因此,据推测,在iOS 4 SDK中,您可以编辑并写入用户的iTunes资料库。我可以从我的iPhone / iPod库成功加载AVAsset,但作为一个快速测试,我试图使用AVAssetExportSession立即覆盖同一个文件,但它总是返回状态“4”我 THINK 是AVAssetExportSessionStatusFailed ...在文档中说:
enum {
AVAssetExportSessionStatusUnknown,
AVAssetExportSessionStatusExporting,
AVAssetExportSessionStatusCompleted,
AVAssetExportSessionStatusFailed,
AVAssetExportSessionStatusCancelled,
AVAssetExportSessionStatusWaiting
};
但是在AVAssetExportSession.h中它说:
enum {
AVAssetExportSessionStatusUnknown,
AVAssetExportSessionStatusWaiting,
AVAssetExportSessionStatusExporting,
AVAssetExportSessionStatusCompleted,
AVAssetExportSessionStatusFailed,
AVAssetExportSessionStatusCancelled
};
typedef NSInteger AVAssetExportSessionStatus;
这是我正在使用的代码:
// before this, i'm using mpmediapicker to pick an m4a file i synched with my itunes library
NSURL *assetUrl = [[self.userMediaItemCollection.items objectAtIndex: 0] valueForProperty: MPMediaItemPropertyAssetURL];
AVURLAsset *asset = [AVURLAsset URLAssetWithURL: assetUrl options: nil];
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset: asset presetName: AVAssetExportPresetAppleM4A];
exportSession.outputURL = asset.URL;
exportSession.outputFileType = AVFileTypeAppleM4A;
NSLog(@"output filetype: %@", exportSession.outputFileType);
// prints "com.apple.m4a-audio"
[exportSession exportAsynchronouslyWithCompletionHandler: ^(void) {
NSLog(@"status: %i for %@", exportSession.status, exportSession.outputURL);
// prints "status: 4 for ipod-library://item/item.m4a?id=3631988601206299774"
}];
[exportSession release];
所以无论如何......我猜它是“失败”或“取消”。有没有其他人成功写入媒体库?
谢谢!
答案 0 :(得分:2)
你不能写入iTunes库,只能现在读取它。
答案 1 :(得分:0)
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
NSParameterAssert(library);
if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:[NSURL fileURLWithPath:movieFileName]]) {
[library writeVideoAtPathToSavedPhotosAlbum:[NSURL fileURLWithPath:movieFileName] completionBlock:^(NSURL *assetURL, NSError *error){}];
}
[library release];