Method of compressing a midi file

摘要

To compress a MIDI format file it is converted to a format 0 file. The format 0 file is then scanned to reduce the number of possible instruments to 16. MIDI commands having no sound output are then eliminated and NoteOn and NoteOff commands are replaced by a PlayNote command. This eliminates instances of DELTAtime equal to 0. Based on the characteristics of an appliance that has to play the compressed file, the notes are recentered in a bandwidth compatible with the appliance, after which the file is scanned to seek instances of polyphony. If an instance of polyphony exceeds the capacities of the appliance it is reduced in accordance with an instrument priority list and a note pitch.