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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
02821 Sound Minor Always Jan 13, 2009, 02:13 Sep 12, 2021, 04:41
Tester Kin View Status Public Platform MAME (Official Binary)
Assigned To Resolution Open OS
Status [?] Confirmed Driver
Version 0.129 Fixed in Version Build
Fixed in Git Commit Github Pull Request #
Summary 02821: jchan, jchan2: Noise/static instead of speech
Description When Project A Jackie wins his 2nd round, you hear noise and static instead of speech.
Steps To Reproduce Simplest way to trigger this bug is:
* Play as Project A Jackie (for jchan2 romset, aka the white jacket Jackie), and enter a second player;
* Win 1st round;
* Win 2nd round with neither a perfect nor a fatality/super move;
Additional Information Move list (reference URL):
A sample of the bug can be heard there, at the very end of it:
Github Commit
Regression Version
Affected Sets / Systems jchan, jchan2
Attached Files
rar file icon jchan.rar (446,829 bytes) Jan 14, 2009, 01:03
There are no relationship linked to this issue.
User avatar
Jan 13, 2009, 15:29
I've changed the set to jchan2 - that I don't think jchan has the a playable Jackie Chan (much less one with the "Imperial" outfit). If you can provide a save state just before ending the 2nd Round or even an .INP file - that would help in debugging.
User avatar
Jan 13, 2009, 17:52
edited on: Jan 13, 2009, 17:54
It's possible that you can get vs. that kind of Jackie Chan as a boss of some sort.
Anyway I already know "when" this's when Jackie grabs his "bottle" and starts to drink as a victory pose.
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Senior Tester
Jan 13, 2009, 18:50
It's probably a more general problem. Many of the games using this sound chip have problems with specific samples. Deroon Dero Dero has some nasty sounds during the Intro, and the sounds in Sengekis Striker are terrible in places too. It might be a problem with the ADPCM decoding as those are usually the bad samples.
User avatar
Jan 13, 2009, 23:49
Confirmed the issue in jchan2.
User avatar
Jan 14, 2009, 00:20
You can hear this bug when you reach the "Imperial" Jackie Chan as a boss in jchan. I may submit a save state tomorrow.
User avatar
Jan 14, 2009, 01:03
Savestate uploaded. Now lose both rounds :D
User avatar
Oct 7, 2017, 20:04
Improved bug report description and steps to reproduce, also added some resources to aid development.
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Senior Tester
Oct 11, 2017, 12:57
probably worth finding out where this sample is in ROM to make sure it isn't a bad dump
User avatar
Mar 7, 2020, 12:38
Update: several winning pose voice samples have some popping at the end and not only Project A/Admiral Jackie.
User avatar
Aug 10, 2021, 18:31
edited on: Aug 10, 2021, 18:33
I received this info from a MAME user named "Senn" on the GamingAlexandria Discord - just playing middleman right now, but I've advised them to create an account for the future :)


Senn writes:

Hello! so up until recently I've been modding the game and encountered quite a few things indicating either a dumping error, or a faulty board, despite its dump status being "good".

In mametesters, I see a bug report open for "jchan, jchan2: Noise/static instead of speech" (, the comments mention of a possible ADPCM decoding error, so I personally checked the dumped files to see if this is true; here is my findings:

One of the most prominent audio bugs in the game, is when Project A Jackie (white suit jackie) spits on you, buzzes and a short bust of static on his win pose (here it is in action on MAME 0.233, timestamp 0:13:
), other samples in the game also feature a variety of strange buzzes and pops in specific samples, but this is the most infamous one among competitive players.

I decided to import the dumped audio chip (jc-300-00.84) on Audacity to check this error, it seems the game has a few (seemingly random?) vocal samples encoded as 8-bit PCM, while others are 4-bit Yamaha ADPCM. This sample was encoded using 8-bit PCM. (selected portion of the affected sample) (zoomed in portion of the irregular buzzing)

This irregular but constant waveform and the static seemed suspicious to me because it would hardly be caused during development or some encoding/decoding error. I've checked as to why this short bust of static seem to happen, and turns out it is reading a 4bit ADPCM sample after it as 8bit PCM, this sample is also unusual in a way that it's a nonsensical, short cropped version of the game's theme song. Here it is encoded as 4bit ADPCM (contains the buzz before it so loud audio warning! although not encoded with the proper Yamaha ADPCM routine, this is for preview only.)
Now as for proof that this most definitely should not be happening, here is footage from a competitive play in Japan that happens to use an actual arcade board of the game, timestamp: 27:31:
. The buzzing and the static does not happen here.

Overall this is a pretty strong case that these audio glitches are not an emulation issue, and seemingly they should not be happening on an actual copy of the game, marking this as either a faulty dump, or an issue found with the board.
User avatar
Sep 12, 2021, 04:41
coolmod redumped the YMZ ROMs and they match the ones already in MAME.