ios - 应用程序将状态从后台更改为前台后 CVBufferRelease 崩溃

Question

我正在使用以下代码来创建给定图像数组的视频。一切正常。代码在串行队列上运行。当状态应用程序从后台更改为前台时，此代码在 CVBufferRelease(buffer) 上崩溃。我还验证了缓冲区不指向空值。

知道如何解决这个问题吗？

UIImage *image = [UIImage imageWithData:imgFrameData];
CVPixelBufferRef buffer = NULL;
buffer = [self newPixelBufferFromCGImage:[image CGImage] andSize:CGSizeMake(frameSize, frameSize)];

BOOL append_ok = NO;

while (!append_ok){
    if (adaptor.assetWriterInput.readyForMoreMediaData)
    {

      CMTime frameTime = CMTimeMake(i*timeBetweenFrame,(int32_t) TIMESCALE);
      CMTimeShow(frameTime); 
      append_ok = [adaptor appendPixelBuffer:buffer withPresentationTime:frameTime];
      if(buffer)
      {          
          CVBufferRelease(buffer);              
      }

      [NSThread sleepForTimeInterval:0.05];
    }
    else
    {
       [NSThread sleepForTimeInterval:0.1];
    }
  }