Initial implementation of USB MIDI SysEx message handling. (#634)

* Initial implementation of USB MIDI SysEx message handling.

* Remove unused parameter from USB message handling.

src/mididevice.h

@@ -30,6 +30,9 @@
 #include <circle/spinlock.h>
 #include "userinterface.h"
 
+#define MAX_DX7_SYSEX_LENGTH 4104
+#define MAX_MIDI_MESSAGE MAX_DX7_SYSEX_LENGTH
+
 class CMiniDexed;
 
 class CMIDIDevice

src/midikeyboard.cpp

@@ -37,6 +37,7 @@ TMIDIPacketHandler * const CMIDIKeyboard::s_pMIDIPacketHandler[MaxInstances] =
 
 CMIDIKeyboard::CMIDIKeyboard (CMiniDexed *pSynthesizer, CConfig *pConfig, CUserInterface *pUI, unsigned nInstance)
 :	CMIDIDevice (pSynthesizer, pConfig, pUI),
+	m_nSysExIdx (0),
 	m_nInstance (nInstance),
 	m_pMIDIDevice (0)
 {
@@ -100,28 +101,86 @@ void CMIDIKeyboard::Send (const u8 *pMessage, size_t nLength, unsigned nCable)
 	m_SendQueue.push (Entry);
 }
 
+// Most packets will be passed straight onto the main MIDI message handler
+// but SysEx messages are multiple USB packets and so will need building up
+// before parsing.
+void CMIDIKeyboard::USBMIDIMessageHandler (u8 *pPacket, unsigned nLength, unsigned nCable)
+{
+	if ((pPacket[0] == 0xF0) && (m_nSysExIdx == 0))
+	{
+		// Start of SysEx message
+		//printf("SysEx Start  Idx=%d, (%d)\n", m_nSysExIdx, nLength);
+		for (unsigned i=0; i<USB_SYSEX_BUFFER_SIZE; i++) {
+			m_SysEx[i] = 0;
+		}
+		for (unsigned i=0; i<nLength; i++) {
+			m_SysEx[m_nSysExIdx++] = pPacket[i];
+		}
+	}
+	else if (m_nSysExIdx != 0)
+	{
+		// Continue processing SysEx message
+		//printf("SysEx Packet Idx=%d, (%d)\n", m_nSysExIdx, nLength);
+		for (unsigned i=0; i<nLength; i++) {
+			if (pPacket[i] == 0xF8 || pPacket[i] == 0xFA || pPacket[i] == 0xFB || pPacket[i] == 0xFC || pPacket[i] == 0xFE || pPacket[i] == 0xFF) {
+				// Singe-byte System Realtime Messages can happen at any time!
+				MIDIMessageHandler (&pPacket[i], 1, nCable);
+			}
+			else if (m_nSysExIdx >= USB_SYSEX_BUFFER_SIZE) {
+				// Run out of space, so reset and ignore rest of the message
+				m_nSysExIdx = 0;
+				break;
+			}
+			else if (pPacket[i] == 0xF7) {
+				// End of SysEx message
+				m_SysEx[m_nSysExIdx++] = pPacket[i];
+				//printf ("SysEx End    Idx=%d\n", m_nSysExIdx);
+				MIDIMessageHandler (m_SysEx, m_nSysExIdx, nCable);
+				// Reset ready for next time
+				m_nSysExIdx = 0;
+			}
+			else if ((pPacket[i] & 0x80) != 0) {
+				// Received another command, so reset processing as something has gone wrong
+				//printf ("SysEx Reset\n");
+				m_nSysExIdx = 0;
+				break;
+			}
+			else
+			{
+				// Store the byte
+				m_SysEx[m_nSysExIdx++] = pPacket[i];
+			}
+		}
+	}
+	else
+	{
+		// Assume it is a standard message
+		MIDIMessageHandler (pPacket, nLength, nCable);
+	}
+}
+
 void CMIDIKeyboard::MIDIPacketHandler0 (unsigned nCable, u8 *pPacket, unsigned nLength)
 {
 	assert (s_pThis[0] != 0);
-	s_pThis[0]->MIDIMessageHandler (pPacket, nLength, nCable);
+	s_pThis[0]->USBMIDIMessageHandler (pPacket, nLength, nCable);
 }
 
 void CMIDIKeyboard::MIDIPacketHandler1 (unsigned nCable, u8 *pPacket, unsigned nLength)
 {
 	assert (s_pThis[1] != 0);
-	s_pThis[1]->MIDIMessageHandler (pPacket, nLength, nCable);
+	s_pThis[1]->USBMIDIMessageHandler (pPacket, nLength, nCable);
 }
 
 void CMIDIKeyboard::MIDIPacketHandler2 (unsigned nCable, u8 *pPacket, unsigned nLength)
 {
 	assert (s_pThis[2] != 0);
-	s_pThis[2]->MIDIMessageHandler (pPacket, nLength, nCable);
+	s_pThis[2]->USBMIDIMessageHandler (pPacket, nLength, nCable);
 }
 
 void CMIDIKeyboard::MIDIPacketHandler3 (unsigned nCable, u8 *pPacket, unsigned nLength)
 {
 	assert (s_pThis[3] != 0);
-	s_pThis[3]->MIDIMessageHandler (pPacket, nLength, nCable);
+	s_pThis[3]->USBMIDIMessageHandler (pPacket, nLength, nCable);
 }
 
 void CMIDIKeyboard::DeviceRemovedHandler (CDevice *pDevice, void *pContext)

src/midikeyboard.h

@@ -31,6 +31,8 @@
 #include <circle/types.h>
 #include <queue>
 
+#define USB_SYSEX_BUFFER_SIZE (MAX_DX7_SYSEX_LENGTH+128) // Allow a bit spare to handle unexpected SysEx messages
+
 class CMiniDexed;
 
 class CMIDIKeyboard : public CMIDIDevice
@@ -53,6 +55,8 @@ private:
 	static void MIDIPacketHandler3 (unsigned nCable, u8 *pPacket, unsigned nLength);
 
 	static void DeviceRemovedHandler (CDevice *pDevice, void *pContext);
+	
+	void USBMIDIMessageHandler (u8 *pPacket, unsigned nLength, unsigned nCable);
 
 private:
 	struct TSendQueueEntry
@@ -61,6 +65,8 @@ private:
 		size_t	 nLength;
 		unsigned nCable;
 	};
+	uint8_t m_SysEx[USB_SYSEX_BUFFER_SIZE];
+	unsigned m_nSysExIdx;
 
 private:
 	unsigned m_nInstance;
@@ -73,6 +79,7 @@ private:
 	static CMIDIKeyboard *s_pThis[MaxInstances];
 
 	static TMIDIPacketHandler * const s_pMIDIPacketHandler[MaxInstances];
+
 };
 
 #endif

src/serialmididevice.cpp

@@ -75,7 +75,7 @@ void CSerialMIDIDevice::Process (void)
 		return;
 	}
 
-        if (m_pConfig->GetMIDIDumpEnabled ())
+/*        if (m_pConfig->GetMIDIDumpEnabled ())
 	{
 		printf("Incoming MIDI data:");
 		for (uint16_t i = 0; i < nResult; i++)
@@ -85,7 +85,7 @@ void CSerialMIDIDevice::Process (void)
 			printf(" 0x%02x",Buffer[i]);
 		}
 		printf("\n");
-	}
+	}*/
 
 	// Process MIDI messages
 	// See: https://www.midi.org/specifications/item/table-1-summary-of-midi-message

src/serialmididevice.h

@@ -30,9 +30,6 @@
 #include <circle/writebuffer.h>
 #include <circle/types.h>
 
-#define MAX_DX7_SYSEX_LENGTH 4104
-#define MAX_MIDI_MESSAGE MAX_DX7_SYSEX_LENGTH
-
 class CMiniDexed;
 
 class CSerialMIDIDevice : public CMIDIDevice