MirOS Manual: XvQueryEncodings(3)

XvQueryEncodings(3X)UNIX Programmer's Manual XvQueryEncodings(3X)


     XvQueryEncodings - return list of encodings for an adaptor


     #include <X11/extensions/Xvlib.h>

     XvQueryEncodings(dpy, port, p_num_encodings,

     register Display *dpy;
     XvPortID port;
     unsigned long *p_num_encodings;
     XvEncodingInfo **pp_encoding_info;


     *dpy           Specifies the display screen on which the Xv
                    Server is to accept requests from Xv clients.
                    If the display option is not specified, Xv
                    uses the display screen specified by your
                    DISPLAY environment variable.  The display
                    option has the format hostname:number.  Using
                    two colons (::) instead of one (:) indicates
                    that DECnet is to be used for transport.

     port           Specifies the port whose adaptor is to be
                    queried for its list of encodings.

                    A pointer to where the number of encodings
                    supported by the adaptor is written.

                    A pointer to where the list of returned
                    encoding information is returned. XvEncodin-
                    gInfo 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 encod-
                    ing when a port's encoding attribute is

     name           A pointer to a formatted string that

XFree86                   Version 4.5.0                         1

XvQueryEncodings(3X)UNIX Programmer's Manual XvQueryEncodings(3X)

                    identifies the encoding.  The string has the
                    format "timing-signaltype".  For example

     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 fractional number.


     XvQueryEncodings(3X) returns encoding information about an
     adaptor.  Each encoding is described by the XvEncodingInfo
     structure described above.  The encodings are identified by
     an encoding-id, which can be used to set or get the encoding
     attribute of a port.

Returned Values

             Returned if XvQueryEncodings(3X) completed success-

             Returned if the Xv extension is unavailable.

             Returned if XvQueryEncodings(3X) failed to allocate
             memory to process the request.


             Generated if the requested port does not exist.

See Also


XFree86                   Version 4.5.0                         2

Generated on 2017-04-03 16:26:17 by $MirOS: src/scripts/roff2htm,v 1.88 2017/01/29 00:51:06 tg Exp $

These manual pages and other documentation are copyrighted by their respective writers; their source is available at our CVSweb, AnonCVS, and other mirrors. The rest is Copyright © 2002–2017 The MirOS Project, Germany.
This product includes material provided by mirabilos.

This manual page’s HTML representation is supposed to be valid XHTML/1.1; if not, please send a bug report — diffs preferred.