DDP Delivery
A DDP packages album audio, PQ data and metadata into one verifiable delivery set.
Related
DDP is not an audio format but a delivery container: one continuous album image, track starts and indices, ISRC, CD-Text and checksums. A plant can cut glass from it without guessing the running order or the gaps.
What the package contains
A usable DDP usually holds a continuous audio image, a PQ description, metadata and a checksum file. The audio is commonly 16-bit / 44.1 kHz PCM to Red Book; loudness and true peak are final before delivery, and no processing changes at the DDP stage. PQ carries track starts, indices, gaps and pre-gaps; metadata carries album, artist, ISRC and CD-Text; the checksum is MD5 or whatever the plant specifies.
Track edges and attacca
Track edges are the usual failure point. In Beethoven's Op. 27 No. 1 the first two movements are marked attacca and the third runs into the fourth, so the music never stops, yet the CD still needs track marks. Put the marks at phrase boundaries with zero gap instead of inserting silence. When a live recording or a song sequence does need air, write the pre-gap and fades into the PQ sheet rather than fixing them by hand later.
Who does what
| Item | Carries | Must not contain |
|---|---|---|
| DDP image | Continuous audio and PQ | A second limiter pass, an unfinalised mix |
| PQ sheet | Order, indices, gaps | Marks moved by ear at the last minute |
| Metadata | Album, artist, ISRC, CD-Text | Spellings that disagree with registrations |
| Checksum | Transfer integrity | An editable audio file |
Check and listen
Audition the DDP as a real CD, from the first second of track one to the last second of the finale. Check that no start clips an attack, no gap adds silence and no ending is cut. Compare source and image with a checksum tool. Then check every ISRC and track number on the plant's receipt, not just the file names.
Where it goes wrong
A 24-bit master dropped into a DDP may be rejected. An unfinalised running order means rebuilding the image. Limiting or dithering after the DDP replaces a file that was already verified. DDP suits albums and CD release, not a single-track streaming upload, and not archiving on its own; keep stems, sessions and the unlimited master as well.
Listen in the library
All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).
Along the same line
Sources
- Red Book（IEC 60908）— CD-DA 的采样率、位深与通道规格。
- DDP 2.0 规范与唱片厂交付惯例 — 映像、PQ 与校验文件的组成。
- ISRC 与 CD-Text 的登记与写入规则 — 对照 IFPI 与国家 ISRC 管理机构的公开说明整理。