ios - 创建图像像素缓冲区时内存泄漏

Question

我正在尝试使用 AVAssetWriterInput 创建带有图像输入的视频，为此我需要创建图像的像素缓冲区。

为此，我调用了下面的函数，但在创建了一些视频后，该应用程序收到了内存警告并崩溃了。我已经使用 Instruments 对其进行了调试，但似乎存在内存泄漏 here .

我曾尝试将变量 pixelBufferPointer 和 pxData 作为类变量，并在视频创建后销毁/解除分配，但这似乎没有任何区别。我应该做些什么来释放这段内存吗？

func createPixelBufferFromCGImage(image: CGImageRef) -> CVPixelBufferRef {
    let options = [
        "kCVPixelBufferCGImageCompatibilityKey": true,
        "kCVPixelBufferCGBitmapContextCompatibilityKey": true
    ]

    var videoWidth = 496
    var videoHeight = 668

    let frameSize = CGSizeMake(CGFloat(videoWidth), CGFloat(videoHeight))

    var pixelBufferPointer = UnsafeMutablePointer<Unmanaged<CVPixelBuffer>?>.alloc(1)

    var status:CVReturn = CVPixelBufferCreate(
        kCFAllocatorDefault,
        Int(frameSize.width),
        Int(frameSize.height),
        OSType(kCVPixelFormatType_32ARGB),
        options,
        pixelBufferPointer
    )

    var lockStatus:CVReturn = CVPixelBufferLockBaseAddress(pixelBufferPointer.memory?.takeUnretainedValue(), 0)

    var pxData:UnsafeMutablePointer<(Void)> = CVPixelBufferGetBaseAddress(pixelBufferPointer.memory?.takeUnretainedValue())

    let bitmapinfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.NoneSkipFirst.rawValue)
    let rgbColorSpace:CGColorSpace = CGColorSpaceCreateDeviceRGB()

    var context:CGContextRef = CGBitmapContextCreate(
        pxData,
        Int(frameSize.width),
        Int(frameSize.height),
        8,
        //4 * CGImageGetWidth(image),
        4 * Int(frameSize.width),
        rgbColorSpace,
        bitmapinfo
    )

    CGContextDrawImage(context, CGRectMake(0, 0, frameSize.width, frameSize.height), image)

    CVPixelBufferUnlockBaseAddress(pixelBufferPointer.memory?.takeUnretainedValue(), 0)

    UIGraphicsEndImageContext()

    return pixelBufferPointer.memory!.takeUnretainedValue()
}

Answer 1

Unmanaged<CVPixelBuffer>正在泄漏。

我更喜欢 Russell Austin 的回答，但我不知道如何通过 pixelBufferPointer至 CVPixelBufferCreate没有语法错误(快速新手)。否则，更改线路

return pixelBufferPointer.memory!.takeUnretainedValue()

到

return pixelBufferPointer.memory!.takeRetainedValue()

修复泄漏