yeah, after reading through xwd's multiVis.c, it looks like ReadAreaToImage 
eventually does:

for (y1 = 0; y1 < srcRect_height; y1++) {
  for (x1 = 0; x1 < srcRect_width; x1++) {
    int pixel_value = XGetPixel(image, x1, y1);
    if (pixel_value & transparentColor) {
      pixel = XGetPixel(ximage_ipm,dst_x+x1,dst_y+y1) ;
      XPutPixel(ximage,dst_x+x1, dst_y+y1,pixel);

I'm not that good with this side of X11 ... Keith, is my analysis at least in 
the right direction?  I don't understand why xwd is going pixel by pixel ...

Is multiVis.c only related to xwd or to the complete X.Org-Server? I'm asking this because if I'm capturing a video with ffmpeg/avconv with the option x11grab I'm seeing this tearing heavily in the captured video too.

This issue still appears on the X.Org-Server 1.15.1.

Edit: Forgot to say that I'm also on x11-apps 7.7+2 in case it is not a direct issue with the X.Org-Server as assumed above. If this is really the case maybe xwd should just dump the image directly from the memory if Xlib provides such a function.

(In reply to sworddragon2 from comment #2)
> Is multiVis.c only related to xwd or to the complete X.Org-Server?

Only to xwd.

(In reply to sworddragon2 from comment #4)
> If this is really the case maybe xwd should just dump the image directly from
> the memory if Xlib provides such a function.

xwd doesn't have direct access to the memory with the screen image in - that's
in the X server (and often in the VRAM, not normal RAM), not in the X client.

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/xorg/app/xwd/issues/1.