add support for Tencent Cloud ASR (#2102)

### What problem does this PR solve?

add support for Tencent Cloud ASR

### Type of change

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

---------

Co-authored-by: Zhedong Cen <cenzhedong2@126.com>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

rag/llm/__init__.py

@@ -128,7 +128,8 @@ Seq2txtModel = {
     "Tongyi-Qianwen": QWenSeq2txt,
     "Ollama": OllamaSeq2txt,
     "Azure-OpenAI": AzureSeq2txt,
-    "Xinference": XinferenceSeq2txt
+    "Xinference": XinferenceSeq2txt,
+    "Tencent Cloud": TencentCloudSeq2txt
 }
 
 TTSModel = {

rag/llm/sequence2txt_model.py

@@ -22,7 +22,8 @@ from openai import OpenAI
 import os
 import json
 from rag.utils import num_tokens_from_string
-
+import base64
+import re
 
 class Base(ABC):
     def __init__(self, key, model_name):
@@ -35,6 +36,13 @@ class Base(ABC):
             response_format="text"
         )
         return transcription.text.strip(), num_tokens_from_string(transcription.text.strip())
+    
+    def audio2base64(self,audio):
+        if isinstance(audio, bytes):
+            return base64.b64encode(audio).decode("utf-8")
+        if isinstance(audio, io.BytesIO):
+            return base64.b64encode(audio.getvalue()).decode("utf-8")
+        raise TypeError("The input audio file should be in binary format.")
 
 
 class GPTSeq2txt(Base):
@@ -87,3 +95,66 @@ class XinferenceSeq2txt(Base):
     def __init__(self, key, model_name="", base_url=""):
         self.client = OpenAI(api_key="xxx", base_url=base_url)
         self.model_name = model_name
+
+
+class TencentCloudSeq2txt(Base):
+    def __init__(
+        self, key, model_name="16k_zh", base_url="https://asr.tencentcloudapi.com"
+    ):
+        from tencentcloud.common import credential
+        from tencentcloud.asr.v20190614 import asr_client
+
+        key = json.loads(key)
+        sid = key.get("tencent_cloud_sid", "")
+        sk = key.get("tencent_cloud_sk", "")
+        cred = credential.Credential(sid, sk)
+        self.client = asr_client.AsrClient(cred, "")
+        self.model_name = model_name
+
+    def transcription(self, audio, max_retries=60, retry_interval=5):
+        from tencentcloud.common.exception.tencent_cloud_sdk_exception import (
+            TencentCloudSDKException,
+        )
+        from tencentcloud.asr.v20190614 import models
+        import time
+
+        b64 = self.audio2base64(audio)
+        try:
+            # dispatch disk
+            req = models.CreateRecTaskRequest()
+            params = {
+                "EngineModelType": self.model_name,
+                "ChannelNum": 1,
+                "ResTextFormat": 0,
+                "SourceType": 1,
+                "Data": b64,
+            }
+            req.from_json_string(json.dumps(params))
+            resp = self.client.CreateRecTask(req)
+
+            # loop query
+            req = models.DescribeTaskStatusRequest()
+            params = {"TaskId": resp.Data.TaskId}
+            req.from_json_string(json.dumps(params))
+            retries = 0
+            while retries < max_retries:
+                resp = self.client.DescribeTaskStatus(req)
+                if resp.Data.StatusStr == "success":
+                    text = re.sub(
+                        r"\[\d+:\d+\.\d+,\d+:\d+\.\d+\]\s*", "", resp.Data.Result
+                    ).strip()
+                    return text, num_tokens_from_string(text)
+                elif resp.Data.StatusStr == "failed":
+                    return (
+                        "**ERROR**: Failed to retrieve speech recognition results.",
+                        0,
+                    )
+                else:
+                    time.sleep(retry_interval)
+                    retries += 1
+            return "**ERROR**: Max retries exceeded. Task may still be processing.", 0
+
+        except TencentCloudSDKException as e:
+            return "**ERROR**: " + str(e), 0
+        except Exception as e:
+            return "**ERROR**: " + str(e), 0