replace dummy tts class

utils/tts_dummy.py

@@ -1,11 +1,53 @@
-def generate_speech(text: str, language: str = "zh") -> str:
-    """Public interface for TTS generation
+class DummyTTS(TTSBase):
+    """Dummy TTS engine that generates sine wave audio
     
-    This is a legacy function maintained for backward compatibility.
-    New code should use the factory pattern implementation directly.
+    This class is used as a fallback when no other TTS engine is available.
     """
-    from utils.tts_base import DummyTTSEngine
     
-    # Create a dummy engine and generate speech
-    dummy_engine = DummyTTSEngine()
-    return dummy_engine.generate_speech(text, "af_heart", 1.0)
+    def generate_speech(self, text: str, voice: str = 'default', speed: float = 1.0) -> str:
+        """Generate a dummy sine wave audio file
+        
+        Args:
+            text (str): Input text (not used)
+            voice (str): Voice ID (not used)
+            speed (float): Speech speed multiplier (not used)
+            
+        Returns:
+            str: Path to the generated audio file
+        """
+        logger.info(f"Generating dummy speech for text length: {len(text)}")
+        
+        # Generate a simple sine wave
+        sample_rate = 24000
+        duration = min(len(text) / 20, 10)  # Rough approximation of speech duration
+        t = np.linspace(0, duration, int(sample_rate * duration), endpoint=False)
+        audio = 0.5 * np.sin(2 * np.pi * 440 * t)  # 440 Hz sine wave
+        
+        # Save to file
+        output_path = self._generate_output_path(prefix="dummy")
+        sf.write(output_path, audio, sample_rate)
+        
+        logger.info(f"Generated dummy audio: {output_path}")
+        return output_path
+    
+    def generate_speech_stream(self, text: str, voice: str = 'default', speed: float = 1.0) -> Generator[Tuple[int, np.ndarray], None, None]:
+        """Generate a dummy sine wave audio stream
+        
+        Args:
+            text (str): Input text (not used)
+            voice (str): Voice ID (not used)
+            speed (float): Speech speed multiplier (not used)
+            
+        Yields:
+            tuple: (sample_rate, audio_data) pairs
+        """
+        logger.info(f"Generating dummy speech stream for text length: {len(text)}")
+        
+        # Generate a simple sine wave
+        sample_rate = 24000
+        duration = min(len(text) / 20, 10)  # Rough approximation of speech duration
+        t = np.linspace(0, duration, int(sample_rate * duration), endpoint=False)
+        audio = 0.5 * np.sin(2 * np.pi * 440 * t)  # 440 Hz sine wave
+        
+        # Yield the audio data
+        yield sample_rate, audio