dlib C++ Library - ffmpeg_screen_grab_ex.cpp

// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
/*
 This is an example that illustrates how to use the ffmpeg wrappers
 for taking screen grabs and plotting to a GUI window.
*/
#include <cstdio>
#include <dlib/media.h>
#include <dlib/gui_widgets.h>
using namespace std;
using namespace dlib;
int main()
try
{
 const auto demuxers = ffmpeg::list_demuxers();
 const bool screen_grab_available = std::find(begin(demuxers), end(demuxers), "x11grab") != demuxers.end();
 if (screen_grab_available)
 {
 ffmpeg::demuxer::args args;
 args.filepath = "";
 args.input_format = "x11grab";
 ffmpeg::demuxer cap(args);
 if (!cap.is_open() || !cap.video_enabled())
 {
 printf("Failed to open demuxer for screen grab\n");
 return EXIT_FAILURE;
 }
 image_window win;
 ffmpeg::frame frame;
 array2d<rgb_pixel> img;
 while (cap.read(frame))
 {
 convert(frame, img);
 win.set_image(img);
 }
 }
 else
 {
 printf("Sorry your installation of ffmpeg doesn't support screen grab\n");
 }
 return EXIT_SUCCESS;
}
catch (const std::exception& e)
{
 printf("%s\n", e.what());
 return EXIT_FAILURE;
}