Access violation when streaming video with emgu opencv - opencv

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Emgu.CV;
using Emgu.CV.Structure;
namespace CrackleTest
{
public static class Controller
{
public static Capture capture = new Capture();
public static VideoWriter CaptureOutput;
public static void Init()
{
capture.SetCaptureProperty(Emgu.CV.CvEnum.CAP_PROP.CV_CAP_PROP_FRAME_WIDTH, 1920);
capture.SetCaptureProperty(Emgu.CV.CvEnum.CAP_PROP.CV_CAP_PROP_FRAME_HEIGHT, 1080);
CaptureOutput = new VideoWriter
(
"output.avi",
-1, //CvInvoke.CV_FOURCC("W","M","V","1"),
30, //fps
(int)capture.GetCaptureProperty(Emgu.CV.CvEnum.CAP_PROP.CV_CAP_PROP_FRAME_WIDTH),
(int)capture.GetCaptureProperty(Emgu.CV.CvEnum.CAP_PROP.CV_CAP_PROP_FRAME_HEIGHT),
true
);
capture.ImageGrabbed += SaveFrame;
capture.Start();
}
public static void Stop()
{
capture.Stop();
CaptureOutput.Dispose();
}
public static void SaveFrame(Object sender, EventArgs e)
{
Image<Bgr, Byte> video = capture.RetrieveBgrFrame();
CaptureOutput.WriteFrame(video);
}
}
}
When I call the stop function I get an error message
An unhandled exception of type 'System.AccessViolationException'
occurred in Emgu.CV.dll
Additional information: Attempted to read or write protected memory.
This is often an indication that other memory is corrupt.
I'm not sure what the best practices are for streaming video from usb webcam in opencv.