如何在Swift中直接用CVPixelBuffer而不是UIImage来制作UIImage？
如何在Swift中直接用CVPixelBuffer而不是UIImage来制作UIImage？
提问于 2019-01-24 19:36:44
我是记录过滤视频通过一个iPhone相机，有一个巨大的增加时，在CIImage转换为UIImage实时记录。生成CVPixelBuffer的缓冲区函数使用UIImage，到目前为止，这要求我进行这种转换。如果可能的话，我想要创建一个接受CIImage的缓冲区函数，这样我就可以跳过从UIImage到CIImage的转换。我认为这将使我在录制视频时的性能大大提高，因为CPU和GPU之间不会有任何联系。
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，这是经过过滤的图像。我使用CVPixelBuffer从缓冲区函数创建一个UIImage，并将其附加到assetWriter的pixelBufferInput中：
let imageUI = UIImage(ciImage: ciImage)
let filteredBuffer:CVPixelBuffer? = buffer(from: imageUI)
let success = self.assetWriterPixelBufferInput?.append(filteredBuffer!, withPresentationTime: self.currentSampleTime!)使用UIImage的缓冲区函数：
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
}Stack Overflow用户
发布于 2019-01-24 20:50:33
为了扩展我从罗布·梅奥夫那里得到的答案，我将展示我在下面改变了什么：
在captureOutput函数中，我将代码更改为：
let filteredBuffer : CVPixelBuffer? = buffer(from: ciImage)
filterContext?.render(_:ciImage, to:filteredBuffer!)
let success = self.assetWriterPixelBufferInput?.append(filteredBuffer!, withPresentationTime: self.currentSampleTime!)注意，缓冲区函数传递一个ciImage。我格式化了我的缓冲区函数以传递CIImage，并且能够处理掉许多内部的内容：
func buffer(from image: CIImage) -> CVPixelBuffer? {
let attrs = [kCVPixelBufferCGImageCompatibilityKey: kCFBooleanTrue, kCVPixelBufferCGBitmapContextCompatibilityKey: kCFBooleanTrue] as CFDictionary
var pixelBuffer : CVPixelBuffer?
let status = CVPixelBufferCreate(kCFAllocatorDefault, Int(image.extent.width), Int(image.extent.height), kCVPixelFormatType_32ARGB, attrs, &pixelBuffer)
guard (status == kCVReturnSuccess) else {
return nil
}
return pixelBuffer
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/54354138
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