How to add watermark to any oriented video in iOS?

Question

I need to add watermark to video but different oriented videos. Below codes are working for me when i add watermark to portrait video, but this code is not working for landscape videos, watermark become stressed.

 UIImage *myImage;
 myImage =[UIImage imageNamed:@"twinbitWaterMark"];
 CALayer *layerCa = [CALayer layer];
 layerCa.contents = (id)myImage.CGImage;

 float newX = videosize.width - imagesize.width;
float newY = videosize.height - imagesize.height;
layerCa.frame = CGRectMake(newX, newY, videosize.width*2, videosize.height*2);
layerCa.opacity = 1.0;
[layerCa setMasksToBounds:YES];

 CALayer *parentLayer=[CALayer layer];
CALayer *videoLayer=[CALayer layer];
parentLayer.frame=CGRectMake(0, 0, videosize.width, videosize.height);

videoLayer.frame=CGRectMake(0, 0, videosize.width, videosize.height);

[parentLayer addSublayer:videoLayer];
[parentLayer addSublayer:layerCa];

composition.animationTool = [AVVideoCompositionCoreAnimationTool
                             videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];

Please help.

Answer 1

I think it is an mistake in your calculation:

Your watermark has landscape or watermark orientation.

By calculating the width and height

layerCa.frame = CGRectMake(newX, newY, videosize.width*2, videosize.height*2);

parentLayer.frame=CGRectMake(0, 0, videosize.width, videosize.height);

you are not preserving the original watermark ratio.

In landscape you have to calculate an offset left and right to your frame to preserve the ratio.

Answer 2

Before saving the file locally create a CATextLayer and attach it to the video. I believe this code will help you which I had written for one my application.

- (void)applyVideoEffectsToComposition:(AVMutableVideoComposition *)composition size:(CGSize)size
{
    NSArray *fieldsArray = overlayFieldsArray;
    // 1 - Set up the text layer
    CATextLayer *subtitle1Text = [[CATextLayer alloc] init];
    subtitle1Text.wrapped=YES;
    subtitle1Text.alignmentMode = kCAAlignmentLeft;
    [subtitle1Text setFont:@"Helvetica-Bold"];
    [subtitle1Text setFontSize:textSize];
    [subtitle1Text setFrame:CGRectMake(0, 0, size.width, fieldsArray.count*textSize+20) ];


    NSMutableString *layerText = [NSMutableString stringWithCapacity:0];

    for(NSDictionary *fieldDictionary in fieldsArray){

        [layerText appendFormat:@" %@ :",[[fieldDictionary allKeys] objectAtIndex:0]];

        [layerText appendFormat:@" %@ \n",[_candidateDictionary valueForKey:[[fieldDictionary allValues] objectAtIndex:0]]];
    }


    [subtitle1Text setString:layerText];

    [subtitle1Text setForegroundColor:[[UIColor colorForText] CGColor]];

    // 2 - The usual overlay
    CALayer *overlayLayer = [CALayer layer];
    overlayLayer.backgroundColor = [UIColor colorForLayer].CGColor;
    overlayLayer.opacity=0.5f;
    CGSize maximumSize = CGSizeMake(600, 600);
    UIFont *myFont = [UIFont fontWithName:@"Helvetica" size:textSize];
    CGSize layerTextSize = [layerText sizeWithFont:myFont
                                 constrainedToSize:maximumSize
                                     lineBreakMode:UILineBreakModeWordWrap];
    overlayLayer.frame = CGRectMake(10, 0, layerTextSize.width*1.1, fieldsArray.count*textSize+20);
    [overlayLayer setMasksToBounds:YES];

    [overlayLayer addSublayer:subtitle1Text];

    CALayer *parentLayer = [CALayer layer];

    CALayer *videoLayer = [CALayer layer];
    videoLayer.frame = CGRectMake(0, 0, size.width, size.height);
    [parentLayer addSublayer:videoLayer];


    parentLayer.frame = CGRectMake(10, 0, layerTextSize.width*1.1, fieldsArray.count*textSize+20);
    [parentLayer addSublayer:overlayLayer];



    composition.animationTool = [AVVideoCompositionCoreAnimationTool
                                 videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];

}