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c++ - opencv + cuda 如何以 64 fps 从屏幕录制视频？

问题描述

下午好。目前，我找不到有关如何使用 opencv + cuda 以 64 fps 从屏幕录制视频的信息。我有一些使用 cpu 但不使用 gpu 的代码，所以它大约是 25 fps。请帮我找资料。

#include <iostream>
#include <opencv2/opencv.hpp>
#include <opencv2/cudaarithm.hpp>
#include <opencv2/video.hpp>
#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"
#include <Windows.h>

using namespace std;
using namespace cv;
using namespace cv::cuda;

Mat hwnd2mat(HWND hwnd)
{
HDC hwindowDC, hwindowCompatibleDC;

int height, width, srcheight, srcwidth;
HBITMAP hbwindow;
Mat src;
BITMAPINFOHEADER  bi;

hwindowDC = GetDC(hwnd);
hwindowCompatibleDC = CreateCompatibleDC(hwindowDC);
SetStretchBltMode(hwindowCompatibleDC, COLORONCOLOR);

RECT windowsize;    // get the height and width of the screen
GetClientRect(hwnd, &windowsize);

srcheight = windowsize.bottom;
srcwidth = windowsize.right;
height = windowsize.bottom / 1;  //change this to whatever size you want to resize to
width = windowsize.right / 1;

src.create(height, width, CV_8UC4);

// create a bitmap
hbwindow = CreateCompatibleBitmap(hwindowDC, width, height);
bi.biSize = sizeof(BITMAPINFOHEADER);    //http://msdn.microsoft.com/en-us/library/windows/window/dd183402%28v=vs.85%29.aspx
bi.biWidth = width;
bi.biHeight = -height;  //this is the line that makes it draw upside down or not
bi.biPlanes = 1;
bi.biBitCount = 32;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrUsed = 0;
bi.biClrImportant = 0;

// use the previously created device context with the bitmap
SelectObject(hwindowCompatibleDC, hbwindow);
// copy from the window device context to the bitmap device context
StretchBlt(hwindowCompatibleDC, 0, 0, width, height, hwindowDC, 0, 0, srcwidth, srcheight, SRCCOPY); //change SRCCOPY to NOTSRCCOPY for wacky colors !
GetDIBits(hwindowCompatibleDC, hbwindow, 0, height, src.data, (BITMAPINFO*)&bi, DIB_RGB_COLORS);  //copy from hwindowCompatibleDC to hbwindow

// avoid memory leak
DeleteObject(hbwindow);
DeleteDC(hwindowCompatibleDC);
ReleaseDC(hwnd, hwindowDC);

return src;
}

int main(int argc, char** argv)
{
HWND hwndDesktop = GetDesktopWindow();
//namedWindow("output", WINDOW_NORMAL);
int key = 0;

while (1)
{
    Mat src = hwnd2mat(hwndDesktop);
    // you can do some image processing here
    imshow("output", src);
    key = waitKey(1);
}

}

如何以 64 fps 从桌面录制视频？我试图用 UMAT 替换 MAT，它主要使用 gpu，但不幸的是，由于这个功能，它不起作用：

GetDIBits(hwindowCompatibleDC, hbwindow, 0, height, src.data, (BITMAPINFO*)&bi, DIB_RGB_COLORS);

因为 UMAT 类没有可变数据。

编辑：下午好，我更新了 gpu 的 hwnd2mat 函数，但由于某种原因它给了我一个黑屏。请帮帮我。

UMat hwnd2mat(HWND hwnd)
{
HDC hwindowDC, hwindowCompatibleDC;

int height, width, srcheight, srcwidth;
HBITMAP hbwindow;
UMat src;
BITMAPINFOHEADER  bi;

hwindowDC = GetDC(hwnd);
hwindowCompatibleDC = CreateCompatibleDC(hwindowDC);
SetStretchBltMode(hwindowCompatibleDC, COLORONCOLOR);

RECT windowsize;    // get the height and width of the screen
GetClientRect(hwnd, &windowsize);

srcheight = windowsize.bottom;
srcwidth = windowsize.right;
height = windowsize.bottom / 1;  //change this to whatever size you want to resize to
width = windowsize.right / 1;

src.create(height, width, CV_8UC4);

// create a bitmap
hbwindow = CreateCompatibleBitmap(hwindowDC, width, height);
bi.biSize = sizeof(BITMAPINFOHEADER);    //http://msdn.microsoft.com/en-us/library/windows/window/dd183402%28v=vs.85%29.aspx
bi.biWidth = width;
bi.biHeight = -height;  //this is the line that makes it draw upside down or not
bi.biPlanes = 1;
bi.biBitCount = 32;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrUsed = 0;
bi.biClrImportant = 0;

// use the previously created device context with the bitmap
SelectObject(hwindowCompatibleDC, hbwindow);
// copy from the window device context to the bitmap device context
StretchBlt(hwindowCompatibleDC, 0, 0, width, height, hwindowDC, 0, 0, srcwidth, srcheight, SRCCOPY); //change SRCCOPY to NOTSRCCOPY for wacky colors !
GetDIBits(hwindowCompatibleDC, hbwindow, 0, height, src.u->data, (BITMAPINFO*)&bi, DIB_RGB_COLORS);  //copy from hwindowCompatibleDC to hbwindow

// avoid memory leak
DeleteObject(hbwindow);
DeleteDC(hwindowCompatibleDC);
ReleaseDC(hwnd, hwindowDC);

return src;
}

标签： c++opencv

解决方案

CUDA 有助于加速处理功能，但不能帮助加速桌面捕获。在这种情况下，瓶颈是您用于捕获屏幕的 blit API (GetDIBits)。由于您似乎拥有 Nvidia GPU，因此您应该查看此处提到的操作系统/驱动程序级别的替代方案 ( https://developer.nvidia.com/capture-sdk )。

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