XvListImageFormats(3) libXv Functions XvListImageFormats(3)NAMEXvListImageFormats - 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.
DESCRIPTIONXvListImageFormats(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 MSB‐
First.
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 rep‐
resents 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 ALSOXvCreateImage(3), XvCreateShmImage(3)X Version 11 libXv 1.0.10 XvListImageFormats(3)
