AVVideoComposition不';t向视频添加文本-iOS 10.3
我最近发布了一篇关于导出带有textOverlay的视频的文章(使用AVVideoComposition不';t向视频添加文本-iOS 10.3,ios,swift3,catextlayer,avvideocomposition,Ios,Swift3,Catextlayer,Avvideocomposition,我最近发布了一篇关于导出带有textOverlay的视频的文章(使用AVVideoComposition)。我正在尝试使用以下方法将CATextLayer覆盖应用于swift中的视频: @IBOutlet weak var subTitle1: UITextField! func applyVideoEffectsToComposition(_ composition: AVMutableVideoComposition!, size: CGSize) { //
AVVideoComposition
)。我正在尝试使用以下方法将CATextLayer
覆盖应用于swift中的视频:
@IBOutlet weak var subTitle1: UITextField!
func applyVideoEffectsToComposition(_ composition: AVMutableVideoComposition!, size: CGSize) {
// 1 - Set up the text layer
let subTitle1Text = CATextLayer()
subTitle1Text.font = "Helvetica-Bold" as CFTypeRef
subTitle1Text.frame = CGRect(x: 0, y: 0, width: size.width, height: 100)
subTitle1Text.string = subTitle1.text
// subTitle1Text.string = "Sheep" ****No subtitle on output video if replace above line with this one ****
subTitle1Text.alignmentMode = kCAAlignmentCenter
subTitle1Text.foregroundColor = UIColor.white.cgColor
// 2 - The usual overlay
let overlayLayer = CALayer()
overlayLayer.addSublayer(subTitle1Text)
overlayLayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
overlayLayer.masksToBounds = true
// 3 - set up the parent layer
let parentLayer = CALayer()
let videoLayer = CALayer()
parentLayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
videoLayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
parentLayer.addSublayer(videoLayer)
parentLayer.addSublayer(overlayLayer)
composition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: parentLayer)
}
问题
当我使用textfield
分配let subTitle1Text:CATextLayer
时,我会得到所需的带有文本的输出视频。但是,如果我要将subTitle1Text.string
属性替换为一些静态文本,例如subTitle1Text.string=“Sheep”
,则字幕上没有任何文本
当我使用AVPlayer
预览此视频时,我可以在视频上看到预期的文本,但在使用AVExportSession
保存视频时,没有添加字幕
所以我的问题是,这种异常行为的原因是什么?我刚刚遇到了同样的问题。你找到正确的解决方案了吗?我刚刚遇到了同样的问题。你找到正确的解决方案了吗?