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XvQueryEncodings(3) libXv Functions XvQueryEncodings(3)
NAME
XvQueryEncodings - return list of encodings for an adaptor
SYNOPSIS
#include <X11/extensions/Xvlib.h>
int XvQueryEncodings(Display *dpy, XvPortID port,
unsigned int *p_num_encodings,
XvEncodingInfo **pp_encoding_info);
ARGUMENTS
dpy Specifies the connection to the X server.
port Specifies the port whose adaptor is to be queried for its list
of encodings.
p_num_encodings
A pointer to where the number of encodings supported by the
adaptor is written.
pp_encoding_info
A pointer to where the list of returned encoding information is
returned. XvEncodingInfo has the following structure:
typedef struct {
XvEncodingID encoding_id;
char *name;
unsigned long width;
unsigned long height;
XvRational rate;
unsigned long num_encodings;
} XvEncodingInfo;
encoding_id
Specifies the encoding-id of the encoding. The encoding-id is
used to identify an encoding when a port's encoding attribute
is changed.
name A pointer to a formatted string that identifies the encoding.
The string has the format "timing-signaltype". For example
"ntsc-composite".
width,height
The width and height, in pixels, of the decoded video image.
rate The field rate of the decoded video.
The XvRational structure is used to specify a fractional number. It
has the following structure:
typedef struct {
int numerator;
int denominator;
} XvRational;
The numerator and denominator fields specify the appropriate parts of a
RETURN VALUES
[Success]
Returned if XvQueryEncodings(3) completed successfully.
[XvBadExtension]
Returned if the Xv extension is unavailable.
[XvBadAlloc]
Returned if XvQueryEncodings(3) failed to allocate memory to
process the request.
DIAGNOSTICS
[XvBadPort]
Generated if the requested port does not exist.
SEE ALSO
XvFreeEncodingInfo(3)
X Version 11 libXv 1.0.12 XvQueryEncodings(3)