The format is known to carry audio streams encoded with:
A typical OMA file consists of the following three parts:
- metadata container
- extended audio header
- actual sound data
The metadata container carries overall music info. Except for starting with "ea3" instead of "ID3", it's fully compatible with the ID3v2 format. It uses standard ID3v2 frame types, such as TIT2, TPE1, TALB and TCON. In addition to these standard frame types, TXXX and GEOB frames contain OpenMG-specific metadata.
TXX OMG_TRACK "track number (ASCII)" TXX OMG_AGENR "content description (ASCII)" TXX OMG_ATPE1 "leader performer (ASCII)" GEOB OMG_BLKSI contains a metadata structure. observed strings include: KEYRING EKB SHARE_P_SID REFID GEOB OMG_OLINF binary blob
Extended audio header
Extended audio header contains information about the encapsulated OpenMG audio. This includes codec type, codec specific info (packet size, sample rate, channels and so on) as well as DRM related info (file encryption, content id).
Encrypted or plain-text sound data organized in packets follows the extended audio header.
The OMA file format contains a payload scrambled with a 32-bit value .