我正在使用swift使用图像叠加来处理视频中的水印效果。我正在使用result，但不知怎的，我没有成功。
以下是我的叠加图片/文字代码
<div class="col-md-4">
Result
<div class="radio">
<label>
<input ng-model="result" type="radio" name="rdoResult" ng-value="'pass'">
pass
</label>
</div>
<div class="radio">
<label>
<input ng-model="result" type="radio" name="rdoResult" ng-value="'fail'">
fail
</label>
</div>
</div>
通过这段代码，我没有实现覆盖......我不知道我做错了什么......
问题：
答案 0 :(得分：7)
@El Captain提供的代码可行。它只是缺失：
var cart = [
{"id":1, "number":1, "other_attributes":"other_values"},
{"id":2, "number":2, "other_attributes":"other_values"},
{"id":"processing", "other_attributes":"other_values"},
{"id":2, "number":1, "other_attributes":"other_values"},
{"id":"deposit", "other_attributes":"other_values"}
];
function makeComparator(identifier) {
return function compare(a,b) {
a = a[identifier];
b = b[identifier];
if (Number.isInteger(a) && Number.isInteger(b) ) {
return a > b;
}
if (Number.isInteger(a)) {
return -1;
}
if (Number.isInteger(b)) {
return 1;
}
return a > b;
}
}
var idComparator = makeComparator("id");
var numberComparator = makeComparator("number");
cart.sort(idComparator);
cart.sort(numberComparator);
console.log(cart);
document.write('<pre>' + JSON.stringify(cart, null, 3) + '</pre>');您可以在 AVAssetExportSession
实例化后立即添加此项注意：最初提供的代码只会导出视频轨道而不会导出音频轨道。如果您需要音轨，可以在配置 compositionvideoTrack 后添加类似的内容：
assetExport.videoComposition = layercomposition
答案 1 :(得分：0)
对我（我在代码中看到的内容），您没有将parentlayer添加到屏幕上。
您创建了一个CALayer（）以将videolayer，imglayer和titleLayer添加到新图层中，但您不会在屏幕上添加最后一个。
yourView.layer.addSublayer(parentlayer)
希望这能帮到你
答案 2 :(得分：0)
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)
}
答案 3 :(得分：0)
作为补充，这是一个函数，该函数基于通过复制UITextViews的旋转，缩放和字体而提供的数组UITextViews创建CATextLayers。只需将它们添加到提供给AVVideoCompositionCoreAnimationTool的容器层即可：
export function Serve(done) {
browserSync.init({
server: {
baseDir: path.build,
index: 'index.html'
},
ghostMode: true,
notify: false,
host: '0.0.0.0',
port: 9000
});
done();
};
使用以下CATextLayer子类将其合并以使文本垂直居中：
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
}
答案 4 :(得分：0)
这是在Swift 4中运行的更新：
import UIKit
import AVFoundation
import AVKit
import Photos
class ViewController: UIViewController {
var myurl: URL?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
@IBAction func saveVideoTapper(_ sender: Any) {
let path = Bundle.main.path(forResource: "sample_video", ofType:"mp4")
let fileURL = NSURL(fileURLWithPath: path!)
let composition = AVMutableComposition()
let vidAsset = AVURLAsset(url: fileURL as URL, options: nil)
// get video track
let vtrack = vidAsset.tracks(withMediaType: AVMediaType.video)
let videoTrack: AVAssetTrack = vtrack[0]
let vid_timerange = CMTimeRangeMake(start: CMTime.zero, duration: vidAsset.duration)
let tr: CMTimeRange = CMTimeRange(start: CMTime.zero, duration: CMTime(seconds: 10.0, preferredTimescale: 600))
composition.insertEmptyTimeRange(tr)
let trackID:CMPersistentTrackID = CMPersistentTrackID(kCMPersistentTrackID_Invalid)
if let compositionvideoTrack: AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaType.video, preferredTrackID: trackID) {
do {
try compositionvideoTrack.insertTimeRange(vid_timerange, of: videoTrack, at: CMTime.zero)
} catch {
print("error")
}
compositionvideoTrack.preferredTransform = videoTrack.preferredTransform
} else {
print("unable to add video track")
return
}
// Watermark Effect
let size = videoTrack.naturalSize
let imglogo = UIImage(named: "image.png")
let imglayer = CALayer()
imglayer.contents = imglogo?.cgImage
imglayer.frame = CGRect(x: 5, y: 5, width: 100, height: 100)
imglayer.opacity = 0.6
// create text Layer
let titleLayer = CATextLayer()
titleLayer.backgroundColor = UIColor.white.cgColor
titleLayer.string = "Dummy text"
titleLayer.font = UIFont(name: "Helvetica", size: 28)
titleLayer.shadowOpacity = 0.5
titleLayer.alignmentMode = CATextLayerAlignmentMode.center
titleLayer.frame = CGRect(x: 0, y: 50, width: size.width, height: size.height / 6)
let videolayer = CALayer()
videolayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
let parentlayer = CALayer()
parentlayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
parentlayer.addSublayer(videolayer)
parentlayer.addSublayer(imglayer)
parentlayer.addSublayer(titleLayer)
let layercomposition = AVMutableVideoComposition()
layercomposition.frameDuration = CMTimeMake(value: 1, timescale: 30)
layercomposition.renderSize = size
layercomposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videolayer, in: parentlayer)
// instruction for watermark
let instruction = AVMutableVideoCompositionInstruction()
instruction.timeRange = CMTimeRangeMake(start: CMTime.zero, duration: composition.duration)
let videotrack = composition.tracks(withMediaType: AVMediaType.video)[0] as AVAssetTrack
let layerinstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: videotrack)
instruction.layerInstructions = NSArray(object: layerinstruction) as [AnyObject] as! [AVVideoCompositionLayerInstruction]
layercomposition.instructions = NSArray(object: instruction) as [AnyObject] as! [AVVideoCompositionInstructionProtocol]
// create new file to receive data
let dirPaths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let docsDir = dirPaths[0] as NSString
let movieFilePath = docsDir.appendingPathComponent("result.mov")
let movieDestinationUrl = NSURL(fileURLWithPath: movieFilePath)
// use AVAssetExportSession to export video
let assetExport = AVAssetExportSession(asset: composition, presetName:AVAssetExportPresetHighestQuality)
assetExport?.outputFileType = AVFileType.mov
assetExport?.videoComposition = layercomposition
// Check exist and remove old file
FileManager.default.removeItemIfExisted(movieDestinationUrl as URL)
assetExport?.outputURL = movieDestinationUrl as URL
assetExport?.exportAsynchronously(completionHandler: {
switch assetExport!.status {
case AVAssetExportSession.Status.failed:
print("failed")
print(assetExport?.error ?? "unknown error")
case AVAssetExportSession.Status.cancelled:
print("cancelled")
print(assetExport?.error ?? "unknown error")
default:
print("Movie complete")
self.myurl = movieDestinationUrl as URL
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: movieDestinationUrl as URL)
}) { saved, error in
if saved {
print("Saved")
}
}
self.playVideo()
}
})
}
func playVideo() {
let player = AVPlayer(url: myurl!)
let playerLayer = AVPlayerLayer(player: player)
playerLayer.frame = self.view.bounds
self.view.layer.addSublayer(playerLayer)
player.play()
print("playing...")
}
}
extension FileManager {
func removeItemIfExisted(_ url:URL) -> Void {
if FileManager.default.fileExists(atPath: url.path) {
do {
try FileManager.default.removeItem(atPath: url.path)
}
catch {
print("Failed to delete file")
}
}
}
}