AVAssetWriter资料泄露

Question

你好，我是ios开发的新手，我遇到了一些问题

我做了一些类似AVAssetWriter的对象的设置(我用它将像素映射作为帧写入视频-它工作得很好)

    self.assetWriter = [[AVAssetWriter alloc] initWithURL:outputPath fileType:AVFileTypeQuickTimeMovie error:&error];

    NSMutableDictionary *dic=[[NSMutableDictionary alloc] init];
    [dic setValue: AVVideoCodecH264 forKey: AVVideoCodecKey];
    [dic setValue:[NSNumber numberWithInt:640] forKey:AVVideoWidthKey];
    [dic setValue:[NSNumber numberWithInt:480] forKey:AVVideoHeightKey];
     self.assetWriterInput = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeVideo outputSettings:dic];
      [dic release];

    assetWriterInputPixelBufferAdaptor =[[AVAssetWriterInputPixelBufferAdaptor alloc] initWithAssetWriterInput:assetWriterInput sourcePixelBufferAttributes:nil];

    self.assetWriterInput.expectsMediaDataInRealTime=YES;
    [self.assetWriter addInput:assetWriterInput];

    [self.assetWriter startWriting];
    [self.assetWriter startSessionAtSourceTime:recordStartTime];

然后保存视频，然后释放实例

[self.assetWriterInput markAsFinished];
[self.assetWriter endSessionAtSourceTime:recordStartTime];
[self.assetWriter finishWriting];

CVPixelBufferPoolRelease(assetWriterInputPixelBufferAdaptor.pixelBufferPool);
[self.assetWriter release];
[self.assetWriterInput release];
[self.assetWriterInputPixelBufferAdaptor release];

问题是，当我多次使用上述对来创建和释放实例以保存几个视频时，Instruments会显示泄漏

帮助!

Answer 1

AVAssetWriter *newWriter = [AVAssetWriter alloc] // retain count is 1. 
self.assetWriter = newWriter // What this actually does:

- (void)setAssetWriter(AVAssetWriter*)newWriter
{
    if (_assetWriter != newWriter)
    {
        [_assetWriter release]
        _assetWriter = [newWriter retain]; //retain count 2
    }
}

[self.assetWriter release]; //retain count 1

如果您忘记在dealloc中添加self.assetWriter = nil；，您最终会泄漏。在分配实例并通过@properties分配它们时，将自动释放附加到分配行，如下所示：

self.assetWriter = [[[AVAssetWriter alloc] initWithURL:outputPath fileType:AVFileTypeQuickTimeMovie error:&error] autorelease];