XvGetStill - capture a single frame of video from a drawable
#include <X11/extensions/Xvlib.h>
int XvGetStill(Display *dpy, XvPortID port, Drawable d, GC gc,
               int vx, int vy, unsigned int vw, unsigned int vh,
               int dx, int dy, unsigned int dw, unsigned int dh);
  - dpy
- Specifies the connection to the X server.
- port
- Defines the port to which the still is output.
- d
- Defines the drawable from which the still is to be captured. Pixmaps are
      currently not supported.
- gc
- Defines the graphical context. GC components are: subwindow-mode,
      clip-x-origin, clip-y-origin, and clip-mask.
- vx,vy,vw,vh
- Define the location and size of the destination video region into which
      the still is to be written. vx and vy define the xand
      y coordinates of the upper-left corner of the video region;
      vwand vh define the width and height, in pixels, of the
      video region.
- dx,dy,dw,dh
- Define the location and size of the source drawable from which the still
      image is to be captured. dxand dy define the xand
      y coordinates of the upper-left corner of the drawable region;
      dwand dh define the width and height, in pixels, of the
      drawable region.
captures a single frame of video from a drawable. The position and size of the
  destination (video) rectangle is specified by vx, vy, vw,
  and vh. The position and size of the source (drawable) rectangle is
  specified by dx, dy, dw, and dh.Drawable data is clipped to the bounds of the drawable, scaled to
    the requested video region size (or the closest size supported) and clipped
    to the bounds of the video encoding. The contents of any region not updated
    with drawable data is undefined.
If the port is grabbed by another client, this request is ignored,
    and an XvVideoNotify event with detail XvBusy is generated for the
  drawable.
  - [Success]
- Returned if XvGetStill(3) completed successfully.
- [XvBadExtension]
- Returned if the Xv extension is unavailable.
- [XvBadAlloc]
- Returned if XvGetStill(3) failed to allocate memory to process the
      request.
  - [XvBadPort]
- Generated if the requested port does not exist.
- [BadDrawable]
- Generated if the requested drawable does not exist.
- [BadGC]
- Generated if the requested graphics context does not exist.
- [BadAlloc]
- Generated if there were insufficient resources to process the
    request.
XvPutStill(3), XvGetVideo(3), XvPutVideo(3),
  XvVideoNotify(3)