swift - 如何在Swift中直接从CIImage而不是UIImage制作CVPixelBuffer？

我正在通过iPhone摄像机录制经过过滤的视频，并且在录制时将CIImage实时转换为UIImage时，CPU使用率大大增加。我制作CVPixelBuffer的缓冲区函数使用UIImage，到目前为止，我需要进行此转换。我想做一个缓冲函数，如果可能的话可以使用CIImage，这样我就可以跳过从UIImage到CIImage的转换。我认为这将在录制视频时极大地提高性能，因为在CPU和GPU之间不会有任何麻烦。

这就是我现在所拥有的。在我的captureOutput函数中，我从CIImage创建一个UIImage，它是过滤后的图像。我使用UIImage从缓冲区函数创建一个CVPixelBuffer，并将其附加到assetWriter的pixelBufferInput上:

let imageUI = UIImage(ciImage: ciImage)

let filteredBuffer:CVPixelBuffer? = buffer(from: imageUI)

let success = self.assetWriterPixelBufferInput?.append(filteredBuffer!, withPresentationTime: self.currentSampleTime!)

我的缓冲区函数使用UIImage:

func buffer(from image: UIImage) -> CVPixelBuffer? {
    let attrs = [kCVPixelBufferCGImageCompatibilityKey: kCFBooleanTrue, kCVPixelBufferCGBitmapContextCompatibilityKey: kCFBooleanTrue] as CFDictionary
    var pixelBuffer : CVPixelBuffer?
    let status = CVPixelBufferCreate(kCFAllocatorDefault, Int(image.size.width), Int(image.size.height), kCVPixelFormatType_32ARGB, attrs, &pixelBuffer)

    guard (status == kCVReturnSuccess) else {
        return nil
    }

    CVPixelBufferLockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))
    let pixelData = CVPixelBufferGetBaseAddress(pixelBuffer!)

    let videoRecContext = CGContext(data: pixelData,
                            width: Int(image.size.width),
                            height: Int(image.size.height),
                            bitsPerComponent: 8,
                            bytesPerRow: videoRecBytesPerRow,
                            space: (MTLCaptureView?.colorSpace)!, // It's getting the current colorspace from a MTKView
                            bitmapInfo: CGImageAlphaInfo.noneSkipFirst.rawValue)

    videoRecContext?.translateBy(x: 0, y: image.size.height)
    videoRecContext?.scaleBy(x: 1.0, y: -1.0)

    UIGraphicsPushContext(videoRecContext!)
    image.draw(in: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))
    UIGraphicsPopContext()
    CVPixelBufferUnlockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))

    return pixelBuffer
}

最佳答案

创建一个CIContext，并使用它来使用 CIImage 将CVPixelBuffer直接呈现为您的CIContext.render(_: CIImage, to buffer: CVPixelBuffer)。

关于swift - 如何在Swift中直接从CIImage而不是UIImage制作CVPixelBuffer？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/54354138/