XvQueryPortAttributes

Section: libXv Functions (3)
Updated: libXv 1.0.5
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NAME

XvQueryPortAttributes - return list of attributes of a video port

SYNOPSIS

#include <X11/extensions/Xvlib.h>

XvAttribute* XvQueryPortAttributes(Display *dpy,
                 XvPortID port,  int *p_num_attributes);

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_attributes: A pointer to where the number of attributes returned in the array is written.

DESCRIPTION

XvQueryPortAttributes(3)returnsthenumberofattributes and an array of XvAttributes valid for the given port. The array may be freed with XFree(3).

RETURN VALUES

XvAttribute has the following structure:

    typedef struct {
      int flags;
      int min_value;
      int max_value;
      char *name;
    } XvAttribute;

flags: May be XvGettable or XvSettable or both OR'd together indicating the particular attribute is readable, writeable or readable and writeable.
min_value: The minimum attribute values which are valid for the driver.
: The maximum attribute values which are valid for the driver.
name: A string describing the name of the attribute that may be used to retrieve the Atom for the particular attribute.

DIAGNOSTICS

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