保存录制的视频太长时,应用程序崩溃

Question

问题:

保存我的应用中记录的视频时,如果视频大小/持续时间太大/太长,我的应用程序崩溃时没有日志/异常.

我的设置:

在我的应用程序中,我使用UIImagePickerController来录制视频.现在我注意到如果我的视频长度非常长(例如使用UIImagePickerControllerQualityTypeMedium 30分钟,或使用UIImagePickerControllerQualityTypeIFrame1280x720超过一分钟),保存视频时应用程序崩溃.有时有,有时没有警告.现在我开始调试并注意到它与内存有关(malloc_error).

我使用分析器来实时检查分配,并注意到,当它要保存视频时,分配突然变得非常大(我想这与视频的临时内存使用情况有关？)在它最终崩溃之前.以下是分析器的屏幕截图:

该应用必须能够录制最长1小时的视频(指定任何质量).

我尝试过的:

• 将picker.videoMaximumDuration设置为更短/更长
• 使用分析器/仪器进行调试
• 检查是否有泄漏
• 关闭所有打开的应用程序和已删除的应用程序设备(用于存储清理)以获得更多内存

码:

- (void)openCamera:(id)sender context:(NSManagedObjectContext*)context {
    self.context = context;
    //Set self as delegate (UIImagePickerControllerDelegate)
    [self.picker setDelegate:self];
    //If the device has a camera
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        self.picker.sourceType = UIImagePickerControllerSourceTypeCamera;
        self.picker.allowsEditing = YES;
        self.picker.videoQuality = [Settings videoQualitySetting];
        //If the camera can record video 
        NSString *desired = (NSString *)kUTTypeMovie;
        if ([[UIImagePickerController availableMediaTypesForSourceType:self.picker.sourceType] containsObject:desired]) {
            //Let the user record video
            self.picker.mediaTypes = [NSArray arrayWithObject:desired];
            self.picker.videoMaximumDuration = MaxDuration;
        }
        else {
            NSLog(@"Can't take videos with this device"); //debug
        }
        //Present the picker fullscreen/in popover
        if ([Settings shouldDisplayFullScreenCamera]){
            [self presentModalViewController:self.picker animated:YES];
            [self.masterPopoverController dismissPopoverAnimated:YES];
        }
        else {
            if (!_popover){
                _popover = [[UIPopoverController alloc] initWithContentViewController:self.picker];
            }
            [_popover presentPopoverFromBarButtonItem:sender permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
        }
    }
    else {
        NSLog(@"Does not have a camera"); //debug
    }    
}

选择图像时的代码:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
    {
    NSString *mediaType = [info objectForKey: UIImagePickerControllerMediaType];

    // Save the video, and close the overlay
    if (CFStringCompare ((__bridge CFStringRef) mediaType, kUTTypeMovie, 0)
        == kCFCompareEqualTo) {

        self.tempVideoPath = [[info objectForKey:
                                UIImagePickerControllerMediaURL] path];
        [LocalVideoStorage saveVideo:[NSData dataWithContentsOfPath:self.tempVideoPath name:self.videoName];
        [_picker dismissModalViewControllerAnimated: YES];
        [[_picker parentViewController] dismissModalViewControllerAnimated:YES];
        [_popover dismissPopoverAnimated:YES];  
    }
}

最后,当它被保存时:

+ (NSString*)saveVideo:(NSData*)video:(NSString*)videoName {
    NSFileManager *fileManager = [NSFileManager defaultManager];//create instance of NSFileManager

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); //create an array and store result of our search for the documents directory in it

    NSString *documentsDirectory = [paths objectAtIndex:0]; //create NSString object, that holds our exact path to the documents directory

    NSString *fullPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.MOV", videoName]]; //add our video to the path

    [fileManager createFileAtPath:fullPath contents:video attributes:nil]; //finally save the path (video)

    NSLog(@"Video saved!");
    return fullPath;

}

我在iOS 5.1.1中使用ARC

更新: 我在malloc_error_break上放了一个断点,在仪器中我可以看到它来自:

#   Address Category    Timestamp   Live    Size    Responsible Library Responsible Caller
0   0x10900000  Malloc 473,29 MB    02:08.951.332   •   496283648   Foundation  -[NSData(NSData) initWithContentsOfFile:]

解决方案: 正如lawicko&john.k.doe所说,我试图将视频从它的路径加载到NSData变量中.这导致整个视频被加载到内存中.我现在只是移动文件(&rename)copyItemAtPath而不是这样做

NSError *error = nil;
if (![fileManager copyItemAtPath:path toPath:fullPath error:&error])
    NSLog(@"Error: %@", error);

Answer 1

你的问题是这一行:

[NSData dataWithContentsOfPath:self.tempVideoPath]

您显然是在尝试将此文件的内容一次性加载到内存中,但iOS绝不会让您一次加载这么多内容.您的saveVideo方法似乎只将文件从临时位置复制到文档目录.如果这是您需要做的唯一事情,那么请看一下copyItemAtPath:toPath: NSFileManager的错误方法.您可以更改saveVideo方法以将临时文件路径作为参数而不是数据.