public void EmguCvCaptureVideoStream(string url, Action <Emgu.CV.Mat> action)
{
using Emgu.CV.VideoCapture capture = new Emgu.CV.VideoCapture(url, Emgu.CV.VideoCapture.API.Any);
if (capture.IsOpened == false)
{
return;
}
using Emgu.CV.Mat frame = capture.QueryFrame();
while (_stopPlay == false)
{
if (capture.Read(frame)) //capture.Retrieve(frame)// 无法继续读取
{
if (!frame.IsEmpty)
{
action?.Invoke(frame);
}
}
}
frame.Dispose();
capture.Dispose();
}
public async void start()
{
if (didStart)
{
return;
}
if (this.CarDidEnter == null)
{
CarDidEnter = CarDidEnterDefault;
}
if (this.CarDidLeave == null)
{
CarDidLeave = CarDidLeaveDefault;
}
if (this.CarProcessingDone == null)
{
CarProcessingDone = CarProcessingDoneDefault;
}
//flag to note process started to prevent changing peramaters that would break the processing
didStart = true;
//sets up the image matrixs for the input raw and output processed
Emgu.CV.Mat iMatrix = new Emgu.CV.Mat();
Emgu.CV.Mat oMatrix = new Emgu.CV.Mat();
await Task.Run(() =>
{
//creates a window if desired, window for testing purposes
if (showWindow)
{
Emgu.CV.CvInvoke.NamedWindow("Car Detection Test", Emgu.CV.CvEnum.NamedWindowType.FreeRatio);
}
//This async task continually pulls the video frame to be processed.
Task.Run(() =>
{
for (; ;)
{
try
{
if (didStop)
{
return;
}
vCapture.Read(iMatrix);
if (iMatrix == null)
{
iMatrix.Dispose(); iMatrix = null; return;
}
if (iMatrix.IsEmpty)
{
iMatrix.Dispose(); iMatrix = null; return;
}
//System.Console.Out.WriteLine(iMatrix.Size.ToString());
// Emgu.CV.CvInvoke.WaitKey((int)(1000/(fps)));
//double FrameRate = vCapture.GetCaptureProperty(Emgu.CV.CvEnum.CapProp.Fps);
//System.Diagnostics.Debug.WriteLine(FrameRate);
if (fps > 0)
{
Thread.Sleep((int)(1000.0 / fps));
}
}
catch (Exception e) { return; }
}
});
//This async task continually process the pulled frames
for (; ;)
{
try
{
//If the matrix used to store the frames is not empty
if (iMatrix == null)
{
oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
if (!iMatrix.IsEmpty)
{
didEnter = true;
if (didStop)
{
oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
//Converts the contents of the imatrix to greyscale, export results to omatrix
//this is to ensure proper processing
Emgu.CV.CvInvoke.CvtColor(iMatrix, oMatrix, Emgu.CV.CvEnum.ColorConversion.Bgr2Gray);
//Uses the cascade xml file provided in the initalizer to draw rectangles arround possible canditates.
Rectangle[] rects = casc.DetectMultiScale(oMatrix, 1.01, 5, new Size(700, 700), new Size(1100, 1100));
//removes the image from the out matrix if one exists to make room for the new one.
if (oMatrix == null)
{
oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
if (oMatrix.IsEmpty)
{
oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
for (int i = 0; i < oMatrix.Total.ToInt32(); i++)
{
oMatrix.PopBack(1);
}
//sets inital value to zero
int carsInFrame = 0;
//loops through all of the rectangles in the discorvered object array
foreach (Rectangle rect in rects)
{
//draws the rectangles on the imatrix image for display if we wish to show the window
//we use imatrix as it is in color
if (showWindow)
{
var x = rect.X;
var y = rect.Y;
var w = rect.Width;
var h = rect.Height;
Emgu.CV.CvInvoke.Rectangle(iMatrix, new Rectangle(x, y, w, h), new Emgu.CV.Structure.MCvScalar(50));
}
//increase the number of cars in frame for each iteration
carsInFrame++;
}
if (carsInFrame == numCarsInLot)
{
steady++;
}
else
{
steady = 0;
}
//update the number of cars
numCarsInLot = carsInFrame;
//if the number of cars has changed
//call the proper delagte the necessary amount of times
if (carsInFrame > oldNumCarsInLot && steady > 20)
{
for (int i = 0; i < carsInFrame - oldNumCarsInLot; i++)
{
dispatcher.Invoke(CarDidEnter, this);
}
oldNumCarsInLot = numCarsInLot;
}
if (carsInFrame < oldNumCarsInLot && steady > 20)
{
for (int i = 0; i < oldNumCarsInLot - carsInFrame; i++)
{
dispatcher.Invoke(CarDidLeave, this);
}
oldNumCarsInLot = numCarsInLot;
}
//if the show window flag is true we push the drawn images to the window
if (showWindow)
{
if (iMatrix == null)
{
oMatrix.Dispose();; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
if (iMatrix.IsEmpty)
{
oMatrix.Dispose();; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
Emgu.CV.CvInvoke.Imshow("Car Detection Test", iMatrix);
}
//discard the now rendered frame
if (iMatrix == null)
{
oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
if (iMatrix.IsEmpty)
{
oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
iMatrix.PopBack(1);
//Distroys windows and stops loop if the escape key is pressed
if (showWindow && Emgu.CV.CvInvoke.WaitKey(33) == 27)
{
if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
break;
}
if (didStop)
{
oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
}
else if (didEnter)
{
oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return;
}
}
catch (Exception e) { oMatrix.Dispose(); oMatrix = null; dispatcher.Invoke(CarProcessingDone, this); if (showWindow)
{
Emgu.CV.CvInvoke.DestroyAllWindows();
}
return; }
}
});
}
