It is currently Mon Nov 19, 2018 8:58 am

 All times are UTC - 7 hours

 Page 1 of 1 [ 3 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: Question concerning the "Overscan" page:Posted: Wed Jul 05, 2017 11:00 am

Joined: Fri Aug 26, 2011 3:20 am
Posts: 43
My question concerns the following line of the section called "For Emulator Developers":

But as a slight optimization, you can scale first (256 * 8/7 = 292) and then pad: stretch the 256x240 pixels to 292x240, 584x480, 876x720, or 1168x960 square pixels or 320x240 or 640x480 non-square pixels.

Isn't it better math to use scaling before correction? For example, say you want to scale to 4x. My formula for that is (256 * 4) * (8/7), which gives 1170 pixels, not 1168. It adds in that extra bit of accuracy in my opinion to scale before correction, not correct before scaling.

Top

 Post subject: Re: Question concerning the "Overscan" page:Posted: Wed Jul 05, 2017 11:27 am

Joined: Sun Sep 19, 2004 11:12 pm
Posts: 20785
Location: NE Indiana, USA (NTSC)
I think I chose the multiples of 292 because 292 is a multiple of 4, making 1168 a multiple of 16.
The difference between the two is 1.1406:1 (292/256) as opposed to 1.1429:1 (true PAR).

Top

 Post subject: Re: Question concerning the "Overscan" page:Posted: Wed Jul 05, 2017 4:56 pm

Joined: Fri Aug 26, 2011 3:20 am
Posts: 43
tepples wrote:
I think I chose the multiples of 292 because 292 is a multiple of 4, making 1168 a multiple of 16.
The difference between the two is 1.1406:1 (292/256) as opposed to 1.1429:1 (true PAR).

I see, so in the case of digital scaling, 1168 makes each pixel integer scaled, though a hair less accurate than scaling before correcting.

On the Framemeister, the horizontal axis is averaged on pixel edges, so 1170 looks just as smooth as any other width.

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 3 posts ]

 All times are UTC - 7 hours

#### Who is online

Users browsing this forum: No registered users and 3 guests

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

Search for:
 Jump to:  Select a forum ------------------ NES / Famicom    NESdev    NESemdev    NES Graphics    NES Music    Homebrew Projects       2018 NESdev Competition       2017 NESdev Competition       2016 NESdev Competition       2014 NESdev Competition       2011 NESdev Competition    Newbie Help Center    NES Hardware and Flash Equipment       Reproduction    NESdev International       FCdev       NESdev China       NESdev Middle East Other    General Stuff    Membler Industries    Other Retro Dev       SNESdev       GBDev    Test Forum Site Issues    phpBB Issues    Web Issues    nesdevWiki