wedding-phone/resample_audio.py

#!/usr/bin/env python3
"""
Audio Resampling Utility for Wedding Phone
Resamples all WAV files in sounds directory to match configured sample rate
"""

import wave
import numpy as np
import os
import json
import shutil
from scipy import signal

def load_config():
    """Load sample rate from config.json"""
    config_path = 'config.json'
    if not os.path.exists(config_path):
        print("config.json not found, using 48000Hz as default")
        return 48000

    with open(config_path, 'r') as f:
        config = json.load(f)
        return config['audio']['sample_rate']

def resample_wav(input_file, output_file, target_rate):
    """Resample a WAV file to target sample rate"""
    try:
        # Open source file
        with wave.open(input_file, 'rb') as wf:
            n_channels = wf.getnchannels()
            sampwidth = wf.getsampwidth()
            source_rate = wf.getframerate()
            n_frames = wf.getnframes()

            # Read audio data
            audio_data = wf.readframes(n_frames)

            # Convert to numpy array
            if sampwidth == 1:
                dtype = np.uint8
            elif sampwidth == 2:
                dtype = np.int16
            elif sampwidth == 4:
                dtype = np.int32
            else:
                print(f"Unsupported sample width: {sampwidth}")
                return False

            audio_array = np.frombuffer(audio_data, dtype=dtype)

            # Handle stereo
            if n_channels == 2:
                audio_array = audio_array.reshape(-1, 2)

            # Resample
            if source_rate != target_rate:
                print(f"  Resampling from {source_rate}Hz to {target_rate}Hz...")
                num_samples = int(len(audio_array) * target_rate / source_rate)

                if n_channels == 1:
                    resampled = signal.resample(audio_array, num_samples)
                else:
                    # Resample each channel separately
                    left = signal.resample(audio_array[:, 0], num_samples)
                    right = signal.resample(audio_array[:, 1], num_samples)
                    resampled = np.column_stack((left, right))

                # Convert back to original dtype
                resampled = np.clip(resampled, np.iinfo(dtype).min, np.iinfo(dtype).max)
                audio_array = resampled.astype(dtype)

            # Write output file
            with wave.open(output_file, 'wb') as wf_out:
                wf_out.setnchannels(n_channels)
                wf_out.setsampwidth(sampwidth)
                wf_out.setframerate(target_rate)
                wf_out.writeframes(audio_array.tobytes())

            return True

    except Exception as e:
        print(f"  Error: {e}")
        return False

def main():
    """Main resampling function"""
    print("Wedding Phone Audio Resampler")
    print("=" * 50)

    # Load target sample rate
    target_rate = load_config()
    print(f"\nTarget sample rate: {target_rate}Hz")

    # Check sounds directory
    sounds_dir = './rotary_phone_data/sounds'
    if not os.path.exists(sounds_dir):
        print(f"\nSounds directory not found: {sounds_dir}")
        return

    # Get all WAV files
    wav_files = [f for f in os.listdir(sounds_dir) if f.endswith('.wav')]

    if not wav_files:
        print("\nNo WAV files found in sounds directory")
        return

    print(f"\nFound {len(wav_files)} WAV file(s)")
    print("-" * 50)

    # Process each file
    for filename in wav_files:
        input_path = os.path.join(sounds_dir, filename)
        print(f"\nProcessing: {filename}")

        # Check current sample rate
        try:
            with wave.open(input_path, 'rb') as wf:
                current_rate = wf.getframerate()
                print(f"  Current rate: {current_rate}Hz")

                if current_rate == target_rate:
                    print(f"  ✓ Already at {target_rate}Hz, skipping")
                    continue
        except Exception as e:
            print(f"  Error reading file: {e}")
            continue

        # Create backup
        backup_path = input_path + '.backup'
        source_path = input_path

        if not os.path.exists(backup_path):
            # Copy to backup instead of rename, so original still exists
            shutil.copy2(input_path, backup_path)
            print(f"  Backup created: {filename}.backup")
            source_path = backup_path
        else:
            print(f"  Using existing backup")
            source_path = backup_path

        # Resample
        output_path = os.path.join(sounds_dir, filename)
        if resample_wav(source_path, output_path, target_rate):
            print(f"  ✓ Successfully resampled to {target_rate}Hz")
        else:
            print(f"  ✗ Failed to resample, restoring backup")
            if os.path.exists(backup_path):
                os.rename(backup_path, output_path)

    print("\n" + "=" * 50)
    print("Resampling complete!")
    print("\nBackup files (.backup) have been created.")
    print("If everything works, you can delete them.")

if __name__ == "__main__":
    main()