Windows API Function AVIFileOpenW takes PAVISTREAM as input but AVIStreamSetFormat takes PAVIFILE - c++

Question

I am making a clipping software which clips the last 30 seconds of your screen. I am trying to write the results to an AVI file, but I am running into issues. Here is my code:
#include <Windows.h>
#include <Vfw.h>
#include <iostream>
#include <vector>
const int BUFFER_SIZE = 30 * 60; // 30 seconds at 60 fps
int main() {
HMONITOR hMonitor = MonitorFromWindow(NULL, MONITOR_DEFAULTTOPRIMARY);
MONITORINFO info;
info.cbSize = sizeof(MONITORINFO);
GetMonitorInfo(hMonitor, &info);
int width = info.rcMonitor.right - info.rcMonitor.left;
int height = info.rcMonitor.bottom - info.rcMonitor.top;
HDC hDC = GetDC(NULL);
HBITMAP hBitmap = CreateCompatibleBitmap(hDC, width, height);
// Create a device context for the bitmap
HDC hMemDC = CreateCompatibleDC(hDC);
SelectObject(hMemDC, hBitmap);
std::vector<HBITMAP> buffer(BUFFER_SIZE);
int index = 0;
while (true) {
BitBlt(hMemDC, 0, 0, width, height, hDC, 0, 0, SRCCOPY);
buffer[index] = hBitmap;
index = (index + 1) % BUFFER_SIZE;
if (GetAsyncKeyState(VK_ESCAPE) & 0x8000) {
break;
}
}
// PROBLEM HERE:
PAVISTREAM pStream;
AVIFileInit();
AVIFileOpenW(&pStream, L"screen_recording.avi", OF_WRITE | OF_CREATE, NULL); // takes PAVIFILE as first parameter
AVIStreamSetFormat(pStream, 0, &hBitmap, sizeof(BITMAPINFOHEADER)); // takes PAVISTREAM as first parameter
// Write the stored frames to the AVISTREAM object
for (int i = 0; i < BUFFER_SIZE; i++) {
AVIStreamWrite(pStream, i, 1, &buffer[i], sizeof(BITMAPINFOHEADER), AVIIF_KEYFRAME, NULL, NULL);
}
AVIStreamClose(pStream);
AVIFileExit();
ReleaseDC(NULL, hDC);
DeleteDC(hMemDC);
DeleteObject(hBitmap);
return 0;
}
Am I doing this right? I am new to C++, so I am not sure if this is what I should be doing.

Answer 1

You can use the function AVIStreamOpenFromFile to open the avi file as stream, that will give the pointer to PAVISTREAM. So, not necessary to call the AVIFileOpen function.