This script compresses audio files in a specified folder using FFmpeg. It reduces the file size by adjusting the bitrate and sample rate.

ffmpeg.compress.py

## Dependencies
#- [FFmpeg](https://ffmpeg.org/download.html): Make sure FFmpeg is installed and accessible from the command line.

## Usage
#```sh
#python ffmpeg.compress.py [input_folder] [--bitrate TARGET_BITRATE] [--sample_rate SAMPLE_RATE]
#python ffmpeg.compress.py ./audio_files --bitrate 128k --sample_rate 44100

import subprocess
import os
import argparse

def compress_audio(input_file, output_file, target_bitrate="64k", sample_rate=16000):
    """
    Compress an audio file to reduce its size.
    
    Args:
        input_file (str): Path to the input audio file.
        output_file (str): Path to the output audio file.
        target_bitrate (str): Target audio bitrate (e.g., '64k', '128k', etc.).
        sample_rate (int): Audio sample rate in Hz.
    """
    try:
        # FFmpeg command to compress audio
        command = [
            "ffmpeg",
            "-i", input_file,        # Input file
            "-b:a", target_bitrate,  # Target bitrate
            "-ar", str(sample_rate), # Sample rate
            "-ac", "1",              # Mono (single channel)
            output_file              # Output file
        ]
        subprocess.run(command, check=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
        print(f"Compression completed: {output_file}")
    except subprocess.CalledProcessError as e:
        print(f"Error compressing {input_file}: {e}")

def process_folder(input_folder, target_bitrate="64k", sample_rate=16000):
    """
    Process all audio files in a folder.
    
    Args:
        input_folder (str): Folder containing the audio files.
        target_bitrate (str): Target audio bitrate.
        sample_rate (int): Audio sample rate in Hz.
    """
    if not os.path.exists(input_folder):
        print("The specified folder does not exist.")
        return
    
    # Create an output folder
    output_folder = os.path.join(input_folder, "compressed_files")
    os.makedirs(output_folder, exist_ok=True)
    
    # Scan all audio files in the folder
    for filename in os.listdir(input_folder):
        input_path = os.path.join(input_folder, filename)
        
        # Filter only audio files with specific extensions
        if os.path.isfile(input_path) and filename.lower().endswith((".m4a", ".mp3", ".wav", ".aac")):
            # Add the .compress suffix before the extension
            base_name, ext = os.path.splitext(filename)
            output_filename = f"{base_name}.compress{ext}"
            output_path = os.path.join(output_folder, output_filename)
            
            # Compress the file
            compress_audio(input_path, output_path, target_bitrate, sample_rate)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Compress audio files in a folder.")
    parser.add_argument("input_folder", nargs="?", default=".", help="Folder containing the audio files to compress (default: current folder)")
    parser.add_argument("--bitrate", default="64k", help="Target audio bitrate (default: 64k)")
    parser.add_argument("--sample_rate", type=int, default=16000, help="Audio sample rate in Hz (default: 16000)")
    
    args = parser.parse_args()

    print("Starting audio file compression...")
    process_folder(args.input_folder, args.bitrate, args.sample_rate)
    print("Compression completed for all files.")