XvQueryPortAttributes (3)

#include <X11/extensions/Xvlib.h>

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

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.

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

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.

[XvBadPort]

Generated if the requested port does not exist.

XvGetPortAttribute(3), XvSetPortAttribute(3)