[model] support youtu-vl model (#10152)

src/llamafactory/data/mm_plugin.py

@@ -2159,6 +2159,40 @@ class LFMVLPlugin(BasePlugin):
         return messages
 
 
+@dataclass
+class YoutuVLPlugin(BasePlugin):
+    r"""Plugin for Youtu-VL vision-language models."""
+
+    vision_bos_token: str = "<|vision_start|>"
+    vision_eos_token: str = "<|vision_end|>"
+
+    @override
+    def process_messages(
+        self,
+        messages: list[dict[str, str]],
+        images: list["ImageInput"],
+        videos: list["VideoInput"],
+        audios: list["AudioInput"],
+        processor: Optional["MMProcessor"],
+    ) -> list[dict[str, str]]:
+        self._validate_input(processor, images, videos, audios)
+        self._validate_messages(messages, images, videos, audios)
+        messages = deepcopy(messages)
+
+        for message in messages:
+            content = message["content"]
+            content = content.replace(
+                IMAGE_PLACEHOLDER, f"{self.vision_bos_token}{self.image_token}{self.vision_eos_token}"
+            )
+            content = content.replace(
+                VIDEO_PLACEHOLDER, f"{self.vision_bos_token}{self.video_token}{self.vision_eos_token}"
+            )
+
+            message["content"] = content
+
+        return messages
+
+
 PLUGINS = {
     "base": BasePlugin,
     "ernie_vl": ErnieVLPlugin,
@@ -2181,6 +2215,7 @@ PLUGINS = {
     "qwen2_vl": Qwen2VLPlugin,
     "qwen3_vl": Qwen3VLPlugin,
     "video_llava": VideoLlavaPlugin,
+    "youtu_vl": YoutuVLPlugin,
 }