Fix sub-patch MIDI I/O.

Make buffer 'joining' (zero-copy connections) significantly less retarded.


git-svn-id: http://svn.drobilla.net/lad/ingen@882 a436a847-0d15-0410-975c-d299462d15a1

17 files changed, 130 insertions, 101 deletions

diff --git a/src/libs/engine/AudioBuffer.cpp b/src/libs/engine/AudioBuffer.cpp
index c302480a..b4038586 100644
--- a/src/libs/engine/AudioBuffer.cpp
+++ b/src/libs/engine/AudioBuffer.cpp
@@ -32,7 +32,6 @@ AudioBuffer::AudioBuffer(size_t size)
 	: Buffer((size == 1) ? DataType::CONTROL : DataType::AUDIO, size)
 	, _data(NULL)
 	, _local_data(NULL)
-	, _joined_buf(NULL)
 	, _size(size)
 	, _filled_size(0)
 	, _state(OK)
@@ -254,17 +253,6 @@ AudioBuffer::unjoin()
 }
 
 
-bool
-AudioBuffer::is_joined_to(Buffer* buf) const
-{
-	AudioBuffer* abuf = dynamic_cast<AudioBuffer*>(buf);
-	if (abuf)
-		return (data() == abuf->data());
-
-	return false;
-}
-
-
 void
 AudioBuffer::prepare_read(SampleCount nframes)
 {
diff --git a/src/libs/engine/AudioBuffer.hpp b/src/libs/engine/AudioBuffer.hpp
index de9fc4a6..44650856 100644
--- a/src/libs/engine/AudioBuffer.hpp
+++ b/src/libs/engine/AudioBuffer.hpp
@@ -41,16 +41,14 @@ public:
 	
 	bool join(Buffer* buf);
 	void unjoin();
-	bool is_joined_to(Buffer* buf) const;
 	
 	/** For driver use only!! */
 	void set_data(Sample* data);
 	
-	inline void* raw_data() const
-		{ return ((_joined_buf != NULL) ? _joined_buf->raw_data() : _data); }
+	inline const void* raw_data() const { return _data; }
+	inline void*       raw_data()       { return _data; }
 	
-	inline Sample* data() const
-		{ return ((_joined_buf != NULL) ? _joined_buf->data() : _data); }
+	inline Sample* data() const { return _data; }
 	
 	inline Sample& value_at(size_t offset) const
 		{ assert(offset < _size); return data()[offset]; }
@@ -73,7 +71,6 @@ private:
 
 	Sample*      _data;        ///< Used data pointer (probably same as _local_data)
 	Sample*      _local_data;  ///< Locally allocated buffer (possibly unused if joined or set_data used)
-	AudioBuffer* _joined_buf;  ///< Buffer to mirror, if joined
 	size_t       _size;        ///< Allocated buffer size
 	size_t       _filled_size; ///< Usable buffer size (for MIDI ports etc)
 	State        _state;       ///< State of buffer for setting values next cycle
diff --git a/src/libs/engine/Buffer.hpp b/src/libs/engine/Buffer.hpp
index d18270f5..30180064 100644
--- a/src/libs/engine/Buffer.hpp
+++ b/src/libs/engine/Buffer.hpp
@@ -34,12 +34,14 @@ public:
 	Buffer(Shared::DataType type, size_t size)
 		: _type(type)
 		, _size(size)
+		, _joined_buf(NULL)
 	{}
 
 	/** Clear contents and reset state */
 	virtual void clear() = 0;
 	
-	virtual void* raw_data() const = 0;
+	virtual void*       raw_data()       = 0;
+	virtual const void* raw_data() const = 0;
 
 	/** Rewing (ie reset read pointer), but leave contents unchanged */
 	virtual void rewind() const = 0;
@@ -47,7 +49,9 @@ public:
 	virtual void prepare_read(SampleCount nframes) = 0;
 	virtual void prepare_write(SampleCount nframes) = 0;
 	
-	virtual bool is_joined_to(Buffer* buf) const = 0;
+	bool is_joined() const { return (_joined_buf != NULL); }
+	Buffer* joined_buffer() const { return _joined_buf; }
+	
 	virtual bool join(Buffer* buf) = 0;
 	virtual void unjoin() = 0;
 	
@@ -61,6 +65,7 @@ public:
 protected:
 	Shared::DataType _type;
 	size_t           _size;
+	Buffer*          _joined_buf;
 };
 
 
diff --git a/src/libs/engine/ConnectionImpl.cpp b/src/libs/engine/ConnectionImpl.cpp
index 57d5e1ad..f2bfeda5 100644
--- a/src/libs/engine/ConnectionImpl.cpp
+++ b/src/libs/engine/ConnectionImpl.cpp
@@ -62,6 +62,7 @@ ConnectionImpl::ConnectionImpl(PortImpl* src_port, PortImpl* dst_port)
 	if (_must_mix)
 		_local_buffer = BufferFactory::create(dst_port->type(), dst_port->buffer(0)->size());
 
+	/* FIXME: 1->1 connections with a destination with fixed buffers copies unecessarily */
 	//cerr << src_port->path() << " -> " << dst_port->path() << " must mix: " << _must_mix << endl;
 }
 
@@ -126,6 +127,10 @@ ConnectionImpl::process(ProcessContext& context)
 	 * a buffer (if it hasn't been done already this cycle) and returns that
 	 * would avoid having to mix multiple times.  Probably not a very common
 	 * case, but it would be faster anyway. */
+
+	/*cerr << src_port()->path() << " * " << src_port()->poly()
+			<< " -> " << dst_port()->path() << " * " << dst_port()->poly()
+			<< "\t\tmust mix: " << _must_mix << endl;*/
 	
 	if (_must_mix && (type() == DataType::CONTROL || type() == DataType::AUDIO)) {
 
diff --git a/src/libs/engine/DuplexPort.cpp b/src/libs/engine/DuplexPort.cpp
index 93b61b8c..0da8d9d4 100644
--- a/src/libs/engine/DuplexPort.cpp
+++ b/src/libs/engine/DuplexPort.cpp
@@ -23,6 +23,7 @@
 #include "ConnectionImpl.hpp"
 #include "OutputPort.hpp"
 #include "NodeImpl.hpp"
+#include "ProcessContext.hpp"
 
 using namespace std;
 
@@ -43,10 +44,26 @@ void
 DuplexPort::pre_process(ProcessContext& context)
 {
 	// <BrainHurt>
-	InputPort::pre_process(context);
+		
+	/*cerr << path() << " duplex pre: fixed buffers: " << fixed_buffers() << endl;
+	cerr << path() << " duplex pre: buffer: " << buffer(0) << endl;
+	cerr << path() << " duplex pre: is_output: " << _is_output << " { " << endl;*/
+	
+	if (_is_output) {
+
+		for (uint32_t i=0; i < _poly; ++i)
+			_buffers->at(i)->prepare_write(context.nframes());
+
+	} else {
+
+		for (uint32_t i=0; i < _poly; ++i)
+			_buffers->at(i)->prepare_read(context.nframes());
 
-	if ( ! _is_output)
 		broadcast(context);
+	}
+
+	//cerr << "} pre " << path() << endl;
+
 	// </BrainHurt>
 }
 
@@ -54,12 +71,20 @@ DuplexPort::pre_process(ProcessContext& context)
 void
 DuplexPort::post_process(ProcessContext& context)
 {
+	/*cerr << path() << " duplex post: fixed buffers: " << fixed_buffers() << endl;
+	cerr << path() << " duplex post: buffer: " << buffer(0) << endl;
+	cerr << path() << " duplex post: is_output: " << _is_output << " { " << endl;*/
+	
 	// <BrainHurt>
-	if (_is_output)
+	if (_is_output) {
+		InputPort::pre_process(context); // Mix down inputs
 		broadcast(context);
+	}
 
 	OutputPort::pre_process(context);
 	// </BrainHurt>
+	
+	//cerr << "} post " << path() << endl;
 }
 
 
diff --git a/src/libs/engine/InputPort.cpp b/src/libs/engine/InputPort.cpp
index b9723855..f64cf97b 100644
--- a/src/libs/engine/InputPort.cpp
+++ b/src/libs/engine/InputPort.cpp
@@ -152,7 +152,7 @@ InputPort::pre_process(ProcessContext& context)
 	
 	if (_connections.size() == 0) {
 		for (uint32_t i=0; i < _poly; ++i)
-			_buffers->at(i)->prepare_read(context.nframes());
+			buffer(i)->prepare_read(context.nframes());
 		return;
 	}
 
@@ -162,8 +162,10 @@ InputPort::pre_process(ProcessContext& context)
 	if ( ! _fixed_buffers) {
 		// If only one connection, try to use buffer directly (zero copy)
 		if (_connections.size() == 1) {
-			for (uint32_t i=0; i < _poly; ++i)
+			for (uint32_t i=0; i < _poly; ++i) {
+				//cerr << path() << " joining to " << (*_connections.begin())->buffer(i) << endl;
 				_buffers->at(i)->join((*_connections.begin())->buffer(i));
+			}
 			do_mixdown = false;
 		}
 		connect_buffers();
@@ -172,22 +174,27 @@ InputPort::pre_process(ProcessContext& context)
 	}
 
 	for (uint32_t i=0; i < _poly; ++i)
-		_buffers->at(i)->prepare_read(context.nframes());
+		buffer(i)->prepare_read(context.nframes());
+	
+	/*cerr << path() << " poly = " << _poly << ", mixdown: " << do_mixdown
+		<< ", fixed buffers: " << _fixed_buffers << endl;
 	
-	//cerr << path() << " poly = " << _poly << ", mixdown: " << do_mixdown << endl;
+	if (type() == DataType::MIDI) 
+		for (uint32_t i=0; i < _poly; ++i)
+			cerr << path() << " (" << buffer(i) << ") # events: " << ((MidiBuffer*)buffer(i))->event_count() << ", joined: " << _buffers->at(i)->is_joined() << endl;*/
 
 	if (!do_mixdown) {
-#ifndef NDEBUG
+/*#ifndef NDEBUG
 		for (uint32_t i=0; i < _poly; ++i)
-			assert(_buffers->at(i)->is_joined_to((*_connections.begin())->buffer(i)));
-#endif
+			assert(buffer(i) == (*_connections.begin())->buffer(i));
+#endif*/
 		return;
 	}
 
 	if (_type == DataType::CONTROL || _type == DataType::AUDIO) {
 		for (uint32_t voice=0; voice < _poly; ++voice) {
 			// Copy first connection
-			_buffers->at(voice)->copy(
+			buffer(voice)->copy(
 				(*_connections.begin())->buffer(voice), 0, _buffer_size-1);
 
 			// Accumulate the rest
@@ -196,7 +203,7 @@ InputPort::pre_process(ProcessContext& context)
 				Connections::iterator c = _connections.begin();
 
 				for (++c; c != _connections.end(); ++c)
-					((AudioBuffer*)_buffers->at(voice))->accumulate(
+					((AudioBuffer*)buffer(voice))->accumulate(
 					((AudioBuffer*)(*c)->buffer(voice)), 0, _buffer_size-1);
 			}
 		}
@@ -221,7 +228,9 @@ InputPort::post_process(ProcessContext& context)
 
 	// Prepare for next cycle
 	for (uint32_t i=0; i < _poly; ++i)
-		_buffers->at(i)->prepare_write(context.nframes());
+		buffer(i)->prepare_write(context.nframes());
+	
+	//cerr << path() << " input post: buffer: " << buffer(0) << endl;
 }
 
 
diff --git a/src/libs/engine/JackAudioDriver.cpp b/src/libs/engine/JackAudioDriver.cpp
index f90e1075..8d8203ce 100644
--- a/src/libs/engine/JackAudioDriver.cpp
+++ b/src/libs/engine/JackAudioDriver.cpp
@@ -79,6 +79,8 @@ JackAudioPort::prepare_buffer(jack_nframes_t nframes)
 
 	AudioBuffer* patch_buf = (AudioBuffer*)_patch_port->buffer(0);
 
+	//cerr << "[JACK] " << _patch_port->path() << " buffer: " << patch_buf << endl;
+
 	if (jack_buf != _jack_buffer) {
 		patch_buf->set_data(jack_buf);
 		_jack_buffer = jack_buf;
diff --git a/src/libs/engine/LADSPANode.cpp b/src/libs/engine/LADSPANode.cpp
index ee5da968..033f3d50 100644
--- a/src/libs/engine/LADSPANode.cpp
+++ b/src/libs/engine/LADSPANode.cpp
@@ -78,10 +78,6 @@ LADSPANode::instantiate()
 	
 	for (size_t j=0; j < _descriptor->PortCount; ++j) {
 		port_name = Path::nameify(_descriptor->PortNames[j]);
-		
-		if (_descriptor->PortNames[j] != port_name)
-			cerr << "WARNING: Translated LADSPA port name: " <<
-				_descriptor->PortNames[j] << " -> " << port_name << endl;
 
 		string::size_type slash_index;
 		
@@ -90,14 +86,18 @@ LADSPANode::instantiate()
 			assert(_descriptor->PortNames[k] != NULL);
 			if (k != j && port_name == _descriptor->PortNames[k]) { // clash
 				if (LADSPA_IS_PORT_CONTROL(_descriptor->PortDescriptors[j]))
-					port_name += "_(CR)";
+					port_name += "(CR)";
 				else
-					port_name += "_(AR)";
+					port_name += "(AR)";
 			}
 			// Replace all slashes with "-" (so they don't screw up paths)
 			while ((slash_index = port_name.find("/")) != string::npos)
 				port_name[slash_index] = '-';
 		}
+		
+		if (_descriptor->PortNames[j] != port_name)
+			cerr << "NOTICE: Translated LADSPA port name: " <<
+				_descriptor->PortNames[j] << " -> " << port_name << endl;
 
 		port_path = path() + "/" + port_name;
 
diff --git a/src/libs/engine/MidiBuffer.cpp b/src/libs/engine/MidiBuffer.cpp
index 618c7476..929ac840 100644
--- a/src/libs/engine/MidiBuffer.cpp
+++ b/src/libs/engine/MidiBuffer.cpp
@@ -31,7 +31,6 @@ namespace Ingen {
 MidiBuffer::MidiBuffer(size_t capacity)
 	: Buffer(DataType(DataType::MIDI), capacity)
 	, _latest_stamp(0)
-	, _joined_buf(NULL)
 {
 	if (capacity > UINT32_MAX) {
 		cerr << "MIDI buffer size " << capacity << " too large, aborting." << endl;
@@ -98,20 +97,11 @@ MidiBuffer::unjoin()
 }
 
 
-bool
-MidiBuffer::is_joined_to(Buffer* buf) const
-{
-	MidiBuffer* mbuf = dynamic_cast<MidiBuffer*>(buf);
-	if (mbuf)
-		return (data() == mbuf->data());
-
-	return false;
-}
-
-
 void
 MidiBuffer::prepare_read(SampleCount nframes)
 {
+	//cerr << "\t" << this << " prepare_read: " << event_count() << endl;
+
 	rewind();
 	_this_nframes = nframes;
 }
@@ -120,6 +110,7 @@ MidiBuffer::prepare_read(SampleCount nframes)
 void
 MidiBuffer::prepare_write(SampleCount nframes)
 {
+	//cerr << "\t" << this << " prepare_write: " << event_count() << endl;
 	reset(nframes);
 }
 	
@@ -214,17 +205,19 @@ MidiBuffer::get_event(double*         timestamp,
                       uint32_t*       size, 
                       unsigned char** data) const
 {
-	if (_position >= _buf->size) {
-		_position = _buf->size;
+	const LV2_MIDI* buf = this->data();
+
+	if (_position >= buf->size) {
+		_position = buf->size;
 		*timestamp = _this_nframes;
 		*size = 0;
 		*data = NULL;
 		return _this_nframes;
 	}
 
-	*timestamp = *(double*)(_buf->data + _position);
-	*size = *(uint32_t*)(_buf->data + _position + sizeof(double));
-	*data = _buf->data + _position + sizeof(double) + sizeof(uint32_t);
+	*timestamp = *(double*)(buf->data + _position);
+	*size = *(uint32_t*)(buf->data + _position + sizeof(double));
+	*data = buf->data + _position + sizeof(double) + sizeof(uint32_t);
 
 	return *timestamp;
 }
diff --git a/src/libs/engine/MidiBuffer.hpp b/src/libs/engine/MidiBuffer.hpp
index fe3d36bb..e5ebc290 100644
--- a/src/libs/engine/MidiBuffer.hpp
+++ b/src/libs/engine/MidiBuffer.hpp
@@ -18,6 +18,7 @@
 #ifndef MIDIBUFFER_H
 #define MIDIBUFFER_H
 
+#include <iostream>
 #include <lv2ext/lv2-midiport.h>
 #include "Buffer.hpp"
 #include "interface/DataType.hpp"
@@ -34,29 +35,27 @@ public:
 	void prepare_read(SampleCount nframes);
 	void prepare_write(SampleCount nframes);
 
-	bool is_joined_to(Buffer* buf) const;
 	bool join(Buffer* buf);
 	void unjoin();
 
-	uint32_t this_nframes() const { return _this_nframes; }
-	uint32_t event_count() const { return _buf->event_count; }
+	inline uint32_t this_nframes() const { return _this_nframes; }
+	inline uint32_t event_count() const { return _buf->event_count; }
 	
-	inline LV2_MIDI* local_data() { return _local_buf; }
-	
-	inline void* raw_data() const
-		{ return ((_joined_buf != NULL) ? _joined_buf->raw_data() : _buf); }
+	inline void*       raw_data()       { return _buf; }
+	inline const void* raw_data() const { return _buf; }
 
-	inline LV2_MIDI* data()
-		{ return ((_joined_buf != NULL) ? _joined_buf->data() : _buf); }
-	
-	inline const LV2_MIDI* data() const
-		{ return ((_joined_buf != NULL) ? _joined_buf->data() : _buf); }
+	inline LV2_MIDI*       local_data() { return _local_buf; }
+	inline const LV2_MIDI* local_data() const { return _local_buf; }
+
+	inline LV2_MIDI*       data()       { return _buf; }
+	inline const LV2_MIDI* data() const { return _buf; }
 	
 	void copy(const Buffer* src, size_t start_sample, size_t end_sample);
 
 	inline void rewind() const { _position = 0; }
-	inline void clear() { if (_joined_buf) reset(_this_nframes); }
+	inline void clear() { reset(_this_nframes); }
 	inline void reset(SampleCount nframes) {
+		//std::cerr << this << " reset" << std::endl;
 		_latest_stamp = 0;
 		_position = 0;
 		_buf->event_count = 0;
@@ -75,7 +74,6 @@ private:
 	double           _latest_stamp; ///< Highest timestamp of all events
 	uint32_t         _this_nframes; ///< Current cycle nframes
 	mutable uint32_t _position; ///< Index into _buf
-	MidiBuffer*      _joined_buf;  ///< Buffer to mirror, if joined
 	LV2_MIDI*        _buf; ///< Contents (maybe belong to _joined_buf)
 	LV2_MIDI*        _local_buf; ///< Local contents
 };
diff --git a/src/libs/engine/MidiNoteNode.cpp b/src/libs/engine/MidiNoteNode.cpp
index 7b3c1c9e..c90f44ae 100644
--- a/src/libs/engine/MidiNoteNode.cpp
+++ b/src/libs/engine/MidiNoteNode.cpp
@@ -130,6 +130,8 @@ MidiNoteNode::process(ProcessContext& context)
 	MidiBuffer* const midi_in = (MidiBuffer*)_midi_in_port->buffer(0);
 	assert(midi_in->this_nframes() == context.nframes());
 
+	//cerr << path() << " # input events: " << midi_in->event_count() << endl;
+
 	if (midi_in->event_count() > 0)
 	while (midi_in->get_event(&timestamp, &size, &buffer) < context.nframes()) {
 		
@@ -167,11 +169,11 @@ MidiNoteNode::process(ProcessContext& context)
 				}
 				break;
 			default:
-				//fprintf(stderr, "Unknown (size %d) MIDI event %X\n", size, buffer[0]);
+				fprintf(stderr, "Unknown (size %d) MIDI event %X\n", size, buffer[0]);
 				break;
 			}
 		} else {
-			//fprintf(stderr, "Unknown (size %d) MIDI event %X\n", size, buffer[0]);
+			fprintf(stderr, "Unknown (size %d) MIDI event %X\n", size, buffer[0]);
 		}
 
 		if (midi_in->increment() == midi_in->this_nframes())
@@ -218,8 +220,8 @@ MidiNoteNode::note_on(uchar note_num, uchar velocity, FrameTime time, ProcessCon
 	assert(voice != NULL);
 	assert(voice == &(*_voices)[voice_num]);
 
-	cerr << "[MidiNoteNode] Note " << (int)note_num << " on @ " << time
-		<< ". Voice " << voice_num << " / " << _polyphony << endl;
+	//cerr << "[MidiNoteNode] Note " << (int)note_num << " on @ " << time
+	//	<< ". Voice " << voice_num << " / " << _polyphony << endl;
 	
 	// Update stolen key, if applicable
 	if (voice->state == Voice::Voice::ACTIVE) {
@@ -273,7 +275,7 @@ MidiNoteNode::note_off(uchar note_num, FrameTime time, ProcessContext& context)
 
 	Key* key = &_keys[note_num];
 	
-	cerr << "[MidiNoteNode] Note off @ " << time << ".  Key " << (int)note_num << endl;
+	//cerr << "[MidiNoteNode] Note " << (int)note_num << " off @ " << time << endl;
 
 	if (key->state == Key::ON_ASSIGNED) {
 		// Assigned key, turn off voice and key
@@ -345,7 +347,7 @@ MidiNoteNode::all_notes_off(FrameTime time, ProcessContext& context)
 	assert(time >= context.start() && time <= context.end());
 	assert(time - context.start() < _buffer_size);
 
-	//cerr << "Note off starting at sample " << offset << endl;
+	//cerr << "All notes off @ " << offset << endl;
 
 	// FIXME: set all keys to Key::OFF?
 	
diff --git a/src/libs/engine/OSCBuffer.cpp b/src/libs/engine/OSCBuffer.cpp
index 977d4e66..f8454a14 100644
--- a/src/libs/engine/OSCBuffer.cpp
+++ b/src/libs/engine/OSCBuffer.cpp
@@ -73,17 +73,6 @@ OSCBuffer::unjoin()
 }
 
 
-bool
-OSCBuffer::is_joined_to(Buffer* buf) const
-{
-	OSCBuffer* obuf = dynamic_cast<OSCBuffer*>(buf);
-	if (obuf)
-		return (data() == obuf->data());
-
-	return false;
-}
-
-
 void
 OSCBuffer::prepare_read(SampleCount nframes)
 {
diff --git a/src/libs/engine/OSCBuffer.hpp b/src/libs/engine/OSCBuffer.hpp
index 31371641..b939b764 100644
--- a/src/libs/engine/OSCBuffer.hpp
+++ b/src/libs/engine/OSCBuffer.hpp
@@ -38,7 +38,6 @@ public:
 	void prepare_read(SampleCount nframes);
 	void prepare_write(SampleCount nframes);
 
-	bool is_joined_to(Buffer* buf) const;
 	bool join(Buffer* buf);
 	void unjoin();
 	
@@ -47,14 +46,10 @@ public:
 	uint32_t this_nframes() const { return _this_nframes; }
 	uint32_t event_count() const { return _buf->message_count; }
 	
-	inline void* raw_data() const
-		{ return ((_joined_buf != NULL) ? _joined_buf->raw_data() : _buf); }
-
-	inline LV2OSCBuffer* data()
-		{ return ((_joined_buf != NULL) ? _joined_buf->data() : _buf); }
-	
-	inline const LV2OSCBuffer* data() const
-		{ return ((_joined_buf != NULL) ? _joined_buf->data() : _buf); }
+	inline void*               raw_data()       { return _buf; }
+	inline const void*         raw_data() const { return _buf; }
+	inline LV2OSCBuffer*       data()           { return _buf; }
+	inline const LV2OSCBuffer* data()     const { return _buf; }
 
 private:
 	LV2OSCBuffer* const _buf;
diff --git a/src/libs/engine/OutputPort.cpp b/src/libs/engine/OutputPort.cpp
index 024f6f39..82e23889 100644
--- a/src/libs/engine/OutputPort.cpp
+++ b/src/libs/engine/OutputPort.cpp
@@ -15,10 +15,13 @@
  * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <iostream>
 #include "OutputPort.hpp"
 #include "Buffer.hpp"
 #include "ProcessContext.hpp"
 
+using namespace std;
+
 namespace Ingen {
 
 
@@ -26,7 +29,7 @@ void
 OutputPort::pre_process(ProcessContext& context)
 {
 	for (uint32_t i=0; i < _poly; ++i)
-		_buffers->at(i)->prepare_write(context.nframes());
+		buffer(i)->prepare_write(context.nframes());
 }
 
 
@@ -34,7 +37,9 @@ void
 OutputPort::post_process(ProcessContext& context)
 {
 	for (uint32_t i=0; i < _poly; ++i)
-		_buffers->at(i)->prepare_read(context.nframes());
+		buffer(i)->prepare_read(context.nframes());
+
+	//cerr << path() << " output post: buffer: " << buffer(0) << endl;
 
 	broadcast(context);
 }
diff --git a/src/libs/engine/PatchImpl.cpp b/src/libs/engine/PatchImpl.cpp
index 9e2becae..7c4e0a65 100644
--- a/src/libs/engine/PatchImpl.cpp
+++ b/src/libs/engine/PatchImpl.cpp
@@ -142,6 +142,13 @@ PatchImpl::process(ProcessContext& context)
 		return;
 	
 	NodeBase::pre_process(context);
+	
+	/*if (_ports)
+		for (size_t i=0; i < _ports->size(); ++i)
+			if (_ports->at(i)->is_input() && _ports->at(i)->type() == DataType::MIDI)
+				cerr << _ports->at(i)->path() << " "
+					<< _ports->at(i)->buffer(0) << " # events: "
+					<< ((MidiBuffer*)_ports->at(i)->buffer(0))->event_count() << endl;*/
 
 	/* Run */
 	if (_engine.process_slaves().size() > 0)
diff --git a/src/libs/engine/PortImpl.cpp b/src/libs/engine/PortImpl.cpp
index 800ba011..4a17a218 100644
--- a/src/libs/engine/PortImpl.cpp
+++ b/src/libs/engine/PortImpl.cpp
@@ -157,7 +157,7 @@ void
 PortImpl::connect_buffers()
 {
 	for (uint32_t i=0; i < _poly; ++i)
-		PortImpl::parent_node()->set_port_buffer(i, _index, _buffers->at(i));
+		PortImpl::parent_node()->set_port_buffer(i, _index, buffer(i));
 }
 
 	
@@ -165,7 +165,7 @@ void
 PortImpl::clear_buffers()
 {
 	for (uint32_t i=0; i < _poly; ++i)
-		_buffers->at(i)->clear();
+		buffer(i)->clear();
 }
 	
 
diff --git a/src/libs/engine/PortImpl.hpp b/src/libs/engine/PortImpl.hpp
index 93972f58..22e44c05 100644
--- a/src/libs/engine/PortImpl.hpp
+++ b/src/libs/engine/PortImpl.hpp
@@ -25,6 +25,7 @@
 #include "types.hpp"
 #include "GraphObjectImpl.hpp"
 #include "interface/DataType.hpp"
+#include "Buffer.hpp"
 
 namespace Raul { class Maid; }
 
@@ -69,7 +70,15 @@ public:
 	
 	virtual Raul::Atom value() const;
 
-	Buffer* buffer(uint32_t voice) const { return _buffers->at(voice); }
+	inline Buffer* buffer(uint32_t voice) const {
+		Buffer* const buf = _buffers->at(voice);
+		if (buf->is_joined()) {
+			assert(buf->joined_buffer());
+			return buf->joined_buffer();
+		} else {
+			return buf;
+		}
+	}
 
 	/** Called once per process cycle */
 	virtual void pre_process(ProcessContext& context) = 0;