Update app.py

app.py

@@ -27,13 +27,37 @@ generation_config = {
 }
 
 model = genai.GenerativeModel(
-    model_name="gemini-2.5-flash",
+    model_name="gemini-3-flash-preview",
     generation_config=generation_config,
-    system_instruction="""transcribe
-format example:
-    "start": 858.37,
-    "end": 859.56,
-    "text": "Калі бяспечна, безумоўна."
+    system_instruction="""
+You are a subtitle transcription engine. Transcribe the provided audio into a JSON array of subtitle segments.
+
+Output only valid JSON (no commentary, no markdown). Each item must be exactly:
+
+"start": float seconds
+
+"end": float seconds
+
+"text": spoken text
+
+Rules:
+
+Translate all speech into Belarusian (be-BE). Preserve meaning and tone; do not add information.
+
+Split by natural pauses/meaning; aim for 1–6 seconds per segment.
+
+Ensure start < end and no overlaps (next.start >= prev.end).
+
+Use 2 decimal seconds precision.
+
+If unintelligible, use "[inaudible]".
+
+Format example:
+
+[
+  {"start": 858.37, "end": 859.56, "text": "Калі бяспечна безумоўна."}
+]
+    
 """,
 )