🎞 Mixtape Organizer

Auto-arrange your music collection across both sides of a cassette tape and export named .m3u8 playlists — perfect for recording your own mixtapes.

  ╔══════════════════════════════════════════════╗
  ║     🎵  Mixtape Organizer  v2.0              ║
  ║  Auto-fill both sides of a cassette tape     ║
  ║  by CrueChan                                 ║
  ╚══════════════════════════════════════════════╝

  Music folder path: /home/user/music/summer-vibes
  Scanning…
  22 tracks found  │  Total duration: 78:42 (78.7 min)

  Mixtape title (used in output filenames) [My Mixtape]: Summer Vibes
  Suggested tape: 90 min  (smallest standard size for all tracks)
  Tape length (minutes) [90]:
  Gap between tracks (seconds) [4]:
  Save playlists to [/home/user/music/summer-vibes]:

  🎞  Summer Vibes  │  90-minute tape
  ──────────────────────────────────────────────────────────
  SIDE A  [████████████████████░░░░░░░░] 87%  38:54 / 45:00
  ──────────────────────────────────────────────────────────
   1. Where Do I Begin                              [4:22]
   2. Fade Into You                                 [4:50]
   ...
  ──────────────────────────────────────────────────────────
  11 tracks  │  Total: 38:54

  ✓  Playlists saved to: /home/user/music/summer-vibes
     Summer_Vibes_C-90_Side_A.m3u8
     Summer_Vibes_C-90_Side_B.m3u8

Features

• Scans a folder for audio files (MP3, FLAC, WAV, M4A, OGG, AAC, Opus, APE, WavPack)
• Suggests the right tape size — shows the smallest standard cassette that fits all your tracks
• Balances both sides using a greedy longest-first algorithm, then refines with iterative swapping
• Named output files — e.g. Summer_Vibes_C-90_Side_A.m3u8
• Configurable output folder — save playlists anywhere
• Adjustable gap — set the silence between tracks in seconds
• Interactive overflow handling — when tracks don't fit, you decide how much extra time to allow (can loop until everything fits or you choose to skip the rest)

Requirements

• Python 3.11 or newer
• mutagen

Windows note: coloured output and progress bars require Windows Terminal or PowerShell 5.1+. The program works fine in the legacy cmd.exe prompt too — it simply falls back to plain text with no colour.

Installation

With uv (recommended)

# Clone the repo, then:
uv run main.py

uv reads pyproject.toml and installs dependencies automatically. On Windows, install uv with:

winget install astral-sh.uv

With pip

pip install mutagen
python main.py

On Windows you may need to use py instead of python:

py -m pip install mutagen
py main.py

Usage

python main.py

The program walks you through these steps interactively.

Windows tip: when prompted for a folder path, you can drag-and-drop a folder from File Explorer into the terminal window — it pastes the full path automatically (with quotes, which the program strips for you). Both backslash (C:\Users\yourname\Music) and forward-slash paths are accepted.

Step	Prompt	Notes
1	Music folder path	Scanned non-recursively by default
2	Include music in sub-directories?	Default: No
3	Mixtape title	Sanitised and used in output filenames
4	Tape length (minutes)	Standard sizes suggested automatically
5	Gap between tracks (seconds)	Default: 4 s
6	Save playlists to	Defaults to the music folder

If some tracks don't fit within the tape length (plus 1 minute default tolerance per side), you'll be asked whether to allow a longer total duration and how many extra minutes per side to add. This loop repeats until everything fits or you choose to skip the remaining tracks.

Output

Two .m3u8 playlist files, one per side:

Summer_Vibes_C-90_Side_A.m3u8
Summer_Vibes_C-90_Side_B.m3u8

These can be opened in VLC, foobar2000, Winamp, Clementine, or any player that supports M3U playlists. Each entry uses a path relative to the playlist file, so the playlist is portable — move the whole folder and it still works.

Algorithm

1. Scan — read audio metadata (duration) via mutagen
2. Pack — sort tracks longest-first; greedily assign each to the shorter side as long as it fits within the limit
3. Balance — iteratively swap tracks between sides to minimise the duration difference, without exceeding the limit
4. Export — write M3U8 files with relative paths (portable across machines)

Standard cassette tape lengths

Minutes	Common name
46	C-46
60	C-60 (most common)
74	C-74
80	C-80
90	C-90
100	C-100
120	C-120

Full list supported: 5, 10, 20, 30, 40, 46, 50, 54, 60, 64, 70, 74, 80, 90, 100, 120, 150 minutes.

Supported audio formats

.mp3 · .flac · .wav · .m4a · .ogg · .aac · .opus · .ape · .wv

License

MIT