```

docs: update media examples and add parameter details for TTS providers

- Updated EdgeTTS example to mention additional audio parameters (`rate`, `volume`, `pitch`)
- Updated gTTS example to include support for `tld` and `slow` audio parameters
- Modified the EdgeTTS provider to use `get_last_message` instead of `format_image_prompt` for prompt handling
- Modified the gTTS provider to use `get_last_message` instead of `format_image_prompt` for prompt handling
- Refactored audio file generation logic in the gTTS provider to handle `language` parameter and update the voice model accordingly
- Refactored backend API code to introduce `cast_str` function for processing responses, including cache management and response formatting
- Fixed a bug in `AnyProvider` where the model string check would fail if the model was `None`
- Added check in `to_string` helper function to handle `None` values correctly
```

docs/media.md

@@ -51,9 +51,13 @@ client = Client(provider=EdgeTTS)
 response = client.media.generate("Hello", audio={"language": "en"})
 response.data[0].save("edge-tts.mp3")
 
+# The EdgeTTS provider also support the audio parameters `rate`, `volume` and `pitch`
+
 client = Client(provider=gTTS)
-response = client.media.generate("Hello", audio={"language": "en"})
+response = client.media.generate("Hello", audio={"language": "en-US"})
 response.data[0].save("google-tts.mp3")
+
+# The gTTS provider also support the audio parameters `tld` and `slow`
 ```
 
 #### **Transcribe an Audio File:**

g4f/Provider/audio/EdgeTTS.py

@@ -15,7 +15,7 @@ from ...typing import AsyncResult, Messages
 from ...providers.response import AudioResponse
 from ...image.copy_images import get_filename, get_media_dir, ensure_media_dir
 from ..base_provider import AsyncGeneratorProvider, ProviderModelMixin
-from ..helper import format_image_prompt
+from ..helper import get_last_message
 
 class EdgeTTS(AsyncGeneratorProvider, ProviderModelMixin):
     label = "Edge TTS"
@@ -43,7 +43,7 @@ class EdgeTTS(AsyncGeneratorProvider, ProviderModelMixin):
         audio: dict = {},
         **kwargs
     ) -> AsyncResult:
-        prompt = format_image_prompt(messages, prompt)
+        prompt = get_last_message(messages, prompt)
         if not prompt:
             raise ValueError("Prompt is empty.")
         voice = audio.get("voice", model if model and model != cls.model_id else None)

g4f/Provider/audio/gTTS.py

@@ -1,8 +1,6 @@
 from __future__ import annotations
 
 import os
-import random
-import asyncio
 
 try:
     from gtts import gTTS as gTTS_Service
@@ -14,7 +12,7 @@ from ...typing import AsyncResult, Messages
 from ...providers.response import AudioResponse
 from ...image.copy_images import get_filename, get_media_dir, ensure_media_dir
 from ..base_provider import AsyncGeneratorProvider, ProviderModelMixin
-from ..helper import format_image_prompt
+from ..helper import get_last_message
 
 locals = {
     "en-AU": ["English (Australia)", "en", "com.au"],
@@ -56,7 +54,7 @@ class gTTS(AsyncGeneratorProvider, ProviderModelMixin):
         audio: dict = {},
         **kwargs
     ) -> AsyncResult:
-        prompt = format_image_prompt(messages, prompt)
+        prompt = get_last_message(messages, prompt)
         if not prompt:
             raise ValueError("Prompt is empty.")
         format = audio.get("format", cls.default_format)
@@ -64,6 +62,9 @@ class gTTS(AsyncGeneratorProvider, ProviderModelMixin):
         target_path = os.path.join(get_media_dir(), filename)
         ensure_media_dir()
 
+        if "language" in audio:
+            model = locals[audio["language"]][0] if audio["language"] in locals else model
+
         gTTS_Service(
             prompt,
             **{

g4f/gui/server/backend_api.py

@@ -63,7 +63,7 @@ class Backend_Api(Api):
         if app.demo:
             @app.route('/', methods=['GET'])
             def home():
-                client_id = os.environ.get("OAUTH_CLIENT_ID", "ed074164-4f8d-4fb2-8bec-44952707965e")
+                client_id = os.environ.get("OAUTH_CLIENT_ID", "")
                 backend_url = os.environ.get("G4F_BACKEND_URL", "")
                 return render_template('demo.html', backend_url=backend_url, client_id=client_id)
         else:
@@ -248,6 +248,14 @@ class Backend_Api(Api):
                     "ignore_stream": not request.args.get("stream"),
                     "tool_calls": tool_calls,
                 }
+                def cast_str(response):
+                    for chunk in response:
+                        if isinstance(chunk, FinishReason):
+                            yield f"[{chunk.reason}]" if chunk.reason != "stop" else ""
+                        elif not isinstance(chunk, Exception):
+                            chunk = str(chunk)
+                            if chunk:
+                                yield chunk
                 if cache_id:
                     cache_id = sha256(cache_id.encode() + json.dumps(parameters, sort_keys=True).encode()).hexdigest()
                     cache_dir = Path(get_cookies_dir()) / ".scrape_cache" / "create"
@@ -255,26 +263,22 @@ class Backend_Api(Api):
                     if cache_file.exists():
                         with cache_file.open("r") as f:
                             response = f.read()
-                    else:
+                    if not response:
                         response = iter_run_tools(ChatCompletion.create, **parameters)
                         cache_dir.mkdir(parents=True, exist_ok=True)
-                        copy_response = [chunk for chunk in response]
-                        with cache_file.open("w") as f:
-                            for chunk in copy_response:
-                                f.write(str(chunk))
+                        copy_response = cast_str(response)
+                        if copy_response:
+                            with cache_file.open("w") as f:
+                                for chunk in copy_response:
+                                    f.write(chunk)
                         response = copy_response
                 else:
-                    response = iter_run_tools(ChatCompletion.create, **parameters)
-
+                    response = cast_str(iter_run_tools(ChatCompletion.create, **parameters))
                 if do_filter_markdown:
-                    return Response(filter_markdown("".join([str(chunk) for chunk in response]), do_filter_markdown), mimetype='text/plain')
-                def cast_str():
-                    for chunk in response:
-                        if isinstance(chunk, FinishReason):
-                            yield f"[{chunk.reason}]" if chunk.reason != "stop" else ""
-                        elif not isinstance(chunk, Exception):
-                            yield str(chunk)
-                return Response(cast_str(), mimetype='text/plain')
+                    is_true_filter_markdown = do_filter_markdown.lower() in ["true", "1"]
+                    response = "".join(response)
+                    return Response(filter_markdown(response, do_filter_markdown, response if is_true_filter_markdown else ""), mimetype='text/plain')
+                return Response(response, mimetype='text/plain')
             except Exception as e:
                 logger.exception(e)
                 return jsonify({"error": {"message": f"{type(e).__name__}: {e}"}}), 500

g4f/providers/any_provider.py

@@ -117,7 +117,7 @@ class AnyProvider(AsyncGeneratorProvider, ProviderModelMixin):
         **kwargs
     ) -> AsyncResult:
         providers = []
-        if ":" in model:
+        if model and ":" in model:
             providers = model.split(":")
             model = providers.pop()
             providers = [getattr(Provider, provider) for provider in providers]

g4f/providers/helper.py

@@ -22,6 +22,8 @@ def to_string(value) -> str:
         return ""
     elif isinstance(value, list):
         return "".join([to_string(v) for v in value if v.get("type", "text") == "text"])
+    elif value is None:
+        return ""
     return str(value)
 
 def render_messages(messages: Messages) -> Iterator:
@@ -71,13 +73,21 @@ def get_last_user_message(messages: Messages) -> str:
     while last_message is not None and messages:
         last_message = messages.pop()
         if last_message["role"] == "user":
-            content = to_string(last_message["content"]).strip()
+            content = to_string(last_message.get("content")).strip()
             if content:
                 user_messages.append(content)
         else:
             return "\n".join(user_messages[::-1])
     return "\n".join(user_messages[::-1])
 
+def get_last_message(messages: Messages, prompt: str = None) -> str:
+    if prompt is None:
+        for message in messages[::-1]:
+            content = to_string(message.get("content")).strip()
+            if content:
+                prompt = content
+    return prompt
+
 def format_image_prompt(messages, prompt: str = None) -> str:
     if prompt is None:
         return get_last_user_message(messages)