小编Mel*_*box的帖子

我希望从麦克风实时输入波形显示.我已经使用installTapOnBus:bufferSize:format:block:来实现,这个函数在一秒钟内被调用三次.我想将此函数设置为每秒调用20次.我在哪里可以设置？

AVAudioSession *audioSession = [AVAudioSession sharedInstance];

NSError* error = nil;
if (audioSession.isInputAvailable) [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:&error];
if(error){
    return;
}

[audioSession setActive:YES error:&error];
if(error){
    retur;
}

self.engine = [[[AVAudioEngine alloc] init] autorelease];

AVAudioMixerNode* mixer = [self.engine mainMixerNode];
AVAudioInputNode* input = [self.engine inputNode];
[self.engine connect:input to:mixer format:[input inputFormatForBus:0]];

// tap ... 1 call in 16537Frames
// It does not change even if you change the bufferSize
[input installTapOnBus:0 bufferSize:4096 format:[input inputFormatForBus:0] block:^(AVAudioPCMBuffer* buffer, AVAudioTime* when) {

    for (UInt32 i = 0; i < …