Explanation of the DDP mastering format

CD sales may be on the decline, but there are still many musicians who need master’s degrees ready for CD duplication. The chosen format is DDP, which stands for Disk Description Protocol. Everything you need to know is explained here …

How we used to do it …

For many years, the standard way to provide a replication-ready master was to create a “redbook” master CD. This was a high quality CDR created on a CD burner. It worked, but there were several downsides. The physical media had to be manually verified several times during the process from initial creation to final replication. Unfortunately, all CDRs contain errors and can sometimes be rejected by the duplication company. Discs are vulnerable to damage and can break easily. Also, it takes additional time and expense to mail them. Garbage!

How do we do it now …

In 2016, the standard and preferred method of shipping a master CD is to provide a ‘DDPi image’ (Disk Description Protocol Image). This format is designed to transport the content of optical discs that include CDs. The DDP is a set of files and must contain five parts.

• Audio image (.DAT file)

• DDP Identifier (DDPID)

• DDP Flow Descriptor (DDPMS)

• Subcode descriptor (PQDESCR)

• Also included is a text file containing track titles and times.

These files can be stored on a hard drive or sent over the Internet. It is a very robust format that has a built-in error checking system (MD5 checksum). This ensures that the masters have not been tampered with and will be identical to what ends up on the replicated CD. The total file size will not exceed 750MB and can be easily sent via a file transfer service or FTP. So there are no postage costs or delays waiting for the postman. The only downside to the DDP format is that it cannot be played on a normal CD player. However, you can get a free PC / Mac software player that will load the DDP file so you can play your CD. You can also check the track IDs, CD text, ISRC codes, and spaces between songs. Smart stuff.

All CD replication companies must accept the DDP format. If not, I would definitely recommend that you change companies. This is a strong indication that they are out of date or not in a good reputation. Also, beware of additional fees to provide your teacher as a DDP.