MDI

[[Category: Formats With {{{Header}}} Headers]] [[Category: Formats With {{{Content}}} Content]] [[Category: Formats With {{{Instruments}}} Instruments]]

MDI
Developer:	Ad Lib, Inc.
Header:	{{{Header}}}
Content:	{{{Content}}}
Instruments:	{{{Instruments}}}
Target Output
Released:	1989/05/08
First Game:	?
Extensions	*.mdi

The MDI format uses the MIDI structure but incorporates OPL2 commands that allow it to store instrument data and change modes, similar to how CMF works. Because the format is so similar to MIDI, some MIDI players are able to play the files, though they won't utilize the instrument data or set the song into the correct mode, so the song won't sound correct.

Converters

? to MDI

• ROL to MIDI - DOS - ROL

Games

Games That Use MDI

Technical

All MDI files begin with "MThd" MIDI header, contain "MTrk" at the start of the MIDI track, and the End Of Track "FF2F" event is located at the end of file, but not included in the track.

Some NoteOff events may have only Velocity parameter to trigger the note off.

Sequencer-specific event format

These events are used to control OPL-compatible chip.

Delta-ticks	Event	Length	Ad Lib ID	Opcode	Data
00	FF 7F	XX	00 00 3F	XX XX	XX .. XX

Possible opcodes

Opcode	Meaning	Data
00 01	Patch (instrument change)	Byte # Meaning 1 Voice number for instrument 2 - 29 28 byte array of parameters
00 02	Card mode	Byte # Meaning 1 0 = melodic, 1 = percussive
00 03	Pitch bend interval	Byte # Meaning 1 1 - 12 inclusive

Channels utilization

Hex channel	MIDI channel	Use in melodic mode	Use in percussive mode
0x00	1	Normal instrument	Normal instrument
0x01	2	Normal instrument	Normal instrument
0x02	3	Normal instrument	Normal instrument
0x03	4	Normal instrument	Normal instrument
0x04	5	Normal instrument	Normal instrument
0x05	6	Normal instrument	Normal instrument
0x06	7	Normal instrument	Bass drum
0x07	8	Normal instrument	Snare drum
0x08	9	Normal instrument	Tom tom
0x09	10	Normal instrument	Top cymbal
0x0A	11	Normal instrument	Hi-hat cymbal
0x0B	12	Normal instrument	Normal instrument
0x0C	13	Normal instrument	Normal instrument
0x0D	14	Normal instrument	Normal instrument
0x0E	15	Normal instrument	Normal instrument
0x0F	16	Normal instrument	Normal instrument

Links

• [1] - Ad Lib software and sources.
• [2] - The Ad Lib sequencer-specific event basic explaination.