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Diffstat (limited to 'backends/midi.md')
| -rw-r--r-- | backends/midi.md | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/backends/midi.md b/backends/midi.md index d3d6e33..6280205 100644 --- a/backends/midi.md +++ b/backends/midi.md @@ -11,10 +11,11 @@ The MIDI backend provides read-write access to the MIDI protocol via virtual por #### Instance configuration -| Option | Example value | Default value | Description | -|---------------|-----------------------|-----------------------|-----------------------| -| `read` | `20:0` | none | MIDI device to connect for input | -| `write` | `DeviceName` | none | MIDI device to connect for output | +| Option | Example value | Default value | Description | +|-----------------------|-----------------------|-----------------------|-----------------------| +| `read` / `source` | `20:0` | none | MIDI device to connect for input | +| `write` / `target` | `DeviceName` | none | MIDI device to connect for output | +| `epn-tx` | `short` | `full` | Configures whether to clear the active parameter number after transmitting an `nrpn` or `rpn` parameter | MIDI device names may either be `client:port` portnames or prefixes of MIDI device names. Run `aconnect -i` to list input ports and `aconnect -o` to list output ports. @@ -30,25 +31,39 @@ The MIDI backend supports mapping different MIDI events to MIDIMonster channels. * `pressure` - Note pressure/aftertouch messages * `aftertouch` - Channel-wide aftertouch messages * `pitch` - Channel pitchbend messages +* `program` - Channel program change messages +* `rpn` - Registered parameter numbers (14-bit extension) +* `nrpn` - Non-registered parameter numbers (14-bit extension) A MIDIMonster channel is specified using the syntax `channel<channel>.<type><index>`. The shorthand `ch` may be used instead of the word `channel` (Note that `channel` here refers to the MIDI channel number). -The `pitch` and `aftertouch` events are channel-wide, thus they can be specified as `channel<channel>.<type>`. +The `pitch`, `aftertouch` and `program` messages/events are channel-wide, thus they can be specified as `channel<channel>.<type>`. MIDI channels range from `0` to `15`. Each MIDI channel consists of 128 notes (numbered `0` through `127`), which additionally each have a pressure control, 128 CC's (numbered likewise), a channel pressure control (also called 'channel aftertouch') and a pitch control which may all be mapped to individual MIDIMonster channels. +Every MIDI channel also provides `rpn` and `nrpn` controls, which are implemented on top of the MIDI protocol, using +the CC controls 101/100/99/98/38/6. Both control types have 14-bit IDs and 14-bit values. + Example mappings: ``` midi1.ch0.note9 > midi2.channel1.cc4 midi1.channel15.pressure1 > midi1.channel0.note0 midi1.ch1.aftertouch > midi2.ch2.cc0 midi1.ch0.pitch > midi2.ch1.pitch +midi1.ch0.nrpn900 > midi2.ch0.rpn1 +midi2.ch15.note1 > midi1.ch2.program ``` #### Known bugs / problems +Extended parameter numbers (EPNs, the `rpn` and `nrpn` control types) will also generate events on the controls (CC 101 through +98, 38 and 6) that are used as the lower layer transport. When using EPNs, mapping those controls is probably not useful. + +EPN control types support only the full 14-bit transfer encoding, not the shorter variant transmitting only the 7 +high-order bits. This may be changed if there is sufficient interest in the functionality. + To access MIDI data, the user running MIDIMonster needs read & write access to the ALSA sequencer. This can usually be done by adding this user to the `audio` system group. |