support llava video (#426)

python/sglang/api.py

@@ -15,6 +15,7 @@ from sglang.lang.ir import (
     SglRoleBegin,
     SglRoleEnd,
     SglSelect,
+    SglVideo,
 )
 
 
@@ -151,6 +152,10 @@ def image(expr: SglExpr):
     return SglImage(expr)
 
 
+def video(path: str, num_frames: int):
+    return SglVideo(path, num_frames)
+
+
 def select(
     name: Optional[str] = None,
     choices: List[str] = None,