试图使用Audiokit将PCM转换为MP3的崩溃

Question

我正在尝试实时转换音频从我的iPhone麦克风到mp3。

我已经设置了它：

        let format = AVAudioFormat(commonFormat: AVAudioCommonFormat.pcmFormatInt16,
                               sampleRate: 44100.0,
                               channels: 1,
                               interleaved: true)
    mic.avAudioUnitOrNode.installTap(onBus: 0, bufferSize: AVAudioFrameCount((format?.sampleRate)!), format: format, block: { (buffer: AVAudioPCMBuffer!, time: AVAudioTime!) -> Void in
        let audioBuffer : AVAudioBuffer = buffer
        self.audioProcessor?.processBuffer( audioBuffer.mutableAudioBufferList)
    })

-(void)processBuffer: (AudioBufferList*) audioBufferList;
{
    const int PCM_SIZE = 8192;
    const int MP3_SIZE = 8192;
    short int pcm_buffer[PCM_SIZE*2];
    unsigned char mp3_buffer[MP3_SIZE];
    int write = lame_encode_buffer_interleaved(mLame, pcm_buffer,(int*) audioBufferList->mBuffers[0].mData, mp3_buffer, MP3_SIZE);
   //some other stuff
}

但是，我一进入编码部分就会崩溃。

编辑：

我让它停止崩溃了，但是音频质量非常苛刻：

    int size = audioBufferList->mBuffers[0].mDataByteSize / 2;
    unsigned char mp3_buffer[size * 4];
    int write = lame_encode_buffer(mLame, audioBufferList->mBuffers[0].mData, audioBufferList->mBuffers[0].mData, size, mp3_buffer, size*4);

Answer 1

源音频和编码器之间的采样率不匹配。