Welcome! Log In Create A New Profile

Advanced

Video rendering question for developers of GX emulators

Posted by TheManuel 
Re: Video rendering question for developers of GX emulators
December 09, 2008 10:20AM
Quote

Can you recommend any SNES game, that shows the "scanline" effect?.
Note: I live in PAL-territories.

this is not a matter of games, as I said, it depends mostly on the TV and connections,.. sometime, active lines blends with blank lines so the later becoms less visible, but there are here (generally more visible with RGB, composite tends to blend colors more).

some screenshots: [www.disgruntleddesigner.com]


Quote

If I understand you right, wouldn't the active lines be output twice?

I'm not sure to understand what you mean by "twice"...
the vertical sync is a 60hz signal so the 240 actives lines are refreshed at 60hz... the video processor will also refreshed the pixel data of these lines at 60hz so technically, this is not the same line that is output on both fields...
more over, fields are a concept related to interlaced video only, the TV itself does not know anything about "fields", it just scans an input video signal at a constant horizontal rate...

Quote

Can you tell me more about that? How did you do it?
reading the datasheet and manual of the original video processor unit (TMS9918, also used in Master System and MSX), it gives pretty all informations about video timings, number of lines, etc
studying visually the RGB output of my Mega Drive in 50hz and 60hz mode and comparing with the gamecube/wii 480i RGB output
tech talking with other sega genesis emulator authors and people who are into retro-console hacking/modding, see [www.gamesx.com] for example
Re: Video rendering question for developers of GX emulators
December 09, 2008 10:57AM
Quote

this is not a matter of games, as I said, it depends mostly on the TV and connections,..

I understand that. Let me rephrase my question: Does Super Mario Wolrd use the 240p mode?
A friend of mine has an rather old TV, and I do not want to end up using a game that did not feature the mode.

Quote

I'm not sure to understand what you mean by "twice"...
Abusing the timing of the video signal to hit every line two times (in 1/25 second), instead of once.

Quote

reading the datasheet and manual of the original video processor unit (TMS9918, also used in Master System and MSX), it gives pretty all informations about video timings, number of lines, etc

Thanks, I will google for it.


And thanks for not giving up on me. I was shown something new. So I hope you do not see this discussiion as a waste of time.

(p.s.: did you name yourself after the "berries" from landstalker?)



Edited 3 time(s). Last edit at 12/09/2008 10:59AM by daniel_c_w.
Re: Video rendering question for developers of GX emulators
December 09, 2008 02:57PM
Quote

I understand that. Let me rephrase my question: Does Super Mario Wolrd use the 240p mode?
yes, most games used non-interlaced modes
only a few used the 256x448 and 512x448 (hi-res) interlaced modes, and probably not in a continuous way

Quote

Abusing the timing of the video signal to hit every line two times (in 1/25 second), instead of once.
you do not abuse anything, this is standard: analog TVs are able to scan a signal at approx. 15khz horizontally (HSYNC) and handle a vertical refresh rate of 60hz or 50hz for PAL (VSYNC).


Quote

(p.s.: did you name yourself after the "berries" from landstalker?)
yes, I have to admit it's pretty lame :-)
but the first time I connected to web forums, I was a lot younger and an extreme fan of that game ;-)
Re: Video rendering question for developers of GX emulators
December 09, 2008 03:53PM
Quote
ekeeke
yes, I have to admit it's pretty lame :-)
but the first time I connected to web forums, I was a lot younger and an extreme fan of that game ;-)

It's not lame. Nigel (or Niels) would have been a lame name :)
I still like the game, bought the VC version (unfortunately Nintendo/Sega/Climax did not release the German version. Perhaps Factor 5 did not agree or wanted too much money)
and I still have the original (the first edition came with a players guide)
Re: Video rendering question for developers of GX emulators
December 10, 2008 03:54AM
Quote
Tantric
Just to add to this, the incompatibility I've experience with my HDTV is it outputs all 240p lines without the spacing in between - so it looks "scrunched" in the top half of the screen.

So, would you consider adding it, even if as a further sub-layer of the video options just for us poor souls still using CRT HDTV's and for everyone else that has gotten this mode to work?

Thanks.
Sorry, only registered users may post in this forum.

Click here to login