AVAssetWriter startWriting状态为3时无法调用方法

Question

我正在使用视频过滤.我使用了BradLarson的 GPUImage.它完美的图像工作,但现在我试图从库过滤视频文件,它给我错误[AVAssetWriter startWriting] Cannot call method when status is 3.我用过IOS7

heare是我的代码

- (void)viewDidLoad
{
    [super viewDidLoad];
    videoEditingPlayView = [[GPUImageView alloc] initWithFrame:CGRectMake(60,108,200,200)];

    [self.view addSubview:videoEditingPlayView];
}

-(IBAction)btnEffectsClick:(id)sender{
     NSURL *videoURl = [NSURL fileURLWithPath:self.strVideoURl];
    if (movieFile != nil) {
        videoFilter = nil;
       movieFile = nil;
     }
movieFile = [[GPUImageMovie alloc] initWithURL:videoURl];
movieFile.runBenchmark = YES;
videoFilter = [[GPUImageBrightnessFilter alloc] init];
[(GPUImageBrightnessFilter *)videoFilter setBrightness:0.0];
[movieFile addTarget:videoFilter];
videoEditingPlayView.hidden = NO;

GPUImageView *filterView = (GPUImageView *)videoEditingPlayView;
[videoFilter addTarget:filterView];

NSString *pathToMovie = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Movie.m4v"];
NSURL *movieURL = [NSURL fileURLWithPath:pathToMovie];

movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:movieURL size:CGSizeMake(480, 360)];
[videoFilter addTarget:movieWriter];

// movieWriter.
movieWriter.shouldPassthroughAudio = YES;
movieFile.audioEncodingTarget = movieWriter;
[movieFile enableSynchronizedEncodingUsingMovieWriter:movieWriter];
[filterView setFillMode:kGPUImageFillModePreserveAspectRatio];
filterView.transform = CGAffineTransformRotate(filterView.transform, 3.14159/2);


double delayToStartRecording = 0.5;
dispatch_time_t startTime = dispatch_time(DISPATCH_TIME_NOW, delayToStartRecording * NSEC_PER_SEC);
dispatch_after(startTime, dispatch_get_main_queue(), ^(void){
    NSLog(@"Start recording");
    [movieWriter startRecording];

    **[movieFile startProcessing];** ***if I remove this line then it is working but not dispying video on videoEditingPlayView***


    double delayInSeconds = 30.0;
    dispatch_time_t stopTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
    dispatch_after(stopTime, dispatch_get_main_queue(), ^(void){
        [filter removeTarget:movieWriter];
        [movieWriter finishRecording];

        [videoFilter removeTarget:movieWriter];

        movieWriter = nil;
        NSLog(@"Movie completed");
    });
});
}

在编码,如果我删除此行

[movieFile startProcessing];

应用程序运行顺畅,但不显示视频.如果我把[movieFile startProcessing]它然后崩溃并给我一个错误.

我试过这个,但无法解决崩溃.

GPUImage因[AVAssetWriter startWriting]而终止,当状态为3时无法调用方法

https://github.com/BradLarson/GPUImage/issues/1228

与GPUImageView的混合没有给出预期的结果

GPUImageMovieWriter - 崩溃时"状态为2时无法调用方法"

还有其他.

谢谢.

Answer 1

检查目标文件是否存在.

如果存在,请删除现有文件.