Fix various MIDI corruption bugs.

Re-enable MIDI CC controller bars and other immediate output (hans commented out, tsk tsk).
Write channel mode as textual enumeration instead of magic number.
Better atomic (almost) channel mode switching on MIDI ring buffer (was a possible, if unlikely, source of corruption).
Handle some cases of broken MIDI, and oversized events, more gracefully.


git-svn-id: svn://localhost/ardour2/branches/3.0@3335 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 87 insertions, 69 deletions

diff --git a/libs/ardour/ardour/midi_ring_buffer.h b/libs/ardour/ardour/midi_ring_buffer.h
index 680e2a7b61..ea0013fe46 100644
--- a/libs/ardour/ardour/midi_ring_buffer.h
+++ b/libs/ardour/ardour/midi_ring_buffer.h
@@ -75,7 +75,7 @@ public:
 		
 		if (w > r) {
 			return ((r - w + _size) % _size) - 1;
-		} else if(w < r) {
+		} else if (w < r) {
 			return (r - w) - 1;
 		} else {
 			return _size - 1;
@@ -101,15 +101,17 @@ public:
 
 	size_t read(size_t size, T* dst);
 	bool   full_read(size_t size, T* dst);
+
+	bool   skip(size_t size);
 	
 	void   write(size_t size, const T* src);
 
 protected:
-	mutable gint _write_ptr;
-	mutable gint _read_ptr;
+	mutable int _write_ptr;
+	mutable int _read_ptr;
 	
 	size_t _size; ///< Size (capacity) in bytes
-	T*  _buf;  ///< size, event, size, event...
+	T*     _buf;  ///< size, event, size, event...
 };
 
 
@@ -130,7 +132,7 @@ MidiRingBufferBase<T>::peek(size_t size, T* dst)
 			: _size - priv_read_ptr;
 	
 	memcpy(dst, &_buf[priv_read_ptr], read_size);
-        
+
 	return read_size;
 }
 
@@ -168,7 +170,7 @@ MidiRingBufferBase<T>::read(size_t size, T* dst)
 			: _size - priv_read_ptr;
 	
 	memcpy(dst, &_buf[priv_read_ptr], read_size);
-        
+
 	g_atomic_int_set(&_read_ptr, (priv_read_ptr + read_size) % _size);
 
 	return read_size;
@@ -192,6 +194,23 @@ MidiRingBufferBase<T>::full_read(size_t size, T* dst)
 
 
 template<typename T>
+bool
+MidiRingBufferBase<T>::skip(size_t size)
+{
+	if (read_space() < size) {
+		std::cerr << "WARNING: Attempt to skip past end of MIDI ring buffer" << std::endl;
+		return false;
+	}
+	
+	const size_t priv_read_ptr = g_atomic_int_get(&_read_ptr);
+	g_atomic_int_set(&_read_ptr, (priv_read_ptr + size) % _size);
+
+	return true;
+}
+
+
+
+template<typename T>
 inline void
 MidiRingBufferBase<T>::write(size_t size, const T* src)
 {
@@ -199,14 +218,14 @@ MidiRingBufferBase<T>::write(size_t size, const T* src)
 	
 	if (priv_write_ptr + size <= _size) {
 		memcpy(&_buf[priv_write_ptr], src, size);
-        g_atomic_int_set(&_write_ptr, (priv_write_ptr + size) % _size);
+		g_atomic_int_set(&_write_ptr, (priv_write_ptr + size) % _size);
 	} else {
 		const size_t this_size = _size - priv_write_ptr;
 		assert(this_size < size);
 		assert(priv_write_ptr + this_size <= _size);
 		memcpy(&_buf[priv_write_ptr], src, this_size);
 		memcpy(&_buf[0], src+this_size, size - this_size);
-        g_atomic_int_set(&_write_ptr, size - this_size);
+		g_atomic_int_set(&_write_ptr, size - this_size);
 	}
 }
 
@@ -223,11 +242,10 @@ MidiRingBufferBase<T>::write(size_t size, const T* src)
  */
 class MidiRingBuffer : public MidiRingBufferBase<Byte> {
 public:
-
 	/** @param size Size in bytes.
 	 */
 	MidiRingBuffer(size_t size)
-		: MidiRingBufferBase<Byte>(size), _channel_mask(0xFFFF), _force_channel(-1)
+		: MidiRingBufferBase<Byte>(size), _channel_mask(0x0000FFFF)
 	{}
 
 	size_t write(double time, size_t size, const Byte* buf);
@@ -238,21 +256,24 @@ public:
 
 	size_t read(MidiBuffer& dst, nframes_t start, nframes_t end, nframes_t offset=0);
 	
-	/**
-	 * @param channel_mask each bit in channel_mask represents a midi channel: bit 0 = channel 0,
-	 *                     bit 1 = channel 1 etc. the read and write methods will only allow
-	 *                     events to pass, whose channel bit is 1.
+	/** Set the channel filtering mode.
+	 * @param mask If mode is FilterChannels, each bit represents a midi channel:
+	 *     bit 0 = channel 0, bit 1 = channel 1 etc. the read and write methods will only
+	 *     process events whose channel bit is 1.
+	 *     If mode is ForceChannel, mask is simply a channel number which all events will
+	 *     be forced to while reading.
 	 */
-	void      set_channel_mask(uint16_t channel_mask) { g_atomic_int_set(&_channel_mask, channel_mask); }
-	uint16_t  get_channel_mask() { return g_atomic_int_get(&_channel_mask); }
+	void set_channel_mode(ChannelMode mode, uint16_t mask) {
+		g_atomic_int_set(&_channel_mask, ((uint16_t)mode << 16) | mask);
+	}
+
+	ChannelMode get_channel_mode() const {
+		return static_cast<ChannelMode>((g_atomic_int_get(&_channel_mask) & 0xFFFF0000) >> 16);
+	}
 	
-	/**
-	 * @param channel if negative, forcing channels is deactivated and filtering channels
-	 *                is activated, if positive, the LSB of channel is the channel number
-	 *                of the channel all events are forced into and filtering is deactivated
-	 */
-	void      set_force_channel(int8_t channel) { g_atomic_int_set(&_force_channel, channel); }
-	int8_t    get_force_channel() { return g_atomic_int_get(&_force_channel); }
+	uint16_t get_channel_mask() const {
+		return static_cast<ChannelMode>((g_atomic_int_get(&_channel_mask) & 0x0000FFFF));
+	}
 	
 protected:
 	inline bool is_channel_event(Byte event_type_byte) {
@@ -263,8 +284,7 @@ protected:
 	}
 	
 private:
-	volatile uint16_t _channel_mask;
-	volatile int8_t   _force_channel;
+	volatile uint32_t _channel_mask; // 16 bits mode, 16 bits mask
 };
 
 
@@ -308,17 +328,18 @@ MidiRingBuffer::read_contents(size_t size, Byte* buf)
 inline size_t
 MidiRingBuffer::write(double time, size_t size, const Byte* buf)
 {
-	//printf("MRB - write %#X %d %d with time %lf\n",
-	//		buf[0], buf[1], buf[2], time);
+	/*fprintf(stderr, "MRB %p write (t = %f) ", this, time);
+	for (size_t i = 0; i < size; ++i)
+		fprintf(stderr, "%X", (char)buf[i]);
+	fprintf(stderr, "\n");*/
 	
 	assert(size > 0);
 	
-	if(is_channel_event(buf[0]) && (g_atomic_int_get(&_force_channel) < 0)) {
-		// filter events for channels
-		Byte channel_nr = buf[0] & 0x0F;
-		if( !(g_atomic_int_get(&_channel_mask) & (1L << channel_nr)) )  {
+	// Don't write event if it doesn't match channel filter
+	if (is_channel_event(buf[0]) && get_channel_mode() == FilterChannels) {
+		Byte channel = buf[0] & 0x0F;
+		if ( !(get_channel_mask() & (1L << channel)) )
 			return 0;
-		}
 	}
 
 	if (write_space() < (sizeof(double) + sizeof(size_t) + size)) {
@@ -326,11 +347,11 @@ MidiRingBuffer::write(double time, size_t size, const Byte* buf)
 	} else {
 		MidiRingBufferBase<Byte>::write(sizeof(double), (Byte*)&time);
 		MidiRingBufferBase<Byte>::write(sizeof(size_t), (Byte*)&size);
-		if(is_channel_event(buf[0]) && (g_atomic_int_get(&_force_channel) >= 0)) {
+		if (is_channel_event(buf[0]) && get_channel_mode() == ForceChannel) {
 			assert(size == 3);
 			Byte tmp_buf[3];
-			//force event into channel
-			tmp_buf[0] = (buf[0] & 0xF0) | (g_atomic_int_get(&_force_channel) & 0x0F);
+			// Force event to channel
+			tmp_buf[0] = (buf[0] & 0xF0) | (get_channel_mask() & 0x0F);
 			tmp_buf[1] = buf[1];
 			tmp_buf[2] = buf[2];
 			MidiRingBufferBase<Byte>::write(size, tmp_buf);
@@ -354,22 +375,23 @@ MidiRingBuffer::read(MidiBuffer& dst, nframes_t start, nframes_t end, nframes_t
 	if (read_space() == 0)
 		return 0;
 
-	MIDI::Event ev;
+	double   ev_time;
+	uint32_t ev_size;
 
 	size_t count = 0;
 
-	//printf("MRB - read %u .. %u + %u\n", start, end, offset);
+	//printf("---- MRB read %u .. %u + %u\n", start, end, offset);
 
 	while (read_space() > sizeof(double) + sizeof(size_t)) {
 	
-		full_peek(sizeof(double), (Byte*)&ev.time());
+		full_peek(sizeof(double), (Byte*)&ev_time);
 	
-		if (ev.time() > end)
+		if (ev_time > end)
 			break;
 		
-		bool success = MidiRingBufferBase<Byte>::full_read(sizeof(double), (Byte*)&ev.time());
+		bool success = MidiRingBufferBase<Byte>::full_read(sizeof(double), (Byte*)&ev_time);
 		if (success) {
-			success = MidiRingBufferBase<Byte>::full_read(sizeof(size_t), (Byte*)&ev.size());
+			success = MidiRingBufferBase<Byte>::full_read(sizeof(size_t), (Byte*)&ev_size);
 		}
 
 		if (!success) {
@@ -377,51 +399,47 @@ MidiRingBuffer::read(MidiBuffer& dst, nframes_t start, nframes_t end, nframes_t
 			continue;
 		}
 		
-		Byte first_event_byte;
-		if(success) {
-			success = full_peek(sizeof(Byte), &first_event_byte);
-		}
-				
-		// could this ever happen???
-		if (!success) {
-			std::cerr << "MRB: PEEK ERROR (first event byte)" << std::endl;
-			continue;
-		}
+		Byte status;
+		success = full_peek(sizeof(Byte), &status);
+		assert(success); // If this failed, buffer is corrupt, all hope is lost
 		
-		// filter events for channels
-		// filtering is only active, if forcing channels is not active
-		if(is_channel_event(first_event_byte) && (g_atomic_int_get(&_force_channel) < 0)) {
-			Byte channel_nr = first_event_byte & 0x0F;
-			if( !(g_atomic_int_get(&_channel_mask) & (1L << channel_nr)) )  {
+		// Ignore event if it doesn't match channel filter
+		if (is_channel_event(status) && get_channel_mode() == FilterChannels) {
+			const Byte channel = status & 0x0F;
+			if ( !(get_channel_mask() & (1L << channel)) ) {
+				skip(ev_size); // Advance read pointer to next event
 				continue;
 			}
 		}
 
-		if (ev.time() >= start) {
-			ev.time() -= start;
-			// TODO: Right now there come MIDI Events with empty buffer
-			if(!ev.buffer()) {
-				std::cerr << "MidiRingBuffer::read WARNING: Skipping MIDI Event with NULL buffer pointer " 
-				     << " and length " << int(ev.size()) << std::endl; 
+		if (ev_time >= start) {
+
+			/*std::cerr << "MRB " << this << " - Reading event, time = "
+			 	<< ev_time << " - " << start << " => " << ev_time - start
+				<< ", size = " << ev_size << std::endl;*/
+			
+			ev_time -= start;
+			
+			Byte* write_loc = dst.reserve(ev_time, ev_size);
+			if (write_loc == NULL) {
+				std::cerr << "MRB: Unable to reserve space in buffer, event skipped";
 				continue;
 			}
 			
-			Byte* write_loc = dst.reserve(ev.time(), ev.size());
-			
-			success = MidiRingBufferBase<Byte>::full_read(ev.size(), write_loc);
+			success = MidiRingBufferBase<Byte>::full_read(ev_size, write_loc);
 		
 			if (success) {
-				if(is_channel_event(first_event_byte) && (g_atomic_int_get(&_force_channel) >= 0)) {
-					write_loc[0] = (write_loc[0] & 0xF0) | (g_atomic_int_get(&_force_channel) & 0x0F);
+				if (is_channel_event(status) && get_channel_mode() == ForceChannel) {
+					write_loc[0] = (write_loc[0] & 0xF0) | (get_channel_mask() & 0x0F);
 				}
 				++count;
-				//printf("MRB - read event at time %lf\n", ev.time());
+				//printf("MRB - read event at time %lf\n", ev_time);
 			} else {
 				std::cerr << "MRB: READ ERROR (data)" << std::endl;
 			}
 			
 		} else {
-			printf("MRB - SKIPPING EVENT AT TIME %f\n", ev.time());
+			printf("MRB (start %u) - Skipping event at (too early) time %f\n", start, ev_time);
 		}
 	}