Question

我目前正在做一个样本iOS移动应用程序（Xcode 7，Swift 2.2），它可以对WebP图像进行编码和解码。我已经下载了一个预编译版本的WebP框架，并使用桥接头文件包含在我的项目中。使用WebPDecodeRGBA解码WebP图像时，它工作正常。但是，当我使用WebPEncodeRGB将jpg图像转换为WebP格式时，它显示编译时错误如下：

Undefined symbols for architecture i386:   
      "_WebPEncodeRGB", referenced from:
          static (extension in WebpImageTest):__ObjC.UIImage.imageToWebPData (__ObjC.NSData) -> __ObjC.UIImage? in ViewController.o  
      "_WebPEncodeRGB", referenced from:  
          WebpImageTest.ViewController.imageToWebPData (__ObjC.NSData) -> __ObjC.UIImage? in ViewController.o  
    ld: symbol(s) not found for architecture i386  
    clang: error: linker command failed with exit code 1 (use -v to see invocation)

我已经将编码代码添加为viewcontroller类的函数，如下所示：

func imageToWebPData(jpgImageData:NSData) -> UIImage? {  
    let imag = UIImage(data: jpgImageData)
    let compressionLevel = 10
    let inputImageWidth = imag!.size.width
    let inputImageHeight = imag!.size.height
    let image:CGImage = imag!.CGImage!
    let provider: CGDataProviderRef? = CGImageGetDataProvider(image)
    let bitmap: CFDataRef? = CGDataProviderCopyData(provider)

    let rgb: UnsafePointer<UInt8> = CFDataGetBytePtr(bitmap)
    let width: Int32 = Int32(inputImageWidth)
    let height: Int32 = Int32(inputImageHeight)
    let stride: Int32 = Int32(CGImageGetBytesPerRow(image))
    let qualityFactor: Float = Float(compressionLevel)

    var webp: NSData
    var output: UnsafeMutablePointer<UInt8> = nil
    var size: size_t = 0

    size = WebPEncodeRGB(rgb,width,height,stride,qualityFactor,&output)

    let afterByteLength = Int(size)
    webp = NSData(bytes: output, length: afterByteLength)
    free(output)
    return UIImage(data: webp)
  }

另外，有没有其他方法可以使用Swift将jpg图像转换为WebP格式？

WebP编码 - “在架构中找不到符号”问题

0 个答案: