Implement audio classification function using YAMNet

- Create a function to load audio, resample, and classify using YAMNet
- Ensure compatibility with different audio formats and sample rates
- Normalize audio and classify it into one of 600 categories

src/preprocessing/classify.py

@@ -14,31 +14,35 @@ def class_names_from_csv(class_map_scv_text):
         reader = csv.DictReader(csvfile)
         for row in reader:
             class_names.append(row['display_name'])
-        
     return class_names
 
-class_map_path = model.class_map_path().numpy()
-class_names = class_names_from_csv(class_map_path)
+# Main function to process audio and classify
+def classify_audio(file_path):
+    """
+    Given an audio file, this function loads the audio, resamples it, 
+    normalizes it, and runs it through the YAMNet model to classify the sound.
 
-wav_file_name = 'cafe_crowd_talk.wav'
-waveform, sample_rate = librosa.load(wav_file_name, sr=16000)
+    Args:
+    - file_path (str): Path to the audio file (WAV, MP3, etc.).
 
-# Show some basic information about the audio.
-duration = len(waveform)/sample_rate
-print(f'Sample rate: {sample_rate} Hz')
-print(f'Total duration: {duration:.2f}s')
-print(f'Size of the input: {len(waveform)}')
+    Returns:
+    - str: Predicted class label of the audio.
+    """
+    # Load audio using librosa (this handles both loading, resampling, and conversion to mono)
+    waveform, sample_rate = librosa.load(file_path, sr=16000, mono=True)  # Ensuring 16k sample rate and mono
 
-# The waveform needs to be normalized to values in [-1.0, 1.0] (librosa load already does this)
-# No need to do this as librosa already normalizes# The wav_data needs to be normalized to values in [-1.0, 1.0]
-
-# Execute the Model
-# Check the output.
-scores, embeddings, spectogram = model(waveform)
-scores_np = scores.numpy()
-spectogram_np = spectogram.numpy()
-infered_class = class_names[scores_np.mean(axis=0).argmax()]
-print(f'The main sound is : {infered_class}')
+    # Normalize the waveform to [-1.0, 1.0] (librosa already returns normalized values)
+    waveform = waveform / np.max(np.abs(waveform))
 
+    # Execute the YAMNet model
+    scores, embeddings, spectrogram = model(waveform)
+    
+    # Extract the class names from the model
+    class_map_path = model.class_map_path().numpy()
+    class_names = class_names_from_csv(class_map_path)
 
+    # Find the class with the highest score
+    scores_np = scores.numpy()
+    inferred_class = class_names[scores_np.mean(axis=0).argmax()]
 
+    return inferred_class