Windows API函数AVIFileOpenW接受PAVISTREAM作为输入，而AVIStreamSetForma

Question

我正在制作一个剪辑软件，可以剪辑屏幕的最后30秒。我正试图将结果写入AVI文件，但我遇到了问题。下面是我的代码:

#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;
}

我这样做对吗?我是c++的新手，所以我不确定这是否是我应该做的。

Answer 1

您可以使用AVIStreamOpenFromFile函数将avi文件打开为流，这将给出指向PAVISTREAM的指针。因此，没有必要调用AVIFileOpen函数。