Gamecube chiptune player

Discussion of development of software for any "obsolete" computer or video game system. See the WSdev wiki and ObscureDev wiki for more information on certain platforms.
mic_
Posts: 922
Joined: Thu Oct 05, 2006 6:29 am

Re: Gamecube chiptune player

Post by mic_ »

If it would help, I can make some reference recordings of Akumajou Dracula and Gimmick!
Recordings from a real NES/FC with a real VRC6/5B cart would be nice. Of course, the best thing would be if someone could run dedicated test ROMs, but the audio output from games that used these chips are better than nothing.
mic_
Posts: 922
Joined: Thu Oct 05, 2006 6:29 am

Re: Gamecube chiptune player

Post by mic_ »

I've now built a Wii version of the player that can be loaded through the Homebrew Channel. It has basic wiimote support (no point-'n-click; just the d-pad and some buttons), but can also be controlled with a Gamecube controller on the Wii.

A small UI change in both versions is that during NSF playback, expansion audio channels are now visualized on the on-screen keyboard (using a slightly different color compared to the other channels).

Download the archive containing the Gamecube DOL and the Wii HBC app.
lidnariq
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Joined: Sun Apr 13, 2008 11:12 am

Re: Gamecube chiptune player

Post by lidnariq »

Looks and sounds nice! Unfortunately I'm foolish enough to be using 480i on a CRT, so the single scanline high white lines flicker obnoxiously.
mic_
Posts: 922
Joined: Thu Oct 05, 2006 6:29 am

Re: Gamecube chiptune player

Post by mic_ »

I've added support for MMC5 audio (pulse channels only). Another new feature is the ability to toggle between output of just the 2A03 channels, and just the expansion audio channels.

Download the archive containing the Gamecube DOL and the Wii HBC app.
Watch a capture on youtube here.
Unfortunately I'm foolish enough to be using 480i on a CRT, so the single scanline high white lines flicker obnoxiously.
I don't have any CRT TVs to test on. I'm using the 4:3 mode on an LCD TV.
tepples
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Re: Gamecube chiptune player

Post by tepples »

To make a user interface look good in standard definition, you need to design it in 320x240, scale it up by a factor of 2, and round off the corners as needed. In 480i, font strokes should be at least 2 pixels wide.
lidnariq
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Joined: Sun Apr 13, 2008 11:12 am

Re: Gamecube chiptune player

Post by lidnariq »

tepples wrote:You need to design it in 320x240, scale it up by a factor of 2, and round off the corners as needed.
You don't need to go that far. Just take the input 480-lines image and filter it vertically with a [.5 1 .5] filter, possibly with gamma correction and de-correction before and after the filter. Horizontally I wouldn't worry about things at all.

The service manual for this TV claims a resolution of 250Wx300H. This isn't equivalent to a 250x300 pixel bitmap, though, because phase information is retained within a pixel.
tepples
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Re: Gamecube chiptune player

Post by tepples »

lidnariq wrote:
tepples wrote:You need to design it in 320x240, scale it up by a factor of 2, and round off the corners as needed.
You don't need to go that far. Just take the input 480-lines image and filter it vertically with a [.5 1 .5] filter
The GameCube and Wii GPU can reportedly do exactly this, and Super Smash Bros. Melee and Super Smash Bros. Brawl give the player options to turn it on and off. But that still won't make tiny text very readable.

Phase information is retained within a low-resolution bitmap too, as gray shades on the sides of objects. That's what font antialiasing is supposed to be about, and it's how the primitive multisample AA worked on the Nintendo 64.
Attachments
Tiny text on an interlaced display<br />Top row: unfiltered; bottom row: filtered with [1 2 1]/4 kernel<br />Left: progressive; right: interlaced
Tiny text on an interlaced display
Top row: unfiltered; bottom row: filtered with [1 2 1]/4 kernel
Left: progressive; right: interlaced
eeor.gif (1.93 KiB) Viewed 5493 times
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: Gamecube chiptune player

Post by lidnariq »

tepples wrote:Phase information is retained within a low-resolution bitmap too, as gray shades on the sides of objects.
But that assumes the horizontal resolution limitation is due to the analog bandwidth of the TV, and is an analog lowpass with a clear extinction frequency, rather than (for example) an artifact of the aperture grille.
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