XSGIvcSetOutputSync(3)
XSGIvcSetOutputSync, XSGIvcQueryOutputSync - Set and query the sync status of a sync port
As shipped in IRIX 6.5.5. Unchanged since IRIX 6.5.
NAME XSGIvcSetOutputSync, XSGIvcQueryOutputSync - Set and query the sync status of a sync port SYNOPSIS #include <X11/extensions/XSGIvc.h> void XSGIvcSetOutputSync(Display *display, int screen, int channel, int syncPortIndex, int syncType) Status XSGIvcQueryOutputSync(Display *display, int screen, int channel, int syncPortIndex, int *syncTypeReturn) PARAMETERS display Specifies the connection to the X server. screen Specifies the screen of the X server. channel Specifies the channel number. syncPortIndex Specifies which sync port. Use one of the following constants for the color components sync outputs: XSGIVC_SPRed, XSGIVC_SPGreen, XSGIVC_SPBlue, and XSGIVC_SPAlpha. For the auxiliary sync ports, use one of the following constants: XSGIVC_SPAux0, XSGIVC_SPAux1, and XSGIVC_SPAux2. Alternatively, for the auxiliary sync ports, you may use one of the constants defined in an include file that may be supplied that is specific to your hardware. Not all sync ports have uniform characteristics; use the function XSGIvcQueryChannelInfo to determine characteristics for each sync port. syncType The sync type to enable on this port. Specify one of the values in the set XSGIVC_SF... DESCRIPTION Terminology The synchronization signal (or sync signal) is a series of pulses that communicate raster geometry to a display device. The horizontal sync (or H-sync) pulse typically indicates the termination of one scan line and the start of another, visually lower, line. The vertical sync (or V-sync) pulse typically indicates the display device should reset its downward drawing of lines and start the next horizontal line at the top of the screen. When horizontal and vertical sync are combined in the same signal, the result is called composite sync (sometimes referred to as H + V-sync). A synchronization pulse is a variation from one level to another. The output voltage can be generated at different voltages: nominal video level or TTL levels. In some video formats (e.g., some HDTV formats) a third level of excursion is required during some sync pulse sequences; this third level is employed in tri-level sync. Server Configurations These functions deal with the synchronization signal's presence on one of the channel's sync output ports. Different servers may have different hardware available for sync output: some ports may be separate connectors (auxiliary sync outputs) on which sync is delivered; the red, green, and blue color component signals may contain sync; some servers provide an alpha channel output connector, and sync may also be available on that port. Sync output may be unique to a channel - and servers may not provide sync outputs uniformly, so each channel's ports must be considered separately. Sync is available in different forms, depending on server hardware. Servers may permit a specific port to generate none, one or both of horizontal and vertical sync; capabilities of the ports may not be uniform among channels, or even among ports for a single channel. Especially for sync on the color components, a server may support independent adjustment of each component's sync, or may support only a global change such that sync is enabled or disabled for all color components simultaneously. Refer to hardware documentation for information on server support. Applications written for use on more than one type of hardware should query all color component values after setting one to determine whether the sync change was independently adjusted. The entire set of all sync ports and sync types available for that port may be determined from the structure returned from the function XSGIvcQueryChannelInfo. Functions XSGIvcSetOutputSync() enables and disables sync on one of the sync output ports. XSGIvcQueryOutputSync() returns the current settings for sync on one of the output ports. Interaction With Screen Saver Programs Some screen savers may use these functions to alter sync output to trigger power-saving measures on monitors which have the capability to run with reduced power during periods of inactivity. Alteration of output sync may interfere with normal operation of these screen savers and monitors. EVENTS When this control is altered, the server generates a OutputSyncNotify event. RETURNED VALUE XSGIvcQueryOutputSync returns TRUE if successful, FALSE upon failure. Specification of non-existent port number returns FALSE. Other errors are reported via standard X protocol error mechanism. Parameter errors are reported via BadValue or BadMatch. STRUCTURES /* Special sync port IDs */ #define XSGIVC_SPRed -1 #define XSGIVC_SPGreen -2 #define XSGIVC_SPBlue -3 #define XSGIVC_SPAlpha -4 #define XSGIVC_SPAux0 0 #define XSGIVC_SPAux1 1 #define XSGIVC_SPAux2 2 /* See syncType in XSGIvcSyncInfo */ #define XSGIVC_SFNone 0 /* No sync */ #define XSGIVC_SFHorizontalVideo 1 /* Horizontal sync, video level */ #define XSGIVC_SFVerticalVideo 2 /* Vertical sync, video level */ #define XSGIVC_SFCompositeVideo 3 /* Composite sync, video level */ #define XSGIVC_SFHorizontalTTL 4 /* Horizontal sync, TTL level */ #define XSGIVC_SFVerticalTTL 5 /* Vertical sync, TTL level */ #define XSGIVC_SFCompositeTTL 6 /* Composite sync, TTL level */ #define XSGIVC_SFHorizontalTriLevel 7 /* Horizontal sync, tri-level */ #define XSGIVC_SFVerticalTriLevel 8 /* Vertical sync, tri-level */ #define XSGIVC_SFCompositeTriLevel 9 /* Composite sync, tri-level */ SEE ALSO XSGIvc, XSGIvcQueryChannelInfo