iOS CMSampleBuffer转为UIImage的方法

iOS camera输出CMSampleBuffer，如何转为UIImage？

第一步：
从sampleBuffer获取CVImageBuffer
let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)

第二步：
CVImageBuffer转为UIImage
let ciImage = CIImage(cvPixelBuffer: imageBuffer)
let context = CIContext(options: nil)
guard let cgImage = context.createCGImage(ciImage, from: ciImage.extent) else { return nil }
let image = UIImage(cgImage: cgImage, scale: 1.0, orientation: orientation)

具体代码如下

/// Converts an image buffer to a `UIImage`.
    /// - Parameters:
    ///   - imageBuffer: The image buffer which should be converted.
    ///   - origentation: The orientation already applied to the image.
    /// - Returns: A new `UIImage` instance.
    public static func createUIImage(from imageBuffer: CVImageBuffer, orientation: UIImage.Orientation) -> UIImage? {
        let ciImage = CIImage(cvPixelBuffer: imageBuffer)
        let context = CIContext(options: nil)
        guard let cgImage = context.createCGImage(ciImage, from: ciImage.extent) else { return nil }
        return UIImage(cgImage: cgImage, scale: 1.0, orientation: orientation)
    }

    //CMSampleBuffer转为UIImage方法
    public static func createUIImage(from sampleBuffer: CMSampleBuffer, orientation: UIImage.Orientation) -> UIImage? {
          // 获取CMSampleBuffer的核心视频图像缓冲的媒体数据
          if let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) {
              return Self.createUIImage(from: imageBuffer, orientation: orientation)
          }
          return nil
      }