AVAssetWriterInputPixelBufferAdaptor内存管理

Question

我正在用AVAssetWriterInputPixelBufferAdaptor为视频写一些帧，当我写了很多帧时，我的应用因内存分配而崩溃。我怎么能防止这种情况？这是代码：

AVAssetWriterInput *writerInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings];  

NSDictionary *sourcePixelBufferAttributesDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                                                       [NSNumber numberWithInt:kCVPixelFormatType_32ARGB], kCVPixelBufferPixelFormatTypeKey, nil];

 AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor           
 assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput  
 sourcePixelBufferAttributes:sourcePixelBufferAttributesDictionary]; 


CVPixelBufferRef buffer = NULL;
                buffer = (CVPixelBufferRef)[self pixelBufferFromCGImage:[tmpImg CGImage] size:size];
                if (buffer)
                {
                    if(![adaptor appendPixelBuffer:buffer withPresentationTime:presentTime])
                        NSLog(@"FAIL");
                    else
                        NSLog(@"Success:%d",i);
                        CFRelease(buffer);

                }

使用Xcode Instruments时，泄漏似乎发生在

中

if(![adaptor appendPixelBuffer:buffer withPresentationTime:presentTime])

（AVAssetWriterInputPixelBufferAdaptor）

真的可以使用一些帮助或指向工作示例的指针。谢谢！