From 039e7448ce8ae4cd637a20704221ee4768112492 Mon Sep 17 00:00:00 2001
From: Devin Acker <d@revenant1.net>
Date: Sun, 19 Dec 2021 14:06:38 -0500
Subject: [PATCH] midiin_device: handle channel remapping at playback time
 instead of load time, also small fix to sysex event parsing (#9019)

---
 src/devices/imagedev/midiin.cpp | 28 ++++++++++++++++------------
 src/devices/imagedev/midiin.h   |  6 +++---
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/src/devices/imagedev/midiin.cpp b/src/devices/imagedev/midiin.cpp
index 30838a36eb9..84b9bfbfd0a 100644
--- a/src/devices/imagedev/midiin.cpp
+++ b/src/devices/imagedev/midiin.cpp
@@ -119,8 +119,15 @@ void midiin_device::device_timer(emu_timer &timer, device_timer_id id, int param
 				// if it's time to process the current event, do it and advance
 				if (curtime >= event->time())
 				{
-					for (auto &curbyte : event->data())
+					const u8 force_channel = m_config->read();
+
+					for (u8 curbyte : event->data())
+					{
+						if (force_channel <= 15 && curbyte >= 0x80 && curbyte < 0xf0)
+							curbyte = (curbyte & 0xf0) | force_channel;
+
 						xmit_char(curbyte);
+					}
 					event = m_sequence.advance_event();
 				}
 
@@ -166,7 +173,7 @@ image_init_result midiin_device::call_load()
 		// if the parsing succeeds, schedule the start to happen at least
 		// 10 seconds after starting to allow the keyboards to initialize
 		// TODO: this should perhaps be a driver-configurable parameter?
-		if (m_sequence.parse(reinterpret_cast<u8 const *>(ptr()), length(), m_config->read()))
+		if (m_sequence.parse(reinterpret_cast<u8 const *>(ptr()), length()))
 		{
 			m_sequence_start = std::max(machine().time(), attotime(10, 0));
 			m_timer->adjust(attotime::zero);
@@ -357,7 +364,7 @@ midiin_device::midi_event &midiin_device::midi_sequence::event_at(u32 tick)
 //  parse - parse a MIDI sequence from a buffer
 //-------------------------------------------------
 
-bool midiin_device::midi_sequence::parse(u8 const *data, u32 length, u8 force_channel)
+bool midiin_device::midi_sequence::parse(u8 const *data, u32 length)
 {
 	// start with an empty list of events
 	m_list.clear();
@@ -370,7 +377,7 @@ bool midiin_device::midi_sequence::parse(u8 const *data, u32 length, u8 force_ch
 	{
 		// if not a RIFF-encoed MIDI, just parse as-is
 		if (buffer.dword_le() != fourcc_le("RIFF"))
-			parse_midi_data(buffer.reset(), force_channel);
+			parse_midi_data(buffer.reset());
 		else
 		{
 			// check the RIFF type and size
@@ -388,7 +395,7 @@ bool midiin_device::midi_sequence::parse(u8 const *data, u32 length, u8 force_ch
 				midi_parser chunk = riffdata.subset(chunksize);
 				if (chunktype == fourcc_le("data"))
 				{
-					parse_midi_data(chunk, force_channel);
+					parse_midi_data(chunk);
 					break;
 				}
 			}
@@ -410,7 +417,7 @@ bool midiin_device::midi_sequence::parse(u8 const *data, u32 length, u8 force_ch
 //  into tracks
 //-------------------------------------------------
 
-void midiin_device::midi_sequence::parse_midi_data(midi_parser &buffer, u8 force_channel)
+void midiin_device::midi_sequence::parse_midi_data(midi_parser &buffer)
 {
 	// scan for syntactic correctness, and to find global state
 	u32 headertype = buffer.dword_le();
@@ -447,7 +454,7 @@ void midiin_device::midi_sequence::parse_midi_data(midi_parser &buffer, u8 force
 
 		// parse the track data
 		midi_parser trackdata = buffer.subset(chunksize);
-		u32 numticks = parse_track_data(trackdata, curtick, force_channel);
+		u32 numticks = parse_track_data(trackdata, curtick);
 		if (format == 2)
 			curtick += numticks;
 	}
@@ -476,7 +483,7 @@ void midiin_device::midi_sequence::parse_midi_data(midi_parser &buffer, u8 force
 //  add it to the buffer
 //-------------------------------------------------
 
-u32 midiin_device::midi_sequence::parse_track_data(midi_parser &buffer, u32 start_tick, u8 force_channel)
+u32 midiin_device::midi_sequence::parse_track_data(midi_parser &buffer, u32 start_tick)
 {
 	u32 curtick = start_tick;
 	u8 last_type = 0;
@@ -501,10 +508,6 @@ u32 midiin_device::midi_sequence::parse_track_data(midi_parser &buffer, u32 star
 		if (eclass != 15)
 		{
 			// simple events: all but program change and aftertouch have a second parameter
-			if (force_channel <= 15)
-			{
-				type = (type & 0xf0) | force_channel;
-			}
 			event.append(type);
 			event.append(buffer.byte());
 			if (eclass != 12 && eclass != 13)
@@ -514,6 +517,7 @@ u32 midiin_device::midi_sequence::parse_track_data(midi_parser &buffer, u32 star
 		{
 			// handle non-meta events
 			midi_parser eventdata = buffer.subset(buffer.variable());
+			event.append(type);
 			while (!eventdata.eob())
 				event.append(eventdata.byte());
 		}
diff --git a/src/devices/imagedev/midiin.h b/src/devices/imagedev/midiin.h
index a6e8e6d5958..70bc5987637 100644
--- a/src/devices/imagedev/midiin.h
+++ b/src/devices/imagedev/midiin.h
@@ -154,7 +154,7 @@ private:
 		void clear() { m_list.clear(); }
 
 		// parse a new sequence
-		bool parse(u8 const *data, u32 length, u8 force_channel);
+		bool parse(u8 const *data, u32 length);
 
 		// rewind to the start of time
 		void rewind(attotime const &basetime);
@@ -165,8 +165,8 @@ private:
 	private:
 		// internal helpers
 		midi_event &event_at(u32 tick);
-		u32 parse_track_data(midi_parser &buffer, u32 start_tick, u8 force_channel);
-		void parse_midi_data(midi_parser &buffer, u8 force_channel);
+		u32 parse_track_data(midi_parser &buffer, u32 start_tick);
+		void parse_midi_data(midi_parser &buffer);
 
 		// internal state
 		std::list<midi_event> m_list;