问适当地从AVCaptureDataOutputSynchronizerDelegate释放缓冲区，原因是缓冲区超出缓冲区

EN

...
guard let imagePixelBuffer = CMSampleBufferGetImageBuffer(videoSampleBuffer) else { fatalError() }


//First lock buffer
CVPixelBufferLockBaseAddress(imagePixelBuffer,
                                     CVPixelBufferLockFlags.readOnly)

//Do something with buffer
self.buffer = createMyBuffer(pixelBuffer: imagePixelBuffer)

//Unlock buffer
CVPixelBufferUnlockBaseAddress(imagePixelBuffer,
                                       CVPixelBufferLockFlags.readOnly)
self.doSomething(self.buffer)

...

func createMyBuffer(pixelBuffer: CVPixelBuffer) -> CVPixelBuffer? {
    let scaleWidth:Int = CVPixelBufferGetWidth(pixelBuffer)
    let scaleHeight:Int = CVPixelBufferGetHeight(pixelBuffer)

    let flags = CVPixelBufferLockFlags(rawValue: 0)
    guard kCVReturnSuccess == CVPixelBufferLockBaseAddress(pixelBuffer, flags) else {
        return nil
    }

    defer { CVPixelBufferUnlockBaseAddress(pixelBuffer, flags) }

    guard let srcData = CVPixelBufferGetBaseAddress(pixelBuffer) else {
        print("Error: could not get pixel buffer base address")
        return nil
    }

    let srcBytesPerRow = CVPixelBufferGetBytesPerRow(pixelBuffer)
    var srcBuffer = vImage_Buffer(data: srcData,
                                      height: vImagePixelCount(CVPixelBufferGetHeight(pixelBuffer)),
                                      width: vImagePixelCount(CVPixelBufferGetWidth(pixelBuffer)),
                                      rowBytes: srcBytesPerRow)

    let destBytesPerRow = scaleWidth*4
    guard let destData = malloc(scaleHeight*destBytesPerRow) else {
        print("Error: out of memory")
        return nil
    }

    var destBuffer = vImage_Buffer(data: destData,
                                       height: vImagePixelCount(scaleHeight),
                                       width: vImagePixelCount(scaleWidth),
                                       rowBytes: destBytesPerRow)

    let error = vImageScale_ARGB8888(&srcBuffer, &destBuffer, nil, vImage_Flags(kvImageLeaveAlphaUnchanged))
    if error != kvImageNoError {
        print("Error:", error)
        free(destData)
        return nil
    }

    let releaseCallback: CVPixelBufferReleaseBytesCallback = { _, ptr in
        if let ptr = ptr {
            free(UnsafeMutableRawPointer(mutating: ptr))
        }
    }

    let pixelFormat = CVPixelBufferGetPixelFormatType(pixelBuffer)
    var dstPixelBuffer: CVPixelBuffer?
    let status = CVPixelBufferCreateWithBytes(nil, scaleWidth, scaleHeight,
                                                  pixelFormat, destData,
                                                  destBytesPerRow, releaseCallback,
                                                  nil, nil, &dstPixelBuffer)
    if status != kCVReturnSuccess {
        print("Error: could not create new pixel buffer")
        free(destData)
        return nil
    }
    return dstPixelBuffer
}