AVAssetExportSession每次都失败（错误-12780）

我试图合并一些audio文件（通过MPMediaPickerController选取），但导出总是失败，错误代码-12780。

当我尝试使用AVPlayer对象播放我的作品时，它会正确播放。 只是导出失败。

我究竟做错了什么？

这是我的代码：

AVAssetExportSession *exportSession; AVPlayer *player; - (void)mergeAudiofiles { // self.mediaItems is an NSArray of MPMediaItems if (self.mediaItems.count == 0) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"No Tracks selected." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; return; } // Configure audio session NSError *sessionError; AVAudioSession *session = [AVAudioSession sharedInstance]; [session setCategory:AVAudioSessionCategoryAudioProcessing error:nil]; [session setActive:YES error:&sessionError]; if (sessionError) NSLog(@"Session-Error: %@", sessionError.localizedDescription); // Create composition AVMutableComposition *composition = [AVMutableComposition composition]; AVMutableCompositionTrack *track = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; CMTime position = kCMTimeZero; for (MPMediaItem *item in self.mediaItems) { NSURL *assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL]; AVAsset *asset = [AVAsset assetWithURL:assetURL]; CMTimeRange duration = CMTimeRangeMake(kCMTimeZero, asset.duration); // duration = CMTimeRangeMake(kCMTimeZero, CMTimeMake(5, 1)); // For player test NSError *error; [track insertTimeRange:duration ofTrack:[[asset tracksWithMediaType:AVMediaTypeAudio] lastObject] atTime:position error:&error]; if (error) NSLog(@"ERROR! :("); position = CMTimeAdd(position, duration.duration); } // Path to output file NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]; NSURL *exportUrl = [NSURL URLWithString:[documentsDirectory stringByAppendingPathComponent:@"export.m4a"]]; NSLog(@"Export URL = %@", exportUrl.description); // Playing works! // """""""""""""" // AVPlayerItem *pitem = [[AVPlayerItem alloc] initWithAsset:composition]; // player = [[AVPlayer alloc] initWithPlayerItem:pitem]; // [player play]; // // return; // Export exportSession = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetAppleM4A]; exportSession.outputURL = exportUrl; exportSession.outputFileType = AVFileTypeAppleM4A; [exportSession exportAsynchronouslyWithCompletionHandler:^{ switch (exportSession.status) { case AVAssetExportSessionStatusFailed: NSLog(@"Export failed -> Reason: %@, User Info: %@", exportSession.error.localizedDescription, exportSession.error.userInfo.description); break; case AVAssetExportSessionStatusCancelled: NSLog(@"Export cancelled"); break; case AVAssetExportSessionStatusCompleted: NSLog(@"Export finished"); break; default: break; } }]; } 

Answer 1

需要将您的导出url更改为：

  NSURL *exportUrl = [NSURL fileURLWithPath:[documentsDirectory stringByAppendingPathComponent:@"export.m4a"]]; 

引用文件path时，必须使用fileURLWithPath。 我也挂了，直到我读了这个： AVAssetExportSession输出文件