How to change video orientation

2019-05-20 00:06发布

站内文章 / iOS
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问题:

I currently have an iPhone app that lets the users take video, upload it to the server, and allows others to view their video from the app. Never had an issue with the video's orientation until I went to make a web site to view the different videos (along with other content).

I consume the video's from the web service, and load them with ajax using videojs, but every single one of them is rotated left 90 degrees. From what I've read, it sounds like orientation information is able to be read in iOS, but not on a website. Is there any way to save a new orientation for the video on the iphone, before sending to the server?

回答1:

It appears that this issue occurs because videojs has trouble reading the orientation. information here: http://help.videojs.com/discussions/problems/1508-video-orientation-for-iphone-wrong

Based on the implied solution you should be checking to make sure when you save the video you are using AVFramework to set the orientation value. Information on how to do that is available in this previous stack overflow post: How do I set the orientation for a frame-by-frame-generated video using AVFoundation?



回答2:

//change Orientation Of video 

//in videoorientation.h 

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
@interface videoorientationViewController : UIViewController
@property AVMutableComposition *mutableComposition;
@property AVMutableVideoComposition *mutableVideoComposition;
@property AVMutableAudioMix *mutableAudioMix;
@property AVAssetExportSession *exportSession;
- (void)performWithAsset : (NSURL *)moviename;
@end

In //viewcontroller.m 

- (void)performWithAsset : (NSURL *)moviename
{

    self.mutableComposition=nil;
    self.mutableVideoComposition=nil;
    self.mutableAudioMix=nil;

//    NSString* filename = [NSString stringWithFormat:@"temp1.mov"];
//    
//    NSLog(@"file name== %@",filename);
//    
//    [[NSUserDefaults standardUserDefaults]setObject:filename forKey:@"currentName"];
//    NSString* path = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];

    // NSLog(@"file number %i",_currentFile);

    // NSURL* url = [NSURL fileURLWithPath:path];

    // NSString *videoURL = [[NSBundle mainBundle] pathForResource:@"Movie" ofType:@"m4v"];

    AVAsset *asset = [[AVURLAsset alloc] initWithURL:moviename options:nil];

    AVMutableVideoCompositionInstruction *instruction = nil;
    AVMutableVideoCompositionLayerInstruction *layerInstruction = nil;
    CGAffineTransform t1;
    CGAffineTransform t2;

    AVAssetTrack *assetVideoTrack = nil;
    AVAssetTrack *assetAudioTrack = nil;
    // Check if the asset contains video and audio tracks
    if ([[asset tracksWithMediaType:AVMediaTypeVideo] count] != 0) {
        assetVideoTrack = [asset tracksWithMediaType:AVMediaTypeVideo][0];
    }
    if ([[asset tracksWithMediaType:AVMediaTypeAudio] count] != 0) {
        assetAudioTrack = [asset tracksWithMediaType:AVMediaTypeAudio][0];
    }

    CMTime insertionPoint = kCMTimeZero;
    NSError *error = nil;


    // Step 1
    // Create a composition with the given asset and insert audio and video tracks into it from the asset
    if (!self.mutableComposition) {

        // Check whether a composition has already been created, i.e, some other tool has already been applied
        // Create a new composition
        self.mutableComposition = [AVMutableComposition composition];

        // Insert the video and audio tracks from AVAsset
        if (assetVideoTrack != nil) {
            AVMutableCompositionTrack *compositionVideoTrack = [self.mutableComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
            [compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, [asset duration]) ofTrack:assetVideoTrack atTime:insertionPoint error:&error];
        }
        if (assetAudioTrack != nil) {
            AVMutableCompositionTrack *compositionAudioTrack = [self.mutableComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
            [compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, [asset duration]) ofTrack:assetAudioTrack atTime:insertionPoint error:&error];
        }

    }


    // Step 2
    // Translate the composition to compensate the movement caused by rotation (since rotation would cause it to move out of frame)
    t1 = CGAffineTransformMakeTranslation(assetVideoTrack.naturalSize.height, 0.0);
        float width=assetVideoTrack.naturalSize.width;
    float height=assetVideoTrack.naturalSize.height;
    float toDiagonal=sqrt(width*width+height*height);
    float toDiagonalAngle = radiansToDegrees(acosf(width/toDiagonal));
    float toDiagonalAngle2=90-radiansToDegrees(acosf(width/toDiagonal));

    float toDiagonalAngleComple;
    float toDiagonalAngleComple2;
    float finalHeight = 0.0;
    float finalWidth = 0.0;

    float degrees=90;

    if(degrees>=0&&degrees<=90){

        toDiagonalAngleComple=toDiagonalAngle+degrees;
        toDiagonalAngleComple2=toDiagonalAngle2+degrees;

        finalHeight=ABS(toDiagonal*sinf(degreesToRadians(toDiagonalAngleComple)));
        finalWidth=ABS(toDiagonal*sinf(degreesToRadians(toDiagonalAngleComple2)));

        t1 = CGAffineTransformMakeTranslation(height*sinf(degreesToRadians(degrees)), 0.0);
    }
    else if(degrees>90&&degrees<=180){


        float degrees2 = degrees-90;

        toDiagonalAngleComple=toDiagonalAngle+degrees2;
        toDiagonalAngleComple2=toDiagonalAngle2+degrees2;

        finalHeight=ABS(toDiagonal*sinf(degreesToRadians(toDiagonalAngleComple2)));
        finalWidth=ABS(toDiagonal*sinf(degreesToRadians(toDiagonalAngleComple)));

        t1 = CGAffineTransformMakeTranslation(width*sinf(degreesToRadians(degrees2))+height*cosf(degreesToRadians(degrees2)), height*sinf(degreesToRadians(degrees2)));
    }
    else if(degrees>=-90&&degrees<0){

        float degrees2 = degrees-90;
        float degreesabs = ABS(degrees);

        toDiagonalAngleComple=toDiagonalAngle+degrees2;
        toDiagonalAngleComple2=toDiagonalAngle2+degrees2;

        finalHeight=ABS(toDiagonal*sinf(degreesToRadians(toDiagonalAngleComple2)));
        finalWidth=ABS(toDiagonal*sinf(degreesToRadians(toDiagonalAngleComple)));

        t1 = CGAffineTransformMakeTranslation(0, width*sinf(degreesToRadians(degreesabs)));

    }
    else if(degrees>=-180&&degrees<-90){

        float degreesabs = ABS(degrees);
        float degreesplus = degreesabs-90;

        toDiagonalAngleComple=toDiagonalAngle+degrees;
        toDiagonalAngleComple2=toDiagonalAngle2+degrees;

        finalHeight=ABS(toDiagonal*sinf(degreesToRadians(toDiagonalAngleComple)));
        finalWidth=ABS(toDiagonal*sinf(degreesToRadians(toDiagonalAngleComple2)));

        t1 = CGAffineTransformMakeTranslation(width*sinf(degreesToRadians(degreesplus)), height*sinf(degreesToRadians(degreesplus))+width*cosf(degreesToRadians(degreesplus)));

    }


    // Rotate transformation
    t2 = CGAffineTransformRotate(t1, degreesToRadians(degrees));
    //t2 = CGAffineTransformRotate(t1, -90);


    // Step 3
    // Set the appropriate render sizes and rotational transforms
    if (!self.mutableVideoComposition) {

        // Create a new video composition
        self.mutableVideoComposition = [AVMutableVideoComposition videoComposition];
        // self.mutableVideoComposition.renderSize = CGSizeMake(assetVideoTrack.naturalSize.height,assetVideoTrack.naturalSize.width);
        self.mutableVideoComposition.renderSize = CGSizeMake(finalWidth,finalHeight);

        self.mutableVideoComposition.frameDuration = CMTimeMake(1,30);

        // The rotate transform is set on a layer instruction
        instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
        instruction.timeRange = CMTimeRangeMake(kCMTimeZero, [self.mutableComposition duration]);
        layerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:(self.mutableComposition.tracks)[0]];
        [layerInstruction setTransform:t2 atTime:kCMTimeZero];

    } else {

        self.mutableVideoComposition.renderSize = CGSizeMake(self.mutableVideoComposition.renderSize.height, self.mutableVideoComposition.renderSize.width);

        // Extract the existing layer instruction on the mutableVideoComposition
        instruction = (self.mutableVideoComposition.instructions)[0];
        layerInstruction = (instruction.layerInstructions)[0];

        // Check if a transform already exists on this layer instruction, this is done to add the current transform on top of previous edits
        CGAffineTransform existingTransform;

        if (![layerInstruction getTransformRampForTime:[self.mutableComposition duration] startTransform:&existingTransform endTransform:NULL timeRange:NULL]) {
            [layerInstruction setTransform:t2 atTime:kCMTimeZero];
        } else {
            // Note: the point of origin for rotation is the upper left corner of the composition, t3 is to compensate for origin
            CGAffineTransform t3 = CGAffineTransformMakeTranslation(-1*assetVideoTrack.naturalSize.height/2, 0.0);
            CGAffineTransform newTransform = CGAffineTransformConcat(existingTransform, CGAffineTransformConcat(t2, t3));
            [layerInstruction setTransform:newTransform atTime:kCMTimeZero];
        }

    }


    // Step 4
    // Add the transform instructions to the video composition
    instruction.layerInstructions = @[layerInstruction];
    self.mutableVideoComposition.instructions = @[instruction];


    // Step 5
    // Notify AVSEViewController about rotation operation completion
    // [[NSNotificationCenter defaultCenter] postNotificationName:AVSEEditCommandCompletionNotification object:self];

    [self performWithAssetExport];
}

- (void)performWithAssetExport
{
    // Step 1
    // Create an outputURL to which the exported movie will be saved

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *outputURL = paths[0];
    NSFileManager *manager = [NSFileManager defaultManager];
    [manager createDirectoryAtPath:outputURL withIntermediateDirectories:YES attributes:nil error:nil];
    outputURL = [outputURL stringByAppendingPathComponent:@"output.mov"];
    // Remove Existing File
    [manager removeItemAtPath:outputURL error:nil];


    // Step 2
    // Create an export session with the composition and write the exported movie to the photo library
    self.exportSession = [[AVAssetExportSession alloc] initWithAsset:[self.mutableComposition copy] presetName:AVAssetExportPreset1280x720];

    self.exportSession.videoComposition = self.mutableVideoComposition;
    self.exportSession.audioMix = self.mutableAudioMix;
    self.exportSession.outputURL = [NSURL fileURLWithPath:outputURL];
    self.exportSession.outputFileType=AVFileTypeQuickTimeMovie;


    [self.exportSession exportAsynchronouslyWithCompletionHandler:^(void){
        switch (self.exportSession.status) {
            case AVAssetExportSessionStatusCompleted:

                //[self playfunction];

                [[NSNotificationCenter defaultCenter]postNotificationName:@"Backhome" object:nil];



                // Step 3
                // Notify AVSEViewController about export completion
                break;
            case AVAssetExportSessionStatusFailed:
                NSLog(@"Failed:%@",self.exportSession.error);
                break;
            case AVAssetExportSessionStatusCancelled:
                NSLog(@"Canceled:%@",self.exportSession.error);
                break;
            default:
                break;
        }
    }];



}


标签： iphone objective-c ios video.js
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