This is a simple script useful to calculate the right timings dots (pixels), lines and the timings for each of the required parameters to drive a mcu or FPGa with accurate timing.
No interlaced calculations are included right now on the script.
This script was done as example in a livestream so little time was spent, you can improve it all you want, it's free.
Sometimes we need to create perfect resolutions for a console an arcade board, etc.. that's when this script is handy. It will calculate the timings for the interrupts, timers, counters and all the values required to generate the right sync.
This script is explained during an event here: Twitch https://www.twitch.tv/kabukiflux
The analog TV uses the sync pulses to generate the raster, the raster is the visible dots and lines on the screen. Once the visible part is drawn on the screen it needs the blanking times to retrace the dot into the new position.
The Sync pulses are required to indicate the end of a line and the end of a frame to retrace the dot. The Sync is Horizontal for the lines and Vertical for the frames.
The blanking time has more than the sync itself, it has the Front Porch (time after the video ended and the sync begins) and the Back Porch (time after the sync ends and the video begins).
The modeline is a direct representation of the resolution used on some devices to be shown on screen. It contains all the data required for the raster zone and the timings required for the blanking and sync.
The modelines are like this:
Modeline "320x240 NTSC (60Hz)" 6.700 320 336 367 426 240 244 247 262 -hsync -vsync
Modeline "384x240 NTSC (60Hz)" 8.040 384 403 440 511 240 244 247 262 -hsync -vsync
modeline "496x384" 15,4752 496 508 570 620 384 386 391 416 -hsync -vsync
modeline '512x384' 14,75 512 520 568 600 384 388 391 410 -hsync -vsync
Modeline "512x384_60,0Hz 25,0KHz" 15.575 512 520 582 624 384 385 390 416 -hsync -vsync
ModeLine "640x480" 25.20 640 656 752 800 480 490 492 525 -HSync -VSync
ModeLine "640x480" 25.18 640 656 752 800 480 490 492 525 -HSync -VSync
ModeLine "640x480" 25.17 640 656 752 800 480 490 492 525 -HSync -VSync
This image shows a representation of the modeline converted into the analog parameters, the modeline structure is usually:
Modeline syntax: pixelclock hres hsyncstart hsyncend htotal vres vsyncstart vsyncend vtotal [flags]
Flags (optional): +HSync, -HSync, +VSync, -VSync, Interlace, DoubleScan, CSync, +CSync, -CSync
You need to have Python installed, nothing more.
Easy, execute
modelinecalculator.py
when prompted paste a modeline.
And yes, read below, no responsability taken on bad use.
Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.
The software is provided "as is" and the author disclaims all warranties with regard to this software including all implied warranties of merchantability and fitness. In no event shall the author be liable for any special, direct, indirect, or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software.