AVAssetExportSession視頻不保存到相機卷軸

Question

我試圖裁剪和合並應用程序中的幾個視頻。我在需要將視頻保存到相機卷軸並且UIVideoAtPathIsCompatibleWithSavedPhotosAlbum返回NO的步驟的最後部分中遇到問題。任何想法出了什麼問題？

- (void)video { 
    self.shouldRotate = NO; 
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init]; 
    imagePicker.delegate = self; 
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; 
    imagePicker.mediaTypes = [[NSArray alloc] initWithObjects:(NSString *)kUTTypeMovie,  nil]; 

    [self presentViewController:imagePicker animated:YES completion:nil]; 
} 


- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info { 
    NSString *mediaType = [info objectForKey: UIImagePickerControllerMediaType]; 
    NSString* moviePath = nil; 
    if (CFStringCompare ((__bridge CFStringRef) mediaType, kUTTypeMovie, 0) == kCFCompareEqualTo) { 
     moviePath = [[info objectForKey:UIImagePickerControllerMediaURL] path]; 
     // NSLog(@"%@",moviePath); 
     //NSURL *videoUrl=(NSURL*)[info objectForKey:UIImagePickerControllerMediaURL]; 

    } 

    NSURL* sourceMovieURL = [NSURL fileURLWithPath:moviePath]; 
    NSURL* outputPath = [sourceMovieURL URLByDeletingPathExtension]; 
    outputPath = [outputPath URLByDeletingLastPathComponent]; 
    NSMutableString* last_path_component = 
      [[NSMutableString alloc] initWithString:[[sourceMovieURL URLByDeletingPathExtension] lastPathComponent]]; 
    [last_path_component appendString:@"~SQUARE"]; 
    outputPath = [outputPath URLByAppendingPathComponent:last_path_component]; 
    outputPath = [outputPath URLByAppendingPathExtension:@"MOV"]; 
    AVURLAsset* asset = [AVURLAsset URLAssetWithURL:sourceMovieURL options:nil]; 

    AVMutableComposition *composition = [AVMutableComposition composition]; 
    [composition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid]; 

    // input clip 
    AVAssetTrack *clipVideoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]; 

    // make it square 
    AVMutableVideoComposition* videoComposition = [AVMutableVideoComposition videoComposition]; 
    videoComposition.renderSize = CGSizeMake(clipVideoTrack.naturalSize.height, clipVideoTrack.naturalSize.height); 
    videoComposition.frameDuration = CMTimeMake(1, 30); 

    AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction]; 
    instruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeMakeWithSeconds(60, 30)); 

    // rotate to portrait 
    AVMutableVideoCompositionLayerInstruction* transformer = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:clipVideoTrack]; 
    CGAffineTransform t1 = CGAffineTransformMakeTranslation(clipVideoTrack.naturalSize.height, -(clipVideoTrack.naturalSize.width - clipVideoTrack.naturalSize.height) /2); 
    CGAffineTransform t2 = CGAffineTransformRotate(t1, M_PI_2); 

    CGAffineTransform finalTransform = t2; 
    [transformer setTransform:finalTransform atTime:kCMTimeZero]; 
    instruction.layerInstructions = [NSArray arrayWithObject:transformer]; 
    videoComposition.instructions = [NSArray arrayWithObject: instruction]; 

    // export 


    AVAssetExportSession* exporter = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetHighestQuality] ; 
    exporter.videoComposition = videoComposition; 
    exporter.outputURL=outputPath; 
    exporter.outputFileType=AVFileTypeQuickTimeMovie; 

    VideoButtonView* button = [self.scrollView buttonAdded]; 
    [exporter exportAsynchronouslyWithCompletionHandler:^(void){ 
     AVURLAsset* new_asset = [AVURLAsset URLAssetWithURL:outputPath options:nil]; 
     [button addVideoAsset:new_asset]; 
     if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum (outputPath.absoluteString)) { 
      UISaveVideoAtPathToSavedPhotosAlbum (outputPath.absoluteString, self, nil, nil); 
     } 

    }]; 

    [self dismissViewControllerAnimated:YES completion:nil]; 
    //[picker release]; 
} 

Answer 1

我解決了它。使用資產庫似乎已經解決了這個問題。

[exporter exportAsynchronouslyWithCompletionHandler:^{ 
    BOOL success = false; 
    switch ([exporter status]) { 
     case AVAssetExportSessionStatusCompleted: 
      success = true; 
      NSLog(@"Export Completed"); 
      break; 
     case AVAssetExportSessionStatusWaiting: 
      NSLog(@"Export Waiting"); 
      break; 
     case AVAssetExportSessionStatusExporting: 
      NSLog(@"Export Exporting"); 
      break; 
     case AVAssetExportSessionStatusFailed: 
     { 
      NSError *error = [exporter error]; 
      NSLog(@"Export failed: %@", [error localizedDescription]); 

      break; 
     } 
     case AVAssetExportSessionStatusCancelled: 
      NSLog(@"Export canceled"); 

      break; 
     default: 
      break; 
    } 

    if (success == true) { 

    ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init]; 
    [assetLibrary writeVideoAtPathToSavedPhotosAlbum:url completionBlock:^(NSURL *assetURL, NSError *error){ 
    NSError *removeError = nil; 
    [[NSFileManager defaultManager] removeItemAtURL:url error:&removeError]; 
    }]; 

    } 
}];