ios – 我想每秒调用20次installTapOnBus：bufferSize：format：block：

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];

AVAu@L_726_5@mixerNode* 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 < buffer.audioBufferList->mnumberBuffers; i++) {
        Float32 *data = buffer.audioBufferList->mBuffers[i].mData;
        UInt32 frames = buffer.audioBufferList->mBuffers[i].mDataByteSize / sizeof(Float32);

        // create waveform
        ...
    }
}];

[self.ENGIne startAndReturnError:&error];
if (error) {
    return;
}

解决方法

[input installTapOnBus:0 bufferSize:1024 format:[mixer outputFormatForBus:0] block:^(AVAudioPCMBuffer *buffer,AVAudioTime *when) {
    buffer.frameLength = 1024; //here