audiounit - Reading chunks of audio with ringbuffer -

i analyze chunks of audio data of 1 second. purpose implemented audio unit fills ringbuffer (tpcircularbuffer michael tyson). in file try read chunks of 1 second using nstimer. unfortunately, receive errors consuming these data.

the buffer filled in kaudiooutputunitproperty_setinputcallback , works fine

device * = (__bridge device *)inrefcon; // render audio buffer audiobufferlist bufferlist; bufferlist.mnumberbuffers = 1; bufferlist.mbuffers[0].mnumberchannels = 2; bufferlist.mbuffers[0].mdata = null; bufferlist.mbuffers[0].mdatabytesize = innumberframes * sizeof(sint16) * 2; checkerror(audiounitrender(this -> riounit, ioactionflags, intimestamp, 1, innumberframes, &bufferlist), "audiounitrender");  // put audio circular buffer tpcircularbufferproducebytes(&circbuffer, bufferlist.mbuffers[0].mdata, innumberframes * 2 * sizeof(sint16)); 

to read 1 second of samples implemented te following code:

    - (void)initializetimer {         timer = [nstimer scheduledtimerwithtimeinterval:1                                                  target:self                                                selector:@selector(timerfired:)                                                userinfo:nil                                                 repeats:yes];     }      - (void) timerfired:(nstimer *)thetimer {         nslog(@"reading %i second(s) ring",1);          int32_t availablebytes;         sint16 *tail = tpcircularbuffertail(&circbuffer, &availablebytes);         int availablesamples = availablebytes / sizeof(sint16);         nslog(@"available samples %i", availablesamples);          (int = 0; < availablesamples; i++) {             printf("%i\n",tail[i]);         }          tpcircularbufferconsume(&circbuffer, sizeof(sint16) * availablebytes);     } 

however, when run code number of samples printed receive following error: assertion failed: (buffer->fillcount >= 0), function tpcircularbufferconsume, file …/tpcircularbuffer.h, line 142.

unfortunately, don’t know going wrong consuming data. buffer length set samplerate * 2 long enough.

i happy if knows going wrong here.

your circular buffer isn't long enough. don't check available size positive before emptying, , time print statements take let buffer over-filled. make buffer @ least 2x larger timer, check before emptying, empty buffer before printing, , use far fewer print statements.