Add midi

1 files changed, 91 insertions, 0 deletions

diff --git a/src/midi.c b/src/midi.c
new file mode 100644
index 0000000..46608cb
--- /dev/null
+++ b/src/midi.c
@@ -0,0 +1,91 @@
+#include "midi.h"
+
+#include <string.h>
+
+void midi_decode(uint32_t msg) {
+  //  printf("MIDI message: 0x%X\n", msg);
+  uint8_t status = msg;
+  uint8_t data1 = (msg >> 8) & 0xFF;
+  uint8_t data2 = (msg >> 16) & 0xFF;
+  uint8_t channel = (status & 0x0F) + 1; // convert to human
+  uint8_t message = status >> 4;
+
+  switch (message) {
+    case 0x08:
+      printf("Note Off: channel=%d, note=%d, velocity=%d\n", channel, data1, data2);
+      break;
+    case 0x09:
+      printf("Note On: channel=%d, note=%d, velocity=%d\n", channel, data1, data2);
+      break;
+    case 0x0A:
+      printf("Aftertouch: channel=%d, note=%d, pressure=%d\n", channel, data1, data2);
+      break;
+    case 0x0B:
+      printf("Control Change: channel=%d, controller=%d, value=%d\n", channel, data1, data2);
+      break;
+    case 0x0C:
+      printf("Program Change: channel=%d, program=%d\n", channel, data1);
+      break;
+    case 0x0D:
+      printf("Channel Pressure: channel=%d, pressure=%d\n", channel, data1);
+      break;
+    case 0x0E:
+      printf("Pitch Bend: channel=%d, value=%d\n", channel, ((data2 << 7) | data1) - 8192);
+      break;
+    default:
+      printf("Unknown MIDI message\n");
+      break;
+  }
+}
+
+
+void
+midiCallback(PtTimestamp timestamp, void *userData) {
+  midi_t * m = (midi_t *)userData;
+
+  if (!m->stream) return;
+
+  if (!Pm_Poll(m->stream)) return;
+
+  PmEvent buf;
+  Pm_Read(m->stream, &buf, 1);
+
+  //printf("%d\n", buf.message);
+  midi_decode(buf.message);
+  
+}
+
+void
+init_midi(midi_t *m, synth_t *synth)
+{
+  m->stream = NULL;
+
+  Pm_Initialize();
+
+  printf("midi devs: %d\n", Pm_CountDevices());
+  const PmDeviceInfo *info;
+  int i;
+  for (i = 0; i < Pm_CountDevices(); i++) {
+    info = Pm_GetDeviceInfo(i);
+    printf("%d: %s [input: %d output: %d opened: %d is_virt:%d] (interf: %s) -- %d\n", i, info->name, info->input, info->output, info->opened, info->is_virtual, info->interf, Pm_GetDefaultInputDeviceID());
+    //if (!strcmp("MPK225 MIDI", info->name) && !info->input) break;
+    if (!strcmp("MPK225 Port A", info->name) && info->input == 1) break;
+  }
+
+  Pt_Start(1, midiCallback, m);
+
+  Pm_OpenInput(&(m->stream),
+               i, //Pm_GetDefaultInputDeviceID(),
+               NULL,
+               128,
+               NULL,
+               NULL);
+}
+
+void
+terminate_midi(midi_t *m)
+{
+  Pm_Close(m->stream);
+  Pt_Stop();
+  Pm_Terminate();
+}