优化角色替换

core/backend/apps/ai/model_routing.py

@@ -48,8 +48,9 @@ class ModelRequirements:
             raise ValueError("reference_mode=single 时 reference_images 必须等于 1")
         if self.reference_mode == "multiple" and self.reference_images < 2:
             raise ValueError("reference_mode=multiple 时 reference_images 必须至少为 2")
-        if self.duration is not None and self.duration <= 0:
-            raise ValueError("duration 必须大于 0")
+        # Seedance 的视频编辑模式用 -1 表示“跟随参考视频时长”。
+        if self.duration is not None and self.duration <= 0 and self.duration != -1:
+            raise ValueError("duration 必须大于 0，或为 -1（跟随参考视频）")
         if self.char_count is not None and self.char_count < 0:
             raise ValueError("char_count 不能为负数")
         if self.speed_ratio is not None and self.speed_ratio <= 0:
@@ -221,10 +222,11 @@ def match_model_requirements(model: ModelConfig, requirements: ModelRequirements
         ("languages", requirements.language, "语言"),
         ("output_formats", requirements.output_format, "输出格式"),
     ):
-        if required and required not in _set(capabilities.get(field_name)):
+        # 视频编辑的 adaptive 比例由火山按输入视频决定，不是模型静态能力表中的比例档。
+        if required and required != "adaptive" and required not in _set(capabilities.get(field_name)):
             reasons.append(f"不支持{label} {required}")
 
-    if requirements.duration is not None:
+    if requirements.duration is not None and requirements.duration != -1:
         durations = capabilities.get("durations")
         supported = set(durations) if isinstance(durations, (list, tuple, set, frozenset)) else set()
         if requirements.duration not in supported: