[Core][VLM] Add precise multi-modal placeholder tracking (#8346)

Signed-off-by: Peter Salas <peter@fixie.ai>

vllm/multimodal/video.py

@@ -1,18 +1,19 @@
 from functools import lru_cache
-from typing import Any, Dict, List, Optional, Union
+from typing import TYPE_CHECKING, Any, Dict, List, Optional, Union
 
 import numpy as np
 
-from vllm.config import ModelConfig
 from vllm.inputs.registry import InputContext
 from vllm.logger import init_logger
 from vllm.transformers_utils.processor import get_video_processor
 from vllm.transformers_utils.tokenizer import get_tokenizer
-from vllm.utils import is_list_of
 
 from .base import MultiModalData, MultiModalInputs
 from .image import ImagePlugin
 
+if TYPE_CHECKING:
+    from vllm.config import ModelConfig
+
 logger = init_logger(__name__)
 
 cached_get_video_processor = lru_cache(get_video_processor)
@@ -38,7 +39,7 @@ class VideoPlugin(ImagePlugin):
 
     def _get_hf_video_processor(
         self,
-        model_config: ModelConfig,
+        model_config: "ModelConfig",
         mm_processor_kwargs: Optional[Dict[str, Any]] = None,
     ):
         if mm_processor_kwargs is None:
@@ -56,7 +57,10 @@ class VideoPlugin(ImagePlugin):
     ) -> MultiModalInputs:
         model_config = ctx.model_config
 
-        if isinstance(data, np.ndarray) or is_list_of(data, np.ndarray):
+        if isinstance(data, list) and len(data) == 1:
+            data = data[0]
+
+        if isinstance(data, np.ndarray):
             video_processor = self._get_hf_video_processor(
                 model_config,
                 mm_processor_kwargs,