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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 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 description of the format.

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

SEE ALSO
       XvCreateImage(3), XvCreateShmImage(3)

X Version 11                     libXv 1.0.12            XvListImageFormats(3)