From cfd2a24804cb56d4e2e31183216c94264252ca20 Mon Sep 17 00:00:00 2001
From: Kevin <68612569+diyelectromusic@users.noreply.github.com>
Date: Sun, 2 Apr 2023 20:29:42 +0100
Subject: [PATCH] Support for headerless SysEx Voice Banks (#463)

* Fix for Issue #457 - changed m_nNumLoadedBanks to be m_nNumHighestBank and updated functionality in menus accordingly.

* Fix for Issue #460 implements MIDI Bank Select MSB/LSB based on PR #395 submitted by @abscisys

* Fix for Issue #458 to not show blank banks in the menus.  Also handles MIDI bank select messages and won't change banks if the final selected bank isn't loaded.

* Firm up bank validity handling slightly.

* Fix for Issue #459 Initial support for loading of headerless SysEx voice banks as a configuraton option

* Fix for Issue #459 Added config option for headerless SysEx voice banks.
---
 src/config.cpp          |  6 ++++++
 src/config.h            |  2 ++
 src/minidexed.cpp       |  2 +-
 src/minidexed.ini       |  1 +
 src/sysexfileloader.cpp | 38 +++++++++++++++++++++++++++++++++++---
 src/sysexfileloader.h   |  4 +++-
 6 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/src/config.cpp b/src/config.cpp
index b5279a8..44ac32f 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -71,6 +71,7 @@ void CConfig::Load (void)
 	m_bMIDIRXProgramChange = m_Properties.GetNumber ("MIDIRXProgramChange", 1) != 0;
 	m_bIgnoreAllNotesOff = m_Properties.GetNumber ("IgnoreAllNotesOff", 0) != 0;
 	m_bMIDIAutoVoiceDumpOnPC = m_Properties.GetNumber ("MIDIAutoVoiceDumpOnPC", 1) != 0;
+	m_bHeaderlessSysExVoices = m_Properties.GetNumber ("HeaderlessSysExVoices", 0) != 0;
 
 	m_bLCDEnabled = m_Properties.GetNumber ("LCDEnabled", 0) != 0;
 	m_nLCDPinEnable = m_Properties.GetNumber ("LCDPinEnable", 4);
@@ -179,6 +180,11 @@ bool CConfig::GetMIDIAutoVoiceDumpOnPC (void) const
 	return m_bMIDIAutoVoiceDumpOnPC;
 }
 
+bool CConfig::GetHeaderlessSysExVoices (void) const
+{
+	return m_bHeaderlessSysExVoices;
+}
+
 bool CConfig::GetLCDEnabled (void) const
 {
 	return m_bLCDEnabled;
diff --git a/src/config.h b/src/config.h
index 8a34239..bc5e7c6 100644
--- a/src/config.h
+++ b/src/config.h
@@ -77,6 +77,7 @@ public:
 	bool GetMIDIRXProgramChange (void) const;	// true if not specified
 	bool GetIgnoreAllNotesOff (void) const;
 	bool GetMIDIAutoVoiceDumpOnPC (void) const; // true if not specified
+	bool GetHeaderlessSysExVoices (void) const; // false if not specified
 
 	// HD44780 LCD
 	// GPIO pin numbers are chip numbers, not header positions
@@ -157,6 +158,7 @@ private:
 	bool m_bMIDIRXProgramChange;
 	bool m_bIgnoreAllNotesOff;
 	bool m_bMIDIAutoVoiceDumpOnPC;
+	bool m_bHeaderlessSysExVoices;
 
 	bool m_bLCDEnabled;
 	unsigned m_nLCDPinEnable;
diff --git a/src/minidexed.cpp b/src/minidexed.cpp
index 66c6151..6acda43 100644
--- a/src/minidexed.cpp
+++ b/src/minidexed.cpp
@@ -170,7 +170,7 @@ bool CMiniDexed::Initialize (void)
 		return false;
 	}
 
-	m_SysExFileLoader.Load ();
+	m_SysExFileLoader.Load (m_pConfig->GetHeaderlessSysExVoices ());
 
 	if (m_SerialMIDI.Initialize ())
 	{
diff --git a/src/minidexed.ini b/src/minidexed.ini
index bb3edd7..2f5ce5b 100644
--- a/src/minidexed.ini
+++ b/src/minidexed.ini
@@ -17,6 +17,7 @@ MIDIBaudRate=31250
 MIDIRXProgramChange=1
 IgnoreAllNotesOff=0
 MIDIAutoVoiceDumpOnPC=1
+HeaderlessSysExVoices=0
 
 # HD44780 LCD
 LCDEnabled=1
diff --git a/src/sysexfileloader.cpp b/src/sysexfileloader.cpp
index d5159eb..4eee065 100644
--- a/src/sysexfileloader.cpp
+++ b/src/sysexfileloader.cpp
@@ -81,7 +81,7 @@ CSysExFileLoader::~CSysExFileLoader (void)
 	}
 }
 
-void CSysExFileLoader::Load (void)
+void CSysExFileLoader::Load (bool bHeaderlessSysExVoices)
 {
 	m_nNumHighestBank = 0;
 
@@ -124,6 +124,7 @@ void CSysExFileLoader::Load (void)
 
 		m_pVoiceBank[nBank] = new TVoiceBank;
 		assert (m_pVoiceBank[nBank]);
+		assert (sizeof(TVoiceBank) == VoiceSysExHdrSize + VoiceSysExSize);
 
 		std::string Filename (m_DirName);
 		Filename += "/";
@@ -132,7 +133,8 @@ void CSysExFileLoader::Load (void)
 		FILE *pFile = fopen (Filename.c_str (), "rb");
 		if (pFile)
 		{
-			if (   fread (m_pVoiceBank[nBank], sizeof (TVoiceBank), 1, pFile) == 1
+			bool bBankLoaded = false;
+			if (   fread (m_pVoiceBank[nBank], VoiceSysExHdrSize+VoiceSysExSize, 1, pFile) == 1
 			    && m_pVoiceBank[nBank]->StatusStart == 0xF0
 			    && m_pVoiceBank[nBank]->CompanyID   == 0x43
 			    && m_pVoiceBank[nBank]->Format      == 0x09
@@ -146,8 +148,38 @@ void CSysExFileLoader::Load (void)
 					// This is the bank ID of the highest loaded bank
 					m_nNumHighestBank = nBank;
 				}
+				bBankLoaded = true;
 			}
-			else
+			else if (bHeaderlessSysExVoices)
+			{
+				// Config says to accept headerless SysEx Voice Banks
+				// so reset file pointer and try again.
+				fseek (pFile, 0, SEEK_SET);
+				if (fread (m_pVoiceBank[nBank]->Voice, VoiceSysExSize, 1, pFile) == 1)
+				{
+					LOGDBG ("Bank #%u successfully loaded (headerless)", nBank);
+
+					// Add in the missing header items.
+					// Naturally it isn't possible to validate these!
+					m_pVoiceBank[nBank]->StatusStart = 0xF0;
+					m_pVoiceBank[nBank]->CompanyID   = 0x43;
+					m_pVoiceBank[nBank]->Format      = 0x09;
+					m_pVoiceBank[nBank]->ByteCountMS = 0x20;
+					m_pVoiceBank[nBank]->ByteCountLS = 0x00;
+					m_pVoiceBank[nBank]->Checksum    = 0x00;
+					m_pVoiceBank[nBank]->StatusEnd   = 0xF7;
+
+					m_BankFileName[nBank] = pEntry->d_name;
+					if (nBank > m_nNumHighestBank)
+					{
+						// This is the bank ID of the highest loaded bank
+						m_nNumHighestBank = nBank;
+					}
+					bBankLoaded = true;
+				}
+			}
+
+			if (!bBankLoaded)
 			{
 				LOGWARN ("%s: Invalid size or format", Filename.c_str ());
 
diff --git a/src/sysexfileloader.h b/src/sysexfileloader.h
index 3c20d0f..d3821da 100644
--- a/src/sysexfileloader.h
+++ b/src/sysexfileloader.h
@@ -33,6 +33,8 @@ public:
 	static const unsigned VoicesPerBank = 32;
 	static const size_t SizePackedVoice = 128;
 	static const size_t SizeSingleVoice = 156;
+	static const unsigned VoiceSysExHdrSize = 8; // Additional (optional) Header/Footer bytes for bank of 32 voices
+	static const unsigned VoiceSysExSize = 4096; // Bank of 32 voices as per DX7 MIDI Spec
 
 	struct TVoiceBank
 	{
@@ -54,7 +56,7 @@ public:
 	CSysExFileLoader (const char *pDirName = "/sysex");
 	~CSysExFileLoader (void);
 
-	void Load (void);
+	void Load (bool bHeaderlessSysExVoices = false);
 
 	std::string GetBankName (unsigned nBankID);	// 0 .. MaxVoiceBankID
 	unsigned GetNumHighestBank (); // 0 .. MaxVoiceBankID