How to read Audio queue service bufer by byte? - objective-c

Question

I am recording sound from mic input using Audio queue service.
-(void)startRecording{
[self setupAudioFormat:&recordState.dataFormat];
recordState.currentPacket = 0;
OSStatus status;
status = AudioQueueNewInput(&recordState.dataFormat,
AudioInputCallback,
&recordState,
CFRunLoopGetCurrent(),
kCFRunLoopCommonModes,
0,
&recordState.queue);
if (status == 0)
{
// Prime recording buffers with empty data
for (int i = 0; i < NUM_BUFFERS; i++)
{
NSLog(#"buf in");
AudioQueueAllocateBuffer(recordState.queue, 16000, &recordState.buffers[i]);
AudioQueueEnqueueBuffer (recordState.queue, recordState.buffers[i], 0, NULL);
}
status = AudioFileCreateWithURL(fileURL,
kAudioFileAIFFType,
&recordState.dataFormat,
kAudioFileFlags_EraseFile,
&recordState.audioFile);
if (status == 0)
{
recordState.recording = true;
status = AudioQueueStart(recordState.queue, NULL);
if (status == 0)
{
NSLog(#"Recording");
}
}
}
if (status != 0)
{
//[self stopRecording];
NSLog(#"recording failed");
}
}
on callback:
void AudioInputCallback(void * inUserData,
AudioQueueRef inAQ,
AudioQueueBufferRef inBuffer,
const AudioTimeStamp * inStartTime,
UInt32 inNumberPacketDescriptions,
const AudioStreamPacketDescription * inPacketDescs)
{
RecordState * recordState = (RecordState*)inUserData;
if (!recordState->recording)
{
printf("Not recording, returning\n");
}
// if (inNumberPacketDescriptions == 0 && recordState->dataFormat.mBytesPerPacket != 0)
// {
// inNumberPacketDescriptions = inBuffer->mAudioDataByteSize / recordState->dataFormat.mBytesPerPacket;
// }
/*
int sampleCount = recordState->buffers[0]->mAudioDataBytesCapacity / sizeof (AUDIO_DATA_TYPE_FORMAT);
NSLog(#"sample count = %i",sampleCount);
AUDIO_DATA_TYPE_FORMAT *p = (AUDIO_DATA_TYPE_FORMAT*)recordState->buffers[0]->mAudioData;
for (int i = 0; i < sampleCount; i++) {
if (p[i] > 1000) {
NSLog(#"%hd",p[i]);
}
}*/
printf("Writing buffer %lld\n", recordState->currentPacket);
OSStatus status = AudioFileWritePackets(recordState->audioFile,
false,
inBuffer->mAudioDataByteSize,
inPacketDescs,
recordState->currentPacket,
&inNumberPacketDescriptions,
inBuffer->mAudioData);
if (status == 0)
{
recordState->buffers[0] = nil;
recordState->currentPacket += inNumberPacketDescriptions;
}
AudioQueueEnqueueBuffer(recordState->queue, inBuffer, 0, NULL);
}
Here i want to read recorded buffer. is it possible to get something like this:
short[] buffer = ?;//here should an audio buffer converted to some structure (short[] just for example)
then i would like to read every element of this structure:
for (int i = 0; i < sizeOfBuffer; i++) {
bufferVal = buffer[i];
}
In short how to handle buffer when recording ?
Thanks.