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CentOS 7.0 - man page for xvlistimageformats (centos section 3)

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 format 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 completely defined by
       the  parameters above, the guid, when available, should provide the most accurate descrip-
       tion of the format.

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

SEE ALSO
       XvCreateImage(3), XvCreateShmImage(3)

X Version 11				   libXv 1.0.9			    XvListImageFormats(3)


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