Ios AVCaptureStillImageOutput.pngStillImageNSDataRepresentation？

我第一次使用AVCaptureStillImageOutput，我在某个时候保存了一幅JPEG图像。 我想保存一个PNG图像，而不是JPEG图像。我需要为此做些什么

我在应用程序中有3行代码：

let stillImageOutput = AVCaptureStillImageOutput()
stillImageOutput.outputSettings = [AVVideoCodecKey:AVVideoCodecJPEG]
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageDataSampleBuffer)

有没有一个简单的方法来修改这些行以得到我想要的？

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浏览完网络后，似乎答案是否定的（除非我不够幸运），但我仍然相信一定有一些好的解决方案。

中有示例代码显示如何将CMSampleBuffer转换为UIImage（在将CMSampleBuffer转换为UIImage对象下）。从那里，您可以使用

UIImagePNGRepresentation（image）

将其编码为PNG数据

下面是该代码的快速翻译：

extension UIImage
{
    // Translated from <https://developer.apple.com/library/ios/documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/06_MediaRepresentations.html#//apple_ref/doc/uid/TP40010188-CH2-SW4>
    convenience init?(fromSampleBuffer sampleBuffer: CMSampleBuffer)
    {
        guard let imageBuffer: CVPixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return nil }

        if CVPixelBufferLockBaseAddress(imageBuffer, kCVPixelBufferLock_ReadOnly) != kCVReturnSuccess { return nil }
        defer { CVPixelBufferUnlockBaseAddress(imageBuffer, kCVPixelBufferLock_ReadOnly) }

        let context = CGBitmapContextCreate(
            CVPixelBufferGetBaseAddress(imageBuffer),
            CVPixelBufferGetWidth(imageBuffer),
            CVPixelBufferGetHeight(imageBuffer),
            8,
            CVPixelBufferGetBytesPerRow(imageBuffer),
            CGColorSpaceCreateDeviceRGB(),
            CGBitmapInfo.ByteOrder32Little.rawValue | CGImageAlphaInfo.PremultipliedFirst.rawValue)

        guard let quartzImage = CGBitmapContextCreateImage(context) else { return nil }
        self.init(CGImage: quartzImage)
    }
}

扩展UIImage { //翻译自 便利初始化？（来自sampleBuffer sampleBuffer:CMSampleBuffer） { guard let imageBuffer:CVPixelBuffer=CMSampleBufferGetImageBuffer（sampleBuffer）else{return nil} 如果CVPixelBufferLockBaseAddress（imageBuffer，kCVPixelBufferLock_ReadOnly）！=kCVReturnSuccess{return nil} 延迟{CVPixelBufferUnlockBaseAddress（imageBuffer，kCVPixelBufferLock_ReadOnly）} 让context=CGBitmapContextCreate( CVPixelBufferGetBaseAddress（imageBuffer）， CVPixelBufferGetWidth（imageBuffer）， CVPixelBufferGetHeight（imageBuffer）， 8. CVPixelBufferGetBytesPerRow（图像缓冲区）， CGColorSpaceCreateDeviceRGB（）， CGBitmapInfo.ByteOrder32Little.rawValue | CGImageAlphaInfo.PremultipledFirst.rawValue） guard let quartzImage=CGBitmapContextCreateImage（上下文）else{return nil} self.init（CGImage:quartzImage） } }

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这是上述代码的Swift 4版本

extension UIImage
{
    convenience init?(fromSampleBuffer sampleBuffer: CMSampleBuffer)
    {
        guard let imageBuffer: CVPixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return nil }

        if CVPixelBufferLockBaseAddress(imageBuffer, .readOnly) != kCVReturnSuccess { return nil }
        defer { CVPixelBufferUnlockBaseAddress(imageBuffer, .readOnly) }

        let context = CGContext(
        data: CVPixelBufferGetBaseAddress(imageBuffer),
        width: CVPixelBufferGetWidth(imageBuffer),
        height: CVPixelBufferGetHeight(imageBuffer),
        bitsPerComponent: 8,
        bytesPerRow: CVPixelBufferGetBytesPerRow(imageBuffer),
        space: CGColorSpaceCreateDeviceRGB(),
        bitmapInfo: CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.premultipliedFirst.rawValue)

        guard let quartzImage = context!.makeImage() else { return nil }
        self.init(cgImage: quartzImage)
    }
}

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谢谢，我搜索得越多，似乎没有更简单的方法了。“我将试着从这一点出发，看看。”米歇尔，我刚刚用苹果示例代码的快速翻译更新了我的答案。试试看，让我知道它是否有效！