import numpy as np import logging from .base_processor import AudioProcessor logger = logging.getLogger(__name__) class RawSpectrogramProcessor(AudioProcessor): """ Raw Spectrogram processor using STFT (Short-Time Fourier Transform). Future implementation will: - Apply STFT to audio data for time-frequency representation - Use CNN classifier trained on spectrogram images - Process raw frequency domain features without mel scaling Currently returns placeholder '00' for testing UI functionality. """ def __init__(self): super().__init__("Raw Spectrogram") logger.info("Raw Spectrogram processor initialized (PLACEHOLDER MODE)") def process_audio(self, audio_data: bytes) -> str: """ Process audio using raw spectrogram analysis. PLACEHOLDER IMPLEMENTATION: Currently returns '00' for UI testing purposes. Future implementation will: 1. Convert audio bytes to numpy array 2. Apply STFT with appropriate window size and overlap 3. Create time-frequency representation 4. Normalize spectrogram values 5. Feed to trained CNN model 6. Return predicted digit Args: audio_data: Raw audio bytes Returns: Predicted digit as string (currently '00') """ logger.debug("Processing audio with Raw Spectrogram (placeholder)") # Simulate processing time import time time.sleep(0.1) # TODO: Implement actual STFT-based processing: # 1. audio_array = np.frombuffer(audio_data, dtype=np.float32) # 2. stft_result = np.abs(librosa.stft(audio_array, n_fft=2048, hop_length=512)) # 3. spectrogram = librosa.amplitude_to_db(stft_result, ref=np.max) # 4. prediction = self.cnn_model.predict(spectrogram) # 5. return str(np.argmax(prediction)) return '00' def get_model_info(self) -> dict: """Get information about the raw spectrogram model.""" return { 'method': 'Raw Spectrogram (STFT)', 'status': 'PLACEHOLDER', 'features': 'Time-frequency representation', 'classifier': 'CNN (not implemented)', 'window_size': 2048, 'hop_length': 512, 'expected_inference_time': '<1s' }