如何在Swift中将图像导出为视频？

Question

我正在Swift中制作一个应用程序（我有最新的xcode更新），该应用程序必须从某些图像生成视频。
我从此答案中获得了代码。如何将UIImage数组导出为电影？
我这样调用该函数：

let size = CGSize(width: 1280, height: 720)
let pathVideo = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let percorsoVideo = pathVideo[0]
writeImagesAsMovie(arrayImmagini, videoPath: percorsoVideo+"/prova.mp4", videoSize: size, videoFPS: 1)

“ arrayImmagini”的字面定义如下：

var arrayImmagini = [UIImage(imageLiteral: "Frames/turtle/turtle0.jpg"), UIImage(imageLiteral: "Frames/turtle/turtle1.jpg"), ...]

当我尝试运行代码时，我得到了一个全黑的视频，而xcode给我这2个错误是数组中图像数量的两倍：

Sep  5 09:24:15  Prova[1554] <Error>: CGBitmapContextCreate: invalid data bytes/row: should be at least 7680 for 8 integer bits/component, 3 components, kCGImageAlphaPremultipliedFirst.
Sep  5 09:24:15  Prova[1554] <Error>: CGContextDrawImage: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.

阅读有关CGBitmapContextCreate的文档，我试图用不同的方式来称呼它：

func fillPixelBufferFromImage(image: UIImage, pixelBuffer: CVPixelBufferRef) {
    CVPixelBufferLockBaseAddress(pixelBuffer, 0)

    let pixelData = CVPixelBufferGetBaseAddress(pixelBuffer)
    let rgbColorSpace = CGColorSpaceCreateDeviceRGB()

    // Create CGBitmapContext
    let context = CGBitmapContextCreate(
        nil,
        Int(image.size.width),
        Int(image.size.height),
        8,
        0,
        rgbColorSpace,
        CGImageAlphaInfo.PremultipliedFirst.rawValue
    )

    // Draw image into context
    CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage)

    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0)
}

代替：

func fillPixelBufferFromImage(image: UIImage, pixelBuffer: CVPixelBufferRef) {
    CVPixelBufferLockBaseAddress(pixelBuffer, 0)

    let pixelData = CVPixelBufferGetBaseAddress(pixelBuffer)
    let rgbColorSpace = CGColorSpaceCreateDeviceRGB()

    // Create CGBitmapContext
    let context = CGBitmapContextCreate(
        pixelData,
        Int(image.size.width),
        Int(image.size.height),
        8,
        CVPixelBufferGetBytesPerRow(pixelBuffer),
        rgbColorSpace,
        CGImageAlphaInfo.PremultipliedFirst.rawValue
    )

    // Draw image into context
    CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage)

    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0)
}

这使xcode停止给我错误，但我仍然得到黑色视频。
请帮助我，我是应用程序开发的新手，甚至是AVFoundation的新手，我没有任何有关如何自己解决问题的线索。

谢谢！

Answer 1

经过多次尝试使这项工作成功后，我发现了问题所在。您指定的视频尺寸不能小于图片尺寸。
一旦我这样做了，一切就正常了：

let size = CGSize(width: 1920, height: 1280)