update turn detector model; more robust to missing terminal punctuation (#1565)

Co-authored-by: David Zhao <dz@livekit.io>

Author: jeradf

.changeset/shaggy-fans-care.md

@@ -0,0 +1,5 @@
+---
+"livekit-plugins-turn-detector": patch
+---
+
+retrained to be robust to missing terminal punctuation

livekit-plugins/livekit-plugins-turn-detector/livekit/plugins/turn_detector/eou.py

@@ -13,9 +13,9 @@
 
 HG_MODEL = "livekit/turn-detector"
 ONNX_FILENAME = "model_q8.onnx"
-MODEL_REVISION = "v1.2.0"
-MAX_HISTORY = 4
+MODEL_REVISION = "v1.2.1"
 MAX_HISTORY_TOKENS = 512
+MAX_HISTORY_TURNS = 6
 
 
 def _download_from_hf_hub(repo_id, filename, **kwargs):
@@ -120,7 +120,7 @@ class EOUModel:
     def __init__(
         self,
         inference_executor: InferenceExecutor | None = None,
-        unlikely_threshold: float = 0.008,
+        unlikely_threshold: float = 0.0289,
     ) -> None:
         self._executor = (
             inference_executor or get_current_job_context().inference_executor
@@ -168,7 +168,7 @@ async def predict_end_of_turn(
                         )
                         break
 
-        messages = messages[-MAX_HISTORY:]
+        messages = messages[-MAX_HISTORY_TURNS:]
 
         json_data = json.dumps({"chat_ctx": messages}).encode()