上传后iOS UIImagePickerController结果视频方向

Question

我的问题类似于iOS UIImagePickerController result image orientation after upload，但我需要修复视频的方向而不是图像。视频也是使用 imagePickerController 捕获的，所以我基本上有视频的 URL。我需要将视频转换为 NSData 以将其上传到服务器，但在服务器上，视频方向与图像类似，取决于视频录制的方向。

NSURL * urlVideo;
//fix orientation here
NSData * videoDataToUpload = [NSData dataWithContentsOfURL:urlVideoFixed];

根据我从本教程中获得的内容，这是我到目前为止所获得的：http://www.raywenderlich.com/13418/how-to-play-record-edit-videos-in-ios 但它不起作用

-(void)videoFixOrientation{
AVAsset *firstAsset = [AVAsset assetWithURL:[self urlVideoLocalLocation]];
AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];
AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
AVMutableVideoCompositionLayerInstruction *FirstlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack];
AVAssetTrack *FirstAssetTrack = [[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
UIImageOrientation FirstAssetOrientation_  = UIImageOrientationUp;
BOOL  isFirstAssetPortrait_  = NO;
CGAffineTransform firstTransform = FirstAssetTrack.preferredTransform;
if(firstTransform.a == 0 && firstTransform.b == 1.0 && firstTransform.c == -1.0 && firstTransform.d == 0)  {FirstAssetOrientation_= UIImageOrientationRight; isFirstAssetPortrait_ = YES;}
if(firstTransform.a == 0 && firstTransform.b == -1.0 && firstTransform.c == 1.0 && firstTransform.d == 0)  {FirstAssetOrientation_ =  UIImageOrientationLeft; isFirstAssetPortrait_ = YES;}
if(firstTransform.a == 1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == 1.0)   {FirstAssetOrientation_ =  UIImageOrientationUp;}
if(firstTransform.a == -1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == -1.0) {FirstAssetOrientation_ = UIImageOrientationDown;}
CGFloat FirstAssetScaleToFitRatio = 320.0/FirstAssetTrack.naturalSize.width;
if(isFirstAssetPortrait_){
    FirstAssetScaleToFitRatio = 320.0/FirstAssetTrack.naturalSize.height;
    CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
    [FirstlayerInstruction setTransform:CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero];
}else{
    CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
    [FirstlayerInstruction setTransform:CGAffineTransformConcat(CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor),CGAffineTransformMakeTranslation(0, 160)) atTime:kCMTimeZero];
}
[FirstlayerInstruction setOpacity:0.0 atTime:firstAsset.duration];

AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
exporter.outputURL=[self urlAMedia];
exporter.outputFileType = AVFileTypeQuickTimeMovie;
//exporter.videoComposition = MainCompositionInst;
exporter.shouldOptimizeForNetworkUse = YES;
[exporter exportAsynchronouslyWithCompletionHandler:^
 {
     dispatch_async(dispatch_get_main_queue(), ^{
         if(exporter.status == AVAssetExportSessionStatusCompleted){
             [self setUrlVideoLocalLocation:exporter.outputURL];
         }
     });
 }];
}

我不知道这是否是正确的方法，我需要它为 IOS 5.0 及更高版本工作。有什么想法吗？

Answer 1

好吧，我终于弄明白了，希望它对某人有所帮助。当然，您需要本教程中使用的导入和框架，这是我获得帮助的地方：http://www.raywenderlich.com/13418/how-to-play-record-edit-videos-in-ios

- (void)videoFixOrientation{
    AVAsset *firstAsset = [AVAsset assetWithURL:[self urlVideoLocalLocation]];
    if(firstAsset !=nil && [[firstAsset tracksWithMediaType:AVMediaTypeVideo] count]>0){
        //Create AVMutableComposition Object.This object will hold our multiple AVMutableCompositionTrack.
        AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init];

    //VIDEO TRACK
    AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    [firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];
    AVMutableVideoCompositionInstruction * MainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
    MainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, firstAsset.duration);

    if ([[firstAsset tracksWithMediaType:AVMediaTypeAudio] count]>0) {
        //AUDIO TRACK
        AVMutableCompositionTrack *firstAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
        [firstAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];
    }else{
        NSLog(@"warning: video has no audio");
    }

    //FIXING ORIENTATION//
    AVMutableVideoCompositionLayerInstruction *FirstlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack];

    AVAssetTrack *FirstAssetTrack = [[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];

    UIImageOrientation FirstAssetOrientation_  = UIImageOrientationUp;

    BOOL  isFirstAssetPortrait_  = NO;

    CGAffineTransform firstTransform = FirstAssetTrack.preferredTransform;

    if(firstTransform.a == 0 && firstTransform.b == 1.0 && firstTransform.c == -1.0 && firstTransform.d == 0)
    {
        FirstAssetOrientation_= UIImageOrientationRight; isFirstAssetPortrait_ = YES;
    }
    if(firstTransform.a == 0 && firstTransform.b == -1.0 && firstTransform.c == 1.0 && firstTransform.d == 0)
    {
        FirstAssetOrientation_ =  UIImageOrientationLeft; isFirstAssetPortrait_ = YES;
    }
    if(firstTransform.a == 1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == 1.0)
    {
        FirstAssetOrientation_ =  UIImageOrientationUp;
    }
    if(firstTransform.a == -1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == -1.0)
    {
        FirstAssetOrientation_ = UIImageOrientationDown;
    }

    CGFloat FirstAssetScaleToFitRatio = 320.0/FirstAssetTrack.naturalSize.width;

    if(isFirstAssetPortrait_)
    {
        FirstAssetScaleToFitRatio = 320.0/FirstAssetTrack.naturalSize.height;
        CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
        [FirstlayerInstruction setTransform:CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero];
    }
    else
    {
        CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio);
        [FirstlayerInstruction setTransform:CGAffineTransformConcat(CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor),CGAffineTransformMakeTranslation(0, 160)) atTime:kCMTimeZero];
    }
    [FirstlayerInstruction setOpacity:0.0 atTime:firstAsset.duration];

    MainInstruction.layerInstructions = [NSArray arrayWithObjects:FirstlayerInstruction,nil];;

    AVMutableVideoComposition *MainCompositionInst = [AVMutableVideoComposition videoComposition];
    MainCompositionInst.instructions = [NSArray arrayWithObject:MainInstruction];
    MainCompositionInst.frameDuration = CMTimeMake(1, 30);
    MainCompositionInst.renderSize = CGSizeMake(320.0, 480.0);

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *myPathDocs =  [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"mergeVideo-%d.mov",arc4random() % 1000]];

    NSURL *url = [NSURL fileURLWithPath:myPathDocs];

    AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];

    exporter.outputURL=url;
    exporter.outputFileType = AVFileTypeQuickTimeMovie;
    exporter.videoComposition = MainCompositionInst;
    exporter.shouldOptimizeForNetworkUse = YES;
    [exporter exportAsynchronouslyWithCompletionHandler:^
     {
         dispatch_async(dispatch_get_main_queue(), ^{
             [self exportDidFinish:exporter];
         });
     }];
}else{
    NSLog(@"Error, video track not found");
}
}

- (void)exportDidFinish:(AVAssetExportSession*)session
{
    if(session.status == AVAssetExportSessionStatusCompleted){
#warning DO WHAT EVER YOU NEED AFTER FIXING ORIENTATION
    }else{
        NSLog(@"error fixing orientation");
    }
}