diff options
| -rw-r--r-- | backends/midi.c | 105 | ||||
| -rw-r--r-- | backends/midi.h | 10 | ||||
| -rw-r--r-- | backends/midi.md | 7 |
3 files changed, 110 insertions, 12 deletions
diff --git a/backends/midi.c b/backends/midi.c index d581a01..7883662 100644 --- a/backends/midi.c +++ b/backends/midi.c @@ -273,11 +273,91 @@ static char* midi_type_name(uint8_t type){ return "unknown"; } +static void midi_handle_epn(instance* inst, uint8_t chan, uint16_t control, uint16_t value){ + midi_instance_data* data = (midi_instance_data*) inst->impl; + midi_channel_ident ident = { + .label = 0 + }; + channel* changed = NULL; + channel_value val; + //check for 3-byte update TODO + + //switching between nrpn and rpn clears all valid bits + if(((data->epn_status[chan] & EPN_NRPN) && (control == 101 || control == 100)) + || (!(data->epn_status[chan] & EPN_NRPN) && (control == 99 || control == 98))){ + data->epn_status[chan] &= ~(EPN_NRPN | EPN_PARAMETER_LO | EPN_PARAMETER_HI); + } + + //setting an address always invalidates the value valid bits + if(control >= 98 && control <= 101){ + data->epn_status[chan] &= ~(EPN_VALUE_HI /*| EPN_VALUE_LO*/); + } + + //parameter hi + if(control == 101 || control == 99){ + data->epn_control[chan] &= 0x7F; + data->epn_control[chan] |= value << 7; + data->epn_status[chan] |= EPN_PARAMETER_HI | ((control == 99) ? EPN_NRPN : 0); + if(control == 101 && value == 127){ + data->epn_status[chan] &= ~EPN_PARAMETER_HI; + } + } + + //parameter lo + if(control == 100 || control == 98){ + data->epn_control[chan] &= ~0x7F; + data->epn_control[chan] |= value & 0x7F; + data->epn_status[chan] |= EPN_PARAMETER_LO | ((control == 98) ? EPN_NRPN : 0); + if(control == 100 && value == 127){ + data->epn_status[chan] &= ~EPN_PARAMETER_LO; + } + } + + //value hi, clears low, mark as update candidate + if(control == 6 + //check if parameter is set before accepting value update + && ((data->epn_status[chan] & (EPN_PARAMETER_HI | EPN_PARAMETER_LO)) == (EPN_PARAMETER_HI | EPN_PARAMETER_LO))){ + data->epn_value[chan] = value << 7; + data->epn_status[chan] |= EPN_VALUE_HI; + } + + //FIXME is the update order for the value bits fixed? + //FIXME can there be standalone updates on CC 38? + + //value lo, flush the value + if(control == 38 + && data->epn_status[chan] & EPN_VALUE_HI){ + data->epn_value[chan] &= ~0x7F; + data->epn_value[chan] |= value & 0x7F; + //FIXME not clearing the valid bit would allow for fast low-order updates + data->epn_status[chan] &= ~EPN_VALUE_HI; + + if(midi_config.detect){ + LOGPF("Incoming EPN data on channel %s.ch%d.%s%d", inst->name, chan, data->epn_status[chan] & EPN_NRPN ? "nrpn" : "rpn", data->epn_control[chan]); + } + + //find the updated channel + ident.fields.type = data->epn_status[chan] & EPN_NRPN ? nrpn : rpn; + ident.fields.channel = chan; + ident.fields.control = data->epn_control[chan]; + val.normalised = (double) data->epn_value[chan] / 16383.0; + + //push the new value + changed = mm_channel(inst, ident.label, 0); + if(changed){ + mm_channel_event(changed, val); + } + } +} + static int midi_handle(size_t num, managed_fd* fds){ snd_seq_event_t* ev = NULL; instance* inst = NULL; + midi_instance_data* data = NULL; + channel* changed = NULL; channel_value val; + char* event_type = NULL; midi_channel_ident ident = { .label = 0 @@ -295,7 +375,14 @@ static int midi_handle(size_t num, managed_fd* fds){ ident.fields.control = ev->data.note.note; val.normalised = (double) ev->data.note.velocity / 127.0; - //TODO (n)rpn RX + //scan for the instance before parsing incoming data, instance state is required for the EPN state machine + inst = mm_instance_find(BACKEND_NAME, ev->dest.port); + if(!inst){ + LOG("Delivered event did not match any instance"); + continue; + } + data = (midi_instance_data*) inst->impl; + switch(ev->type){ case SND_SEQ_EVENT_NOTEON: case SND_SEQ_EVENT_NOTEOFF: @@ -323,6 +410,15 @@ static int midi_handle(size_t num, managed_fd* fds){ ident.fields.channel = ev->data.control.channel; ident.fields.control = ev->data.control.param; val.normalised = (double) ev->data.control.value / 127.0; + + //check for EPN CCs and update the state machine + if((ident.fields.control <= 101 && ident.fields.control >= 98) + || ident.fields.control == 6 + || ident.fields.control == 38 + //if the high-order value bits are set, forward any control to the state machine for the short update form + || data->epn_status[ident.fields.channel] & EPN_VALUE_HI){ + midi_handle_epn(inst, ident.fields.channel, ident.fields.control, ev->data.control.value); + } break; default: LOG("Ignored event of unsupported type"); @@ -330,13 +426,6 @@ static int midi_handle(size_t num, managed_fd* fds){ } event_type = midi_type_name(ident.fields.type); - inst = mm_instance_find(BACKEND_NAME, ev->dest.port); - if(!inst){ - //FIXME might want to return failure - LOG("Delivered event did not match any instance"); - continue; - } - changed = mm_channel(inst, ident.label, 0); if(changed){ if(mm_channel_event(changed, val)){ diff --git a/backends/midi.h b/backends/midi.h index 4e2ac09..51b4a30 100644 --- a/backends/midi.h +++ b/backends/midi.h @@ -10,14 +10,20 @@ static int midi_handle(size_t num, managed_fd* fds); static int midi_start(size_t n, instance** inst); static int midi_shutdown(size_t n, instance** inst); +#define EPN_NRPN 8 +#define EPN_PARAMETER_HI 4 +#define EPN_PARAMETER_LO 2 +#define EPN_VALUE_HI 1 + typedef struct /*_midi_instance_data*/ { int port; char* read; char* write; uint8_t epn_tx_short; - uint16_t epn_control; - uint16_t epn_value; + uint16_t epn_control[16]; + uint16_t epn_value[16]; + uint8_t epn_status[16]; } midi_instance_data; typedef union { diff --git a/backends/midi.md b/backends/midi.md index 4732452..87d06a1 100644 --- a/backends/midi.md +++ b/backends/midi.md @@ -56,8 +56,11 @@ midi1.ch0.nrpn900 > midi2.ch0.rpn1 ``` #### Known bugs / problems -Extended parameter numbers (`rpn` and `nrpn` control types) can currently only be transmitted, not properly -received as such. Support for this functionality is planned. +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. |