ROL Format
| Format type | Music |
|---|---|
| Notation type | Custom |
| Instruments | OPL |
| Max channel count | 9 or 11 |
| Max track count | 45 |
| Max pattern count | 1 |
| Max order count | 0 |
| Tags? | None |
| Games |
The ROL Format is created by Ad Lib, Inc. for AdLib Visual Composer program. Some games use it for the background music.
Earlier ROL files goes with instrument files, but later they were superseded by single instrument bank file.
File format
Header
| Data type | Name | Description |
|---|---|---|
| UINT16LE | majorVersion | Major version number (usually 0) |
| UINT16LE | minorVersion | Minor version number (usually 4) |
| char[40] | signature | Signature, null terminated (usually "\roll\default") |
| UINT16LE | tickBeat | Number of ticks per beat |
| UINT16LE | beatMeasure | Number of beats per measure |
| UINT16LE | scaleY | Editing scale (Y axis) |
| UINT16LE | scaleX | Editing scale (X axis) |
| BYTE | reserved | Unused, set to zero |
| UINT8 | isMelodic | OPL rhythm mode: 0 = percussive, 1 = melodic |
| UINT16LE[45] | counters | Counter values for each track (see below) |
| BYTE[38] | filler | Padding, set to zero |
The most known version of this format is 0.4.
The fields tickBeat and beatMeasure are used to convert ticks into beats and measures for drawing a musical staff in AdLib Visual Composer.
Tracks
Header is followed by 45 tracks of different type. The first is always a tempo track. Then it's followed by Voice, Timbre, Volume, and Pitch tracks, repeated 11 times for each possible AdLib voice.
This resulting in actual track count:
1 + 4 * 11 = 45
ROL files always contain 45 tracks even if 9-voice melodic mode is used.
Tempo track
| Data type | Name | Description |
|---|---|---|
| char[15] | trackName | Track name, null terminated (usually "Tempo") |
| Single | basicTempo | Song tempo, in beats-per-minute |
| UINT16LE | nEvents | Number of events |
| E_TEMPO[nEvents] | tempoEvents | Array of tempo events |
E_TEMPO structure:
| Data type | Name | Description |
|---|---|---|
| UINT16LE | atTick | Time of event, in ticks (absolute) |
| Single | multiplier | Tempo multiplier (in range 0.01 - 10.0) |
The basicTempo field controls the song playback speed and is measured in beats per minute. The playback frequency can be calculated as follows:
frequency = (basicTempo / 60) * tickBeat
For a song that plays at 120BPM and with 10 ticks per beat, this works out as:
frequency = (120 / 60) * 10
= 20 Hz
Therefore playback should happen at 20 ticks per second to be at the correct tempo.
Tempo multiplier allows to change song speed during playback, so the actual frequency is calculated like this:
frequency = (basicTempo / 60) * tickBeat * multiplier
Voice track
| Data type | Name | Description |
|---|---|---|
| char[15] | trackName | Track name, null terminated (usually "Voix ##", # - voice number from 0) |
| UINT16LE | nTicks | Total ticks for current track |
| E_NOTE[] | noteEvents | Array of note events |
E_NOTE structure:
| Data type | Name | Description |
|---|---|---|
| UINT16LE | note | Note number (0: note off, 12..107: note on) |
| UINT16LE | duration | Note duration, in ticks |
This structure is repeated while the sum of duration values is less than nTicks value.
The note value is compatible with MIDI standard (48 is middle-C).
Timbre track
| Data type | Name | Description |
|---|---|---|
| char[15] | trackName | Track name, null terminated (usually "Timbre ##", # - voice number from 0) |
| UINT16LE | nEvents | Number of events |
| E_TIMBRE[nEvents] | timbreEvents | Array of timbre events |
E_TIMBRE structure:
| Data type | Name | Description |
|---|---|---|
| UINT16LE | atTick | Time of event, in ticks (absolute) |
| char[9] | instName | Instrument name, null terminated |
| BYTE | filler | Padding, set to zero |
| UINT16LE | unknown | Unknown value, sometimes equal to instrument index |
These events set the instrument to be played on specified channel.
Instrument name is a reference to INSTNAME.INS file, or an instrument name inside STANDARD.BNK file.
Volume track
| Data type | Name | Description |
|---|---|---|
| char[15] | trackName | Track name, null terminated (usually "Volume ##", # - voice number from 0) |
| UINT16LE | nEvents | Number of events |
| E_VOLUME[nEvents] | volumeEvents | Array of volume events |
E_VOLUME structure:
| Data type | Name | Description |
|---|---|---|
| UINT16LE | atTick | Time of event, in ticks (absolute) |
| Single | volume | Volume multiplier (in range 0.0 - 1.0) |
These events set the volume for specified channel.
Pitch track
| Data type | Name | Description |
|---|---|---|
| char[15] | trackName | Track name, null terminated (usually "Pitch ##", # - voice number from 0) |
| UINT16LE | nEvents | Number of events |
| E_PITCH[nEvents] | pitchEvents | Array of pitch events |
E_PITCH structure:
| Data type | Name | Description |
|---|---|---|
| UINT16LE | atTick | Time of event, in ticks (absolute) |
| Single | pitch | Pitch variation (in range 0.0 - 2.0) |
These events works the same as Pitch Bend events. Nominal pitch value is 1.0.
Counter values
There are 45 counter values for each track.
| Data type | Name | Description |
|---|---|---|
| UINT16LE[11] | cTicks | Total ticks for each voice track |
| UINT16LE[11] | cTimbreEvents | Number of events for each timbre track |
| UINT16LE[11] | cVolumeEvents | Number of events for each volume track |
| UINT16LE[11] | cPitchEvents | Number of events for each pitch track |
| UINT16LE | cTempoEvents | Number of events in the tempo track |
Rhythm mode
If isMelodic is 1, then rhythm mode is off. Valid channels are 0 to 8 inclusive.
When isMelodic is 0, then rhythm mode is on. Valid channels are 0 to 10, with 0 to 5 being melodic and 6 to 10 being percussive (see table below).
Both the top cymbal and the snare drum only use the OPL carrier registers, but the values for these registers are actually stored in the file's modulator fields. The carrier fields for these instruments appear to be unused. In other words, percussive instruments always have their settings loaded from the instrument's modulator fields, even when the values are loaded into the OPL chip's carrier registers.
| Channel | Percussive instrument | Operator used in file | OPL cell |
|---|---|---|---|
| 0-5 | Melodic | Modulator Carrier |
Modulator Carrier |
| 6 | Bass drum | Modulator Carrier |
13 - Channel 7 Modulator 16 - Channel 7 Carrier |
| 7 | Snare drum | Modulator | 17 - Channel 8 Carrier |
| 8 | Tom tom | Modulator | 15 - Channel 9 Modulator |
| 9 | Top cymbal | Modulator | 18 - Channel 9 Carrier |
| 10 | Hi-hat | Modulator | 14 - Channel 8 Modulator |
BNK files have an indicator whether a patch is percussive or melodic, however it is not used by official ROL player. It's controlled entirely by which channel it is used on. It is possible to use the same patch for both percussive and melodic channels.
In percussive mode, the pitch of the single-operator percussive instruments is handled specially (that is, the snare drum, tom tom, top cymbal and hi-hat. The bass drum is not considered here.) When a note is played on channel 8 (tom-tom), the pitch on the other instruments is changed also. The changes are:
| Channel | Percussive instrument | Note pitch |
|---|---|---|
| 7 | Snare drum | 7 semitones higher than the last tom-tom note on channel 8 |
| 8 | Tom tom | Use pitch as indicated in the note-on event |
| 9 | Top cymbal | Use pitch from last tom-tom note on channel 8 |
| 10 | Hi-hat | 7 semitones higher than the last tom-tom note on channel 8 |
The initial frequency for the tom-tom is supposed to be two octaves below middle-C according to comments in the official adlib.c, however ! this doesn't seem to be the case.
Tools
The following tools are able to work with files in this format.
| Name | Platform | Play? | Create new? | Modify? | Convert/export to other? | Import from other? | Access hidden data? | Edit metadata? | Notes |
|---|---|---|---|---|---|---|---|---|---|
| playrol.exe | DOS | Yes | No | No | No | No | No | No | Included with AdLib Visual Composer |
| AdLib convert.exe | DOS | No | No | No | Yes; .mus | No | No | No | Part of AdLib Programmer's Guide |
| AdLib rol2midi.exe | DOS | No | No | No | Yes; .mdi | No | No | No | Part of AdLib Programmer's Guide |
See also
- AdLib Instrument Format - first time companion format for storing instruments for songs in this format
- AdLib Instrument Bank Format - second time companion format for storing instruments for songs in this format
- http://hwiegman.home.xs4all.nl/fileformats/rol/Rol-form.txt - format described by Chris Holmes
- AdLib MIDI Format, IMS Format, MDI Format - derived formats
Credits
This file format was described by Chris Holmes in 1992 and then adapted and supplemented by binarymaster. If you find this information helpful in a project you're working on, please give credit where credit is due. (A link back to this wiki would be nice too!)