Configurating Video Mode

Description

Structures and functions for configuring video modes.

The sVgaCfg structure contains the required properties of the video mode: the display resolution, the minimum processor frequency and the timing of the sVideo signal, possibly also the required overlay mode. You can first call the VgaCfgDef() function, which presets the structure to the default parameters. The VgaCfg() function prepares the sVmode descriptor structure, which is later passed to the VgaInitReq() function. At this point no operations are taking place only the necessary settings are being calculated. After the calculation, some items of the sVmode structure can be adjusted. In the library there are global structures Cfg and Vmode that can be used for the function. The required screen resolution and signal timing are two independent properties. For timing, you are limited only by the number of video lines of the image, but otherwise you can set any screen resolution within them. For example, for PAL and NTSC video, you can set a VGA video resolution. To make the program versatile so that it can be run on both a VGA monitor and a TV, use a VGA resolution of 640x480 or 320x240 (or 512x400 and 256x192, due to RAM limitations). When changing the display, just select VGA/PAL or NTSC timing, the resolution does not change for the program.

Data Structures
struct	sVideo
	Video timings structure. More...
struct	sVgaCfg
	Required configuration to initialize VGA output. More...
struct	sVmode
	Videomode table - used to setup video driver. More...

Macros
#define	VIDEO_NAME_LEN   5
	length of video timing name

Enumerations
enum	{ DEV_PAL = 0, DEV_NTSC, DEV_VGA, DEV_MAX }
	Output device. More...
enum	{   RES_ZX = 0, RES_CGA, RES_QVGA, RES_EGA,   RES_VGA, RES_SVGA, RES_XGA, RES_HD,   RES_MAX }
	Preset videomode resolution. More...
enum	{   FORM_8BIT = 0, FORM_4BIT, FORM_MONO, FORM_TILE8,   FORM_TILE12, FORM_TILE16, FORM_TILE24, FORM_TILE32,   FORM_TILE48, FORM_TILE64, FORM_MTEXT8, FORM_MTEXT16,   FORM_TEXT8, FORM_TEXT16, FORM_RLE, FORM_MAX }
	Graphics formats. More...

Functions
void	VgaCfgDef (sVgaCfg *cfg)
	Initialize configuration structure to VGA defaults. More...
void	VgaPrintCfg (const sVmode *vmode)
	Debug print videomode setup. More...
void	VgaCfg (const sVgaCfg *cfg, sVmode *vmode)
	Calculate the structure for setting up the video mode. More...

Variables
const sVideo	VideoPAL
	TV PAL interlaced 5:4 720x576 (4:3 768x576, 16:9 1024x576)
const sVideo	VideoPALp
	TV PAL progressive 5:4 360x288 (4:3 384x288, 16:9 512x288)
const sVideo	VideoNTSC
	TV NTSC interlaced 4:3 640x480 (5:4 600x480, 16:9 848x480)
const sVideo	VideoNTSCp
	TV NTSC progressive 4:3 320x240 (5:4 300x240, 16:9 424x240)
const sVideo	VideoEGA
	EGA 8:5 640x400 (5:4 500x400, 4:3 528x400, 16:9 704x400), vert. 70 Hz, hor. 31.4685 kHz, pixel clock 25.175 MHz.
const sVideo	VideoVGA
	VGA 4:3 640x480 (16:9 848x480), vert. 60 Hz, hor. 31.4685 kHz, pixel clock 25.175 MHz.
const sVideo	VideoSVGA
	SVGA 4:3 800x600 (16:9 1064x600), vert. 60 Hz, hor. 37.897 kHz, pixel clock 40 MHz.
const sVideo	VideoXGA
	XGA 4:3 1024x768 (16:9 1360x768), vert. 60 Hz, hor. 48.36310 kHz, pixel clock 65 MHz.
const sVideo	VideoVESA
	VESA 4:3 1152x864, vert. 60 Hz, hor. 53.697 kHz, pixel clock 81.62 MHz.
const sVideo	VideoHD
	HD 4:3 1280x960, vert. 53 Hz, hor. 51.858 kHz, pixel clock 102.1 MHz.
sVmode	Vmode
	Videomode setup.
sVgaCfg	Cfg
	Required configuration.
sCanvas	Canvas
	Canvas of draw box.
u16	Pal16Trans [256]
	16-color palette translation table

Enumeration Type Documentation

anonymous enum

anonymous enum

Output device.

Enumerator
DEV_PAL	PAL TV.
DEV_NTSC	NTSC TV.
DEV_VGA	VGA monitor.

anonymous enum

anonymous enum

Preset videomode resolution.

Enumerator
RES_ZX	256x192
RES_CGA	320x200
RES_QVGA	320x240
RES_EGA	512x400
RES_VGA	640x480
RES_SVGA	800x600 (not for TV device)
RES_XGA	1024x768 (not for TV device)
RES_HD	1280x960 (not for TV device)

anonymous enum

anonymous enum

Graphics formats.

Enumerator
FORM_8BIT	8-bit pixel graphics (up to EGA resolution)
FORM_4BIT	4-bit pixel graphics (up to SVGA graphics)
FORM_MONO	1-bit pixel graphics
FORM_TILE8	8x8 tiles
FORM_TILE12	12x12 tiles
FORM_TILE16	16x16 tiles
FORM_TILE24	24x24 tiles
FORM_TILE32	32x32 tiles
FORM_TILE48	48x48 tiles
FORM_TILE64	64x64 tiles
FORM_MTEXT8	mono text with font 8x8
FORM_MTEXT16	mono text with font 8x16
FORM_TEXT8	attribute text with font 8x8
FORM_TEXT16	attribute text with font 8x16
FORM_RLE	images with RLE compression (on overlapped layer 1)

Function Documentation

VgaCfgDef()

void VgaCfgDef

(

sVgaCfg *

cfg

)

Initialize configuration structure to VGA defaults.

The function presets the structure to the default parameters: 640x480 resolution, VGA display, processor frequency 120 to 270 MHz.

Parameters

cfg	Configuration to modify

VgaPrintCfg()

void VgaPrintCfg

(

const sVmode *

vmode

)

Debug print videomode setup.

Parameters

vmode

Video mode table

VgaCfg()

void VgaCfg	(	const sVgaCfg *	cfg,
		sVmode *	vmode
	)

Calculate the structure for setting up the video mode.

Parameters

cfg	Source configuration structure
vmode	Destination videomode setup for driver

See also

VgaInitReq()