将 AVVideoComposition 初始化程序转换为 Nativescript

Question

在将此 Objective-c 类方法移植到 JS/nativescript 方面寻求一些帮助。我尝试的每个变体都导致了 TypeError: undefined is not a function...

https://developer.apple.com/documentation/avfoundation/avvideocomposition/1389556-init

我尝试用 JS 写成：

const videoComp = AVVideoComposition.alloc().initWithAssetApplyingCIFiltersWithHandler(asset, (request) => { ... });

//OR
const videoComp = AVVideoComposition.alloc().initAssetApplyingCIFiltersWithHandler(asset, (request) => { ... });

//OR
const videoComp = AVVideoComposition.alloc().initAssetApplyingCIFiltersWithHandlerApplier(asset, (request) => { ... });

//OR
const videoComp = new AVVideoComposition(asset, (request) => { ... });

仅举几例。本质上，我正在尝试将此代码移植到 nativescript/JS：

let blurRadius = 6.0
let asset = AVAsset(url: streamURL)
let item = AVPlayerItem(asset: asset)
item.videoComposition= AVVideoComposition(asset: asset) { request in
    let blurred = request.sourceImage.clampedToExtent().applyingGaussianBlur(sigma: blurRadius)
    let output = blurred.clampedToRect(request.sourceImage.extent)
    request.finish(with: output, context: nil)
}

在这篇博文中找到：https://willowtreeapps.com/ideas/how-to-apply-a-filter-to-a-video-stream-in-ios

Answer 1

使用 JavaScript / Typescript 应该看起来像这样，

let blurRadius = 6.0;
let asset = AVAsset.assetWithURL(streamURL);
let item = AVPlayerItem.alloc().initWithAsset(asset);
item.videoComposition = AVVideoComposition.videoCompositionWithAssetApplyingCIFiltersWithHandler(asset, request => {
    let blurred = request.sourceImage.imageByClampingToExtent().imageByApplyingGaussianBlurWithSigma(blurRadius);
    let output = blurred.imageByClampingToRect(request.sourceImage.extent);
    request.finishWithImageContext(output, null);
});

注意：该代码未经测试，仅为给定本机代码的翻译。使用 tns-platform-declarations 获得 IntelliSense 支持。