Intel 82854 GMCH - Manual (Page 34)

34 Intel® Digital Set Top Box Display Driver
User’s Guide for Microsoft* Windows* CE 5.0
7.1.1.5 ICEGD_ESCAPE_SET_OVL_COLOR_PARAMS
Input Data Structure Output Data Structure Notes
esc_color_params_t N/A
esc_color_params flag options:
Optional:
GAMMA_FLAG (0x1)
BRIGHTNESS_FLAG (0x2)
CONTRAST_FLAG (0x4)
SATURATION_FLAG (0x8)
Mandatory:
OVL_COLOR_FLAG (0x10)
Description
This escape code is used to set overlay attributes (brightness, contrast, saturation, and gamma). Please make sure
that OVL_COLOR_FLAG should always be set. The sample affect only when using overlay.
Input Data Structure Definition
The data structure esc_color_params_t should be filled in with parameters of gamma, brightness, contrast,
saturation and so on. Please refer to icegd_public_escape.h for details.
Example
esc_color_params_t color;
memset(&color, 0, sizeof(esc_color_params_t));
//right now we change only brightness and contrast
color.flag = OVL_COLOR_FLAG | BRIGHTNESS_FLAG | CONTRAST_FLAG;
color.brightness = 0x0;
color.contrast = 0x0;
for(int i=0;i<20;i++){
//change the brightness and contrast gradually
ExtEscape(
Hdc,
ICEGD_ESCAPE_SET_OVL_COLOR_PARAMS,
sizeof(esc_color_params_t),
(LPCSTR)&color,
0,
NULL);
//Check error status returned by ExtEscape
// …
// Wait a while for HW to complete the operation of changing the overlay color
parameters
Sleep(500);
color.brightness+=3000;
color.contrast+=3000;
}