MPEG Interactive Musioc Application Format
MPEG doc#: N11012
Date: October 2009
In modern digital music, the producer or music engineer creates music contents as a single track through the recording, mixing and mastering processes. Therefore, it is impossible to control the specific instrument or vocal as user wants, because audio tracks were already mixed as one track.
For interactive music service, users can freely control the individual audio track because interactive music content is packaged with audio tracks before mixing process. And producers creates several versions (producer mixing 1, producer mixing 2, karaoke, rhythmic, and so on), and mixing rules, with one music piece using the metadata structure for mixing information.
2. Features of IM AF
An IM AF file is composed of:
- multiple audio tracks which represent the several parts of a song
- groups of tracks which define a hierarchical structure of audio tracks
- preset data which is pre-defined mixing information on multiple audio tracks
- rules which introduce specific data related to user’s interaction
- timed text, image and metadata
By means of an interactive music player, users can listen and handle audio tracks that compose an IM AF file. Two possible mix modes are defined for interaction and playback:
- Preset-mix mode: user selects one preset among the presets then audio tracks are mixed according to preset parameters associated with selected preset.
- User-mix mode: user selects/unselects the audio tracks/groups and/or controls the volume of each of them then each user’s interaction is analyzed in order to determine compatibility with rules defined by the producer and/or the artist.