OpenAITTS (#2493)

### What problem does this PR solve?

OpenAITTS

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: liuhua <10215101452@stu.ecun.edu.cn>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

conf/llm_factories.json

@@ -77,6 +77,12 @@
                     "tags": "LLM,CHAT,IMAGE2TEXT",
                     "max_tokens": 765,
                     "model_type": "image2text"
+                },
+                {
+                    "llm_name": "tts-1",
+                    "tags": "TTS",
+                    "max_tokens": 2048,
+                    "model_type": "tts"
                 }
             ]
         },

rag/llm/__init__.py

@@ -138,5 +138,6 @@ Seq2txtModel = {
 
 TTSModel = {
     "Fish Audio": FishAudioTTS,
-    "Tongyi-Qianwen": QwenTTS
+    "Tongyi-Qianwen": QwenTTS,
+    "OpenAI":OpenAITTS
 }

rag/llm/tts_model.py

@@ -14,6 +14,7 @@
 #  limitations under the License.
 #
 
+import requests
 from typing import Annotated, Literal
 from abc import ABC
 import httpx
@@ -23,6 +24,8 @@ from rag.utils import num_tokens_from_string
 import json
 import re
 import time
+
+
 class ServeReferenceAudio(BaseModel):
     audio: bytes
     text: str
@@ -154,3 +157,30 @@ class QwenTTS(Base):
 
         except Exception as e:
             raise RuntimeError(f"**ERROR**: {e}")
+
+
+class OpenAITTS(Base):
+    def __init__(self, key, model_name="tts-1", base_url="https://api.openai.com/v1"):
+        self.api_key = key
+        self.model_name = model_name
+        self.base_url = base_url
+        self.headers = {
+            "Authorization": f"Bearer {self.api_key}",
+            "Content-Type": "application/json"
+        }
+
+    def tts(self, text, voice="alloy"):
+        text = self.normalize_text(text)
+        payload = {
+            "model": self.model_name,
+            "voice": voice,
+            "input": text
+        }
+
+        response = requests.post(f"{self.base_url}/audio/speech", headers=self.headers, json=payload, stream=True)
+
+        if response.status_code != 200:
+            raise Exception(f"**Error**: {response.status_code}, {response.text}")
+        for chunk in response.iter_content(chunk_size=1024):
+            if chunk:
+                yield chunk