Audiofile DDP — Help
Professional DDP disc image playback, mastering-grade analysis, and signed branded delivery for macOS and iOS.
Requirements
- macOS 14 (Sonoma) or later
- iOS 17 or later (artist playback app)
Getting Started (macOS)
- Choose File → Import DDP Image… (⌘O) and select the folder containing the DDP descriptor files (DDPID, DDPMS, image.dat, etc.).
- Imported discs appear in the sidebar library — click to load. The library persists across launches.
- Click any track in the track list to seek to it and start playback.
- The transport shows two timelines: a Track bar (position within the current track) and a Disc bar (position across the full disc). Drag either to scrub.
Disc & Track Metadata
The Identification panel surfaces every PQ field the engineer cares about:
- UPC/EAN — disc-level barcode
- ISRC — per-track recording code (visible in the row and in the panel for the selected track)
- Master ID — DDP master identifier
- DDP User Text — free-form engineer note from the DDP master
- Start / Duration / End — Red Book timecode (MM:SS:FF at 75 fps) for the selected track
- SCMS — copy-management flag
- CD-Text — Title, Performer, Songwriter, Composer, Arranger, Message
Mastering-Grade Analysis
The Analysis panel runs a single audio tap into multiple meters at the post-engine point — the same signal you hear. The meters follow mastering-meter convention (ADPTR StreamLiner, iZotope Insight, Pro-L 2): live values track the program in real time; "max" indicators only ever move up when the live value exceeds them, never decay on their own, and are cleared together by the Reset button.
- Peak / Level — L/R bargraphs with analog-needle ballistics. The peak tick on each bar is the bar's true high-water-mark — pushed up by the bar, never decays. Pk L / R numeric readouts beneath the bars give you the exact dBFS values (red at clip).
- LUFS — momentary (M, 400 ms), short-term (S, 3 s), and integrated (I, gated, since reset) loudness per EBU R128 / ITU-R BS.1770-4. The tick on the LUFS bar is Max-M (highest momentary loudness reached since reset).
- LRA — loudness range (R) per EBU Tech 3342.
- LUFS targets — quick-reference buttons for −23 LUFS (broadcast) and −14 LUFS (streaming).
- Phase / Goniometer — Lissajous stereo display with correlation meter.
- Reset — one click clears every session high-water-mark together: VU peak, Max-M, Max-S, Integrated, LRA. Tapping the I readout has the same effect.
When you pause, the live bars coast smoothly to floor and the goniometer fades to center. The peak indicators (VU peak tick, Max-M, Max-S) hold their values across pause and resume — pause is not a reset event, only the Reset button is.
Bit-Perfect Playback
Audiofile DDP plays each disc bit-perfect by default. On macOS, when the connected output device supports 44.1 kHz, the engine switches the device to 44.1 kHz and bypasses sample-rate conversion entirely. If the device cannot do 44.1 kHz (or you've disabled bit-perfect), the engine falls back to r8brain SRC at its highest quality with linear phase.
On iOS, the audio session enforces the device rate (typically 48 kHz). Audiofile DDP routes through the same r8brain SRC at .highest, replacing AVAudioSession's lower-quality implicit conversion.
When the app quits, any device whose sample rate Audiofile DDP changed is restored to its launch-time rate so other apps don't inherit DDP's bit-perfect choice.
Audio Output (macOS)
Open Settings → Output to choose how playback reaches your interface. Mastering engineers shouldn't have to guess which output macOS picked — pin the choice here and Audiofile DDP routes there.
- Output Device — pick from every CoreAudio device installed on the Mac. Configure… opens Audio MIDI Setup with the current device pre-selected.
- Sample Rate — shows the device's current rate. Read-only because bit-perfect mode is locked on for DDP — every file is 44.1 kHz, so the engine drives the device rate from the file. The caption explains why.
- Channel Routing — if your interface has more than two outputs, the matrix lets you map L / R to specific output channels (main monitors on 1–2, sub on 3–4, headphone amp on 5–6, etc.). Reset to Default restores stereo passthrough.
Your selections persist across launches (per device for routing).
Studio Profile
Open Settings → Studio to configure the identity that brands every delivery:
- Studio name, website, contact email
- Logo — drop a PNG or JPEG; appears on the artist's playback screen
- About — short studio description
- Welcome Message Template — default greeting for the artist on first open. Supports
{artist}and{title}placeholders.
Artist Profiles
Open Settings → Artists to save artists you deliver to repeatedly. Each artist can have:
- Name and contact info
- Default cover art (used when the export sheet's Cover Art field is empty)
- A per-artist welcome message override that supersedes the studio template
Branded Delivery Export
Choose File → Export Branded Bundle… (⇧⌘E) to produce a signed .audiofileddp bundle for the artist. The export sheet pulls in the Studio block automatically and lets you set:
- Artist — pick from your saved profiles, or leave as None.
- Album Title — seeded from CD-Text or the DDP folder name; editable.
- Cover Art — drop an image to override the artist's default for this delivery.
- Track Filenames — pick a preset or write a custom pattern. Tokens:
{number},{title},{artist},{album}. The picker shows a live preview ({number} {title}→01 Overture.wav). - Welcome Message — auto-filled from the studio + artist defaults; editable per delivery.
The save panel suggests {album} — {artist}.audiofileddp as the default filename. After export, Finder reveals the bundle so you can drop it into your delivery pipe.
PQ Sheet & WAV Export
- Export PQ Sheet… (⇧⌘P) — printable PDF with disc-level metadata and per-track times, ISRC, and CD-Text.
- Export All Tracks as WAV… (⇧⌘W) — pick a destination folder; each track is decoded to a separate WAV at the disc's native rate.
- Right-click any track and choose Export as WAV… for a single-track export.
iOS — For Artists Receiving a Bundle
The iOS app opens signed .audiofileddp bundles delivered by your engineer. There is no IAP and no separate "player maker" — opening a valid signed bundle is what unlocks playback.
- Tap the bundle from Files, Mail, Messages, AirDrop, or an iCloud share link. Audiofile DDP launches and verifies the engineer's signature.
- If the app isn't installed, iOS offers to find it in the App Store directly from the bundle's preview.
- Full hero album view with cover art, track list, mastering meters (peak / LUFS / phase), and transport controls.
- One-tap Send Feedback opens an email pre-filled with the disc title, artist, track, and current playhead timestamp.
Keyboard Shortcuts (macOS)
| Play / Pause | Space |
| Next Track | ⌘→ |
| Previous Track | ⌘← |
| Skip Forward 5s | → |
| Skip Back 5s | ← |
| Next Transition | ⇧⌘→ |
| Previous Transition | ⇧⌘← |
| Import DDP Image | ⌘O |
| Export Branded Bundle | ⇧⌘E |
| Export All Tracks as WAV | ⇧⌘W |
| Export PQ Sheet | ⇧⌘P |
| Audiofile DDP Help | ⌘? |
Diagnostics
If something goes wrong, choose Help → Send Diagnostic Report…. Audiofile DDP collects crash and hang reports automatically via MetricKit and stores them locally in ~/Library/Application Support/DDP Player/Diagnostics/. The Send Diagnostic Report command opens a pre-filled email with the most recent reports attached so support can start with data, not back-and-forth.
Troubleshooting
DDP won't import
Make sure you're selecting the folder that contains the DDP descriptor files (DDPID, DDPMS, image.dat, etc.), not a parent directory.
No audio on playback
Check the output device in Settings → Output first — that's where Audiofile DDP routes audio, and it overrides macOS's "default" device. If the device is right but you still hear nothing, check System Settings → Sound in case the device isn't connected or its volume is muted at the OS level. DDP audio is PCM at 44.1 kHz / 16-bit (Red Book); make sure the selected output supports 44.1 kHz, or expect bit-perfect mode to fall back to r8brain SRC.
Tracks show incorrect times
This usually indicates a malformed PQ sheet in the source DDP master. Verify the source DDP with the mastering engineer who produced it.
iOS won't open a bundle
Audiofile DDP for iOS only opens .audiofileddp bundles produced by the macOS branded-export flow. Plain DDP folders and bare zip archives are a mastering-engineer concern and are handled by the macOS app. If a bundle won't open, ask your engineer to re-export from Audiofile DDP for macOS.
Contact Support
Questions or issues? Reach us at support@audiofile.engineering. Sending a Diagnostic Report from the Help menu helps us reproduce problems much faster.