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Tricky-to-emulate sound stuff from games?
http://forums.nesdev.com/viewtopic.php?f=3&t=10059
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Author:  ulfalizer [ Wed May 01, 2013 12:48 am ]
Post subject:  Tricky-to-emulate sound stuff from games?

Many APU-related things aren't program-visible and don't have test ROMs (afaik), so some examples of tricky-to-emulate sound stuff from games would be nice as a reference to see if you've gotten things right. Trickiness isn't really a prerequisite I guess, as long as it makes a good test.

Got anything? :)

Author:  cpow [ Wed May 01, 2013 6:46 am ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

ulfalizer wrote:
Many APU-related things aren't program-visible and don't have test ROMs (afaik), so some examples of tricky-to-emulate sound stuff from games would be nice as a reference to see if you've gotten things right. Trickiness isn't really a prerequisite I guess, as long as it makes a good test.

Got anything? :)


There are various games that Eugene.S has pointed out over time that sounded like shit in my emulator. :oops:

Overlord (intro)
Solstice (first level)
Akumajou Densetsu VRC6 (DMC popping)
Power Blade: Sector 2. Strange Hi-freqs, Sector 5. Pitch of squares and triangle sweeps during tune (especially intro and ending...)

There were a few others but I don't feel like dredging the threads at the moment. Search for Eugene.S author and "NESICIDE". He's usually pretty descriptive about what's wrong.

Author:  Dwedit [ Wed May 01, 2013 6:56 am ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Dr. Mario. If the "drop" sound effect goes for too long, you aren't shutting off the channel when the period gets too high. (nsfplug fails at this)
Streemerz, it tests the ability for the sweep unit to change the high bytes of the period.
Quattro Adventure - Treasure Island Dizzy. Opening song will have glitches if emulated improperly.

Author:  tepples [ Wed May 01, 2013 7:14 am ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Skate or Die 2: The Search for Double Trouble. It tests whether $4011 writes do anything. The NSF format wasn't designed for an execution model useful for timed writes to $4011, and PocketNES doesn't implement $4011.


I didn't mention that game.

Author:  rainwarrior [ Wed May 01, 2013 7:19 am ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Some of Zelda 2's sound effects are very good for testing your sweeps.

Author:  ulfalizer [ Wed May 01, 2013 3:23 pm ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Thanks for the examples so far!

Mega Man 5's explosions were mentioned in #nesdev.

Author:  rainwarrior [ Wed May 01, 2013 7:04 pm ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Dwedit wrote:
Dr. Mario. If the "drop" sound effect goes for too long, you aren't shutting off the channel when the period gets too high. (nsfplug fails at this)


Old NSFPlug, or the current version? If the current version, could you tell me the track of the NSF it's failing on? (Seems to be fine in my tests.)

Author:  Dwedit [ Wed May 01, 2013 10:02 pm ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Apparently, a really old version with a modification date from 2006. Crazy stuff happens when you hard drive goes back in time 6 months. Works fine in the current version.

Author:  Hamtaro126 [ Thu May 02, 2013 6:16 am ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Hebereke (Ufouria) - Some Sound Effects sound very wonky if using old players, I remember it very noticably in NESTicle back when I still used it!

Author:  ulfalizer [ Tue May 07, 2013 10:37 am ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

That base from the Overlord intro sounds really cool btw. Do you get that sound just by setting the triangle to a low frequency, or is there more to it? :)

Wasn't expecting to find awesome music through this thread.

Author:  lidnariq [ Tue May 07, 2013 12:04 pm ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Sounds like he made up for the triangle's lack of volume register by using a rapid jump down two octaves (something like a [+24 +19 +12 +7 |0] semitone envelope). The rest of it is just how delightfully crunchy the triangle wave is normally.

Tangentially, man, is Jeroen Tel good.

Author:  Dwedit [ Tue May 07, 2013 12:09 pm ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

Done entirely with the triangle channel. There is some drum effects by playing arpeggios, then after that, there's a vibrato in there too. At low frequencies, the stairstep part of the wave which is 16x the frequency of the note will become an audible high note. The kick drums done in the triangle channel are masterfully done here.

Look at them in NSFImporter, wonderful stuff here, I might have to steal these.

Author:  ulfalizer [ Tue May 07, 2013 12:58 pm ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

I'm guessing getting it to sound decent requires generating the correct stair-step triangle shape so you get the right overtone (not any triangle will do). Maybe it should be added to the tricky-to-emulate games page if that is correct.

I'm doing easy/slow per-cycle sample generation, and it sounds nice in my emu. :)

Author:  rainwarrior [ Tue May 07, 2013 1:09 pm ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

The 16-step triangle is important to the triangle sound in every game, not just this one. Is there anything particular you think was hard to emulate in this one game?

Author:  lidnariq [ Tue May 07, 2013 1:11 pm ]
Post subject:  Re: Tricky-to-emulate sound stuff from games?

ulfalizer wrote:
I'm guessing getting it to sound decent requires generating the correct stair-step triangle shape so you get the right overtone (not any triangle will do).

If the triangle channel is implemented using just a 4-bit DAC, it should sound right regardless. There might be some funny edge cases if someone makes the 32-step sequence go 1,0,1…15,16,15… instead of 1,0,0,1…14,15,15,14… but I strongly suspect that won't be audible.

(Yes, I know 16 doesn't fit in a 4 bit DAC)

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