file_location(name, path)
+    assert spec is not None and spec.loader is not None
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+@pytest.fixture(scope="module")
+def text_to_video() -> ModuleType:
+    return _load_example(
+        "magi2_text_to_video_example",
+        "examples/offline_inference/text_to_video/text_to_video.py",
+    )
+
+
+@pytest.mark.parametrize(
+    ("extra_body", "expected_size"),
+    [
+        (None, (896, 512)),
+        ({"resolution": "540p"}, (896, 512)),
+        ({"resolution": "272p"}, (448, 256)),
+    ],
+)
+def test_shared_text_to_video_uses_native_preview_defaults(
+    text_to_video: ModuleType,
+    extra_body: dict[str, object] | None,
+    expected_size: tuple[int, int],
+) -> None:
+    preset = text_to_video._detect_preset(
+        "sand-ai/MAGI-2-preview",
+        "Magi2Pipeline",
+        extra_body,
+    )
+    assert (preset["width"], preset["height"]) == expected_size
+    assert preset["num_frames"] == 125
+    assert preset["num_inference_steps"] == 100
+    assert preset["fps"] == 12.5