CoreAudio Stuff From C++ to Swift - c++

Question

How to convert the code below to swift? Someone help.
I want to convert this cpp code to swift, from project FreeStreamer.
But some C++ struct and some C callback drive me crazy.
Help.
Here is the code from audio_stream.h and audio_stream.cpp
// var
queued_packet_t *m_queuedHead;
queued_packet_t *m_queuedTail;
queued_packet_t *m_playPacket;
std::list <queued_packet_t*> m_processedPackets;
//struct
typedef struct queued_packet {
UInt64 identifier;
AudioStreamPacketDescription desc;
struct queued_packet *next;
char data[];
} queued_packet_t;
//function one
OSStatus Audio_Stream::encoderDataCallback(AudioConverterRef inAudioConverter, UInt32 *ioNumberDataPackets, AudioBufferList *ioData, AudioStreamPacketDescription **outDataPacketDescription, void *inUserData) {
Audio_Stream *THIS = (Audio_Stream *)inUserData;
pthread_mutex_trylock(&THIS->m_packetQueueMutex);
// Dequeue one packet per time for the decoder
queued_packet_t *front = THIS->m_playPacket;
if (!front) {
/* Don't deadlock */
AS_LOCK_TRACE("encoderDataCallback 2: unlock\n");
pthread_mutex_unlock(&THIS->m_packetQueueMutex);
pthread_mutex_trylock(&THIS->m_streamStateMutex);
THIS->m_converterRunOutOfData = true;
pthread_mutex_unlock(&THIS->m_streamStateMutex);
*ioNumberDataPackets = 0;
ioData->mBuffers[0].mDataByteSize = 0;
return noErr;
}
*ioNumberDataPackets = 1;
ioData->mBuffers[0].mData = front->data;
ioData->mBuffers[0].mDataByteSize = front->desc.mDataByteSize;
ioData->mBuffers[0].mNumberChannels = THIS->m_srcFormat.mChannelsPerFrame;
if (outDataPacketDescription) {
*outDataPacketDescription = &front->desc;
}
THIS->m_playPacket = front->next;
THIS->m_processedPackets.push_front(front);
AS_LOCK_TRACE("encoderDataCallback 5: unlock\n");
pthread_mutex_unlock(&THIS->m_packetQueueMutex);
return noErr;
}
//function two
void Audio_Stream::streamDataCallback(void *inClientData, UInt32 inNumberBytes, UInt32 inNumberPackets, const void *inInputData, AudioStreamPacketDescription *inPacketDescriptions) {
AS_TRACE("%s: inNumberBytes %u, inNumberPackets %u\n", __FUNCTION__, (unsigned int)inNumberBytes, (unsigned int)inNumberPackets);
Audio_Stream *THIS = static_cast<Audio_Stream*>(inClientData);
if (!THIS->m_audioStreamParserRunning) {
AS_TRACE("%s: stray callback detected!\n", __PRETTY_FUNCTION__);
return;
}
for (int i = 0; i < inNumberPackets; i++) {
/* Allocate the packet */
UInt32 size = inPacketDescriptions[i].mDataByteSize;
queued_packet_t *packet = (queued_packet_t *)malloc(sizeof(queued_packet_t) + size);
packet->identifier = THIS->m_packetIdentifier;
// If the stream didn't provide bitRate (m_bitRate == 0), then let's calculate it
if (THIS->m_bitRate == 0 && THIS->m_bitrateBufferIndex < kAudioStreamBitrateBufferSize) {
// Only keep sampling for one buffer cycle; this is to keep the counters (for instance) duration
// stable.
THIS->m_bitrateBuffer[THIS->m_bitrateBufferIndex++] = 8 * inPacketDescriptions[i].mDataByteSize / THIS->m_packetDuration;
if (THIS->m_bitrateBufferIndex == kAudioStreamBitrateBufferSize) {
if (THIS->m_delegate) {
THIS->m_delegate->bitrateAvailable();
}
}
}
AS_LOCK_TRACE("streamDataCallback: lock\n");
pthread_mutex_trylock(&THIS->m_packetQueueMutex);
/* Prepare the packet */
packet->next = NULL;
packet->desc = inPacketDescriptions[i];
packet->desc.mStartOffset = 0;
memcpy(packet->data, (const char *)inInputData + inPacketDescriptions[i].mStartOffset,
size);
if (THIS->m_queuedHead == NULL) {
THIS->m_queuedHead = THIS->m_queuedTail = THIS->m_playPacket = packet;
} else {
THIS->m_queuedTail->next = packet;
THIS->m_queuedTail = packet;
}
THIS->m_cachedDataSize += size;
THIS->m_packetIdentifier++;
AS_LOCK_TRACE("streamDataCallback: unlock\n");
pthread_mutex_unlock(&THIS->m_packetQueueMutex);
}
THIS->determineBufferingLimits();
}

Answer 1

All the FreeStreamer project has been rewrite wieth Swift 3.0 in here FreePlayer
Answer can be found here AudioStream