If we break into debugger when this codec selection dialog box is open, we can see that it's the result of this call to AVISaveOptions(...). So, one way to find out what you picked would be to set a breakpoint on say line 799 and inspect the contents of fourcc.
However, there is even simpler way:
- Create a dummy video foo.avi with just 1 black frame, selecting the codec using the GUI.
- Open foo.avi using
cv::VideoCapture.
- Get the
CAP_PROP_FOURCC from the cv::VideoCapture instance.
- Decode and print it.
- [Optional] Create a dummy video bar.avi with just 1 black frame, and use the FOURCC code you determined in step 3. Compare foo.avi and bar.avi to verify they are the same.
Sorry, I don't use C#/EmguCV, so I can't provide you an exact example, but the following should be easy enough to port.
C++ Sample
#include <opencv2/opencv.hpp>
#include <iostream>
int main()
{
{
cv::VideoWriter outputVideo;
outputVideo.open("foo.avi", -1, 25.0, cv::Size(640, 480), true);
cv::Mat frame(480, 640, CV_8UC3);
outputVideo.write(frame);
}
cv::VideoCapture inputVideo("foo.avi");
int fourcc = static_cast<int>(inputVideo.get(CV_CAP_PROP_FOURCC));
char FOURCC_STR[] = {
(char)(fourcc & 0XFF)
, (char)((fourcc & 0XFF00) >> 8)
, (char)((fourcc & 0XFF0000) >> 16)
, (char)((fourcc & 0XFF000000) >> 24)
, 0
};
std::cout << "FOURCC is '" << FOURCC_STR << "'\n";
return 0;
}
Console output:
FOURCC is 'DIB '
Python Sample
import cv2
import numpy as np
import struct
outputVideo = cv2.VideoWriter()
outputVideo.open("foo.avi", -1, 25, (640,480), True)
frame = np.zeros((480,640,3), dtype=np.uint8)
outputVideo.write(frame)
outputVideo.release()
inputVideo = cv2.VideoCapture("foo.avi")
fourcc = int(inputVideo.get(cv2.cv.CV_CAP_PROP_FOURCC))
print "FOURCC is '%s'" % struct.pack("<I", fourcc)
Console output:
FOURCC is 'DIB '
