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DS development > Homebrew Screen capture?

#68941 - Mrshlee - Fri Jan 27, 2006 2:42 pm

Whats the easiest way to capture homebrew screen shots?
I've failed at trying to emulator homebrew - My digicam is pretty good but whats the change of someone creating a Screen capture hotkey in there homebrew demos?

press L+R = screencapture BMP to CF card or something.

Whats the chances.. I've started a DS homebrew news RSS Link and i'm after clearer screen grabs.

#68957 - CubeGuy - Fri Jan 27, 2006 4:46 pm

It should be possible to use the new WiFi link to send it to your PC. Anyone up for figureing it out? It would have to be incorporated into the program you want to use it on.
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#68987 - The 9th Sage - Fri Jan 27, 2006 8:15 pm

Mrshlee wrote:

Whats the chances.. I've started a DS homebrew news RSS Link and i'm after clearer screen grabs.


Thanks for that...I was looking for a decent site like this with an RSS feed.
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#68992 - HyperHacker - Fri Jan 27, 2006 8:37 pm

Taking the screenshot should be simple enough, just copy the data out of VRAM. Implementing it into homebrew would require editing the source, though. Or if you can't/don't want to, and know a bit about reverse engineering... most homebrew apps use libnds, and many only use the vblank interrupt. A loader could probably find the code bits in the program that set up interrupt handlers, and tweak them to add its own code. One way might be to note the address it would set the vblank handler to, and instead set it to your own code and have that code call the original address, then your code can do whatever it needs there. (If it causes the program to run out of vblank time, you can do something else like set a timer interrupt, and then un-hook the vblank interrupt. Most homebrew only sets interrupt handlers once. Or just use another interrupt, set it before loading, and tweak the init code to not disable it.)

Hacking another app, especially one that already uses wifi, to send the image back to your PC would be more difficult (I'd instead suggest dumping to the flash card). Making your own program (or one whose source you have) do it, however, shouldn't be too hard, though I haven't used wifi yet so I'm not sure what it's like.

#69018 - FluBBa - Sat Jan 28, 2006 12:08 am

Yepp, emulating scaling/rotating sprites/backgrounds, why not spend the time to update one of the open source emulators right away?
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#69023 - arog - Sat Jan 28, 2006 12:54 am

Quote:
Thanks for that...I was looking for a decent site like this with an RSS feed.


What's wrong with http://www.drunkencoders.com/? I have to say it's one of the most up-to-date homebrew sites out there, and I should know!

- Aaron Rogers
http://www.aaronrogers.com/nintendods/

#69031 - Mrshlee - Sat Jan 28, 2006 1:50 am

arog wrote:
Quote:
Thanks for that...I was looking for a decent site like this with an RSS feed.


What's wrong with http://www.drunkencoders.com/? I have to say it's one of the most up-to-date homebrew sites out there, and I should know!

- Aaron Rogers
http://www.aaronrogers.com/nintendods/


Hey arog - I'm a fan of Drunken coders.. Nothing wrong with a secondary news source :) Imagine only watching FOX news.

I have alot to offer the community - News is just one part.

#69069 - arog - Sat Jan 28, 2006 8:51 am

Quote:
Nothing wrong with a secondary news source :)


I believe you mean yet another news source.

http://nintendo-ds.dcemu.co.uk/
http://dsdev.org/
http://www.ndshb.com/
http://ndsupdates.com/
http://www.maxconsole.net/?mode=news&feed=nds
http://pdroms.de/index.php

But honestly, I agree, competition is always good. Let's just hope you stand up to the challenge better than some of the other sites that have come and gone.

Oh, and thanks for the comparison to FOX news.

- Aaron Rogers
http://www.aaronrogers.com/nintendods/

#69074 - Mrshlee - Sat Jan 28, 2006 9:26 am

arog wrote:
Quote:
Nothing wrong with a secondary news source :)


Oh, and thanks for the comparison to FOX news.

- Aaron Rogers


I'm from Australia - So I wasn't sure if that was a complement or not :)

#69089 - HyperHacker - Sat Jan 28, 2006 12:10 pm

I can't speak for him but I'd be rather insulted. I imagine that's not what you were going for.

#69121 - tepples - Sat Jan 28, 2006 4:17 pm

Explanation for those not familiar with USA cable TV news: CNN is liberal. FOX News is conservative. Fans of one channel like to claim that the other channel distorts the issues.
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#69202 - The 9th Sage - Sun Jan 29, 2006 5:25 am

arog wrote:

What's wrong with http://www.drunkencoders.com/? I have to say it's one of the most up-to-date homebrew sites out there, and I should know!

- Aaron Rogers
http://www.aaronrogers.com/nintendods/


Haha, actually, come to think of it I hadn't thought to check wether Drunken Coders had an RSS feed or not. I'll add that one as well. :)
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#69272 - HyperHacker - Sun Jan 29, 2006 6:58 pm

tepples wrote:
Explanation for those not familiar with USA cable TV news: CNN is liberal. FOX News is conservative. Fans of one channel like to claim that the other channel distorts the issues.

And then there's people like me who just don't like the media in general. ;-)

#69291 - Dwedit - Sun Jan 29, 2006 8:33 pm

tepples wrote:
Explanation for those not familiar with USA cable TV news: CNN is liberal. FOX News is conservative. Fans of one channel like to claim that the other channel distorts the issues.


Then what's fark.com?
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#69319 - Filb - Mon Jan 30, 2006 12:42 am

So, is this thread about newsfeeds or screen captures?

#69336 - tepples - Mon Jan 30, 2006 3:20 am

</sidetrack>

If the emulators don't show signs of improvement, you might want to get Mr. Video Capture on the case.
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#69355 - Mrshlee - Mon Jan 30, 2006 6:52 am

mmm thats a wee bit of overkill
but thanks for keeping the thread in topic :)

My cam does an ok job.. I dislike the glare/unbalanced colours
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#69370 - IxthusTiger - Mon Jan 30, 2006 10:39 am

Dwedit wrote:
tepples wrote:
Explanation for those not familiar with USA cable TV news: CNN is liberal. FOX News is conservative. Fans of one channel like to claim that the other channel distorts the issues.


Then what's fark.com?


It's not news...

#69760 - genfish - Wed Feb 01, 2006 6:27 pm

i dont know if im getting the point here... but cant u just run it in ideas and take a screenshot

<noob>
chris
</noob>

#69793 - tepples - Wed Feb 01, 2006 10:56 pm

genfish wrote:
but cant u just run it in ideas

No. The final version of iDeaS is still a very incomplete emulator. It's not like the GBA where the emulators were already usable within 6 months after the system was released in the United States.
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#69847 - LiraNuna - Thu Feb 02, 2006 10:01 am

I made a screen capture to my WIP game.

http://LiraNuna.drunkencoders.com/RPG_Game.zip
press R+L in game to save a screenshot into a GBAMP/M3CF/SCCF/SCSD.

the output is a RAW format and need to be converted using dstoraw (included) using the syntax dstoraw <input raw>
then using PhotoShop to open out.raw using those settings : http://LiraNuna.drunkencoders.com/options.jpg

the capture uses a key IRQ, and i believe that a ROM loader (homebrew one like the MoonShell or Kicker) will be able to set the IRQ before executing the ROM.

It uses the screen capture device and it saves to VRAM bank C (that's why you see a flicker when saving a screenshot) then save in any format you wish

Note: The game DO NOT check if a CF compatible device is inserted and i am unaware of what will happened without one!

--LiraNuna


Last edited by LiraNuna on Thu Feb 02, 2006 2:02 pm; edited 1 time in total

#69848 - Filb - Thu Feb 02, 2006 10:07 am

Good work! Works.

I wonder if this would work for commercial games (some PassMe pre-loader or whatever is used for the Mario Kart hack). It would be so friggin awesome!
Since Nintendo just won't sell IS-NITRO-CAPTURE devices to people who are not developers or similar, this would be some crazy cool stuff.

Note: This post is NOT about piracy...

#69859 - m2pt5 - Thu Feb 02, 2006 1:31 pm

Filb wrote:
(some PassMe pre-loader or whatever is used for the Mario Kart hack)

It's a modified stub of the MK ROM that passes execution to the actual game after it triggers the hack.
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#69966 - LiraNuna - Fri Feb 03, 2006 11:31 am

with the help of DesktopMan, my RPG now saves to GBAMP to a BMP format! \o/

#70066 - MaHe - Sat Feb 04, 2006 2:22 am

LiraNuna: Do you think you could build this as a 'loader'? Like Pepsiman's M3/G6 fix ... And it should allow the output in .nds of course :)

#70068 - Dudu.exe - Sat Feb 04, 2006 2:57 am

Lira... amazing GFX in ths demo!!!! i loved!
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#70181 - LiraNuna - Sat Feb 04, 2006 9:56 pm

I don't know anything about loaders, but the code to actually save the capture is big - as it uses chishms' FAT lib.

I think we might be able to load backuped games with the aid of a screen capturer application - maybe with the custom firmware?

Also, people! do not email me about stupid stuff regarding my RPG demo (like "Why can't i go down the stairs?!").
it's a basic engine and that's all it is for now!

#70183 - sajiimori - Sat Feb 04, 2006 10:01 pm

For a second I thought it would be about politics. :P

#70517 - Empyrean - Mon Feb 06, 2006 11:59 pm

Quote:
Also, people! do not email me about stupid stuff regarding my RPG demo (like "Why can't i go down the stairs?!").
it's a basic engine and that's all it is for now!


Okay, but I'm level 42 and I'm facing Bahamut, but his Mega Flare kills off my entire party before I can cast Reflect on my White Mage. Any tips?

Wonderful job, btw! I can't wait till you update this!
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#70553 - LiraNuna - Tue Feb 07, 2006 6:45 am

Maybe i will create a custom firmware to take screenshots...