Table of Contents
XvQueryAdaptors - return adaptor information for a screen
#include
<X11/extensions/Xvlib.h>
int XvQueryAdaptors(Display *dpy, Window window,
unsigned int *p_num_adaptors,
XvAdaptorInfo **pp_adaptor_info);
- dpy
- Specifies the connection to the X server.
- window
- Specifies a
window of the screen for which the adaptor information is desired.
- p_num_adaptors
- A
pointer to where the number of adaptors for the specified screen is returned.
- pp_adaptor_info
- A pointer to where the list of returned adaptor information
is returned.
XvQueryAdaptors(3)
returns an video adaptor information
for
the screen of the specified drawable. The XvAdaptorInfo structure has
the following organization:
typedef struct {
XvPortID base_id;
unsigned long num_ports;
char type;
char *name;
unsigned long num_formats;
XvFormat *formats;
unsigned long num_adaptors;
} XvAdaptorInfo;
- base_id
- The resource ID of the first adaptor port.
- num_ports
- The number
of ports supported by the adaptor.
- type
- A bit mask with the value XvInputMask
asserted if the adaptor supports video input, and value XvOutputMask asserted
if the adaptor supports video output. In Xv protocol 2.2 and later, there
are 3 new bits defined - XvVideoMask, XvStillMask and XvImageMask indicating
that the adaptor is capable of video, still or image primitives respectively.
- name
- A vendor specific name that identifies the adaptor.
- num_formats
- The number
of depth/visual id formats supported by the adaptor.
- formats
- A pointer to
an array of XvFormat structures.
The XvFormat structure has the following
organization:
typedef struct {
char depth;
unsigned long visual_id;
} XvFormat;
- depth
- A drawable depth supported by the adaptor.
- visual_id
- A visual-id supported
for the given depth by the adaptor.
- [Success]
- Returned if XvQueryAdaptors(3)
completed successfully.
- [XvBadExtension]
- Returned if the Xv extension is
unavailable.
- [XvBadAlloc]
- Returned if XvQueryAdaptors(3)
failed to allocate
memory to process the request.
- [Drawable]
- Returned if the requested
drawable does not exist.
XvFreeAdaptorInfo(3)