Apple

On Aug 27, 2013, at 7:08 PM, Tamas Nagy <email@hidden> wrote:

Hi list,

I'm trying to create an internal MIDI clock in my app, but wanted to the clock could be seen in other apps by sending the clock messages to midi out nodes.

I achieved the internal clock working, but using kCAClockProperty_MIDIClockDestinations to output the clock message is not working. Probably I missed something, but the "documentation" of Core Audio does not provide me any useful information.

Here is the code I'm using:

CAClockNew(0, &theClock);

syncMode = kCAClockSyncMode_Internal;
timeBase = kCAClockTimebase_HostTime;

tempoMap.beats = 4;
tempoMap.tempoBPM = 120.0f;

CAClockSetProperty(theClock,kCAClockProperty_SyncMode,sizeof(syncMode), &syncMode);
CAClockSetProperty(theClock,kCAClockProperty_InternalTimebase,sizeof(timeBase), &timeBase);
CAClockSetProperty(theClock,kCAClockProperty_TempoMap,sizeof(tempoMap), &tempoMap);

MIDIEndpointRef *sources;
int i, j;

ItemCount num_sources = MIDIGetNumberOfSources();
sources = (MIDIEndpointRef *)malloc(sizeof(MIDIEndpointRef) * num_sources);
j = 0;
for (i = 0; i < num_sources; i++) {
MIDIEndpointRef source;
source = MIDIGetSource(i);
sources[j++] = source;
}

CFArrayRef sourcesArray = CFArrayCreate(NULL, (void *)sources, j, NULL);

CAClockSetProperty(theClock,kCAClockProperty_MIDIClockDestinations,sizeof(sourcesArray), &sourcesArray);


CAClockStart(theClock);

thanks for any advice.

Tamas

References:
	>Creating a MIDI Clock via Core Audio (From: Tamas Nagy <email@hidden>)