.MID File Format – Universal system exclusive

Sample dump (01, 02, 03)

A dump of audio data, a sample at a time. Numbers across several bytes hold seven bits a byte, the least significant byte first.

MIDI Time Code cueing (04)

Bytes after the sub-IDs: hr mn sc fr ff sl sh and additional information. The hours byte holds the frame rate in bits 5 and 6, as in MIDI Time Code itself. sl sh is an event number. Additional information is a run of bytes split into two nibbles each, the low nibble first.

Sample dump extensions (05)

Identity request and reply (06)

06 01 asks a device to identify itself and has no body. The reply is:

7E <device> 06 02 <manufacturer> <family> <member> <software revision>

The manufacturer is one byte or 00 and two more; the list of IDs gives their names. Family and member are 14-bit numbers, LSB first, and the software revision is four bytes; what they mean is up to the maker.

File dump (07)

MIDI Tuning Standard (08)

A tuning program gives each MIDI key a pitch as a semitone number xx and a 14-bit fraction yy zz of a semitone, in steps of 100/16384 of a cent; 7F 7F 7F means no change.

General MIDI (09)

01 General MIDI 1 system on; 02 General MIDI system off; 03 General MIDI 2 system on. Files often send one at the start. No body.

Downloadable Sounds (0A)

01 turn DLS on, 02 turn DLS off, 03 turn DLS voice allocation off, 04 turn DLS voice allocation on. No body.

File reference (0B)

01 open file, 02 select or reselect contents, 03 open file and select contents, 04 close file. Each carries a two-byte context number, a two-byte byte count and then its data: a four-character file type and a URL or a selection. The exact layout of the selection is in a document for members, so the explorer shows the fields after the context and count as text.

MIDI Visual Control (0C)

Sub-IDs 00 to 7F are the commands of MIDI Visual Control. Their definitions are in the MVC documentation, which is not publicly available; the explorer names the message and shows the command as bytes.

MIDI Capability Inquiry (0D)

MIDI-CI messages share a header after the sub-IDs: one byte, the MIDI-CI version, then two 28-bit MUIDs, source and destination, each four bytes of seven bits, LSB first. 0FFFFFFF as the destination is a broadcast. The sub-ID #2 names the message; the explorer shows the rest as bytes, as the bodies are defined in the MIDI-CI specification, which needs a registration with the MIDI Association.

Handshaking (7B to 7F)

The replies a device gives during a dump: 7B end of file, 7C wait, 7D cancel, 7E NAK, 7F ACK. Each has one byte after the sub-ID, the packet number it refers to.

Other sub-IDs

Any other sub-ID #1 is reserved. The explorer names it “not defined” and shows its bytes.

MIDI Time Code (01)

01 full message: hr mn sc fr, the hours byte carrying the frame rate in bits 5 and 6 (0 = 24, 1 = 25, 2 = 29.97 drop-frame, 3 = 30). 02 user bits: nine bytes for the eight user-bit nibbles and the two binary group flags.

MIDI Show Control (02)

Sub-ID #2 is the command format, the kind of equipment; the byte after it is the command; then its data as text, separated by zero bytes.

Commands: 01 GO, 02 STOP, 03 RESUME, 04 TIMED_GO, 05 LOAD, 06 SET, 07 FIRE, 08 ALL_OFF, 09 RESTORE, 0A RESET, 0B GO_OFF, 10 GO/JAM_CLOCK, 11 STANDBY_+, 12 STANDBY_-, 13 SEQUENCE_+, 14 SEQUENCE_-, 15 START_CLOCK, 16 STOP_CLOCK, 17 ZERO_CLOCK, 18 SET_CLOCK, 19 MTC_CHASE_ON, 1A MTC_CHASE_OFF, 1B OPEN_CUE_LIST, 1C CLOSE_CUE_LIST, 1D OPEN_CUE_PATH, 1E CLOSE_CUE_PATH.

Notation information (03)

01 bar number: a signed 14-bit number, LSB first. 02 time signature, immediate, and 42, delayed: a byte count, then for each signature nn dd qq: numerator, denominator as a power of two, and thirty-second notes to a quarter note.

Device control (04)

Real-time MTC cueing (05)

As non-real-time cueing, for sub-IDs 00–02, 05–08, 0B, 0C and 0E, but only an event number and additional information follow, with no time; the event happens now. 03, 04, 09, 0A and 0D are reserved.

MIDI Machine Control (06, 07)

06 carries commands, one after another. Commands 01 to 0F and 7F are a single byte; commands 40 to 77 are the command, a byte count and that many bytes. 07 carries responses; its information fields are defined in the MMC section of the MIDI 1.0 specification and the explorer shows them as bytes.

MIDI Tuning Standard, real time (08)

02 single note tuning change: tt nn then kk xx yy zz for each key. 07 the same with a bank before the program. 08 and 09 scale/octave tuning, as in the non-real-time messages of the same numbers.

Controller destination setting (09)

Used with General MIDI 2. 01 channel pressure and 02 poly pressure: a channel, then pairs of destination and range. 03 a control change: a channel, a controller number, then pairs. Destinations are 00 pitch, 01 filter cutoff, 02 amplitude, 03 LFO pitch depth, 04 LFO filter depth, 05 LFO amplitude depth; the range is an offset from 40.

Key-based instrument control (0A)

01: a channel and a key, then pairs of controller number and value, for that key only: 07 volume, 0A pan, 5B reverb send and 5D chorus send are the ones General MIDI 2 names.

Scalable Polyphony MIDI (0B)

01: pairs of channel and maximum instantaneous polyphony, the number of voices the channels up to and including that one need, used to drop parts on devices with few voices.

Mobile phone control message (0C)

00. The body is defined in a document for members of the MIDI Association and is not publicly available; the explorer names the message and shows the body as bytes.

Other sub-IDs

Any other sub-ID #1 is reserved. The explorer names it “not defined” and shows its bytes.