livetrax/libs/backends/coreaudio/coremidi_io.cc

/*
 * Copyright (C) 2015 Robin Gareus <robin@gareus.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <sstream>
#include "coremidi_io.h"
#include <CoreAudio/HostTime.h>

static void notifyProc (const MIDINotification *message, void *refCon) {
	CoreMidiIo *self = static_cast<CoreMidiIo*>(refCon);
	self->notify_proc(message);
}

static void midiInputCallback(const MIDIPacketList *list, void *procRef, void *srcRef) {
	CoreMidiIo *self = static_cast<CoreMidiIo*> (procRef);
	if (!self || !self->enabled()) {
		// skip while freewheeling
		return;
	}
	RingBuffer<uint8_t> * rb  = static_cast<RingBuffer < uint8_t > *> (srcRef);
	if (!rb) return;
	for (UInt32 i = 0; i < list->numPackets; i++) {
		const MIDIPacket *packet = &list->packet[i];
		if (rb->write_space() < sizeof(MIDIPacket)) {
			fprintf(stderr, "CoreMIDI: dropped MIDI event\n");
			continue;
		}
		rb->write((uint8_t*)packet, sizeof(MIDIPacket));
	}
}

static std::string getDisplayName(MIDIObjectRef object)
{
	CFStringRef name = nil;
	if (noErr != MIDIObjectGetStringProperty(object, kMIDIPropertyDisplayName, &name)) {
		return "";
	}
	if (!CFStringGetCStringPtr(name, kCFStringEncodingUTF8)) {
		if (name) CFRelease(name);
		return "";
	}
	std::string rv (CFStringGetCStringPtr(name, kCFStringEncodingUTF8));
	CFRelease(name);

	return rv;
}

CoreMidiIo::CoreMidiIo()
	: _midi_client (0)
	, _input_endpoints (0)
	, _output_endpoints (0)
	, _input_ports (0)
	, _output_ports (0)
	, _input_queue (0)
	, _rb (0)
	, _n_midi_in (0)
	, _n_midi_out (0)
	, _time_at_cycle_start (0)
	, _active (false)
	, _enabled (true)
	, _run (false)
	, _changed_callback (0)
	, _changed_arg (0)
{
	pthread_mutex_init (&_discovery_lock, 0);
}

CoreMidiIo::~CoreMidiIo()
{
	pthread_mutex_lock (&_discovery_lock);
	cleanup();
	if (_midi_client) {
		MIDIClientDispose(_midi_client);
		_midi_client = 0;
	}
	pthread_mutex_unlock (&_discovery_lock);
	pthread_mutex_destroy (&_discovery_lock);
}

void
CoreMidiIo::cleanup()
{
	_active = false;
	for (uint32_t i = 0 ; i < _n_midi_in ; ++i) {
		MIDIPortDispose(_input_ports[i]);
		_input_queue[i].clear();
		delete _rb[i];
	}
	for (uint32_t i = 0 ; i < _n_midi_out ; ++i) {
		MIDIPortDispose(_output_ports[i]);
	}

	free(_input_ports); _input_ports = 0;
	free(_input_endpoints); _input_endpoints = 0;
	free(_input_queue); _input_queue = 0;
	free(_output_ports); _output_ports = 0;
	free(_output_endpoints); _output_endpoints = 0;
	free(_rb); _rb = 0;

	_n_midi_in = 0;
	_n_midi_out = 0;
}

void
CoreMidiIo::start_cycle()
{
	_time_at_cycle_start = AudioGetCurrentHostTime();
}

void
CoreMidiIo::notify_proc(const MIDINotification *message)
{
	switch(message->messageID) {
		case kMIDIMsgSetupChanged:
			/* this one catches all of the added/removed/changed below */
			//printf("kMIDIMsgSetupChanged\n");
			discover();
			break;
		case kMIDIMsgObjectAdded:
			{
			//const MIDIObjectAddRemoveNotification *n = (const MIDIObjectAddRemoveNotification*) message;
			//printf("kMIDIMsgObjectAdded\n");
			}
			break;
		case kMIDIMsgObjectRemoved:
			{
			//const MIDIObjectAddRemoveNotification *n = (const MIDIObjectAddRemoveNotification*) message;
			//printf("kMIDIMsgObjectRemoved\n");
			}
			break;
		case kMIDIMsgPropertyChanged:
			{
			//const MIDIObjectPropertyChangeNotification *n = (const MIDIObjectPropertyChangeNotification*) message;
			//printf("kMIDIMsgObjectRemoved\n");
			}
			break;
		case kMIDIMsgThruConnectionsChanged:
			//printf("kMIDIMsgThruConnectionsChanged\n");
			break;
		case kMIDIMsgSerialPortOwnerChanged:
			//printf("kMIDIMsgSerialPortOwnerChanged\n");
			break;
		case kMIDIMsgIOError:
			fprintf(stderr, "kMIDIMsgIOError\n");
			discover();
			break;
	}
}

size_t
CoreMidiIo::recv_event (uint32_t port, double cycle_time_us, uint64_t &time, uint8_t *d, size_t &s)
{
	if (!_active || _time_at_cycle_start == 0) {
		return 0;
	}
	assert(port < _n_midi_in);

	while (_rb[port]->read_space() >= sizeof(MIDIPacket)) {
		MIDIPacket packet;
		size_t rv = _rb[port]->read((uint8_t*)&packet, sizeof(MIDIPacket));
		assert(rv == sizeof(MIDIPacket));
		_input_queue[port].push_back(boost::shared_ptr<CoreMIDIPacket>(new _CoreMIDIPacket (&packet)));
	}

	UInt64 start = _time_at_cycle_start;
	UInt64 end = AudioConvertNanosToHostTime(AudioConvertHostTimeToNanos(_time_at_cycle_start) + cycle_time_us * 1e3);

	for (CoreMIDIQueue::iterator it = _input_queue[port].begin (); it != _input_queue[port].end (); ) {
		if ((*it)->timeStamp < end) {
			if ((*it)->timeStamp < start) {
				uint64_t dt = AudioConvertHostTimeToNanos(start - (*it)->timeStamp);
				//printf("Stale Midi Event dt:%.2fms\n", dt * 1e-6);
				if (dt > 1e-4) { // 100ms, maybe too large
					it = _input_queue[port].erase(it);
					continue;
				}
				time = 0;
			} else {
				time = AudioConvertHostTimeToNanos((*it)->timeStamp - start);
			}
			s = std::min(s, (size_t) (*it)->length);
			if (s > 0) {
				memcpy(d, (*it)->data, s);
			}
			_input_queue[port].erase(it);
			return s;
		}
		++it;

	}
	return 0;
}

int
CoreMidiIo::send_event (uint32_t port, double reltime_us, const uint8_t *d, const size_t s)
{
	if (!_active || _time_at_cycle_start == 0) {
		return 0;
	}

	assert(port < _n_midi_out);
	UInt64 ts = AudioConvertHostTimeToNanos(_time_at_cycle_start);
	ts += reltime_us * 1e3;

	// TODO use a single packet list.. queue all events first..
	MIDIPacketList pl;

	pl.numPackets = 1;
	MIDIPacket *mp = &(pl.packet[0]);

	mp->timeStamp = AudioConvertNanosToHostTime(ts);
	mp->length = s;
	assert(s < 256);
	memcpy(mp->data, d, s);

	MIDISend(_output_ports[port], _output_endpoints[port], &pl);
	return 0;
}

std::string
CoreMidiIo::port_name (uint32_t port, bool input)
{
	std::stringstream ss;
	std::string pn;
	// XXX including the number will not yield persistent port-names
	// when disconnecting devices in the middle.
	if (input) {
		ss << "system:midi_capture_" << port;
		if (port < _n_midi_in) {
			pn = getDisplayName(_input_endpoints[port]);
		}
	} else {
		ss << "system:midi_playback_" << port;
		if (port < _n_midi_out) {
			pn = getDisplayName(_output_endpoints[port]);
		}
	}
	if (!pn.empty()) {
		ss << " - " << pn;
	}
	return ss.str();
}

void
CoreMidiIo::start () {
	_run = true;
	if (!_midi_client) {
		OSStatus err;
		err = MIDIClientCreate(CFSTR("Ardour"), &notifyProc, this, &_midi_client);
		if (noErr != err) {
			fprintf(stderr, "Creating Midi Client failed\n");
		}
	}
	discover();
}

void
CoreMidiIo::stop ()
{
	_run = false;
	pthread_mutex_lock (&_discovery_lock);
	cleanup();
	pthread_mutex_unlock (&_discovery_lock);
#if 0
	if (_midi_client) {
		MIDIClientDispose(_midi_client);
		_midi_client = 0;
	}
#endif
}

void
CoreMidiIo::discover()
{
	if (!_run || !_midi_client) { return; }

	if (pthread_mutex_trylock (&_discovery_lock)) {
		return;
	}

	cleanup();

	ItemCount srcCount = MIDIGetNumberOfSources();
	ItemCount dstCount = MIDIGetNumberOfDestinations();

	if (srcCount > 0) {
		_input_ports = (MIDIPortRef *) malloc (srcCount * sizeof(MIDIPortRef));
		_input_endpoints = (MIDIEndpointRef*) malloc (srcCount * sizeof(MIDIEndpointRef));
		_input_queue = (CoreMIDIQueue*) calloc (srcCount, sizeof(CoreMIDIQueue));
		_rb = (RingBuffer<uint8_t> **) malloc (srcCount * sizeof(RingBuffer<uint8_t>*));
	}
	if (dstCount > 0) {
		_output_ports = (MIDIPortRef *) malloc (dstCount * sizeof(MIDIPortRef));
		_output_endpoints = (MIDIEndpointRef*) malloc (dstCount * sizeof(MIDIEndpointRef));
	}

	for (ItemCount i = 0; i < srcCount; i++) {
		OSStatus err;
		MIDIEndpointRef src = MIDIGetSource(i);
		if (!src) continue;
#ifndef NDEBUG
		printf("MIDI IN DEVICE: %s\n", getDisplayName(src).c_str());
#endif

		CFStringRef port_name;
		port_name = CFStringCreateWithFormat(NULL, NULL, CFSTR("midi_capture_%lu"), i);

		err = MIDIInputPortCreate (_midi_client, port_name, midiInputCallback, this, &_input_ports[_n_midi_in]);
		if (noErr != err) {
			fprintf(stderr, "Cannot create Midi Output\n");
			continue;
		}
		_rb[_n_midi_in] = new RingBuffer<uint8_t>(1024 * sizeof(MIDIPacket));
		_input_queue[_n_midi_in] = CoreMIDIQueue();
		MIDIPortConnectSource(_input_ports[_n_midi_in], src, (void*) _rb[_n_midi_in]);
		CFRelease(port_name);
		_input_endpoints[_n_midi_in] = src;
		++_n_midi_in;
	}

	for (ItemCount i = 0; i < dstCount; i++) {
		MIDIEndpointRef dst = MIDIGetDestination(i);
		CFStringRef port_name;
		port_name = CFStringCreateWithFormat(NULL, NULL, CFSTR("midi_playback_%lu"), i);

		OSStatus err;
		err = MIDIOutputPortCreate (_midi_client, port_name, &_output_ports[_n_midi_out]);
		if (noErr != err) {
			fprintf(stderr, "Cannot create Midi Output\n");
			continue;
		}

#ifndef NDEBUG
		printf("MIDI OUT DEVICE: %s\n", getDisplayName(dst).c_str());
#endif

		MIDIPortConnectSource(_output_ports[_n_midi_out], dst, NULL);
		CFRelease(port_name);
		_output_endpoints[_n_midi_out] = dst;
		++_n_midi_out;
	}

	if (_changed_callback) {
		_changed_callback(_changed_arg);
	}

	_active = true;
	pthread_mutex_unlock (&_discovery_lock);
}