07211: midtunit: MK music tempo slower then actual arcade

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
07211	Sound	Minor	Always	Jan 25, 2019, 03:53	1 day ago

Tester	Chamajid	View Status	Public	Platform	MAME (Official Binary)
Assigned To		Resolution	No change required	OS	Windows 10 (64-bit)
Status [?]	Closed			Driver	midway/midtunit.cpp
Version	0.205	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	07211: midtunit: MK music tempo slower then actual arcade
Description	Hi First of all, thankyou for fixing the extra drums on 0.193 for midtunit.cpp. Now the only imperfection remaining in the game sound is the tempo of the music. It sounds like the music is slower in mame then the arcade. I have included an mp3 of the one of the intro tracks. There is also a youtube video which has same music running on arcade PCB but the video host is talking. You can definitely see the music speed is right speed there. &feature=youtu.be&t=91
Steps To Reproduce	you can hear it in the player intro or at the character screen. But this affects all music of the game.
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	midtunit

Attached Files	02 - In the Beginning.mp3 (2,178,949 bytes) Jan 25, 2019, 03:53 Uploaded by Chamajid Mp3 from actual

No.16073 vidpro1 Developer Jan 25, 2019, 21:48 edited on: Jan 25, 2019, 22:01	I took a look at this and the tempo is slower on mame. It could be a clock speed Yamaha YM2151 ADPCM sound board issue. I will take a look at the sound driver. This could affect other games like NBA Jam, Total Carnage, and T2 as well.
No.16074 Chamajid Tester Jan 25, 2019, 22:20	Can you please tell me which file you will be looking at from the source? I tried to search but having no clue of how MAME works I couldnt guess. This will be educational.
No.16077 vidpro1 Developer Jan 26, 2019, 14:17	To understand how MAME works I would refer to the documentation manual here. https://docs.mamedev.org/ There are multiple files for the game driver src/mame/drivers/midtunit.c - main game driver MK, T2, NBA JAM etc. There are references to the video and machine folders as well depends on the game. src/mame/audio/williams.c - Most likely it would be here. This game uses a Yamaha YM2151 for FM, a DAC Chip, and OKI 6295 for ADPCM speech Now is this an easy fix? No. This hardware is quite complicated. I have consulted with someone I know from the VGM music forums that is an expert with sound drivers. The fix is either something with the timers, interrupts or the way the main pcb and the sound board updates for the emulation. Definitely a timing problem somewhere to make the sound tempo slower than the real machine but the pitch is correct. .c file is source file .h is header
No.16078 Chamajid Tester Jan 26, 2019, 17:12	Thanks vidpro1. I tried overclocking the adpcm sound cpu to 104% and it looks like that fixes it. Is there a way to save the overclock setting?
No.16080 kirishima Tester Jan 27, 2019, 00:40	Hmmm. I always thought it was slower by design. I could've sworn the music speed up as the match went on similar to how the music behaves in the Megadrive version of Super Street Fighter 2 or the game and watch gallery series. Here's another pcb video for checking:
No.16082 vidpro1 Developer Jan 27, 2019, 12:55 edited on: Jan 27, 2019, 16:34	Mortal Kombat's Arcade Music does not speed up when a player is about to be defeated as it uses a different sound call for that.
No.17453 Chamajid Tester Mar 5, 2020, 02:06	So its been more then year. Does some try looking into this?
No.17454 Osso Moderator Mar 5, 2020, 07:05 edited on: Mar 5, 2020, 07:06	The oldest open bug registered here is from 2008. What's 1 year? ;) Jokes aside, if you don't see the report changed to fixed, assume no one has worked on it.
No.18566 alphabeta2 Tester Mar 16, 2021, 02:47	Trying to set the clock speed from 100 to 114 percent speeds up the YM2151 synth but the pitch is going higher.
No.18568 Chamajid Tester Mar 16, 2021, 06:22	you gotta do something as no one has looked into it yet.
No.18569 cuavas Administrator Mar 16, 2021, 12:06	Being annoying is the easiest way to ensure no-one looks into it. If you keep this up, you’ll get demoted to viewer.
No.19765 Chamajid Tester Feb 7, 2022, 02:18	Is there a way to find out who developed the emulation for midtunit in mame?
No.19770 Tafoid Administrator Feb 8, 2022, 04:32	There is an outside chance the recent YM core adjustment which fixed several Konami games might also have an effect on music for this game (YM2151). Perhaps you could test 0.240 to see how it compares @Chamajid?
No.19773 Chamajid Tester Feb 8, 2022, 06:00	Yes I did. It is still the same.
No.23883 Chamajid Tester 1 day ago	How can I get this to mame developers and include it in the next release? I'm writing to report an audio timing issue in the Mortal Kombat (1992) driver (midyunit.cpp). After extensive testing and comparison with the original PCB, I've found that the OKI6295 ADPCM chip emulation runs approximately 4% slow, causing the music tempo and pitch to be incorrect. This issue is giving me a lot of pain because suspect other projects such as arcade1up and MK Legacy Kollection is using the same mame code as I see the same sound issues there. I also described the issue in the mametester bug id: 07211 Issue Details: - Game: Mortal Kombat (1992) [mk] - Driver: src/mame/midway/midyunit.cpp - Core Issue: OKI6295 clock speed is 4% slower than PCB - Effect: Music tempo/pitch is audibly slow compared to original hardware Evidence: 1. PCB Reference Recording: 2. MAME Default: Runs at 100% speed (F11 shows 100%, but audio is slow) 3. Required Correction: 104% ADPCM overclock matches PCB tempo exactly 4. Verification Method: Manual overclock via MAME slider to 104% fixes tempo Additional Audio Balance Issues: While testing, I also identified incorrect default volume levels: - YM2151 (FM music): Default 0.10 volume (-20dB) is too quiet - OKI6295 (ADPCM drums/FX): Default 1.0 volume overpowers music - Correct Balance: YM2151=1.0 (0dB), OKI6295=0.35 (-9dB) Suggested Fix: The following source changes produce PCB-accurate audio: In src/mame/midway/midyunit.cpp (around OKIM6295 configuration): // Change from: OKIM6295(config, m_oki, XTAL(8'000'000) / 8, okim6295_device::PIN7_HIGH).add_route(ALL_OUTPUTS, "speaker", 1.0); // To: OKIM6295(config, m_oki, (XTAL(8'000'000) / 8) * 1.04, okim6295_device::PIN7_HIGH).add_route(ALL_OUTPUTS, "speaker", 0.35); In src/mame/shared/williamssound.cpp (YM2151 routing): // Change from: m_ym2151->add_route(ALL_OUTPUTS, this, 0.10); // To: m_ym2151->add_route(ALL_OUTPUTS, this, 1.0); Testing Methodology: 1. Recorded attract mode audio from MAME and PCB reference 2. Compared waveforms and measured BPM difference 3. Verified 104% overclock produces identical tempo 4. Tested across multiple MAME versions (issue persists) Request: Could this clock correction and volume balance be implemented in the official driver? This would bring Mortal Kombat's audio to true PCB accuracy. Thank you for your time and for maintaining this incredible project. Best regards, Kashif MAME User
No.23885 hap Developer 1 day ago edited on: 1 hour ago	Don't crosspost ( https://github.com/mamedev/mame/issues/14667 ), now I don't know where to reply. An OST is not accurate PCB recording, often it's just a recording from an emulator. And if not, the producer may have edited the sound. Anyway, I tried overclocking the OKI in MAME, and the gong sound effect becomes higher pitched than the video you linked (and actual PCB video as well). The sound PCB for Mortal Kombat has 8MHz and 3.57MHz XTALs. No resonator near the OKI.
No.23886 cuavas Administrator 1 day ago	If someone can provide convincing evidence from a well-maintained arcade board, this can be revisited. Right now it looks like an invalid report.