(a) What is MIDI? How is a basic MIDI message structured?
(b) In what ways can MIDI be used effectively in Multimedia Applications, as opposed to strictly musical applications?
(c) How can MIDI be used with modern data compression techniques? Briefly describe how such compression techniques may be implemented.
(a) What is MIDI ? How is a basic MIDI message structured ?
MIDI : a protocol that enables computer, synthesizers, keyboards, and other musical or (even) multimedia devices to communicate with each other.
MIDI MESSAGE:
• MIDI message includes a status byte and up to two data bytes.
• Status byte
The most significant bit of status byte is set to 1.
•The 4 low-order bits identify which channel it belongs to (four bits produce 16 possible channels).
•The 3 remaining bits identify the message.
•The most significant bit of data byte is set to 0.
(b) In what ways can MIDI be used effectively in Multimedia Applications, as opposed to strictly musical applications ?
Many Application: Low Bandwidth/(Low Quality?) Music on Web, Quicktime etc supports Midi musical instrument set Sound Effectts --- Low Bandwidth alternative to audio samples, Sound Set part of GM soundset Control of external devices --- e.g Synchronistaion of Video and Audio (SMPTE), Midi System Exclusive, AUDIO RECORDERS, SAMPLERS Control of synthesis --- envelope control etc MPEG 4 Compression control --- see Part (c) Digital Audio
(c) How can MIDI be used with modern data compression techniques?
Briefly describe how such compression techniques may be implemented?
• We have seen the need for compression already in Digital Audio -- Large Data Files
• Basic Ideas of compression (see next Chapter) used as integral part of audio format --
MP3, real audio etc.
• Mpeg-4 audio -- actually combines compression synthesis and midi to have