[diffusion] cli: add argument --adjust-frames and --override-protected-fields (#13996)

Co-authored-by: dev <devnull@example.com>
Co-authored-by: Mick <mickjagger19@icloud.com>

python/sglang/multimodal_gen/configs/pipeline_configs/wan.py

@@ -106,6 +106,7 @@ class WanT2V720PConfig(WanT2V480PConfig):
 class WanI2V480PConfig(WanT2V480PConfig, WanI2VCommonConfig):
     """Base configuration for Wan I2V 14B 480P pipeline architecture."""
 
+    max_area: int = 480 * 832
     # WanConfig-specific parameters with defaults
     task_type: ModelTaskType = ModelTaskType.I2V
     # Precision for each component
@@ -130,6 +131,7 @@ class WanI2V480PConfig(WanT2V480PConfig, WanI2VCommonConfig):
 class WanI2V720PConfig(WanI2V480PConfig):
     """Base configuration for Wan I2V 14B 720P pipeline architecture."""
 
+    max_area: int = 720 * 1280
     # WanConfig-specific parameters with defaults
 
     # Denoising stage

python/sglang/multimodal_gen/configs/sample/sampling_params.py

@@ -17,7 +17,7 @@ from typing import Any
 
 from sglang.multimodal_gen.runtime.server_args import ServerArgs
 from sglang.multimodal_gen.runtime.utils.logging_utils import init_logger
-from sglang.multimodal_gen.utils import align_to
+from sglang.multimodal_gen.utils import StoreBoolean, align_to
 
 logger = init_logger(__name__)
 
@@ -137,6 +137,10 @@ class SamplingParams:
     return_frames: bool = False
     return_trajectory_latents: bool = False  # returns all latents for each timestep
     return_trajectory_decoded: bool = False  # returns decoded latents for each timestep
+    # if True, allow user params to override subclass-defined protected fields
+    override_protected_fields: bool = False
+    # whether to adjust num_frames for multi-GPU friendly splitting (default: True)
+    adjust_frames: bool = True
 
     def _set_output_file_ext(self):
         # add extension if needed
@@ -517,6 +521,25 @@ class SamplingParams:
             default=SamplingParams.return_trajectory_decoded,
             help="Whether to return the decoded trajectory",
         )
+        parser.add_argument(
+            "--override-protected-fields",
+            action="store_true",
+            default=SamplingParams.override_protected_fields,
+            help=(
+                "If set, allow user params to override fields defined in subclasses "
+                "(protected by default)."
+            ),
+        )
+        parser.add_argument(
+            "--adjust-frames",
+            action=StoreBoolean,
+            default=SamplingParams.adjust_frames,
+            help=(
+                "Enable/disable adjusting num_frames to evenly split latent frames across GPUs "
+                "and satisfy model temporal constraints. Default: true. "
+                "Examples: --adjust-frames, --adjust-frames true, --adjust-frames false."
+            ),
+        )
         return parser
 
     @classmethod
@@ -543,7 +566,7 @@ class SamplingParams:
     def output_file_path(self):
         return os.path.join(self.output_path, self.output_file_name)
 
-    def _merge_with_user_params(self, user_params):
+    def _merge_with_user_params(self, user_params: "SamplingParams"):
         """
         Merges parameters from a user-provided SamplingParams object.
 
@@ -559,6 +582,11 @@ class SamplingParams:
         # user is not allowed to modify any param defined in the SamplingParams subclass
         subclass_defined_fields = set(type(self).__annotations__.keys())
 
+        # global switch: if True, allow overriding protected fields
+        allow_override_protected = bool(
+            user_params.override_protected_fields or self.override_protected_fields
+        )
+
         # Compare against current instance to avoid constructing a default instance
         default_params = SamplingParams()
 
@@ -575,7 +603,9 @@ class SamplingParams:
                 if field_name != "output_file_name"
                 else user_params.output_file_path is not None
             )
-            if is_user_modified and field_name not in subclass_defined_fields:
+            if is_user_modified and (
+                allow_override_protected or field_name not in subclass_defined_fields
+            ):
                 if hasattr(self, field_name):
                     setattr(self, field_name, user_value)
 

python/sglang/multimodal_gen/runtime/entrypoints/utils.py

@@ -8,6 +8,7 @@ This module provides a consolidated interface for generating videos using
 diffusion models.
 """
 
+import dataclasses
 
 from sglang.multimodal_gen.configs.sample.sampling_params import SamplingParams
 from sglang.multimodal_gen.runtime.pipelines_core.schedule_batch import Req
@@ -26,11 +27,12 @@ def prepare_request(
     Settle SamplingParams according to ServerArgs
 
     """
-    # Create a copy of inference args to avoid modifying the original
-    req = Req(
-        **shallow_asdict(sampling_params),
-        VSA_sparsity=server_args.VSA_sparsity,
-    )
+    # Create a copy of inference args to avoid modifying the original.
+    # Filter out fields not defined in Req to avoid unexpected-kw TypeError.
+    params_dict = shallow_asdict(sampling_params)
+    req_field_names = {f.name for f in dataclasses.fields(Req)}
+    filtered_params = {k: v for k, v in params_dict.items() if k in req_field_names}
+    req = Req(**filtered_params, VSA_sparsity=server_args.VSA_sparsity)
     req.adjust_size(server_args)
 
     if req.width <= 0 or req.height <= 0:

python/sglang/multimodal_gen/runtime/pipelines_core/stages/input_validation.py

@@ -146,7 +146,7 @@ class InputValidationStage(PipelineStage):
         elif isinstance(server_args.pipeline_config, WanI2V480PConfig):
             # TODO: could we merge with above?
             # resize image only, Wan2.1 I2V
-            max_area = 720 * 1280
+            max_area = server_args.pipeline_config.max_area
             aspect_ratio = condition_image_height / condition_image_width
             mod_value = (
                 server_args.pipeline_config.vae_config.arch_config.scale_factor_spatial