Patent · US Expired

Method of compressing a midi file

US6525256B2 · kind B2 · utility

10Cited by
6References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 18, 2001
Grant dateFeb 25, 2003
Priority date
Expiry dateApr 18, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG10H2240/285
  • WIPO fieldOther consumer goods
  • WIPO sectorOther fields

Abstract

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 &Dgr;time 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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.