DDP: Disc Description Protocol, also referred to as DDPi (DDP Image) or DDP File Set. An error-protected audio delivery format that has become the industry standard for reliable CD & DVD replication.
Think of it as a virtual image of a compact disc that can be easily transferred via the internet.
A CD plant will replicate discs from the exact same DDP image I deliver, so what you hear and see on the DDP is exactly what will be on your replicated CDs.
The DDP image is not a single file, but a folder. All files inside this folder belong to the DDP image and must always be used in this combination.
Additionally there is usually a MD5 checksum file. Using a checksum ensures that the single files of the image have not been modified or corrupted during transfer over the internet.
How Do I Play My DDP?
In order to play a DDP image in your computer a specialised player is required. Such a player is included Inside the DDP image folder I supply.
To play the DDP image simply double-click the appropriate player for your operating system and the player will launch and load the DDP.
IMPORTANT: The DDP player will only work with its enclosing DDP folder. Do not move the DDP player to another location.
From the DDP player you can:
- Listen to the master like a virtual CD player on your computer
- Burn a reference CD-R
- Export each track as a 16-bit/44.1kHz WAV file or mp3
Distributing DDP Images
I deliver the DDP image as a compressed ZIP file. When sending the DDP image to the CD pressing plant you should use this original ZIP file.
This ensures that all files are received with the original subfolder structure. If the folder structure is modified, the plant may not be able to open the DDP image.
ISRC
The ISRC (International Standard Recording Code) is an identifier that is unique for a track on a CD. When the track is played on the radio, this code can be used to manage license fees.
The ISRC consists of two letters followed by a 10 digit number. The single parts are:
- Country code (2 letters)
- Registrant code (3 digits)
- Year (2 digits)
- Designation code (5 digits)
Example: A recording of the song “Crazy Eyes” by American duo Daryl Hall & John Oates has been allocated the ISRC code USRC17607839:
- US for United States
- RC1 for RCA
- 76 for 1976
- 07839 as the unique id identifying this particular recording
The ISRC is always provided by a registrant and always belongs to a specific recording of a song. If a song is re-released, for example, on a compilation, it will keep its ISRC. Remixes will require a new code.
Click here for further information on ISCR.
UPC/EAN
The UPC (Universal Product Code) or the EAN (European Article Number) are the numbers under the bar code found on the packaging of any product. This number can also be stored within the CD data.
This code is also provided by a registrant. It is a number with 12 (UPC) or 13 (EAN) digits. A 12-digit UPC will be displayed as 13 digit number with a leading zero, as this is mandatory for CDs and DDP images.
CD-Text
CD-Text is an extension to the CD “red book” standard which is supported by several hardware CD players.
Be aware that when playing a CD in your computer, not every software player will show CD-Text information. The title information is commonly downloaded from the internet (such as Gracenote) and can differ from the information that is stored on the CD itself.
Apple iTunes and Windows Media Player do not show any CD-Text information!
However, there are extensions and other players that make it possible. For example:
- Extension for iTunes
- Extension for Windows Media Player
- VLC Media Player
- drutil – type drutil cdtext in the Terminal window. This will list all CD-Text information contained on the CD in plist format.
CD-Text can store the following information for the entire album and for each track:
- Title
- Artist/Performer
- Songwriter
- Composer
- Arranger
- Additional message
You can also specify a genre for the entire album.