无法停止assetWriter完成写入

Question

我正在尝试进行屏幕捕获并写入视频文件。

assetWriterTimer = [NSTimer scheduledTimerWithTimeInterval:0.5
                                                    target:self
                                                  selector:@selector (writeSample:)
                                                  userInfo:nil
                                                   repeats:YES] ;

-(void) writeSample: (NSTimer*) _timer
{
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
           //capture and save image to video
        });
}

为了停止记录，我写了

-(void) stopRecording 
{

[assetWriterTimer invalidate];
assetWriterTimer = nil;
[assetWriterTimer release];

[assetWriter finishWritingWithCompletionHandler:^(){
    NSLog (@"finished writing completion handler");
}];

NSLog (@"finished writing");
}

但是，我大多会收到此错误和应用程序崩溃。我应该怎么做？
-[AVAssetWriter finishWriting] status 为 2' 时无法调用方法

Answer 1

你在某处调用 [assetWriter startWriting] 吗？

这个错误基本上意味着作者现在并没有真正在写作，所以它不能真正停止写作。如果您确实查看了 AVWriter's status codes 的含义，您会看到 2 表示完成写入时。

enum {
 AVAssetWriterStatusUnknown = 0,
 AVAssetWriterStatusWriting,
 AVAssetWriterStatusCompleted,
 AVAssetWriterStatusFailed,
 AVAssetWriterStatusCancelled
};