Helpful scripts made to help to condition mp3 files to my old car mp3 player

fix_mp3_encode.sh

for f in *.mp3; do
  ffmpeg -hide_banner -loglevel error -i "$f" -vn -ar 44100 -ac 2 -sample_fmt s16 -b:a 320k -f mp3 "reencoded_$f"
done

fix_prefix_script.py

import re
from pathlib import Path

def fix_double_prefix(directory="."):
    path = Path(directory).resolve()
    renamed = []

    # Regex: match filenames like 12_34_SONGNAME.mp3 → keep 12 and SONGNAME
    pattern = re.compile(r"^(\d{2})_(\d{2})_([a-zA-Z0-9_]+)\.mp3$")

    for file in path.iterdir():
        if file.is_file() and file.suffix.lower() == ".mp3":
            match = pattern.match(file.name)
            if match:
                first_prefix, _, name_part = match.groups()
                new_name = f"{first_prefix}_{name_part}.mp3"
                new_path = file.with_name(new_name)

                if new_path.exists():
                    print(f"Error: Cannot rename '{file.name}' → '{new_name}' (target exists)")
                    continue

                file.rename(new_path)
                renamed.append((file.name, new_name))

    print(f"\nRenamed {len(renamed)} file(s):")
    for old, new in renamed:
        print(f"  {old} → {new}")

if __name__ == "__main__":
    fix_double_prefix()

rename_files_to_playlist_order.py

import os
import unicodedata
import re
from pathlib import Path

def sanitize_filename(filename):
    # Transliterate to closest ASCII equivalent
    normalized = unicodedata.normalize('NFKD', filename)
    ascii_str = normalized.encode('ascii', 'ignore').decode('ascii')
    # Replace non-alphanumeric characters with underscores
    safe_str = re.sub(r'[^a-zA-Z0-9_]', '_', ascii_str)
    # Avoid repeated underscores and trim leading/trailing
    safe_str = re.sub(r'_+', '_', safe_str).strip('_')
    return safe_str or "file"  # fallback to 'file' if empty

def make_unique(name, existing_names, suffix=""):
    candidate = name + suffix
    count = 1
    while candidate in existing_names:
        candidate = f"{name}_{count}"
        count += 1
    existing_names.add(candidate)
    return candidate

def rename_files_to_ascii(directory="."):
    path = Path(directory).resolve()
    if not path.is_dir():
        print(f"Error: '{directory}' is not a valid directory.")
        return

    renamed = []
    existing_names = set()

    for file in path.iterdir():
        if not file.is_file():
            continue

        original_name = file.name
        name_no_ext = file.stem
        ext = file.suffix

        sanitized_base = sanitize_filename(name_no_ext)
        sanitized_name = make_unique(sanitized_base, existing_names) + ext

        if sanitized_name != original_name:
            new_path = path / sanitized_name
            file.rename(new_path)
            renamed.append((original_name, sanitized_name))

    print(f"\nRenamed {len(renamed)} files:")
    for old, new in renamed:
        print(f"  {old} → {new}")

if __name__ == "__main__":
    rename_files_to_ascii()

sanitize_filename.py

import os
import re
from pathlib import Path

def strip_prefix(filename):
    """Remove NNN_ prefix from filename if it exists."""
    return re.sub(r'^\d{3,}_', '', filename)

def rename_mp3s_by_playlist(playlist_filename="__playlist.m3u"):
    playlist_path = Path(playlist_filename).resolve()
    base_dir = playlist_path.parent

    if not playlist_path.exists():
        print(f"Playlist file '{playlist_filename}' not found.")
        return

    # Try UTF-8 first, fallback to Latin-1
    try:
        with open(playlist_path, "r", encoding="utf-8") as f:
            lines = [line.strip() for line in f if line.strip() and not line.startswith("#")]
    except UnicodeDecodeError:
        with open(playlist_path, "r", encoding="latin1") as f:
            lines = [line.strip() for line in f if line.strip() and not line.startswith("#")]

    mp3_names_in_playlist = [Path(line).name for line in lines if line.lower().endswith(".mp3")]

    num_digits = len(str(len(mp3_names_in_playlist)))
    renamed = []

    for i, name_in_playlist in enumerate(mp3_names_in_playlist, 1):
        # Strip prefix from playlist entry (in case it's already renamed)
        target_base_name = strip_prefix(name_in_playlist)

        # Find actual file with or without prefix
        candidates = list(base_dir.glob(f"*{target_base_name}"))
        if not candidates:
            print(f"Warning: File matching '{target_base_name}' not found. Skipping.")
            continue

        # Use the first matching candidate
        original_path = candidates[0]

        new_prefix = f"{i:0{num_digits}d}_"
        new_name = new_prefix + target_base_name
        new_path = base_dir / new_name

        if original_path.name == new_path.name:
            print(f"Skipping: {original_path.name} (already correct)")
            continue

        if new_path.exists():
            print(f"Error: '{new_path.name}' already exists. Skipping rename of '{original_path.name}'.")
            continue

        original_path.rename(new_path)
        renamed.append((original_path.name, new_name))

    print(f"\nRenamed {len(renamed)} files:")
    for old, new in renamed:
        print(f"  {old} → {new}")

if __name__ == "__main__":
    rename_mp3s_by_playlist()