如何获取缓冲区获取缓冲屏幕设备android

Question

我有一个功能获取缓冲屏幕设备android

struct fb_var_screeninfo scrinfo;
struct fb_fix_screeninfo fscrinfo;
int initFB(void)
{  
  L("--Initializing framebuffer access method--n");
  fbmmap = MAP_FAILED;
  if ((fbfd = open("/dev/graphics/fb0", O_RDWR)) == -1) { 
    L("Cannot open fb device %sn", framebuffer_device);
    sendMsgToGui("~SHOW|Cannot open fb device, please try out other display grab methodn");
    return -1;
  }
  update_fb_info();

  if (ioctl(fbfd, FBIOGET_FSCREENINFO, &fscrinfo) != 0) {
    L("ioctl errorn");
    return -1;
  }
  L("line_lenght=%d xres=%d, yres=%d, xresv=%d, yresv=%d, xoffs=%d, yoffs=%d, bpp=%dn",
    (int)fscrinfo.line_length,(int)scrinfo.xres, (int)scrinfo.yres,
    (int)scrinfo.xres_virtual, (int)scrinfo.yres_virtual,
    (int)scrinfo.xoffset, (int)scrinfo.yoffset,
    (int)scrinfo.bits_per_pixel);
  size_t size = scrinfo.yres_virtual;
  if (size < scrinfo.yres * 2) {
    L("Using Droid workaroundn");
    size = scrinfo.yres * 2;
  }
  if ((scrinfo.bits_per_pixel == 24)) {
    scrinfo.bits_per_pixel = 32;
    L("24-bit XRGB display detectedn");
  }
  size_t fbSize = roundUpToPageSize(fscrinfo.line_length * size);
  fbmmap = mmap(NULL, fbSize , PROT_READ|PROT_WRITE ,  MAP_SHARED , fbfd, 0);
  if (fbmmap == MAP_FAILED) { 
    L("mmap failedn");
    sendMsgToGui("~SHOW|Framebuffer mmap failed, please try out other display grab methodn");
    return -1;
  }
  return 1;
}

它在xperia u上运行良好，但在nexus 10和三星galaxy tab 3上返回黑屏。能帮我找到比它更好的缓冲屏幕吗？

感谢

Answer 1

我会使用screencap:

adb shell screencap –p /data/screen.png
adb pull /data/screen.png

它会返回屏幕当前显示的任何内容的PNG图像。screencap是安卓系统的一个内置实用程序。