public void WriteAndCapture()
{
using var image = Image("lenna.png");
{
using var writer = new VideoWriter("dummy1.avi", FourCCValues.MJPG, 10, image.Size());
Assert.True(writer.IsOpened());
writer.Write(image);
writer.Write(image);
writer.Write(image);
}
using var capture = new VideoCapture("dummy1.avi");
Assert.True(capture.IsOpened());
Assert.Equal("CV_MJPEG", capture.GetBackendName());
Assert.Equal(3, capture.FrameCount);
using var frame1 = new Mat();
using var frame2 = new Mat();
using var frame3 = new Mat();
using var frame4 = new Mat();
Assert.True(capture.Read(frame1));
Assert.True(capture.Read(frame2));
Assert.True(capture.Read(frame3));
Assert.False(capture.Read(frame4));
Assert.False(frame1.Empty());
Assert.False(frame2.Empty());
Assert.False(frame3.Empty());
Assert.True(frame4.Empty());
Assert.Equal(image.Size(), frame1.Size());
}
public void WriteAndCapture()
{
const string fileName = "dummy1.avi";
try
{
using var image = Image("lenna.png");
{
using var writer = new VideoWriter(fileName, VideoCaptureAPIs.OPENCV_MJPEG, FourCC.MJPG, 10, image.Size());
Assert.True(writer.IsOpened());
writer.Write(image);
writer.Write(image);
writer.Write(image);
}
using var capture = new VideoCapture(fileName);
Assert.True(capture.IsOpened());
var backendName = capture.GetBackendName();
testOutputHelper.WriteLine($"[{nameof(WriteAndCapture)}] BackendName: {backendName}");
Assert.True(backendName == "MSMF" || backendName == "CV_MJPEG" || backendName == "FFMPEG",
$"Unexpected VideoWriter backend: {backendName}");
Assert.Equal(3, capture.FrameCount);
using var frame1 = new Mat();
using var frame2 = new Mat();
using var frame3 = new Mat();
using var frame4 = new Mat();
Assert.True(capture.Read(frame1));
Assert.True(capture.Read(frame2));
Assert.True(capture.Read(frame3));
Assert.False(capture.Read(frame4));
Assert.False(frame1.Empty());
Assert.False(frame2.Empty());
Assert.False(frame3.Empty());
Assert.True(frame4.Empty());
Assert.Equal(image.Size(), frame1.Size());
}
finally
{
DeleteFile(fileName);
}
}
public void GrabAndRetrieveImageSequence()
{
using var capture = new VideoCapture("_data/image/blob/shapes%d.png");
using var image1 = new Mat("_data/image/blob/shapes1.png", ImreadModes.Color);
using var image2 = new Mat("_data/image/blob/shapes2.png", ImreadModes.Color);
using var image3 = new Mat("_data/image/blob/shapes3.png", ImreadModes.Color);
Assert.True(capture.IsOpened());
Assert.Equal("CV_IMAGES", capture.GetBackendName());
Assert.Equal(3, capture.FrameCount);
using var frame1 = new Mat();
using var frame2 = new Mat();
using var frame3 = new Mat();
using var frame4 = new Mat();
Assert.True(capture.Grab());
Assert.True(capture.Retrieve(frame1));
Assert.True(capture.Grab());
Assert.True(capture.Retrieve(frame2));
Assert.True(capture.Grab());
Assert.True(capture.Retrieve(frame3));
Assert.False(capture.Grab());
Assert.False(capture.Retrieve(frame4));
Assert.False(frame1.Empty());
Assert.False(frame2.Empty());
Assert.False(frame3.Empty());
Assert.True(frame4.Empty());
Cv2.CvtColor(frame1, frame1, ColorConversionCodes.BGRA2BGR);
Cv2.CvtColor(frame2, frame2, ColorConversionCodes.BGRA2BGR);
Cv2.CvtColor(frame3, frame3, ColorConversionCodes.BGRA2BGR);
ImageEquals(image1, frame1);
ImageEquals(image2, frame2);
ImageEquals(image3, frame3);
if (Debugger.IsAttached)
{
Window.ShowImages(frame1, frame2, frame3, frame4);
}
}
public void StartWebcam()
{
Log.Debug("Starting Camera... {0}", "Channel 0");
frame = new Mat();
capture = new VideoCapture();
try
{
capture.Open(0);
Log.Debug("GetBackendName {0}", capture.GetBackendName());
Log.Debug("Channel {0}", capture.Get(VideoCaptureProperties.Channel));
Log.Debug("IsOpened {0}", capture.IsOpened());
}
catch (Exception e)
{
Log.Fatal("Failed to find cam {0} ", e.Message);
return;
}
}
