Ну, Gnome это отдельная тема, у них там "стандартные" (без префикса z) gtk_text_input_manager и gtk_shell1.

mpv почему-то на отсутствие аналогичных и "более стандартных" механизмов не жалуется:

static int xss_suspend(Display *mDisplay, Bool suspend)
{
    int event, error, major, minor;
    if (XScreenSaverQueryExtension(mDisplay, &event, &error) != True ||
        XScreenSaverQueryVersion(mDisplay, &major, &minor) != True)
        return 0;
    if (major < 1 || (major == 1 && minor < 1))
        return 0;
    XScreenSaverSuspend(mDisplay, suspend);
    return 1;
}
static void set_screensaver(struct vo_x11_state *x11, bool enabled)
{
    Display *mDisplay = x11->display;
    if (!mDisplay || x11->screensaver_enabled == enabled)
        return;
    MP_VERBOSE(x11, "%s screensaver.\n", enabled ? "Enabling" : "Disabling");
    x11->screensaver_enabled = enabled;
    if (xss_suspend(mDisplay, !enabled))
        return;
    int nothing;
    if (DPMSQueryExtension(mDisplay, ¬hing, ¬hing)) {
        BOOL onoff = 0;
        CARD16 state;
        DPMSInfo(mDisplay, &state, &onoff);
        if (!x11->dpms_touched && enabled)
            return; // enable DPMS only we we disabled it before
        if (enabled != !!onoff) {
            MP_VERBOSE(x11, "Setting DMPS: %s.\n", enabled ? "on" : "off");
            if (enabled) {
                DPMSEnable(mDisplay);
            } else {
                DPMSDisable(mDisplay);
                x11->dpms_touched = true;
            }
            DPMSInfo(mDisplay, &state, &onoff);
            if (enabled != !!onoff)
                MP_WARN(x11, "DPMS state could not be set.\n");
        }
    }
}