[Core][Diffusion] Add a typed pre-D2H video media contract (#6615)

Signed-off-by: NancyFyong <NancyFyong@users.noreply.github.com>
Signed-off-by: Samit <285365963@qq.com>
Co-authored-by: NancyFyong <NancyFyong@users.noreply.github.com>
Co-authored-by: Samit <285365963@qq.com>

tests/docs/test_generate_argparse.py

@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM-Omni project
+
+import importlib.util
+from pathlib import Path
+
+import pytest
+
+pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
+
+ROOT_DIR = Path(__file__).parents[2]
+HOOK_PATH = ROOT_DIR / "docs/mkdocs/hooks/generate_argparse.py"
+SPEC = importlib.util.spec_from_file_location("generate_argparse", HOOK_PATH)
+assert SPEC and SPEC.loader
+generate_argparse = importlib.util.module_from_spec(SPEC)
+SPEC.loader.exec_module(generate_argparse)
+
+
+def test_static_serve_parser_supports_video_output_transport() -> None:
+    parser = generate_argparse.create_parser_subparser_init(generate_argparse.OmniServeCommand)
+
+    args = parser.parse_args(["--omni", "--video-output-transport", '{"enable_device_postprocess": true}'])
+
+    assert args.video_output_transport == {"enable_device_postprocess": True}