当我使用AVAssetWriterInput时，readyForMoreMediaData的值总是为NO，但是为什么呢？

Question

当我使用AVFoundation录制视频时，视频没有音轨，这段代码是怎么回事? readyForMoreMediaData的值总是返回no，方法‘appendSampleBuffer：’不执行...？？

1.
AVAssetWriterInput *audioWriterInput = [self audioWriterInput];
if ([self.assetWriter canAddInput:audioWriterInput]) {
    [self.assetWriter addInput:audioWriterInput];
}
2.
- (AVAssetWriterInput *)audioWriterInput {
    NSDictionary *audioCompressionSettings =
  @{
        AVEncoderBitRatePerChannelKey:@(28000),
        AVFormatIDKey : @(kAudioFormatMPEG4AAC),
        AVNumberOfChannelsKey : @(1),
        AVSampleRateKey : @(22050)
  };
    AVAssetWriterInput *audioWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeAudio outputSettings:audioCompressionSettings];
    audioWriterInput.expectsMediaDataInRealTime = YES;
    self.audioWriterInput = audioWriterInput;
    return audioWriterInput;
}
3.
- (void)appendingAudioSampleBuffer:(CMSampleBufferRef)sampleBuffer {
    // readyForMoreMediaData is always return NO
    if(self.audioWriterInput.readyForMoreMediaData) {
        BOOL success = [self.audioWriterInput appendSampleBuffer:sampleBuffer];
        if (success) {
            NSLog(@"");
        } else {

        }
    }
}

Answer 1

我真是个傻孩子。我错误地使用了getter方法！