AudioCDBurner

A simple, native macOS app for burning Red-Book audio CDs from MP3 / FLAC / AAC / M4A / WAV / AIFF / ALAC files. Written in Swift + SwiftUI, using Apple's DiscRecording.framework.

Author: Robert Vloothuis (rvlo) Bundle ID: rvlo.AudioCDBurner

Features

• Drag & drop or "Add Files…" import (FLAC, MP3, AAC, M4A, WAV, AIFF, ALAC)
• Numbered track list, reorderable, with per-track duration
• Live total-time display with 80-min capacity warning (soft warning at 79:30)
• Disc title (CD-Text), capped to 64 characters
• Gap mode: 2 second gap (Red-Book default) or Gapless
• Auto-discovers CD/DVD burners; "Rescan" button picks up drives plugged in after launch
• Per-drive supported burn-speed picker, plus "Max"
• Auto-eject when the burn finishes (and on failure)

Building

1. Open AudioCDBurner.xcodeproj in Xcode 15 or newer.
2. Select the AudioCDBurner target → Signing & Capabilities → set your Team.
   • Bundle identifier is rvlo.AudioCDBurner. Change it if you prefer.
   • "Automatically manage signing" works fine for personal/Developer ID signing.
3. Choose My Mac (Apple Silicon) as the run destination and press ⌘R.

Deployment target is macOS 14, so it runs on Sonoma, Sequoia, and Tahoe. Apple Silicon native; Intel still works (universal binary by default).

Notes / design

• All input files are decoded once into a temporary AIFF in CD-DA format (44.1 kHz, 16-bit signed big-endian, stereo) using AVFoundation + AudioToolbox. This makes FLAC/MP3/AAC/etc. work uniformly through DRTrack(forAudioOfURL:) and gives exact sector counts.
• Gapless mode sets DRPreGapLengthKey = 0 on tracks 2…N and DRAudioPreGapIsSilentKey = false so consecutive tracks are joined without silence (track 1 still has the standard 2-second pre-gap that the Red-Book spec requires).
• 2-second mode leaves the default 150-frame pre-gap untouched.
• Speed 0 in the picker means "let the drive use its maximum" (DRDeviceBurnSpeedMax). Other values are taken from DRDeviceBurnSpeedsKey of the currently inserted disc.
• The disc title is attached to the first track via DRCDTextSpecialAlbumKey, which DiscRecording uses to populate the CD-Text album field.
• The app is sandboxed with com.apple.security.device.optical-drive and com.apple.security.files.user-selected.read-only, so it has exactly the entitlements it needs and nothing more.

Limitations / things to know

• DiscRecording itself does not let you append to a multi-session audio CD; this app always burns a single closed audio session, which is what every consumer CD player expects.
• macOS sandbox + DiscRecording require the user to actually click "Burn" with a writable disc inserted; nothing in this app burns silently.
• If you want per-track CD-Text (title/performer per track), the framework supports it via DRCDTextSpecialPerformerKey / DRCDTextSpecialTitleKey on each DRTrack. The current UI is intentionally minimal (disc title only).