[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/helpers/tests/test_video_response_contract.py

@@ -0,0 +1,99 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM-Omni project
+
+from fractions import Fraction
+from io import BytesIO
+from types import SimpleNamespace
+
+import av
+import numpy as np
+import pytest
+
+from tests.helpers.assertions import assert_video_diffusion_response, assert_video_valid
+
+pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
+
+
+def _encode_clip(fps=12.5, *, audio_rate=44100, audio_layout="stereo"):
+    output = BytesIO()
+    with av.open(output, "w", format="mp4") as container:
+        video = container.add_stream("mpeg4", rate=Fraction(str(fps)))
+        video.width = video.height = 32
+        video.pix_fmt = "yuv420p"
+        audio = None
+        if audio_rate is not None:
+            audio = container.add_stream("aac", rate=audio_rate)
+            audio.layout = audio_layout
+        for _ in range(5):
+            frame = av.VideoFrame.from_ndarray(np.zeros((32, 32, 3), dtype=np.uint8), format="rgb24")
+            for packet in video.encode(frame):
+                container.mux(packet)
+        for packet in video.encode():
+            container.mux(packet)
+        if audio is not None:
+            channels = len(audio.layout.channels)
+            frame = av.AudioFrame.from_ndarray(
+                np.zeros((channels, 1024), dtype=np.float32), format="fltp", layout=audio_layout
+            )
+            frame.sample_rate = audio_rate
+            for packet in audio.encode(frame):
+                container.mux(packet)
+            for packet in audio.encode():
+                container.mux(packet)
+    return output.getvalue()
+
+
+@pytest.mark.parametrize(
+    ("fps", "audio_rate", "audio_layout", "error"),
+    [
+        (12.5, 44100, "stereo", None),
+        (12.0, 44100, "stereo", "Expected fps"),
+        (13.0, 44100, "stereo", "Expected fps"),
+        (12.5, None, "stereo", "does not contain an audio stream"),
+        (12.5, 48000, "stereo", "Expected audio sample rate"),
+        (12.5, 44100, "mono", "Expected audio channels"),
+    ],
+)
+def test_fixed_rate_video_audio_response_contract(fps, audio_rate, audio_layout, error):
+    response = SimpleNamespace(videos=[_encode_clip(fps, audio_rate=audio_rate, audio_layout=audio_layout)])
+    request_config = {
+        "form_data": {"fps": "12.5", "num_frames": 5, "width": 32, "height": 32},
+        "fps_tolerance": 0.01,
+        "expected_audio": {"sample_rate": 44100, "channels": 2},
+    }
+    if error is None:
+        assert_video_diffusion_response(response, request_config)
+    else:
+        with pytest.raises(AssertionError, match=error):
+            assert_video_diffusion_response(response, request_config)
+
+
+def test_video_response_retains_default_fps_tolerance():
+    response = SimpleNamespace(videos=[_encode_clip(12.0, audio_rate=None)])
+    assert_video_diffusion_response(response, {"form_data": {"fps": 12.5}})
+
+
+@pytest.mark.parametrize("reported_fps", [0.0, float("nan"), float("inf")])
+def test_video_response_rejects_invalid_reported_fps(monkeypatch, tmp_path, reported_fps):
+    import cv2
+
+    path = tmp_path / "clip.mp4"
+    path.write_bytes(_encode_clip(audio_rate=None))
+    real_capture = cv2.VideoCapture
+
+    class InvalidFpsCapture:
+        def __init__(self, path):
+            self.capture = real_capture(path)
+
+        def isOpened(self):
+            return self.capture.isOpened()
+
+        def get(self, prop):
+            return reported_fps if prop == cv2.CAP_PROP_FPS else self.capture.get(prop)
+
+        def release(self):
+            self.capture.release()
+
+    monkeypatch.setattr(cv2, "VideoCapture", InvalidFpsCapture)
+    with pytest.raises(AssertionError, match="Invalid video fps"):
+        assert_video_valid(path, fps=12.5, fps_tolerance=0.01)