This is something I've finished working on a couple days ago. It's a video and audio player that will replace the regular NSMBDS cutscene. Messy, half-working code ahead, because I don't know what the fuck I'm doing.

The video player portion is a version of Dirbaio's fireworlds video player, modified to compile and work in NSMBDS:
https://github.com/Dirbaio/Fireworlds/blob/master/fireworlds-game/arm9/source/video.itcm.cpp

The audio player portion is a version of Dirabio's WavPlayer code from the now-dead NSMBCR:
https://github.com/Dirbaio/NSMBCR/blob/master/source/wavplayer.cpp

1. Usage

1. Set up the ASM Hacks template using DevkitARM v41.
2. Copy the "IntroCode.cpp" and "IntroCode.h" files from /source in the downloaded RAR into the template's /source folder. You also need the "nsmb.h" file that's included with the template, but may skip the others.
3. Put a ROM in the template folder and open it in NSMBe.
4. Insert the code into the ROM by pressing "Run make and insert" on the "Tools/Options" tab in NSMBe.
5. Replace ARCHIVE/vs_wrecking_crew.narc with "SampleVideo.vds" and replace ARCHIVE/wrecking_crew.narc with "SampleMusic.raw"

2. Making your own video:

1. Render an avi video at the DS resolution (256x192)
2. Install VLC Media Player
3. Go into Tools -> Preferences. At the bottom-left corner, select "All" in "Show settings"
4. Click on "Video/Filters" and check "Scene video filter"
5. Expand the "Video/Filters" list and select "Scene filter"
6. Create a directory somewhere and enter a path to said directory under "Directory path prefix"
7. Change image format to jpg.
8. Change recording ratio to 1.
9. Press save. Close VLC Media Player.
10. Reopen VLC and open the rendered avi video with it. Let it play all the way through.
11. The directory you made earlier should now have images in it. Now, run VideoMake.jar and point it to said directory.
After a while, it'll create an "out.vds" file in the same folder. You're done.

3. Making your own sound clip:

1. Open a sound file in Audacity
2. If the track is stereo, split it to Mono by opening a drop-down list next to individual track's delete button (top-left corner of the track listing).
3. From that same drop-down list, select "Set rate -> other" and put it at 32768.
4. Input the same rate at the bottom in "Project Rate" field.
5. Go to File->Export audio. Save as type "Other uncompressed types". Click "options" and select "RAW (headerless) as the header and "Signed 8bit PCM" as the encoding. Confirm. You're done.

4. Problems

1. Couldn't get any timers working, so the video plays significantly faster than it does on a flashcart. By modifying line 246, you can even make it run 60fps on an emulator.
2. If you "Go back to titlescreen" and try to open a new file, no sound will play.
3. The video/audio player is picky with files and may crash if it dislikes one.

5. Download

https://www.dropbox.com/s/9vnl1cf6f7ffs1j/VideoIntro.rar?dl=0

Very nice

Something I wanted to do for years...
_________________________
GitHub - Kuribo64 - YouTube

It would be, sure. Just add a hook there and change the videoStart() and wavPlayer::playFile() functions to take an int FileID instead of it being hardcoded.

Sorry, but this problem thing means?

read the error, maybe?

nsmb.h doesn't exist

Weird. Is this the first time you're trying to insert an ASM Hack?



Nevermind.

Ah okay. Well, to prevent that you might not get it to work, here are things that I had to do to get inserting ASM Hacks to work.

1.) The path from your hard disk to the ASM Hacking Template on your computer shouldn't have any folders with spaces in their names. Otherwise, 'make' and insert won't work. For example:

Wrong:
G:\NSMB Stuff\ASM_Hacking_New

Right:
G:\NSMB_Stuff\ASM_Hacking_New


2.) Remove '-lgcc' in the 'Makefile' file.
(Don't do this if 'make' and insert works without removing '-lgcc')

Well, did your intro work? ~11000 frames does seem like it mightn't.

Oh... Thanks, but, this problem?

Huh. Which version of Devkit Pro did you install?

I think the 1.6.0

...Oh. Right. You NEED -lgcc in the makefile to compile this. I think devkitARM rev41 has it setup right.

Well, maybe, someday, we'll be able to change the movements of Mario, Peach and Bowser Jr in the original video.

EDIT: But I wouldn't know how that intro exactly works. All animations of the 3D models are stored in the NSBCAs. But there has to be some file (I think) which arranges when each 3D model has to make which animation and determines the coordinates of each model on each moment.

EDIT2: Now I'm thinking about it, I think it would be kinda the same as sprites work.

Edit the for loop in PlayOutIntro() function.