bool ARDevice::CreateAudioEngine()
{
// initialize some locals
AREngine* theEngine = NULL;
// set the return value
bool theAnswer = true;
// get the description of th engine to build
OSDictionary* theEngineDictionary = OSDynamicCast(OSDictionary, getProperty(AUDIO_ENGINE_KEY));
FailIfNULLWithAction(theEngineDictionary, theAnswer = false, Done, "ARDevice::CreateAudioEngines: couldn't get the engine description");
// create the engine
theEngine = new AREngine;
if(theEngine != NULL)
{
// initialize the engine
if(theEngine->init(theEngineDictionary))
{
// activate the new engine, if initialization was successful
activateAudioEngine(theEngine);
}
// release the engine
theEngine->release();
}
Done:
return theAnswer;
}
bool AREngine::CreateStreams(IOAudioSampleRate* outInitialSampleRate, UInt32* outNumberChannels)
{
// set the return values
bool theAnswer = true;
*outNumberChannels = 0;
// set up some local variables
OSArray* theFormatArray = NULL;
OSArray* theSampleRateArray = NULL;
OSString* theOSString = NULL;
UInt32 theNumberStreams = NUM_STREAMS;
OSNumber* theOSNumber = NULL;
// get the array of formats
theFormatArray = OSDynamicCast(OSArray, getProperty(FORMATS_KEY));
FailIfNULLWithAction(theFormatArray, theAnswer = false, Done, "AREngine::CreateStreams: Couldn't get the format array");
// get the array of sample rates
theSampleRateArray = OSDynamicCast(OSArray, getProperty(SAMPLE_RATES_KEY));
FailIfNULLWithAction(theSampleRateArray, theAnswer = false, Done, "AREngine::CreateStreams: Couldn't get the sample rate array");
// get the description
theOSString = OSDynamicCast(OSString, getProperty(DESCRIPTION_KEY));
if(theOSString != NULL)
{
setDescription(theOSString->getCStringNoCopy());
}
// get the number of streams
theOSNumber = OSDynamicCast(OSNumber, getProperty(NUM_STREAMS_KEY));
if(theOSNumber != NULL)
{
theNumberStreams = theOSNumber->unsigned32BitValue();
}
// make the streams
for(UInt32 theStreamNumber = 0; theStreamNumber < theNumberStreams; ++theStreamNumber)
{
// initialize some local variables
bool theResult = false;
UInt32 theMaxBitWidth = 0;
UInt32 theMaxNumberChannels = 0;
IOAudioStream* theInputStream = NULL;
IOAudioStream* theOutputStream = NULL;
OSCollectionIterator* theFormatIterator = NULL;
OSCollectionIterator* theSampleRateIterator = NULL;
OSDictionary* theFormatDictionary = NULL;
IOAudioSampleRate theSampleRate = { 0, 0 };
IOAudioStreamFormat theInitialFormat;
bool theInitialFormatSet = false;
char theInputStreamName[32];
char theOutputStreamName[32];
UInt32 theStreamBufferSize = 0;
// allocate and initialize the input stream
if(theNumberStreams > 1)
{
snprintf(theInputStreamName, 32, "Input Stream #%ld", theStreamNumber + 1);
}
else
{
snprintf(theInputStreamName, 32, "Input Stream");
}
theInputStream = new IOAudioStream;
FailIfNULLWithAction(theInputStream, theAnswer = false, Error, "AREngine::CreateStreams: couldn't create the input stream");
theResult = theInputStream->initWithAudioEngine(this, kIOAudioStreamDirectionInput, *outNumberChannels + 1, theInputStreamName);
FailIfWithAction(!theResult, theAnswer = false, Error, "AREngine::CreateStreams: couldn't initialize the input stream");
// allocate and initialize the output stream
if(theNumberStreams > 1)
{
snprintf(theOutputStreamName, 32, "Output Stream #%ld", theStreamNumber + 1);
}
else
{
snprintf(theOutputStreamName, 32, "Output Stream");
}
theOutputStream = new IOAudioStream;
FailIfNULLWithAction(theOutputStream, theAnswer = false, Error, "AREngine::CreateStreams: couldn't create the output stream");
theResult = theOutputStream->initWithAudioEngine(this, kIOAudioStreamDirectionOutput, *outNumberChannels + 1, theOutputStreamName);
FailIfWithAction(!theResult, theAnswer = false, Error, "AREngine::CreateStreams: couldn't initialize the output stream");
// make an iterator for the format array
theFormatIterator = OSCollectionIterator::withCollection(theFormatArray);
FailIfNULLWithAction(theFormatIterator, theAnswer = false, Error, "AREngine::CreateStreams: couldn't create the format iterator");
// make an iterator for the sample rate array
theSampleRateIterator = OSCollectionIterator::withCollection(theSampleRateArray);
FailIfNULLWithAction(theSampleRateIterator, theAnswer = false, Error, "AREngine::CreateStreams: couldn't create the sample rate iterator");
// iterate through the formats
theFormatIterator->reset();
theFormatDictionary = (OSDictionary*)theFormatIterator->getNextObject();
while(theFormatDictionary != NULL)
{
// make sure we have a dictionary
if(OSDynamicCast(OSDictionary, theFormatDictionary) != NULL)
{
// convert the dictionary into something we can deal with
IOAudioStreamFormat theFormat;
FailIfNULLWithAction(IOAudioStream::createFormatFromDictionary(theFormatDictionary, &theFormat), theAnswer = false, Error, "AREngine::CreateStreams: couldn't make a format out of the dictionary");
// make sure the initial format is set
if(!theInitialFormatSet)
{
theInitialFormat = theFormat;
}
// iterate through the sample rates
theSampleRateIterator->reset();
theOSNumber = (OSNumber*)theSampleRateIterator->getNextObject();
while(theOSNumber != NULL)
{
// make sure we have a number
if(OSDynamicCast(OSNumber, theOSNumber) != NULL)
{
// get the sample rate
theSampleRate.whole = theOSNumber->unsigned32BitValue();
// make sure the initial sample rate is set
if(outInitialSampleRate->whole == 0)
{
outInitialSampleRate->whole = theSampleRate.whole;
}
// add the format to the input stream
theInputStream->addAvailableFormat(&theFormat, &theSampleRate, &theSampleRate);
// add the format to the output stream
theOutputStream->addAvailableFormat(&theFormat, &theSampleRate, &theSampleRate);
// track a few things
theMaxNumberChannels = (theFormat.fNumChannels > theMaxNumberChannels) ? theFormat.fNumChannels : theMaxNumberChannels;
theMaxBitWidth = (theFormat.fBitWidth > theMaxBitWidth) ? theFormat.fBitWidth : theMaxBitWidth;
}
// go to the next sample rate
theOSNumber = (OSNumber*)theSampleRateIterator->getNextObject();
}
}
// go to the next format
theFormatDictionary = (OSDictionary*)theFormatIterator->getNextObject();
}
// calculate the size of the stream buffer
theStreamBufferSize = mBlockSize * mNumberBlocks * theMaxNumberChannels * theMaxBitWidth / 8;
// allocate the buffers if necessary
if(mOutputBuffer == NULL)
{
// calculate the size
mOutputBufferSize = theStreamBufferSize * theNumberStreams;
// allocate the output buffer
mOutputBuffer = (void*)IOMallocAligned(mOutputBufferSize, PAGE_SIZE);
FailIfNULLWithAction(mOutputBuffer, theAnswer = false, Error, "AREngine::CreateStreams: couldn't allocate the output buffer");
// the input size is the same as the output size
mInputBufferSize = mOutputBufferSize;
// allocate the input buffer
mInputBuffer = mOutputBuffer;
}
// set some info about the stream
theInputStream->setTerminalType(INPUT_UNDEFINED);
theOutputStream->setTerminalType(OUTPUT_UNDEFINED);
// set the initial stream formats
theInputStream->setFormat(&theInitialFormat, false);
theOutputStream->setFormat(&theInitialFormat, false);
// set the data buffer for the streams
theInputStream->setSampleBuffer(&((UInt8*)mInputBuffer)[theStreamBufferSize * theStreamNumber], theStreamBufferSize);
theOutputStream->setSampleBuffer(&((UInt8*)mOutputBuffer)[theStreamBufferSize * theStreamNumber], theStreamBufferSize);
// add the streams to the engine
addAudioStream(theInputStream);
theInputStream->release();
theInputStream = NULL;
addAudioStream(theOutputStream);
theOutputStream->release();
theOutputStream = NULL;
theFormatIterator->release();
theFormatIterator = NULL;
theSampleRateIterator->release();
theSampleRateIterator = NULL;
*outNumberChannels += theMaxNumberChannels;
continue;
Error:
if(theInputStream)
{
theInputStream->release();
}
if(theOutputStream)
{
theOutputStream->release();
}
if(theFormatIterator)
{
theFormatIterator->release();
}
if(theSampleRateIterator)
{
theSampleRateIterator->release();
}
goto Done;
}
Done:
return theAnswer;
}
