I am Using AUdioQueue to record the audio from built-in mic and send it over socket, I have set the AudioQueue buffer to record buffer of say 30 sec in once shot and allocating bufferSize appropriately, This is the function i am using to set the AudioDataFormat.
AudioStreamBasicDescription sRecordFormat;
FillOutASBDForLPCM (sRecordFormat,
16000,
1,
16,
16,
false,
false
);
Following Code calculate the bufferSize that needs to be allocated to capture the audio,
int AQRecorder::ComputeRecordBufferSize(const AudioStreamBasicDescription *format, float seconds)
{
int packets, frames, bytes = 0;
try {
frames = (int)ceil(seconds * format->mSampleRate);
if (format->mBytesPerFrame > 0)
bytes = frames * format->mBytesPerFrame;
else {
UInt32 maxPacketSize;
if (format->mBytesPerPacket > 0)
maxPacketSize = format->mBytesPerPacket; // constant packet size
else {
UInt32 propertySize = sizeof(maxPacketSize);
XThrowIfError(AudioQueueGetProperty(mQueue, kAudioQueueProperty_MaximumOutputPacketSize, &maxPacketSize,
&propertySize), "couldn't get queue's maximum output packet size");
}
if (format->mFramesPerPacket > 0)
packets = frames / format->mFramesPerPacket;
else
packets = frames; // worst-case scenario: 1 frame in a packet
if (packets == 0) // sanity check
packets = 1;
bytes = packets * maxPacketSize;
}
} catch (CAXException e) {
char buf[256];
gLog<<[[NSString stringWithFormat:@"Error:%s (%s)\n",e.mOperation,e.FormatError(buf)] UTF8String]<<endl;
return 0;
}
return bytes;
}
Following code Sample to allocate the buffer,
// allocate and enqueue buffers
bufferByteSize = ComputeRecordBufferSize(&mRecordFormat, kBufferDurationSeconds); // enough bytes for 20 ms
for (i = 0; i < kNumberRecordBuffers; ++i) {
XThrowIfE开发者_运维技巧rror(AudioQueueAllocateBuffer(mQueue, bufferByteSize, &mBuffers[i]),
"AudioQueueAllocateBuffer failed");
XThrowIfError(AudioQueueEnqueueBuffer(mQueue, mBuffers[i], 0, NULL),
"AudioQueueEnqueueBuffer failed");
}
Yes, you guessed it right, most of the code referred from SpeakHere example, When it comes to AudioCallback, i need to Capture the buffer and send it to other machine over socket,
// ____________________________________________________________________________________
// AudioQueue callback function, called when an input buffers has been filled.
void AQRecorder::MyInputBufferHandler( void * inUserData,
AudioQueueRef inAQ,
AudioQueueBufferRef inBuffer,
const AudioTimeStamp * inStartTime,
UInt32 inNumPackets,
const AudioStreamPacketDescription* inPacketDesc)
{
AQRecorder *aqr = (AQRecorder *)inUserData;
try {
NSLog([NSString stringWithFormat:"Inside AudioBufferCallback no of packet [%d]",inMumPackets]);
if (inNumPackets > 0) {
// write packets to file
// This is only for the test
XThrowIfError(AudioFileWritePackets(aqr->mRecordFile, FALSE, inBuffer->mAudioDataByteSize,
inPacketDesc, aqr->mRecordPacket, &inNumPackets, inBuffer->mAudioData),
"AudioFileWritePackets failed");
aqr->mRecordPacket += inNumPackets;
if(aqr->pInputListener){
aqr->pInputListener(aqr->pClientUserData,inBuffer->mAudioData,(int)inBuffer->mAudioDataByteSize);
}
}
// if we're not stopping, re-enqueue the buffe so that it gets filled again
if (aqr->IsRunning())
XThrowIfError(AudioQueueEnqueueBuffer(inAQ, inBuffer, 0, NULL), "AudioQueueEnqueueBuffer failed");
}
}
Now when i see the log, data are coming but it says no of packets are 256, 320 like that, when i pass the data at the other end, its not audible, Can anyone tell me, what do i need to do WIth the packetSize, i was under impression to bufferSize is enough to send the data but i guess, something has got to do with the Number of Packet also.
Some problem in buffer management, This application needs to send data in 20 ms +- 5 ms possible, in my case, this particular case was not handled.
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