c The text terminal directly writes the framebuffer to display a straight line

According to this idea, the framebuffer is operated to display pictures and videos. Pictures and videos in any format must finally be converted into RGB values ​​for each pixel. deepin uses RGB32, or BGRA. This method must be used in a text terminal and cannot be used in a terminal with GUI enabled. My computer uses ctrl+alt+F2 to start a text terminal. ctrl+alt+F1 Return to the gui interface from the terminal.

fim: This program can display pictures in a text terminal

ffmpeg: Add parameters to display video in a text terminal

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <string.h>
#include <unistd.h>
#include <linux/fb.h>


int main(int argc, char *argv[])
{
	struct fb_var_screeninfo var;
	
	int fd_fb = open("/dev/fb0", O_RDWR);
	if (fd_fb < 0)
	{
		puts("/dev/fb0 error");
		return -1;
	}
	if (ioctl(fd_fb, FBIOGET_VSCREENINFO, &var))
	{
		puts("ioctl error");
		return -1;
	}
	unsigned int line_width = var.xres * var.bits_per_pixel / 8;
	unsigned int  pixel_width = var.bits_per_pixel / 8;                  //deepin=32
	int screen_size = var.xres * var.yres * var.bits_per_pixel / 8;
	
	unsigned char *fb_base = (unsigned char *)mmap(NULL, screen_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd_fb, 0);
	if (fb_base == NULL)
	{
		puts("mmap error");
		return -1;
	}
	
	memset(fb_base, 0xff, screen_size);
	
	for (int i = 0; i < 1920; i++)
	{
		
		int x=i;
		int y = var.yres / 2;
		int color = 0;            //block
		unsigned char *pen_8 = fb_base + y * line_width + x * pixel_width; 
		unsigned int *pen_32 = (unsigned int *)pen_8;      //char->int 这句非常重要
		*pen_32=color;
	}
	
	munmap(fb_base, screen_size);
	
	close(fd_fb);
	return 0;
}