See below for more in-depth descriptions of our accepted formats.
1.1 DDP (Disc Description Protocol)
A DDP is used to write a CD image on a hard disk/data disk, and is the standard delivery format for CD replication. A DDP consists of 3 metadata files: DDPPQ, DDPMS & DDPID. These files contain information pertaining to ISRC’s, Index locations and all other master metadata. Along with the metadata files, the DDP contains “.trk” files which hold the actual audio for the DDP. A .trk file is a DDP’s version of a .wav file. DDP’s can be created in the following formats:
- DDPi: This is the standard DDP output for most audio mastering or audio editing programs. The DDP holds all three metadata files along with a “Image.DAT” file which contains the audio.
- DDP 1.0: This level of DDP covers the Red Book, Yellow Book and Green Book audio formats.
- DDP 2.0: This level of DDP covers the same formats as DDP 1.0, but adds Multi-Session capabilities.
CD Text or text is product metadata that shows up on text-compatible CD players, displaying information such as artist name, album name, track name, etc. This should not be confused with the metadata that is displayed by iTunes and other digital distribution download networks. Text can be supplied encoded on the DDP provided for registration (Native) or it can alternatively be encoded onto the DDP on export from AOMA, using the label copy information in GRAS.
A PMCD (PreMaster CD), is the physical equivalent of a DDP and is a standard delivery format for CD replication. Like DDPs, they can additionally carry copy protection, CD text, ISRCs and other master metadata with the audio. While similar to a standard “Audio CD” formatted CD-R, a PMCD is specifically designed/formatted for replication, encoded as ‘burn proof’ and is typically tested by the supplying mastering facility to ensure a low read-error rate. Compared with DDPs, PMCDs are generally not as highly recommended as there is a slightly higher risk of a burn or read error (see section 1.1).
2.1 WAV and AIFF
WAV and AIFF files are lossless digital audio file formats that capture waveform data using a 16, 24, or 32float bit depth with a number of different sample rates. The higher the bit depth and sample rate, the higher resolution of the audio. Typically audio with 24 or more active bits is referred to as HiRes or HD.
The main difference between WAV and AIF is the formatting of the Resource Interchange File Format (RIFF) for WAV, and the Audio Interchange File Format (AIFF) for AIF. Broadcast .Wav files (BWF) can carry additional non-standardized information in the header section of the file, including markers (which are sometimes requested by vinyl cutting engineers).
2.2 ADM (formerly MFiT)
ADM is a delivery standard and testing system designed to encourage delivery of higher-resolution audio, while minimizing the encoding/decoding errors caused when converting to and from Apple’s AAC format. Apple requires that ADM masters be created at an ADM-certified mastering facility. Additionally, Apple requires 24bit WAV files (with 24 active bits), and a minimized number of sample and intersample peaks. Apple lastly encourages ADM masters to be delivered at the highest possible sample rate without upconversion (ideally 96kHz), although they accept sample rates as low as 44.1kHz. Masters that meet the above requirements will be given the “Mastered For iTunes” badge and will be marketed as such.
3.1 Side WAV
A side wav is a single wav file that contains all tracks for a single physical side of a component (typically vinyl or cassette, i.e. ‘Side A’, ‘Side B’, etc.)
Track index markers are encoded/carried in the header section of Broadcast WAV files (BWFs). The ability to encode and especially read these markers consistently across multiple workstations is a relatively new technology. That said, delivery of vinyl side WAVs containing these markers is sometimes requested/required by vinyl cutting engineers.
4.1 DSD (Direct Stream Digital)
DSD is a high resolution audio format that has a bit depth of 1 and an ultrafast sample rate. It is used for the Hi Res layer on all SACD discs. DSD audio can be converted to individual digital files (.dsf), which can be registered to AOMA. DSD sample rates can be 2.8224MHz (DSD64), 5.6448MHz (DSD128), or 11.2MHz (DSD256).
4.2 SACD (Super Audio Compact Disc)
The SACD format is a high resolution physical audio disc. It utilizes the DSD format (1 bit with a 2.8224MHz sampling rate). There are three types of SACD.
- Hybrid – The Hybrid SACD contains both a DSD layer as well as a PCM (normal audio CD) layer.
- Single-layer – Contains only the DSD high resolution layer on a DVD-5.
- Dual-layer – Contains two DSD layers on a DVD-9. This has twice the data.