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XvListImageFormats(3)		 libXv Functions	   XvListImageFormats(3)

NAME
     XvListImageFormats - return list of image formats supported by a video port

SYNTAX
     #include <X11/extensions/Xvlib.h>

     XvImageFormatValues * XvListImageFormats (Display *dpy,
		      XvPortID port,  int *p_num_formats);

ARGUMENTS
     dpy     Specifies the connection to the X server.

     port    Specifies	the  port whose adaptor is to be queried for its list of
	     attributes.

     p_num_formats
	     A pointer to where the number of formats returned in the  array  is
	     written.

DESCRIPTION
     XvListImageFormats(3)  returns  the  XvImageFormatValues  supported  by the
     specified port. This list should be freed with XFree(3).

RETURN VALUES
     XvImageFormatValues has the following structure:

	 typedef struct {
	   int id;			/* Unique descriptor for the format */
	   int type;			/* XvRGB, XvYUV */
	   int byte_order;		/* LSBFirst, MSBFirst */
	   char guid[16];		/* Globally Unique IDentifier */
	   int bits_per_pixel;
	   int format;			/* XvPacked, XvPlanar */
	   int num_planes;

	   /* for RGB formats */
	   int depth;
	   unsigned int red_mask;
	   unsigned int green_mask;
	   unsigned int blue_mask;

	   /* for YUV formats */
	   unsigned int y_sample_bits;
	   unsigned int u_sample_bits;
	   unsigned int v_sample_bits;
	   unsigned int horz_y_period;
	   unsigned int horz_u_period;
	   unsigned int horz_v_period;
	   unsigned int vert_y_period;
	   unsigned int vert_u_period;
	   unsigned int vert_v_period;
	   char component_order[32];	/* eg. UYVY */
	   int scanline_order;		/* XvTopToBottom, XvBottomToTop */
	 } XvImageFormatValues;

     id      A unique descriptor for the format.  This is often the  FOURCC  for
	     the  format, when applicable.  This id is used to describe the for-
	     mat during XvImage creation.

     type    XvRGB or XvYUV.

     byte_order
	     The byte order of the image.  It is either LSBFirst or MSBFirst.

     guid    The Globally Unique IDentifier (also known  as  Universally  Unique
	     IDentifier).  When not applicable, all characters are NULL.

     bits_per_pixel
	     The  bits	taken up (but not necessarily used) by each pixel.  Note
	     that for some planar formats which have fractional bits  per  pixel
	     (such as IF09) this number may be rounded _down_.

     format  XvPacked or XvPlanar.

     num_planes
	     The number of planes in planar formats.

     depth   Significant bits per pixel.

     red_mask, green_mask, blue_mask
	     The red, green and blue bitmasks (RGB formats only).

     ?_sample_bits
	     The size of each sample in bits (YUV formats only).

     horz_?_period, vert_?_period
	     The period (in pixels) on which samples occur in the horizontal and
	     vertical directions (YUV formats only).

     component_order
	     Upper case ascii characters representing the order that samples are
	     stored  within  packed formats.  For planar formats this represents
	     the ordering of the planes.

     scanline_order
	     XvTopToBottom or XvBottomToTop.

NOTES
     Since some formats (particularly some planar YUV formats) may not	be  com-
     pletely  defined  by the parameters above, the guid, when available, should
     provide the most accurate description of the format.

DIAGNOSTICS
     [XvBadPort]
	     Generated if the requested port does not exist.

SEE ALSO
     XvCreateImage(3), XvCreateShmImage(3)

X Version 11			  libXv 1.0.13		   XvListImageFormats(3)

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