Function StartRecording

native-audio/app/src/main/cpp/native-audio-jni.cpp:864–898

set the recording state for the audio recorder

// set the recording state for the audio recorder
void StartRecording(JNIEnv*, jclass) {
  SLresult result;

  if (pthread_mutex_trylock(&audioEngineLock)) {
    return;
  }
  // in case already recording, stop recording and clear buffer queue
  result =
      (*recorderRecord)->SetRecordState(recorderRecord, SL_RECORDSTATE_STOPPED);
  assert(SL_RESULT_SUCCESS == result);
  (void)result;
  result = (*recorderBufferQueue)->Clear(recorderBufferQueue);
  assert(SL_RESULT_SUCCESS == result);
  (void)result;

  // the buffer is not valid for playback yet
  recorderSize = 0;

  // enqueue an empty buffer to be filled by the recorder
  // (for streaming recording, we would enqueue at least 2 empty buffers to
  // start things off)
  result = (*recorderBufferQueue)
               ->Enqueue(recorderBufferQueue, recorderBuffer,
                         RECORDER_FRAMES * sizeof(short));
  // the most likely other result is SL_RESULT_BUFFER_INSUFFICIENT,
  // which for this code example would indicate a programming error
  assert(SL_RESULT_SUCCESS == result);
  (void)result;

  // start recording
  result = (*recorderRecord)
               ->SetRecordState(recorderRecord, SL_RECORDSTATE_RECORDING);
  assert(SL_RESULT_SUCCESS == result);
  (void)result;
}

// shut down the native audio system
void Shutdown(JNIEnv*, jclass) {