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Image/Text overlay in video swift

由 若如初见. 提交于 2019-12-02 17:46:00

The code provided by @El Captain would work. It's only missing:

    assetExport.videoComposition = layercomposition

You can add this right after the instantiation of the AVAssetExportSession

NOTE: The code originally provided would only export the video track but not the audio track. If you need the audio track you could add something like this after you configure the compositionvideoTrack:

let compositionAudioTrack:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
    for audioTrack in audioTracks {
        try! compositionAudioTrack.insertTimeRange(audioTrack.timeRange, ofTrack: audioTrack, atTime: kCMTimeZero)
    }

For me (what I see in your code), your are not adding the parentlayer to the screen.

You create a CALayer() to add videolayer, imglayer and titleLayer into a new layer but you don't add this last one on the screen.

yourView.layer.addSublayer(parentlayer)

Hope this help you

@Rey Hernandez this just helped me a lot! If anyone wants further clarification on how to add an audio asset with to the video here is the code to combine them

    let vtrack =  vidAsset.tracksWithMediaType(AVMediaTypeVideo)
    let videoTrack:AVAssetTrack = vtrack[0] 
    let vid_duration = videoTrack.timeRange.duration
    let vid_timerange = CMTimeRangeMake(kCMTimeZero, vidAsset.duration)

    let atrack =  vidAsset.tracksWithMediaType(AVMediaTypeAudio)
    let audioTrack:AVAssetTrack = atrack[0]
    let audio_duration = audioTrack.timeRange.duration
    let audio_timerange = CMTimeRangeMake(kCMTimeZero, vidAsset.duration)

    do {
        let compositionvideoTrack:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID())

        try compositionvideoTrack.insertTimeRange(vid_timerange, ofTrack: videoTrack, atTime: kCMTimeZero)

        compositionvideoTrack.preferredTransform = videoTrack.preferredTransform



        let compositionAudioTrack:AVMutableCompositionTrack = composition.addMutableTrackWithMediaType(AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID())
        try! compositionAudioTrack.insertTimeRange(audio_timerange, ofTrack: audioTrack, atTime: kCMTimeZero)

        compositionvideoTrack.preferredTransform = audioTrack.preferredTransform

    } catch {
        print(error)
    }

To supplement, here's a function that creates CATextLayers based on an array UITextViews supplied by copying over their rotation, scale and font. Just add these to your container-layer supplied to AVVideoCompositionCoreAnimationTool:

private static func createTextLayer(totalSize: CGSize,
                                        textView: UITextView) -> CATextLayer {
        let textLayer: CACenteredTextLayer = CACenteredTextLayer()
        textLayer.backgroundColor = UIColor.clear
        textLayer.foregroundColor = textView.textColor?.cgColor
        textLayer.masksToBounds = false
        textLayer.isWrapped = true

        let scale: CGFloat = UIScreen.main.scale

        if let font: UIFont = textView.font {
            let upscaledFont: UIFont = font.withSize(font.pointSize * scale)
            let attributedString = NSAttributedString(
                string: textView.text,
                attributes: [NSAttributedString.Key.font: upscaledFont,
                             NSAttributedString.Key.foregroundColor: textView.textColor ?? UIColor.white])
            textLayer.string = attributedString
        }

        // Set text alignment
        let alignment: CATextLayerAlignmentMode
        switch textView.textAlignment {
        case NSTextAlignment.left:
            alignment = CATextLayerAlignmentMode.left
        case NSTextAlignment.center:
            alignment = CATextLayerAlignmentMode.center
        default:
            alignment = CATextLayerAlignmentMode.right
        }
        textLayer.alignmentMode = alignment

        let originalFrame: CGRect = textView.frame

        // Also take scale into consideration
        let targetSize: CGSize = CGSize(width: originalFrame.width * scale,
                                        height: originalFrame.height * scale)

        // The CALayer positioning is inverted on the Y-axes, so apply this
        let origin: CGPoint = CGPoint(x: originalFrame.origin.x * scale,
                                      y: (totalSize.height - (originalFrame.origin.y * scale)) - targetSize.height)

        textLayer.frame = CGRect(x: origin.x,
                                 y: origin.y,
                                 width: targetSize.width,
                                 height: targetSize.height)

        // Determine the scale
        textLayer.anchorPoint = CGPoint(x: 0.5,
                                        y: 0.5)

        var newTransform: CATransform3D = CATransform3DMakeScale(textView.transform.xScale,
                                                                 textView.transform.yScale,
                                                                 0)

        // Convert to degrees, invert the amount and convert back to radians to apply
        newTransform = CATransform3DRotate(newTransform,
                                           textView.transform.radiansFor3DTransform,
                                           0,
                                           0,
                                           1)
        textLayer.transform = newTransform

        return textLayer
}

Combine this with this subclassing of CATextLayer to center the text vertically:

final class CACenteredTextLayer: CATextLayer {
    override func draw(in ctx: CGContext) {
        guard let attributedString = string as? NSAttributedString else { return }

        let height = self.bounds.size.height
        let boundingRect: CGRect = attributedString.boundingRect(
            with: CGSize(width: bounds.width,
                         height: CGFloat.greatestFiniteMagnitude),
            options: NSStringDrawingOptions.usesLineFragmentOrigin,
            context: nil)
        let yDiff: CGFloat = (height - boundingRect.size.height) / 2

        ctx.saveGState()
        ctx.translateBy(x: 0.0, y: yDiff)
        super.draw(in: ctx)
        ctx.restoreGState()
    }
}

private extension CGAffineTransform {
    var xScale: CGFloat {
        return sqrt((a*a) + (c*c))
    }

    var yScale: CGFloat {
        return sqrt((b*b) + (d*d))
    }

    var radiansFor3DTransform: CGFloat {
        let radians: CGFloat = atan2(b, a);
        let degrees: CGFloat = -(radians * 180 / CGFloat.pi)
        let convertedRadians: CGFloat = CGFloat(degrees * (CGFloat.pi / 180))
        return convertedRadians
    }
}
标签
ios
swift
avfoundation
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