Burn Red Book audio CDs or MP3 data CDs on macOS via cdrdao, sourcing from Hoodrat HDD or local files. Audio CDs carry CD-Text from ID3 tags; MP3 discs use ISO9660+Joliet (~700 MB). Handles full-album burns and cherry-picked playlists. Triggers on 'burn CD', 'burn album', 'make audio CD', 'mixtape disc', 'soundtrack for the car'.
Burn Red Book audio CDs or MP3 data CDs on macOS via cdrdao, sourcing from Hoodrat HDD or local files. Audio CDs carry CD-Text from ID3 tags; MP3 discs use ISO9660+Joliet (~700 MB). Handles full-album burns and cherry-picked playlists. Triggers on 'burn CD', 'burn album', 'make audio CD', 'mixtape disc', 'soundtrack for the car'.
Automated CD burning for macOS via cdrdao. Two modes:
Audio CD (default) — Red Book, plays in any CD player, 80-min capacity, CD-Text from ID3 tags
MP3 data CD (--mp3-disc) — plays in MP3-capable stereos (most 2005+ car head units), 700 MB capacity, ISO9660+Joliet filesystem
Turns "burn the BSG soundtrack to a CD" or "make an MP3 disc of these mantras" into a single command.
When to Use
User asks to burn an album, soundtrack, or playlist to an audio CD for a car stereo / home stereo
Source music lives on Hoodrat HDD (Mac Mini) or in a local folder
A USB CD burner is plugged into the current Mac
User wants either a Red Book audio CD or an MP3 data CD
Out of scope: DVD burning, CD ripping (use XLD — see ~/.claude/agent_docs/music.md), multi-session discs, DDP mastering, mixed-mode discs (audio + data on one disc).
Quick Start
Burn a full album from Hoodrat HDD with one command:
That runs the full pipeline: preflight → tar-over-SSH stage → duration check → parallel WAV conversion → TOC build with CD-Text → cdrdao write at 16x → cleanup → eject. Takes ~5–7 minutes for an 80-minute disc. cdrdao streams its own progress to stdout; a 10-second countdown precedes the actual burn so Ctrl-C still aborts safely.
Before the first burn, make sure a blank writable CD-R or CD-RW is in the drive — preflight.py will abort early if not.
The Pipeline
burn_audio_cd.py is the master orchestrator. It chains the stage scripts in sequence and halts on any failure, preserving staging for debugging. Each script is also independently usable.
Shared stages (both modes):
Stage
Script
What it does
1
preflight.py
Verifies cdrdao + ffmpeg, drive reachable, blank writable disc inserted. Retries drutil status for ~3 s after cdrdao drive-info (which briefly locks the drive). Surfaces the Unsupported drutil label as an informational note — cdrdao bypasses DiscRecording.
2
stage_tracks.py
Pulls source files. Remote sources (mac-mini-ts:/path) use tar-over-SSH, not rsync. Local sources use cp. Filters to one format (default mp3) to dedupe MP3+WMA and MP3+M4A siblings.
final
cdrdao write
Actual burn. --speed 16 --eject by default. Streams progress.
Audio CD stages (default):
Stage
Script
What it does
3
check_duration.py
Totals runtime via ffprobe. Aborts if the album overruns 80-min Red Book capacity. Prints a format histogram so leftover duplicates show up.
4
convert_to_wav.py
Parallel ffmpeg MP3→44.1 kHz/16-bit/stereo PCM (the exact Red Book format). Idempotent — skips WAVs already fresh.
5
build_toc.py
cdrdao TOC with CD_TEXT blocks. Pulls title/artist/album from the original source file's ID3 tags (WAVs don't carry ID3). Gapless by default; --gaps inserts 2-sec spacers.
cleanup
inline
Deletes <name>-wav/ on success. Keeps <name>/ MP3 staging for re-burns.
MP3 data CD stages (--mp3-disc):
Stage
Script
What it does
3
inline (orchestrator)
Sum of file sizes vs. 700 MB ceiling. Aborts if over.
4
build_data_toc.py
hdiutil makehybrid -iso -joliet builds an ISO9660+Joliet image containing the files. Emits a cdrdao data TOC (CD_ROM / TRACK MODE1 / DATAFILE). Volume label derived from --name (sanitized A-Z/0-9/_).
cleanup
inline
Deletes <name>.iso on success. Keeps <name>/ source staging for re-burns.
Scripts
All scripts support --help. All live under ~/.claude/skills/disc-forge/scripts/. Default staging root is ~/burn-staging/<name>/.
--mp3-disc — burn an MP3 data CD (ISO9660+Joliet) instead of a Red Book audio CD. 700 MB capacity, plays in MP3-capable car stereos (most 2005+ head units).
--data-ceiling N — MP3 data disc capacity ceiling in MB (default 700, only with --mp3-disc).
--dry-run — runs everything through TOC generation, skips the cdrdao write. Use to validate the whole pipeline on a disposable run.
--gaps — 2-sec spacers between tracks (pop albums). Default is gapless (right for OSTs, film scores, live albums). Audio mode only.
--speed N — cdrdao write speed multiplier. Default 16. Drop to 10 for maximum reliability on cheap media.
--keep-wavs — preserve the intermediate WAV staging dir (audio mode) or ISO (data mode) after the burn.
--ceiling N — audio CD capacity in minutes for the fit check. Default 80. Set to 74 for older 74-min media.
Recipes
Burn a full soundtrack from Hoodrat HDD (the canonical path):
Volume label derives from --name (sanitized to uppercase A-Z/0-9/_). Stage MP3s with numeric prefixes (01 Foo.mp3, 02 Bar.mp3) to force track order — most stereos play alphabetically. For MP4/Opus/M4A sources, transcode to MP3 first (stage_tracks.py filters to .mp3 by default).
Pop album with 2-sec gaps (Led Zeppelin, Pink Floyd, etc.):
python3 ~/.claude/skills/disc-forge/scripts/burn_audio_cd.py \
--source"mac-mini-ts:/Volumes/Hoodrat HDD/Musica/Dark Side Of The Moon/" \
--name DSOTM \
--gaps
Cherry-picked mixtape (tracks from multiple albums):
Stage tracks manually into a single folder first, then point the orchestrator at it:
mkdir -p ~/burn-staging/my-mixtape
scp "mac-mini-ts:/Volumes/Hoodrat HDD/Musica/Blade Runner - OST/01 Main Titles.mp3" ~/burn-staging/my-mixtape/
scp "mac-mini-ts:/Volumes/Hoodrat HDD/Musica/Inception OST [2010]/01 Half Remembered Dream.mp3" ~/burn-staging/my-mixtape/
# ... rename files with numeric prefixes to force desired order ...
python3 ~/.claude/skills/disc-forge/scripts/burn_audio_cd.py --source ~/burn-staging/my-mixtape --name my-mixtape
Track order is determined by sorted() on filenames — use numeric prefixes (01_, 02_, …) to force a specific sequence.
Critical Reminders
Full expansions (with why) live in references/gotchas.md.
SMB is not reachable over Tailscale. Port 445 is refused on mac-mini-ts; only port 22 works. Use SSH transport. stage_tracks.py already does this.
Apple's bundled rsync (openrsync 2.6.9) splits remote paths on spaces.stage_tracks.py uses tar-over-SSH instead. Never use rsync for Hoodrat HDD.
cdrdao 1.2.6 rejects MP3 input directly. The binary contains the literal string "AIFF and MP3 not supported by cdrdao". WAV conversion is mandatory — convert_to_wav.py handles it. (Burn.app is the alternative if you want to skip WAV conversion — see references/burn-app-fallback.md.)
drutil "Unsupported" label is a red herring for cdrdao. It only affects Apple's DiscRecording framework (Finder burn / Music.app burn / Burn.app), not cdrdao. preflight.py surfaces the label as a warning, not an error.
CD-Text must come from source ID3 tags, not WAVs. PCM WAV has no tagging container. build_toc.py reads tags from the original file, references the matching WAV in AUDIOFILE.
macOS Sequoia killed Music.app and Finder's burn-to-disc. Don't fall back to them.
References
File
Contents
references/gotchas.md
Full expanded failure-mode inventory from the author's first burn. Every trap explained with why, so the rule generalizes to novel drives and macOS versions.
references/cdrdao-toc-format.md
cdrdao TOC syntax cheatsheet: minimal skeleton, CD_TEXT blocks, PREGAP semantics, special-character escaping, how to run cdrdao show-toc to validate.
references/hoodrat-layout.md
Pointer to ~/.claude/agent_docs/music.md (the canonical Hoodrat HDD layout) plus a one-line cheatsheet.
references/burn-app-fallback.md
If cdrdao refuses the drive: Burn.app GUI fallback with exact click sequence.
Dependencies
cdrdao — brew install cdrdao
ffmpeg + ffprobe — brew install ffmpeg
SSH access to mac-mini-ts (only when sourcing from Hoodrat HDD)
A USB CD burner that speaks MMC. The ASUS SDRW-08U9M-U works despite drutil labeling it Unsupported.
