Adjust video capture input port using C++ / python - c++

Question

I am having a video capture device (VCD) that acquires frames from a TV which have various output ports (VGA, HDMI, DVI). I read these frames using C++/OpenCV, process them and then show the output on a C++/Qt QLabel.
My problems show up when I change the input port (DVI to HDMI or HDMI to VGA,...), at then I need to manually open the crossbar dialog window for the VCD and switch the input port.
Shows command window with ffmpeg command line + crossbar window for the video capture device
Moreover, for each input port, I need to adjust some parameters relating to color range, scaling size and wire's length.
I need to automate this process of selecting the right input port with the corresponding right parameters using a C++ or python code.
I was searching for a way to read all the input pins of the crossbar dialog box for the video capture device and this set/unset the required pins.
Thanks in advance.

Answer 1

Here is the example in C++/WinAPI how you can set/unset the VIDEO INPUT pins on settings dialog. This code assumes, that checkboxes are children elements of the main dialog; there can be case, when they are nested inside the tab control "Custom settings", so in this case you need find the that tab at first.
#include <windows.h>
#include <string>
#include <vector>
#include <map>
#include <iostream>
int main(int, char **)
{
// Find the dialog
HWND hwnd = FindWindowA(NULL, "%Your settings dialog caption%");
if (hwnd == NULL)
{
std::cerr << "cannot find settings dialog" << std::endl;
return 1;
}
std::map<std::string, HWND> options;
// Get first dialog element
HWND h = GetWindow(hwnd, GW_CHILD);
char caption[250];
std::vector<std::string> inputs{
"1/HDMI",
"2/DVI-D",
"3/COMPONENT",
"DVI",
"4/VGA",
"SOG",
"5/SDI",
"6/COMPOSITE",
"7/S-VIDEO",
"8/AUTO"
};
while (h != NULL)
{
// Get element text
if (GetWindowTextA(h, caption, 250))
{
std::string scaption(caption);
// Check the text, if it's in the list of the option, put it into map.
if (std::find(inputs.begin(), inputs.end(), scaption) != inputs.end())
{
options[caption] = h;
}
}
h = GetWindow(h, GW_HWNDNEXT);
}
// Check the 4/VGA option.
SendMessageA(options["4/VGA"], BM_CLICK, 0, 0);
return 0;
}