CVPixelBuffer通过vImage转换成CGImage

CVPixelBuffer(vImage).swift

import Accelerate.vImage

func getImageBuffer(from pixelBuffer: CVPixelBuffer) -> vImage_Buffer? {
    var buffer = vImage_Buffer()
    let bitmapInfo = CGBitmapInfo(rawValue: CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.first.rawValue)
    var cgFormat = vImage_CGImageFormat(bitsPerComponent: 8,
                                        bitsPerPixel: 32,
                                        colorSpace: nil,
                                        bitmapInfo: bitmapInfo,
                                        version: 0,
                                        decode: nil,
                                        renderingIntent: .defaultIntent)
    let cvFormat = vImageCVImageFormat_Create(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange,
                                              kvImage_ARGBToYpCbCrMatrix_ITU_R_709_2,
                                              kCVImageBufferChromaLocation_TopLeft,
                                              CGColorSpaceCreateDeviceRGB(), 0).takeRetainedValue()

    var error: vImage_Error
    error = vImageBuffer_InitWithCVPixelBuffer(&buffer,
                                               &cgFormat,
                                               pixelBuffer,
                                               cvFormat,
                                               nil,
                                               vImage_Flags(0))
    guard error == kvImageNoError else { return nil }

    return buffer
}


func getPixelBuffer(from buffer: vImage_Buffer, width: Int, height: Int) -> CVPixelBuffer? {
    var buffer = buffer
    let bitmapInfo = CGBitmapInfo(rawValue: CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.first.rawValue)
    var cgFormat = vImage_CGImageFormat(bitsPerComponent: 8,
                                        bitsPerPixel: 32,
                                        colorSpace: nil,
                                        bitmapInfo: bitmapInfo,
                                        version: 0,
                                        decode: nil,
                                        renderingIntent: .defaultIntent)
    let cvFormat = vImageCVImageFormat_Create(kCVPixelFormatType_420YpCbCr8BiPlanarFullRange,
                                              kvImage_ARGBToYpCbCrMatrix_ITU_R_709_2,
                                              kCVImageBufferChromaLocation_TopLeft,
                                              CGColorSpaceCreateDeviceRGB(), 0).takeRetainedValue()

    var pixelBuffer: CVPixelBuffer?
    let status = CVPixelBufferCreate(kCFAllocatorDefault,
                                     width,
                                     height,
                                     kCVPixelFormatType_420YpCbCr8BiPlanarFullRange,
                                     nil,
                                     &pixelBuffer)
    guard status == kCVReturnSuccess else { return nil }

    let error = vImageBuffer_CopyToCVPixelBuffer(&buffer,
                                                 &cgFormat,
                                                 pixelBuffer!,
                                                 cvFormat,
                                                 nil,
                                                 vImage_Flags(0))
    guard error == kvImageNoError else { return nil }

    return pixelBuffer
}

func getCGImage(from buffer: vImage_Buffer) -> CGImage? {
    var buffer = buffer
    let bitmapInfo = CGBitmapInfo(rawValue: CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.first.rawValue)
    var cgFormat = vImage_CGImageFormat(bitsPerComponent: 8, bitsPerPixel: 32, colorSpace: nil, bitmapInfo: bitmapInfo, version: 0, decode: nil, renderingIntent: .defaultIntent)

    var error: vImage_Error = kvImageNoError
    let cgImage = vImageCreateCGImageFromBuffer(&buffer, &cgFormat, nil, nil, vImage_Flags(0), &error).takeRetainedValue()
    free(buffer.data)
    guard error == kvImageNoError else { return nil }

    return cgImage
}