问题：
保存在我的应用程序中录制的视频时，如果视频大小/持续时间太大/太长，我的应用程序会崩溃而没有日志/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，如果我制作的视频长度很长（例如，使用 UIImagePickerControllerQualityTypeMedium 时为 30 分钟，或者使用 UIImagePickerControllerQualityTypeIFrame1280x720 时超过一分钟），则在保存视频时，应用程序会崩溃。有时有警告，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（我猜这与视频的临时内存使用有关？）在它最终崩溃之前。这是分析器的屏幕截图：
该应用程序必须能够录制最长持续时间为 1 小时的视频（以任何指定的质量）。
我试过的：
- 设置 picker.videoMaximumDuration 更短/更长
- 使用探查器/仪器进行调试
- 检查泄漏
- 关闭设备上所有打开的应用程序和已删除的应用程序（用于存储清理）以获取更多内存
代码：
- (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
}
}
并在选择图像时编写代码：
- (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是从以下位置调用的：
# 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一个NSData 变量中。这导致整个视频被加载到内存中。而不是这样做，我现在只是移动文件（&重命名）copyItemAtPath
NSError *error = nil;
if (![fileManager copyItemAtPath:path toPath:fullPath error:&error])
NSLog(@"Error: %@", error);