Also for http://stackoverflow.com/questions/23249034/how-to-simply-play-a-cmsamplebufferref-audio-data

gistfile1.m

// Get audio format description.
CMFormatDescriptionRef formatDescription = CMSampleBufferGetFormatDescription(sampleBuffer);
const AudioStreamBasicDescription format = *CMAudioFormatDescriptionGetStreamBasicDescription(formatDescription);

// Get sample count.
CMItemCount sampleCount = CMSampleBufferGetNumSamples(sampleBuffer);
     
AudioBufferList audioBufferList;
CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(
                                                        sampleBuffer,
                                                        NULL,
                                                        &audioBufferList,
                                                        sizeof(audioBufferList),
                                                        NULL,
                                                        NULL,
                                                        kCMSampleBufferFlag_AudioBufferList_Assure16ByteAlignment,
                                                        &sampleBuffer
                                                        );
    
// Enumerate buffers.
for (int bufferCount = 0; bufferCount < audioBufferList.mNumberBuffers; bufferCount++)
{
    SInt16 *samples = (SInt16*)audioBufferList.mBuffers[sampleCount].mData;
        
    // OpenAL format.
    ALenum alFormat;
    if (format.mBitsPerChannel == 16)
    { alFormat = (format.mChannelsPerFrame > 1) ? AL_FORMAT_STEREO16 : AL_FORMAT_MONO16; }
    if (format.mBitsPerChannel == 8)
    { alFormat = (format.mChannelsPerFrame > 1) ? AL_FORMAT_STEREO8 : AL_FORMAT_MONO8; }

    static int counter;
    counter++;
    NSString *bufferName = [NSString stringWithFormat:@"buffer_%i", counter];

    ALBuffer *alBuffer = [ALBuffer bufferWithName:bufferName
                                             data:samples
                                             size:sampleCount * sizeof(UInt32)
                                           format:alFormat
                                        frequency:(ALsizei)round(format.mSampleRate)];
        
    // Retain.
    if (alBuffer != nil)
    [self.alBuffers addObject:alBuffer];
        
    // Keep the queue at 50 at most.
    if (self.alBuffers.count > 50)
    { [self.alBuffers removeObject:self.alBuffers.firstObject]; }
        
    NSLog(@"sampleCount: %li duration:%f", sampleCount, alBuffer.duration);
}
    
// Release the buffer when done with the samples
// (retained by CMSampleBufferGetAudioBufferListWithRetainedblockBuffer)
CFRelease(sampleBuffer);